Skip to content

Mini Review

Frontiers in Disaster and Emergency Medicine ·

Volume 4 - 2026 | https://doi.org/10.3389/femer.2026.1786702

Beyond major earthquakes: cardiovascular health impact of Low-magnitude seismic activity and the need for preventive strategies

  • Tora Sadigova1*corresponding author
  • Leyla Afandiyeva1
  • Shafaq Ibrahimova1
  • Konul Mammadyarova1
  • Sevinc Mammadli1
  1. Azerbaijan Medical University, Baku, Azerbaijan
Article metrics0 viewsView details

Abstract

Natural disasters are traditionally associated with mass trauma and acute injuries; however, non-communicable diseases account for the majority of premature mortality worldwide, with cardiovascular diseases (CVDs) alone responsible for an estimated 17.9 million deaths annually and approximately one third of all global deaths. Within disaster medicine, CVDs constitute a substantial yet often underrecognized component of disaster-related morbidity and mortality. While the cardiovascular consequences of major earthquakes have been relatively well described—including a documented several-fold rise in sudden cardiac death and acute coronary syndromes in the hours to weeks after the event—far less attention has been paid to the health impact of low-magnitud e, recurrent seismic activity. Emerging observational and ecological data suggest that even minor seismic events, when occurring frequently, are associated with measurable increases in cardiovascular hospitalizations and may act as chronic disaster-related stressors capable of destabilizing cardiovascular health, particularly in patients with established CVD and in older adults. This Mini Review examines the cardiovascular implications of low-magnitude seismic activity from a disaster medicine perspective. We summarize current knowledge on seismic exposure in chronically active regions, patterns of cardiovascular healthcare utilization during periods without major earthquakes, and the biological and psychosocial mechanisms linking seismic stress to cardiovascular events. Attention is given to the South Caucasus, with Azerbaijan discussed as a model region characterized by persistent seismicity and a high burden of cardiovascular disease. We highlight critical knowledge gaps related to background seismic exposure and non-traumatic cardiovascular outcomes and argue for the integration of cardiovascular risk mitigation into disaster preparedness frameworks. Preventive strategies based on prevention, prediction, and awareness are discussed in alignment with disaster risk reduction principles. Recognizing low-magnitude seismic activity as a relevant health stressor may support more resilient and context-sensitive approaches to disaster medicine in seismically active regions.

Keywords

Introduction

Disaster medicine has historically focused on the immediate management of traumatic injuries, mass casualties, and infectious disease outbreaks following natural catastrophes (1). Earthquakes, in particular, are commonly conceptualized through the lens of collapsed infrastructure, acute trauma, and emergency surgical care (2). While this focus is clinically essential, it captures only part of the health burden associated with seismic events. Globally, CVDs are the leading cause of death, responsible for an estimated 17.9 million deaths per year and roughly 32% of all-cause mortality (3), and they are increasingly recognized as major contributors to disaster-related morbidity and mortality (3–5).

Cardiovascular complications during and after disasters are typically attributed to acute psychoemotional stress (6–8), disruption of healthcare services (9), and interruption of chronic disease management (9, 10). Most existing research in this area has concentrated on major earthquakes, where the temporal association between a catastrophic event and a surge in cardiovascular events is relatively easy to identify (4, 11, 12). For example, in the days following the 1995 Hanshin-Awaji and 2011 Great East Japan earthquakes, increases in acute coronary syndromes, stroke, and decompensated heart failure of 30% or more were observed in affected regions (12–14), and similar patterns were reported in the immediate aftermath of the 2023 Türkiye–Syria earthquake (15). However, this event-centered approach overlooks a critical reality in many seismically active regions: seismic exposure is often chronic rather than episodic (16, 17).

Low-magnitude earthquakes and background seismic activity occur frequently in geodynamically unstable areas, with hundreds to thousands of detectable events per year in tectonically active belts (16). Although such events rarely cause structural damage or trigger formal disaster responses, they may exert persistent psychological and physiological stress on exposed populations (7, 18). From a disaster medicine perspective, these low-level hazards are particularly challenging because they fall below traditional thresholds for emergency preparedness (1) yet may contribute meaningfully to population-level cardiovascular risk through repeated activation of stress-response pathways (5, 6).

According to WHO estimates, noncommunicable diseases account for approximately 89% of all-cause mortality in Azerbaijan, with cardiovascular diseases alone responsible for roughly 60% of total deaths—among the highest age-standardized CVD mortality rates in the WHO European Region (19). Country-level Global Burden of Disease estimates similarly identify ischaemic heart disease and stroke as the two leading causes of premature mortality in Azerbaijan and the wider South Caucasus, providing a quantitatively robust baseline against which any environmental contributor to cardiovascular risk including chronic seismic exposure must be evaluated (20).

This Mini Review shifts the focus beyond major earthquakes to examine the cardiovascular health impact of low-magnitude seismic activity. By integrating insights from seismology, environmental cardiology (8, 21), and disaster risk reduction (2, 22), we aim to highlight an underrecognized dimension of disaster-related health risk and to outline the need for preventive strategies tailored to chronically seismically active regions (9, 17). An exclusive focus on catastrophic events risks overlooking a substantial burden of disaster-related cardiovascular morbidity arising outside formally recognized disaster periods (11, 16). A conceptual overview of the proposed pathways linking chronic low-magnitude seismic exposure to cardiovascular morbidity and health-system burden is presented in Figure 1.

Conceptual framework linking chronic low-magnitude seismic activity to cardiovascular morbidity and health-system burden. Frequent, sub-felt to felt seismic events (M < 5) in geodynamically active regions act as a chronic environmental exposure that operates through two converging mechanistic pathways: psychosocial (anticipatory anxiety, hypervigilance, post-traumatic stress, disturbed sleep, erosion of perceived control and social support) and biological (sympathetic and HPA-axis activation, catecholamine release, systemic low-grade inflammation, endothelial dysfunction, prothrombotic and prohypertensive state). These pathways jointly drive behavioral mediators (sleep disruption, medication non-adherence, reduced physical activity, poor diet, increased smoking and alcohol use, delayed care-seeking), which translate into measurable cardiovascular outcomes—including hypertensive crises, acute coronary syndromes, stroke, arrhythmias, and heart-failure decompensation with short-term relative risk increases of approximately 10%–30% during periods of measurable seismic activity. The resulting non-traumatic cardiovascular morbidity generates a largely hidden health-system burden, often classified as routine clinical workload and excluded from formal disaster surveillance. The dashed loop indicates cumulative, recurrent re-exposure over months to years. HPA, hypothalamic–pituitary–adrenal; CV, cardiovascular; M, moment magnitude.
Figure 1. Conceptual framework linking chronic low-magnitude seismic activity to cardiovascular morbidity and health-system burden. Frequent, sub-felt to felt seismic events (M < 5) in geodynamically active regions act as a chronic environmental exposure that operates through two converging mechanistic pathways: psychosocial (anticipatory anxiety, hypervigilance, post-traumatic stress, disturbed sleep, erosion of perceived control and social support) and biological (sympathetic and HPA-axis activation, catecholamine release, systemic low-grade inflammation, endothelial dysfunction, prothrombotic and prohypertensive state). These pathways jointly drive behavioral mediators (sleep disruption, medication non-adherence, reduced physical activity, poor diet, increased smoking and alcohol use, delayed care-seeking), which translate into measurable cardiovascular outcomes—including hypertensive crises, acute coronary syndromes, stroke, arrhythmias, and heart-failure decompensation with short-term relative risk increases of approximately 10%–30% during periods of measurable seismic activity. The resulting non-traumatic cardiovascular morbidity generates a largely hidden health-system burden, often classified as routine clinical workload and excluded from formal disaster surveillance. The dashed loop indicates cumulative, recurrent re-exposure over months to years. HPA, hypothalamic–pituitary–adrenal; CV, cardiovascular; M, moment magnitude.

In Azerbaijan, where cardiovascular diseases account for approximately 60% of all-cause mortality (19) and where the population is chronically exposed to several hundred low-magnitude (M < 5) earthquakes per year (16, 23), even the conservative 10%–30% relative increases in cardiovascular hospitalizations reported during periods of measurable seismic activity (16) would translate into thousands of additional, potentially preventable acute cardiovascular events annually establishing low-magnitude seismic activity as a quantitatively important, modifiable component of regional cardiovascular risk that warrants explicit inclusion in disaster medicine practice, surveillance, and policy (2, 22).

Seismic activity beyond catastrophic events: a regional perspective

Seismic activity is a continuous geophysical process rather than a discrete series of catastrophic events (16). In many regions worldwide, low-magnitude earthquakes occur regularly as part of ongoing tectonic adjustment along active faults and plate boundaries (17). Although these events are frequently perceived as routine or insignificant by both the public and emergency services (1), their cumulative impact on human health warrants closer examination from a disaster medicine perspective (3, 16).

The South Caucasus represents a region of persistent geodynamic instability, situated at the convergence of the Eurasian, Arabian, and Anatolian lithospheric plates (23). Azerbaijan, located within this active tectonic zone, experiences frequent seismic events of varying magnitude, with national seismological monitoring routinely registering several hundred low-magnitude (M < 4) earthquakes per year, the majority of which fall below thresholds typically associated with disaster declarations or formal emergency response activation (16). In parallel, the country carries a substantial burden of cardiovascular disease: in Azerbaijan and neighboring countries of the South Caucasus and Eastern Europe, age-standardized CVD mortality rates exceed 400–600 deaths per 100,000 population annually, among the highest in the WHO European Region (3, 21). This intersection of chronic seismic exposure and high baseline cardiovascular risk creates a population particularly susceptible to seismically-related cardiovascular destabilization (8, 13).

From a disaster medicine standpoint, such regions challenge conventional risk-assessment models that prioritize rare, high-impact events over chronic, low-intensity hazards (1). Persistent seismic exposure may contribute to a sustained state of population-level alertness, uncertainty, and psychosocial stress (7, 18). Unlike major earthquakes, which are followed by clearly delineated response and recovery phases (2), background seismic activity represents an ongoing exposure with no defined beginning or end, complicating traditional surveillance, triage, and resource-allocation paradigms (9, 23, 24).

Recognizing this regional context is essential for reframing seismic risk as a chronic, disaster-related stressor rather than an exclusively acute phenomenon (16, 17). Such a shift is necessary to align disaster-medicine practice with the realities of populations living in chronically seismic regions, where the cardiovascular health burden may accumulate silently over years of recurrent low-level exposure (6, 16).

Cardiovascular healthcare utilization during periods of low seismic activity

Observations from seismically active regions indicate that cardiovascular healthcare utilization may remain elevated even in the absence of major earthquakes (11, 16). Ecological analyses of earthquake-prone regions beginning with the classic natural experiment of the 1981 Athens earthquake, which documented a marked, transient rise in fatal cardiovascular events in the absence of significant structural damage (16) have shown that periods of measurable seismic activity are associated with measurable increases in cardiovascular hospitalizations and acute events, with reported short-term relative risks typically rising on the order of tens of percent above baseline in vulnerable populations (11, 16, 25). Comparable signals emergency department visits and hospital admissions for acute coronary syndromes (12, 15), hypertensive crises (5, 26), arrhythmias and decompensated heart failure (13, 14), and cerebrovascular events (4) have been documented during periods characterized by low-magnitude or background seismic activity (16, 27). These patterns suggest that cardiovascular destabilization is not limited to catastrophic seismic events but may also occur in response to chronic geophysical stress (8).

Recurrent minor tremors and ongoing tectonic instability may act as continuous stressors capable of precipitating clinical deterioration in vulnerable individuals, particularly those with pre-existing cardiovascular disease (5, 10, 13). Importantly, such increases in cardiovascular healthcare utilization often occur without triggering formal disaster alerts or emergency response mechanisms (1, 22), resulting in limited preparedness at the health system level (9). Cardiovascular admissions occurring under conditions of background seismicity are therefore typically classified as routine clinical workload rather than as disaster-related health outcomes (2, 9).

This misclassification has important implications for disaster medicine. Failure to recognize low-level seismic activity as a relevant health stressor may lead to underestimation of the true cardiovascular burden associated with seismic exposure (16), delayed resource mobilization (9), and insufficient preparedness of emergency and cardiology services (9). From a systems perspective, these observations challenge the traditional binary distinction between “disaster” and “non-disaster” periods (23) and instead support a continuum-based model in which chronic low-level hazards exert sustained pressure on population health and healthcare infrastructure (1, 9).

The spectrum of cardiovascular outcomes reported in association with different seismic contexts including: major earthquakes, aftershock periods, and chronic low-magnitude seismicity together with representative effect estimates and supporting studies, is summarized in Table 1. Across the seismic intensity continuum, the magnitude of the cardiovascular signal appears to scale with the duration and intensity of exposure rather than with the occurrence of any single discrete event (11, 16). Recognizing cardiovascular healthcare utilization during periods of low seismic activity as part of the disaster-related health spectrum (3) therefore underscores the need to broaden disaster surveillance and preparedness frameworks to include non-traumatic cardiovascular outcomes in chronically seismically active regions (2, 22).

Table 1. Cardiovascular outcomes reported across the seismic-intensity continuum, with representative effect estimates, key populations, and supporting studies.

Seismic contextPrincipal cardiovascular outcomesReported effect direction/magnitudeKey populationsRepresentative studies
Major earthquakes (M ≥ 6)Acute coronary syndromes, sudden cardiac death, strokeSeveral-fold short-term increase (e.g., ∼3–5× rise in sudden cardiac death in days after the event)Patients with pre-existing CVD; general adult populationLeor 1996 (12); Kloner 1997 (16); Aoki 2013 (28); Nakamura 2014 (17)
Aftershock and early recovery periodBlood pressure instability, anxiety-related cardiac eventsSystolic BP elevation of ≈10–25 mmHg lasting weeks; sustained heart-rate variability changesVulnerable hypertensive patients, displaced populationsKario 2012 (18); Giorgini 2013 (9); Kario 1997 (3)
Low-magnitude recurrent seismicity (M < 5)Hypertensive crises, arrhythmias, heart-failure decompensation, increased CV admissionsRelative increases of ∼10%–30% in CV hospitalizations during weeks of measurable seismic activityMiddle-aged and older adults with chronic CVDTrichopoulos 1983 (16); Watanabe 2005 (6); Bromet 2017 (26)
Chronic seismic regions (long-term residence)Persistent CV risk-factor deterioration; elevated baseline healthcare utilizationLong-term adverse changes in BP, weight, and lipids persisting years after exposureWhole exposed population; high-burden regions (e.g., South Caucasus)Ohira 2017 (1); Hasegawa 2016 (9); Bhatnagar 2017 (13)

CV, cardiovascular; CVD, cardiovascular disease; M, moment magnitude; BP, blood pressure. Effect estimates are indicative ranges synthesized from the cited primary studies and meta-analyses (4, 8, 9, 16, 22, 24, 25, 29) and are intended to illustrate the direction and approximate magnitude of association rather than to represent pooled meta-analytic values. Numbers in parentheses correspond to references in the bibliography.

Taken together, Table 1 highlights a graded, continuum-based pattern of cardiovascular response across seismic exposures: from short-lived but large-magnitude surges after catastrophic earthquakes, to persistent blood-pressure and autonomic effects in aftershock periods, to subtler but cumulative increases in admissions associated with low-magnitude recurrent seismicity and chronic residence in seismically active regions (10, 11, 16).

Low-magnitude seismic activity as an underrecognized disaster hazard

Disaster medicine traditionally prioritizes sudden, high-impact hazards that produce immediate casualties and infrastructure damage (1). Low-magnitude seismic activity does not fit neatly within this paradigm: such events rarely cause visible destruction (23), attract limited media attention, and seldom activate emergency response mechanisms (24). Nevertheless, their cumulative health impact may be substantial when exposure is frequent and prolonged ecological data suggest that even sub-felt seismic activity is associated with modest but measurable increases in cardiovascular event rates in exposed populations (16).

In geodynamically active regions, background seismicity represents a form of chronic hazard exposure. Unlike major earthquakes, which are temporally discrete (4), low-magnitude seismic events occur repeatedly and unpredictably, generating persistent uncertainty and anticipatory stress (18). This pattern aligns with contemporary disaster risk reduction concepts that emphasize the cumulative effects of small but frequent hazards (1, 2, 17).

Despite this relevance, low-magnitude seismicity remains largely absent from disaster health frameworks (16). Most disaster-related cardiovascular studies focus on single catastrophic events (4, 12), short-term mortality (3), or trauma-dominated outcomes (2). Consequently, the cardiovascular consequences of chronic seismic exposure remain poorly characterized, representing a significant blind spot in disaster medicine research (1, 16).

Pathophysiological and psychosocial mechanisms

The cardiovascular effects of low-magnitude seismic activity are likely mediated through a combination of biological and psychosocial mechanisms (5, 6, 30). Acute and chronic stress responses play a central role. Even minor seismic events can trigger sympathetic nervous system activation and hypothalamic–pituitary–adrenal axis stimulation, leading to surges in circulating catecholamines and cortisol (6). Post-earthquake studies have documented average systolic blood pressure elevations of 10–25 mmHg lasting several weeks among hypertensive patients, with proportionally greater increases in those with poorly controlled disease (5, 12, 26). These responses also produce transient increases in heart rate and myocardial oxygen demand, providing a plausible substrate for acute coronary events (8).

Repeated exposure to such stress responses may contribute to sustained autonomic imbalance, endothelial dysfunction, and prothrombotic states (6, 8, 33). In individuals with pre-existing atherosclerosis or impaired cardiovascular reserve, these changes may increase susceptibility to acute events; case-crossover and registry data have linked post-disaster periods to a several-fold short-term rise in sudden cardiac death and myocardial infarction (4, 11, 13). Importantly, the absence of overt disaster cues during periods of low-magnitude seismicity may prolong uncertainty and anxiety, amplifying psychosocial stress without triggering the protective social mobilization that often follows major events (18, 27).

Psychological factors are particularly relevant in regions with chronic seismicity, where anticipatory stress and hypervigilance may persist over long periods (7, 27, 28). Population-based surveys after major earthquakes have reported clinically significant anxiety or post-traumatic stress symptoms in 15%–40% of exposed adults, and similar though less well-quantified symptoms have been documented in communities experiencing recurrent low-magnitude activity (18, 27, 28). This continuous stress burden can adversely affect cardiovascular health through behavioral pathways, including reduced physical activity, poor sleep quality, and diminished adherence to medical therapy (6, 7, 10).

Taken together, these mechanisms support the concept of low-magnitude seismic activity as a biologically meaningful stressor with measurable cardiovascular consequences (5, 6, 8, 30).

Vulnerable populations in chronically seismic regions

Disaster medicine places strong emphasis on identifying vulnerable populations (2, 22). In the context of chronic seismic exposure, individuals with established cardiovascular disease represent a key at-risk group (11, 13). Hypertension, which affects approximately 30%–40% of adults globally and exceeds 45% in many parts of Eastern Europe and the South Caucasus (3, 21, 31), is consistently associated with heightened sensitivity to stress-related triggers and shows pronounced blood pressure variability under disaster conditions (5, 26). Ischemic heart disease, heart failure, and cerebrovascular disease similarly demonstrate stress-related exacerbation patterns in post-disaster cohorts (4, 8, 13, 14).

Age further modifies vulnerability. Adults aged 65 years and older account for the majority of post-earthquake cardiovascular hospitalizations and deaths, reflecting reduced physiological reserve and a higher prevalence of comorbidities in this group (3, 10, 13). Sex-specific differences in stress perception, coping strategies, and healthcare utilization may also influence cardiovascular outcomes in seismically active settings, with women reporting higher levels of anxiety and post-traumatic stress but men exhibiting greater short-term increases in cardiac event rates after disasters (27, 28).

Socioeconomic and psychosocial factors compound these risks. Limited access to healthcare (9), low health literacy (28), and weak social support networks (23) may reduce resilience to chronic environmental stress (8, 17). In disaster medicine, such layered vulnerability underscores the importance of integrating chronic disease management into preparedness planning, even when hazards are perceived as low intensity (2, 9, 22).

Knowledge gaps in disaster medicine

Despite growing recognition of environmental determinants of cardiovascular health (8, 32), low-magnitude seismic activity remains insufficiently studied within disaster medicine (16). Most existing literature focuses on major earthquakes (4, 12), short-term mortality (3), and trauma-dominated outcomes (2). This event-centric approach leaves several critical gaps in understanding the broader cardiovascular consequences of seismic exposure (16).

First, there is limited understanding of the cumulative cardiovascular impact of recurrent minor seismic events; published studies are predominantly cross-sectional or short-window time-series analyses, with few cohorts followed for more than 12–24 months (16). Second, non-traumatic outcomes—such as cardiovascular destabilization and increased healthcare utilization are systematically underrepresented in disaster health assessments, where mortality and trauma metrics dominate (2, 3). Third, patterns of cardiovascular healthcare utilization during periods of background seismicity are rarely examined through a disaster medicine lens, despite their potential implications for preparedness and health-system resilience (9).

Another important limitation of the current literature is the lack of standardized definitions and exposure metrics for low-magnitude seismic activity (16). Studies vary widely in how seismic exposure is characterized, including differences in magnitude thresholds (often ranging from M 2.5 to M 5.0 in published analyses), temporal windows of analysis (hours to months), and selected clinical endpoints (17). This heterogeneity limits comparability across studies and hampers the synthesis of evidence relevant to disaster risk reduction (1).

Furthermore, relatively few investigations explicitly frame cardiovascular outcomes of seismic exposure within disaster medicine or disaster risk reduction paradigms (1, 24). As a result, evidence remains fragmented across cardiology (21), environmental health (8, 32), and geophysical disciplines (23). Longitudinal data addressing cumulative exposure and long-term cardiovascular trajectories are particularly scarce, with most available studies relying on short-term observational designs (3, 9).

The principal gaps in the current disaster medicine literature related to low-magnitude seismic activity and cardiovascular health, together with the corresponding implications for research and practice, are summarized in Table 2. Addressing these gaps will require interdisciplinary collaboration linking cardiology, environmental health, seismology, and disaster risk science (8, 9, 17), and is essential for developing prevention-oriented, resilience-based strategies that adequately reflect the full spectrum of health risks associated with chronic seismic exposure (2, 22, 28).

Table 2. Gaps in the current literature on low-magnitude seismic activity and cardiovascular health, with recommended research directions and key supporting references for each domain.

DomainCurrent literature focusIdentified gapRecommended research directionKey references
Hazard definitionMajor (M ≥ 6) earthquakesLack of standardized definitions and exposure metrics for low-magnitude, cumulative exposureDevelop consensus exposure metrics (magnitude thresholds, distance buffers, lag windows)(1, 16, 17)
OutcomesTrauma, all-cause mortalityNon-traumatic CVD outcomes systematically under-reportedHarmonized cardiovascular endpoint set for disaster surveillance(2, 3, 11)
TimeframeShort-term (hours–months)Long-term, cumulative effects of recurrent low-magnitude exposure poorly characterizedProspective longitudinal cohorts with ≥5–10 years follow-up(9, 10, 16)
MechanismsPost-major-earthquake stress physiologyLimited mechanistic data in populations exposed only to background seismicityIntegrate biomarker, autonomic, and psychometric studies in chronically exposed cohorts(5, 6, 8)
Health systemsEmergency response capacityContinuity of chronic CVD care during periods of seismic instabilityHealth-system–focused resilience studies linking seismic and CV surveillance data(9)
Policy framingCatastrophic-event paradigmFew studies framed within disaster risk reduction or Sendai-aligned frameworksEmbed CVD outcomes in disaster risk reduction monitoring and reporting(2, 22)

CVD, cardiovascular disease; DRR, disaster risk reduction. Each row links a domain of weakness in the current evidence base to a concrete research direction; the rightmost column lists representative references that substantiate both the existing focus and the identified gap.

Collectively, the six domains summarized in Table 2 outline a coherent research agenda: harmonized exposure and outcome definitions, prospective longitudinal cohorts, mechanistic studies in chronically exposed populations, and explicit framing within Sendai-aligned disaster risk reduction frameworks (1, 2, 9, 16, 17, 22).

The need for preventive strategies in disaster medicine

Recognizing low-magnitude seismic activity as a chronic, disaster-related stressor has important implications for prevention (1, 16). Within disaster medicine, prevention does not imply eliminating the geophysical hazard itself, which is not feasible, but rather reducing underlying biological, behavioral, and structural vulnerabilities (2). For cardiovascular health, this translates into optimizing primary and secondary prevention among populations residing in chronically seismically active regions (5, 21) and embedding cardiovascular protection within broader disaster risk reduction strategies (22). Given that even modest reductions in population blood pressure are estimated to substantially decrease cardiovascular mortality (3, 21), such measures are likely to yield large public-health gains in high-burden, seismically active regions.

At the individual level, preventive measures include the effective control of established cardiovascular risk factors: hypertension (5, 26), dyslipidemia (21), diabetes (8), smoking, and obesity alongside ensured continuity of essential pharmacotherapy (9) and reinforcement of evidence-based lifestyle interventions, such as physical activity, dietary modification, and sleep hygiene (6). Targeted psychosocial support and structured stress-management education may further enhance resilience by mitigating the cardiovascular impact of chronic anxiety, anticipatory stress, and uncertainty associated with recurrent seismic events (6, 7, 18, 28).

At the health-system level, preparedness frameworks should explicitly account for predictable, sustained increases in non-traumatic cardiovascular emergencies during periods of heightened seismic instability (9, 16). This may involve early-warning indicators based on seismic monitoring data (16), surge capacity planning for cardiology and emergency services (9), protected supply chains for essential cardiovascular medications (9), and the integration of cardiovascular destabilization into disaster surveillance systems (3, 13). Embedding cardiovascular considerations into disaster planning, training, simulation exercises, and recovery frameworks aligns with contemporary disaster risk reduction principles (2, 22) and supports more resilient, context-sensitive health services in chronically seismic regions (1, 24).

At the policy and community level, prevention should be conceptualized as continuous rather than event-bound (1, 22). Public health communication strategies should foster realistic risk awareness without amplifying anxiety (18, 27), while community-based interventions can promote adherence to chronic disease management (28) and strengthen social support networks (23). Such an integrated, multilevel approach, outlined in Table 3, reframes cardiovascular risk reduction as an inherent component of disaster preparedness in seismically active settings (2, 9, 22, 24).

Table 3. Proposed multilevel preventive strategies for cardiovascular risk reduction in chronically seismically active regions.

Level of interventionRecommended preventive actionsExpected impact on cardiovascular riskKey references
Individual/clinicalOptimal control of hypertension, dyslipidemia, diabetes; ensured continuity of pharmacotherapy; lifestyle counselling; psychosocial and stress-management supportReduces acute event risk during seismic episodes; lowers long-term CV mortality(5, 6, 10, 21, 26)
Health systemSeismic-data–informed surge capacity planning; protected supply chains for CV medications; integration of CV destabilization into disaster surveillance; training and simulation exercisesMitigates non-traumatic CV surges; improves resilience and continuity of chronic care(9)
Policy/communityRisk-aware public communication; community-based adherence and social-support programmes; embedding CVD outcomes within Sendai-aligned national DRR strategiesReduces population-level vulnerability; aligns CV protection with disaster risk reduction targets(2, 18, 22, 24)

CV, cardiovascular; CVD, cardiovascular disease; DRR, disaster risk reduction. Strategies are structured according to the three levels of action emphasized in contemporary disaster risk reduction frameworks (2, 22), and align with current guideline-based cardiovascular prevention (21). Numbers in parentheses correspond to references in the bibliography.

Table 3 frames cardiovascular risk reduction in chronically seismic regions as a multilevel, continuous intervention rather than an event-bound emergency response, connecting individual clinical care, health-system preparedness, and population-level policy within a single coherent prevention model (1, 2, 21, 22, 24).

Discussion

Moving beyond major earthquakes allows for a more nuanced and operationally relevant understanding of seismic risk within disaster medicine (1, 11, 16). While catastrophic seismic events understandably dominate emergency preparedness and response planning (4, 15), growing evidence suggests that low-magnitude seismic activity may exert meaningful effects on cardiovascular health through cumulative biological and psychosocial stress mechanisms (5, 6, 8). The persistence of elevated cardiovascular healthcare utilization in chronically seismically active regions with reported short-term increases in CV hospitalizations of approximately 10%–30% during periods of measurable but sub-catastrophic seismic activity (16) highlights the limitations of disaster models focused exclusively on rare, high-impact events (8, 16).

Comparison with existing literature

The findings reviewed here are broadly consistent with three distinct but converging bodies of evidence. First, classical post-earthquake cardiovascular studies, including those from Hanshin-Awaji (1995), Northridge (1994), L'Aquila (2009), Great East Japan (2011), and Türkiye–Syria (2023), consistently document acute surges in sudden cardiac death, acute coronary syndromes, and stroke in the days to weeks after a major event (4, 12–15). Second, longer follow-up cohorts, most notably from Fukushima Prefecture, demonstrate that adverse cardiovascular risk-factor changes (e.g., increases in blood pressure, weight, and dyslipidemia) can persist for years after the inciting disaster, indicating a chronic rather than purely acute biological footprint (10, 14). Third, ecological analyses of low-magnitude or background seismic exposure, although still few in number, report measurable increases in cardiovascular hospitalizations during periods that fall well below conventional disaster thresholds (11, 16). Taken together, these strands of evidence suggest a continuum of cardiovascular risk extending from sub-felt seismic activity to catastrophic events, rather than a sharp dichotomy between disaster and non-disaster states (8, 11, 16). However, direct comparisons across studies are constrained by substantial heterogeneity in exposure definitions, outcome ascertainment, and follow-up durations (1, 16, 17).

Regional implications

The South Caucasus, with Azerbaijan as a representative model region, illustrates how chronic seismic exposure (23) and a high burden of cardiovascular disease (3, 21, 31) may intersect, creating a context in which traditional disaster preparedness frameworks are insufficient (9). In such settings, cardiovascular complications associated with background seismicity may remain largely invisible to disaster surveillance systems (2, 9), despite their relevance to population health and healthcare-system resilience (9). Recognizing low-level seismic activity as a disaster-relevant health stressor supports a shift from event-centered response toward prevention-oriented disaster medicine (1, 2, 22) and is consistent with the broader environmental cardiology agenda, which conceptualizes the cardiovascular system as a sensitive integrator of multiple chronic environmental exposures (8, 17).

Alignment with disaster risk reduction frameworks

Reframing seismic risk in this manner aligns closely with contemporary disaster risk reduction principles, including those articulated in the Sendai Framework for Disaster Risk Reduction 2015–2030, the WHO Health Emergency and Disaster Risk Management Framework, and the UNDRR Global Assessment Report 2022 (2, 22). Emphasizing prevention, preparedness, and resilience over reactive emergency response enables a more comprehensive approach to disaster-related health risk (1, 9, 24). Within this paradigm, cardiovascular disease should be recognized as a major non-traumatic contributor to disaster-related morbidity (4, 5, 11), particularly in regions exposed to chronic environmental hazards (8, 17, 32).

Critical appraisal and remaining knowledge gaps

Several methodological limitations temper the strength of the current evidence base. Most published analyses of low-magnitude seismic exposure rely on retrospective, ecological, or short time-series designs, which are vulnerable to residual confounding by co-occurring environmental exposures (e.g., air pollution, temperature, socioeconomic disruption) and by secular trends in cardiovascular care (16, 17, 32). Outcome definitions are heterogeneous, ranging from all-cause cardiovascular admissions to specific endpoints such as acute coronary syndromes or out-of-hospital sudden cardiac death, limiting cross-study comparability (1, 3, 17). Exposure metrics are equally inconsistent, with magnitude thresholds, distance buffers, and lag windows differing widely across studies (16, 17). Few studies have examined dose–response relationships between cumulative seismic exposure and long-term cardiovascular outcomes, and even fewer have explicitly framed their analyses within a disaster medicine or disaster risk reduction conceptual model (1, 22, 24). Mechanistic data, although biologically plausible (5, 6, 8), remain dominated by post-major-earthquake cohorts and are seldom obtained in populations exposed only to background seismicity (27).

Implications for future research and practice

Future research should prioritize interdisciplinary approaches that integrate seismological data, cardiovascular epidemiology, and disaster risk science (16, 17). Standardized definitions of low-magnitude seismic exposure (16), prospective longitudinal cohorts assessing cumulative cardiovascular effects (9, 10, 16), and health-system–focused analyses linking seismic monitoring data with cardiovascular surveillance (9) are needed to inform evidence-based disaster preparedness strategies (22, 28). Integrating cardiovascular considerations into disaster risk reduction frameworks may enhance the ability of healthcare systems to anticipate non-traumatic surges in demand (3, 11, 13) and to mitigate preventable cardiovascular complications in seismically active regions (5, 21).

Failure to address these gaps risks perpetuating an incomplete disaster health paradigm that overlooks a substantial and potentially preventable component of cardiovascular morbidity associated with chronic seismic exposure (1, 11, 16, 21).

Generative AI statement

The author(s) declared that generative AI was used in the creation of this manuscript. Generative AI was used to assist with language editing and stylistic refinement of the manuscript. All scientific content, interpretation, conclusions, and references were developed, reviewed, and approved by the authors, who take full responsibility for the accuracy and integrity of the work.

Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.

Publisher's note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

Footnotes

Edited by: Ives Hubloue, Vrije University Brussels, Belgium

Reviewed by: Berna Büşra Ergin, Ministry of Health (Turkey), Türkiye

Statements

Conflict of interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Funding

The author(s) declared that financial support was not received for this work and/or its publication.

Author contributions

TS: Supervision, Writing – review & editing. LA: Data curation, Writing – original draft, Investigation, Conceptualization. SI: Resources, Methodology, Writing – original draft. KM: Funding acquisition, Resources, Writing – original draft. SM: Methodology, Conceptualization, Funding acquisition, Writing – original draft.

References

  1. 1. United Nations Office for Disaster Risk Reduction. Sendai Framework for Disaster Risk Reduction 2015–2030. Geneva: UNDRR (2015). Available online at: (Accessed June 20, 2026).
  2. 2. World Health Organization. Health Emergency and Disaster Risk Management Framework. Geneva: WHO (2019). Available online at: (Accessed June 20, 2026).
  3. 3. World Health Organization. Cardiovascular Diseases (CVDs) Fact Sheet. Geneva: WHO (2021). Available online at:) (Accessed June 20, 2026).
  4. 4. Leor J, Poole WK, Kloner RA. Sudden cardiac death triggered by an earthquake. N Engl J Med. (1996) 334 (7): 413 – 9. doi:10.1056/NEJM199602153340701
  5. 5. Kario K. Disaster hypertension — its characteristics, mechanism, and management. Circ J. (2012) 76 (3): 553 – 62. doi:10.1253/circj.CJ-11-1510
  6. 6. Steptoe A, Kivimäki M. Stress and cardiovascular disease. Nat Rev Cardiol. (2012) 9 (6): 360 – 70. doi:10.1038/nrcardio.2012.45
  7. 7. Edmondson D, Cohen BE. Posttraumatic stress disorder and cardiovascular disease. Prog Cardiovasc Dis. (2013) 55 (6): 548 – 56. doi:10.1016/j.pcad.2013.03.004
  8. 8. Bhatnagar A. Environmental determinants of cardiovascular disease. Circ Res. (2017) 121 (2): 162 – 80. doi:10.1161/CIRCRESAHA.117.306458
  9. 9. Kruk ME, Ling EJ, Bitton A, Cammett M, Cavanaugh K, Chopra M. Building resilient health systems: a proposal for a resilience index. Br Med J. (2017) 357: j2323. doi:10.1136/bmj.j2323
  10. 10. Ohira T, Nakano H, Nagai M, Yumiya Y, Zhang W, Uemura M. Changes in cardiovascular risk factors after the great east Japan earthquake. Asia Pac J Public Health. (2017) 29 (2_suppl): 47S – 55. doi:10.1177/1010539517695436
  11. 11. Watanabe H, Kodama M, Okura Y, Aizawa Y, Chinushi M, Nakamura Y. Impact of earthquakes on takotsubo cardiomyopathy. JAMA. (2005) 294 (3): 305 – 7. doi:10.1001/jama.294.3.305
  12. 12. Aoki T, Takahashi J, Fukumoto Y, Yasuda S, Ito K, Miyata S. Effect of the great east Japan earthquake on cardiovascular diseases — report from the 10 hospitals in the disaster area. Circ J. (2013) 77 (2): 490 – 3. doi:10.1253/circj.CJ-12-1594
  13. 13. Nakamura A, Nozaki E, Fukui K, Endo H, Takahashi T, Tamaki K. Increased risk of acute myocardial infarction after the great east Japan earthquake. Heart Vessels. (2014) 29 (2): 206 – 12. doi:10.1007/s00380-013-0353-y
  14. 14. Hasegawa A, Ohira T, Maeda M, Yasumura S, Tanigawa K. Emergency responses and health consequences after the fukushima accident; evacuation and relocation. Clin Oncol (R Coll Radiol). (2016) 28 (4): 237 – 44. doi:10.1016/j.clon.2016.01.002
  15. 15. Kario K, Nishizawa M, Hoshide S, Shimpo M, Ishibashi Y, Kunii O. Development of a disaster cardiovascular prevention network. Lancet. (2011) 378 (9797): 1125 – 7. doi:10.1016/S0140-6736(11)61187-2
  16. 16. Trichopoulos D, Katsouyanni K, Zavitsanos X, Tzonou A, Dalla-Vorgia P. Psychological stress and fatal heart attack: the Athens (1981) earthquake natural experiment. Lancet. (1983) 1 (8322): 441 – 4. doi:10.1016/S0140-6736(83)91439-3
  17. 17. Cosselman KE, Navas-Acien A, Kaufman JD. Environmental factors in cardiovascular disease. Nat Rev Cardiol. (2015) 12 (11): 627 – 42. doi:10.1038/nrcardio.2015.152
  18. 18. Norris FH, Friedman MJ, Watson PJ, Byrne CM, Diaz E, Kaniasty K. 60,000 Disaster victims speak: part I. An empirical review of the empirical literature, 1981–2001. Psychiatry. (2002) 65 (3): 207 – 39. doi:10.1521/psyc.65.3.207.20173
  19. 19. World Health Organization. Noncommunicable Diseases Country Profile. Azerbaijan. Geneva: World Health Organization (2018). Available online at: (Accessed June 20, 2026).
  20. 20. GBD 2019 Diseases and Injuries Collaborators. Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the global burden of disease study 2019. Lancet. (2020) 396 (10258): 1204 – 22. doi:10.1016/S0140-6736(20)30925-9
  21. 21. Visseren FLJ, Mach F, Smulders YM, Carballo D, Koskinas KC, Bäck M. 2021 ESC guidelines on cardiovascular disease prevention in clinical practice. Eur Heart J. (2021) 42 (34): 3227 – 337. doi:10.1093/eurheartj/ehab484
  22. 22. United Nations Office for Disaster Risk Reduction. Global Assessment Report on Disaster Risk Reduction 2022: Our World at Risk — transforming Governance for a Resilient Future. Geneva: UNDRR (2022). Available online at: (Accessed June 20, 2026).
  23. 23. Reilinger R, McClusky S, Vernant P, Lawrence S, Ergintav S, Cakmak R. GPS Constraints on continental deformation in the Africa–Arabia–eurasia continental collision zone and implications for the dynamics of plate interactions. J Geophys Res. (2006) 111 (B5): B05411. doi:10.1029/2005JB004051
  24. 24. Aitsi-Selmi A, Egawa S, Sasaki H, Wannous C, Murray V. The sendai framework for disaster risk reduction: renewing the global commitment to people’s resilience, health, and well-being. Int J Disaster Risk Sci. (2015) 6 (2): 164 – 76. doi:10.1007/s13753-015-0050-9
  25. 25. Kloner RA, Leor J, Poole WK, Perritt R. Population-based analysis of the effect of the northridge earthquake on cardiac death in Los Angeles county, California. J Am Coll Cardiol. (1997) 30 (5): 1174 – 80. doi:10.1016/S0735-1097(97)00281-7
  26. 26. Giorgini P, Striuli R, Petrarca M, Paciência I, Barros H, Araújo J. Long-term blood pressure changes induced by the 2009 L’Aquila earthquake: assessment by 24 h ambulatory monitoring. Hypertens Res. (2013) 36 (9): 795 – 8. doi:10.1038/hr.2013.37
  27. 27. Bromet EJ, Atwoli L, Kawakami N, Navarro-Mateu F, Piotrowski P, King AJ. Post-traumatic stress disorder associated with natural and human-made disasters in the world mental health surveys. Psychol Med. (2017) 47 (2): 227 – 41. doi:10.1017/S0033291716002026
  28. 28. Goldmann E, Galea S. Mental health consequences of disasters. Annu Rev Public Health. (2014) 35: 169 – 83. doi:10.1146/annurev-publhealth-032013-182435
  29. 29. Roth GA, Mensah GA, Johnson CO, Addolorato G, Ammirati E, Baddour LM. Global burden of cardiovascular diseases and risk factors, 1990–2019: update from the GBD 2019 study. J Am Coll Cardiol. (2020) 76 (25): 2982 – 3021. doi:10.1016/j.jacc.2020.11.010
  30. 30. Kivimäki M, Steptoe A. Effects of stress on the development and progression of cardiovascular disease. Nat Rev Cardiol. (2018) 15 (4): 215 – 29. doi:10.1038/nrcardio.2017.189
  31. 31. Vaduganathan M, Mensah GA, Turco JV, Fuster V, Roth GA. The global burden of cardiovascular diseases and risk: a compass for future health. J Am Coll Cardiol. (2022) 80 (25): 2361 – 71. doi:10.1016/j.jacc.2022.11.005
  32. 32. Brook RD, Rajagopalan S, Pope CA 3rd, Bhatnagar A, Diez-Roux AV, Holguin F. Particulate matter air pollution and cardiovascular disease: an update to the scientific statement from the American Heart Association. Circulation. (2010) 121 (21): 2331 – 78. doi:10.1161/CIR.0b013e3181dbece1
  33. 33. Kario K, Matsuo T, Kobayashi H, Yamamoto K, Shimada K. Earthquake-induced potentiation of acute risk factors in hypertensive elderly patients: possible triggering of cardiovascular events after a major earthquake. J Am Coll Cardiol. (1997) 29 (5): 926 – 33. doi:10.1016/S0735-1097(97)00002-8

Citation

Sadigova, T., et al. (2026). Beyond major earthquakes: cardiovascular health impact of Low-magnitude seismic activity and the need for preventive strategies. Frontiers in Disaster and Emergency Medicine, Volume 4. https://doi.org/
Received
Accepted
Published
Volume
4 - 2026

Copyright

© 2026 Sadigova, Afandiyeva, Ibrahimova, Mammadyarova and Mammadli.

License: https://creativecommons.org/licenses/by/4.0/

*Correspondence: Tora Sadigova

Article metrics

Views
0
Downloads
0
Citations
0
Shares
0