European Journal of Cardiovascular Medicine

Sudden cardiac death (SCD) is a catastrophic and often unanticipated event, accounting for approximately 4–5 million deaths annually worldwide and nearly 10% of all deaths in India. Despite its staggering contribution to cardiovascular mortality, SCD remains a largely silent epidemic in the Indian context, where awareness of its risk factors, early warning signs, and emergency response strategies is alarmingly low. Unlike other non-communicable diseases that progress with overt symptoms, SCD frequently occurs in apparently healthy individuals, leaving families and communities devastated and healthcare systems challenged to respond promptly.^1-3

The underlying pathophysiology of SCD is most commonly linked to malignant ventricular arrhythmias, such as ventricular tachycardia and ventricular fibrillation, often triggered by structural heart diseases, ischemic heart disease, or inherited channelopathies. While advances in diagnostics, preventive cardiology, and the availability of implantable cardioverter-defibrillators (ICDs) have significantly improved outcomes in high-income countries, the translation of these strategies to low- and middle-income nations, including India, is hindered by gaps in public knowledge, limited access to timely defibrillation, and inadequate emergency medical infrastructure.^4-6

In India, the dual burden of rising cardiovascular risk factors—hypertension, diabetes, dyslipidemia—and widespread misconceptions about cardiac health amplify vulnerability to SCD. A lack of public understanding about the importance of automated external defibrillators (AEDs), cardiopulmonary resuscitation (CPR), and early symptom recognition often results in fatal delays. Existing community-based programs and national initiatives for cardiovascular disease control seldom incorporate targeted awareness drives for arrhythmia and SCD prevention, leaving a critical gap in preparedness at both household and societal levels.^7-9

Globally, several studies highlight the role of education in improving bystander CPR rates and AED utilization, thereby reducing mortality.^10-12 However, data on the Indian population’s knowledge, attitudes, and perceptions regarding SCD and arrhythmia are sparse. Identifying these gaps is essential for shaping behavior change communication strategies, strengthening public health policies, and integrating life-saving interventions within the continuum of cardiac care.

This study aims to assess the awareness, risk perception, and emergency preparedness related to sudden cardiac death and arrhythmias among the general public in India, and to explore socio-demographic correlates influencing knowledge levels. By generating context-specific evidence, the findings are expected to inform the design of culturally sensitive educational campaigns and community-based cardiac emergency response models that can ultimately mitigate preventable deaths due to SCD.

Study Design and Setting

A descriptive, cross-sectional study was conducted to assess public knowledge, risk perception, and emergency preparedness regarding sudden cardiac death (SCD) and arrhythmias in India. The study was carried out from Sep 2024 to Dec 2024, leveraging a digital platform to ensure broad outreach across diverse socio-demographic segments. Considering the widespread internet penetration and smartphone usage in India, data collection was implemented through a Google Form–based questionnaire, ensuring accessibility while maintaining uniformity in administration.

Study Population and Eligibility Criteria

The target population comprised Indian residents aged 18 years and above, regardless of gender, educational background, or occupation. Inclusion criteria were:

1. Willingness to provide informed consent.
2. Access to a smartphone or computer with internet connectivity.

Healthcare professionals, medical students, and individuals with formal training in cardiology or emergency care were excluded to prevent bias toward higher awareness levels.

Sample Size Determination

The sample size was calculated using the single population proportion formula:

n=Z²×p(1−p)d²

Assuming a 50% prevalence of adequate awareness (p = 0.5) for maximum variability, a 95% confidence level (Z = 1.96), and a 5% margin of error (d = 0.05), the minimum required sample size was 384 respondents. To account for incomplete responses, the sample was rounded up to 400 participants.

Sampling Technique

A non-probability, purposive-cum-snowball sampling method was employed. The Google Form link was circulated through social media platforms (WhatsApp, Facebook, Twitter), institutional networks, and community groups, encouraging participants to share the link further to expand reach. Special efforts were made to include respondents from both urban and rural regions to capture heterogeneity.

Development of Data Collection Tool

A structured questionnaire was designed in English and Hindi, drawing from guidelines by the American Heart Association (AHA), European Society of Cardiology (ESC), and national cardiovascular disease prevention frameworks. The instrument consisted of four sections:

1. Socio-demographic details: age, gender, education, occupation, income, region (urban/rural).
2. Knowledge of SCD and arrhythmia: 20 multiple-choice questions on definitions, risk factors, warning symptoms, and preventive measures.
3. Risk perception and emergency preparedness: awareness of CPR, AED use, previous exposure to cardiac emergencies, willingness to attend life-saving skills training.
4. Behavioral intention: hypothetical response scenarios (e.g., immediate steps during sudden collapse).

Each correct knowledge response was awarded 1 point, while incorrect or “don’t know” responses scored 0, generating a cumulative knowledge score. Scores were categorized as:

• Very Good: 16–20
• Good: 12–15
• Fair: 8–11
• Poor: 0–7

Pilot Testing and Validation

The questionnaire underwent pre-testing on 30 respondents (excluded from the final analysis) to ensure clarity, cultural appropriateness, and technical functionality on the Google Form interface. Based on feedback, minor modifications were made to simplify terminology. Internal consistency was measured using Cronbach’s alpha (α = 0.82), confirming high reliability.

Data Collection Procedure

The Google Form was designed with mandatory responses, eliminating missing data. It incorporated adaptive logic for a smooth user experience and required approximately 8–10 minutes for completion. Upon form initiation, participants viewed an electronic informed consent page. Data were securely stored in Google Sheets, accessible only to the principal investigator.

Data Analysis

Data were exported to Microsoft Excel and analyzed using IBM SPSS Statistics version 25. Descriptive statistics (frequency, percentage, mean, standard deviation) summarized socio-demographics and knowledge responses. Chi-square tests assessed associations between knowledge levels and socio-demographic variables, while multivariate logistic regression identified independent predictors of good awareness (score ≥12). Results were expressed as Adjusted Odds Ratios (AORs) with 95% Confidence Intervals (CIs), and p < 0.05 was considered statistically significant.

Ethical Considerations

The study adhered to the principles of the Declaration of Helsinki. Participation was voluntary, and confidentiality was maintained by not collecting identifiable personal data.

Table 1 summarizes the socio-demographic profile of the 400 respondents. The majority (37.0%) were aged between 25–34 years, followed by 35–44 years (24.0%) and 18–24 years (23.0%), while 16.0% were aged ≥45 years. Gender distribution was slightly skewed towards males (53.0%) compared to females (47.0%). More than half of the respondents resided in urban areas (57.5%), with the remainder from rural settings (42.5%). In terms of education, 43.0% had completed graduation, 20.5% had postgraduate or higher qualifications, while 29.5% reported secondary school education and 7.0% had no formal education. Regarding occupation, 41.5% were employed in service or professional roles, 31.0% were homemakers, and 27.5% worked as skilled or unskilled laborers. These findings reflect a relatively well-educated and urbanized sample, yet with significant representation from rural and lower-education groups.

Table 1: Socio-Demographic Characteristics of Respondents (n = 400)

Table 2 details participant responses to 20 questions assessing awareness and misconceptions about sudden cardiac death (SCD) and arrhythmia. Knowledge gaps were evident across critical domains. While 59.0% correctly identified abnormal heart rhythm as the primary cause of SCD, less than half (47.0%) recognized ventricular fibrillation as the most fatal arrhythmia. Awareness regarding major risk factors was moderate (65.5% identified coronary artery disease), and 74.5% correctly reported sudden fainting as a warning sign. However, practical emergency knowledge was poor; only 38.5% knew the purpose of an automated external defibrillator (AED), and 35.5% were aware of the correct CPR compression-ventilation ratio. Alarmingly, only 33.0% knew the recommended chest compression depth, and just 37.0% identified the ideal time window for defibrillation (within 3–5 minutes). Although 78.0% endorsed CPR/AED training for all, misconceptions persisted, with nearly half (49.5%) believing SCD occurs only in athletes and 53.0% considering CPR harmful. Overall, these findings reveal significant deficits in both conceptual and practical life-saving knowledge.

Table 2: Awareness and Misconception Questions on SCD and Arrhythmia (n = 400)

Table 3 presents indicators related to perceived risk and readiness to act during cardiac emergencies. While 63.0% were aware that young adults can experience SCD, only 22.0% reported knowing someone who had collapsed suddenly, which may influence perceived urgency. Confidence in recognizing cardiac arrest was low (28.5%), and only 11.5% had formal CPR or Basic Life Support (BLS) training. Awareness of AED was limited (33.0%), with just 19.5% feeling comfortable using the device during an emergency. Despite these gaps, willingness to improve skills was high—81.5% expressed readiness to attend CPR/AED training. This pattern highlights a critical mismatch between current capability and perceived responsibility, underscoring the need for large-scale community-based training programs.

Table 3: Risk Perception and Emergency Preparedness Indicators (n = 400)

Table 4 categorizes participants’ overall knowledge scores based on 20 awareness questions. Only 18.0% achieved a “very good” score (16–20), while 29.0% scored in the “good” range (12–15). The largest proportion (35.5%) fell into the “fair” category (8–11), and 17.5% demonstrated poor knowledge (0–7). These results indicate that while nearly half of respondents possess moderate to good awareness, a significant proportion lack critical knowledge needed for timely recognition and management of SCD. The overall distribution suggests systemic gaps in public education regarding cardiac emergencies, particularly in practical life-saving measures.

Table 4: Knowledge Score Classification of Participants (n = 400)

Table 5 explores the association between overall knowledge levels and socio-demographic characteristics. Education emerged as the strongest determinant (p < 0.001), with graduates and above showing markedly higher proportions of very good knowledge (22.7%) compared to those with no formal education (7.1%). Occupation and income were also significant predictors—service/professional workers and respondents from higher-income households demonstrated better awareness (p < 0.001), while homemakers and low-income groups were overrepresented in the fair/poor knowledge categories. Urban residents performed significantly better than their rural counterparts (p = 0.038). In contrast, age and gender showed no significant association, suggesting that educational and socio-economic factors exert a stronger influence on knowledge than demographic characteristics. These findings underscore the importance of targeting awareness campaigns toward low-income, rural, and less-educated populations.

Table 5: Association Between Overall Knowledge and ALL Socio-Demographic Variables (n = 400)

Table 6 presents the results of multivariate logistic regression identifying independent predictors of good knowledge on SCD and arrhythmia. Higher education remained the most powerful predictor—graduates and above were nearly five times more likely to have good knowledge compared to those with no formal education (AOR = 4.82, 95% CI: 2.35–9.88, p < 0.001). Urban residence (AOR = 1.86, p = 0.021) and higher household income (>INR 30,000; AOR = 3.12, p < 0.001) were also significant. Importantly, prior CPR training (AOR = 3.24, p < 0.001) and awareness of AED (AOR = 2.06, p = 0.017) independently predicted higher knowledge scores, emphasizing the role of structured training in bridging awareness gaps. Gender and age were not statistically significant after adjustment, suggesting that targeted educational interventions could substantially improve public readiness across demographic groups.

Table 6: Multivariate Logistic Regression

This cross-sectional study reveals critical gaps in public awareness, risk perception, and emergency preparedness for sudden cardiac death (SCD) and arrhythmia in India. Although cardiovascular diseases constitute the leading cause of mortality in the country, the understanding of SCD-specific risk factors, early warning symptoms, and life-saving interventions among the general population remains inadequate. Our results show that while some conceptual knowledge—such as recognizing coronary artery disease as a major risk factor (65.5%) and sudden fainting as a warning sign (74.5%)—is reasonably good, practical knowledge essential for survival outcomes, including CPR techniques and AED use, is alarmingly deficient. Only 11.5% of respondents had ever received CPR training, and less than 40% were aware of the correct CPR-to-ventilation ratio or the ideal time frame for defibrillation. These findings indicate that India faces a dual challenge: limited access to emergency resources and pervasive knowledge gaps that compromise timely bystander intervention.^8,10,11

Globally, community readiness for cardiac emergencies is considered a cornerstone of SCD survival. Studies in the United States, Japan, and Scandinavia consistently report higher bystander CPR rates (>40%) and widespread AED awareness, translating to significantly better out-of-hospital cardiac arrest survival rates (15–20%). In contrast, our findings align with other low- and middle-income countries (LMICs), where bystander CPR rates hover below 5%. The poor awareness regarding AED use in our sample (only 33% knew about AEDs, and 19.5% felt confident using them) underscores the absence of robust community-based emergency response systems in India.

Interestingly, misconceptions persist even among educated groups, with nearly half of respondents believing SCD occurs primarily in athletes and over 50% fearing CPR may cause harm. Similar misconceptions were observed in prior Asian studies, suggesting a strong cultural component influencing health perceptions.^6,8,9,10 This highlights the need for culturally sensitive behavior change interventions tailored to Indian communities.

Our analysis demonstrates that education, occupation, and income strongly predict SCD awareness, with graduates being nearly five times more likely to possess good knowledge compared to those without formal schooling (AOR 4.82). Urban residence and higher household income also correlated with better awareness, reflecting the broader health literacy divide between rural and urban populations. These disparities mirror the social determinants of health described in prior Indian studies on non-communicable diseases, where socio-economic disadvantage translates into poorer preventive knowledge and delayed emergency response. Importantly, gender and age were not significant predictors after adjustment, indicating that knowledge deficits transcend demographic boundaries and affect men and women across age groups.

Implications for Public Health and Policy

The implications of these findings are profound for public health planning in India. While national initiatives like NPCDCS (National Programme for Prevention and Control of Cancer, Diabetes, Cardiovascular Diseases and Stroke) have expanded screening and treatment services, they lack specific community-level strategies for SCD prevention and cardiac arrest response. Our results highlight the urgent need to embed CPR and AED training into school curricula, workplace wellness programs, and community health initiatives, similar to models implemented successfully in countries like Singapore and Denmark.

Equally critical is the deployment of AEDs in high-footfall public areas—airports, railway stations, shopping malls—combined with clear signage and community drills. However, AED access alone will not suffice; structured awareness campaigns emphasizing the chain of survival—early recognition, immediate CPR, and defibrillation—must be launched through multimedia platforms and grassroots networks such as Accredited Social Health Activists (ASHAs).

Bridging Knowledge into Action

A striking observation in our study was the high willingness to learn—over 80% of respondents expressed interest in attending CPR/AED training. This reflects a fertile ground for intervention and underscores the need for scalable, low-cost, and culturally adapted CPR training programs. Technology-enabled solutions, such as mobile-based CPR tutorials and virtual AED simulations, could complement traditional classroom training, especially in resource-constrained rural areas.

Strengths and Limitations

The study’s strengths include a large sample size, diverse representation across urban and rural settings, and rigorous statistical analysis identifying independent predictors of awareness. Furthermore, the use of a validated questionnaire based on international guidelines enhances the robustness of findings. However, limitations include the reliance on self-reported data and digital platforms, which may bias the sample toward literate, tech-savvy individuals. The cross-sectional design limits causal inference, and actual emergency behavior was not assessed. Despite these constraints, the study provides critical baseline evidence to inform national strategies for cardiac emergency preparedness.

Future Directions

Future research should focus on interventional trials assessing the effectiveness of community-based CPR and AED training programs, evaluating their impact on bystander response rates and survival outcomes. Additionally, qualitative studies exploring cultural barriers and psychological determinants of emergency response in Indian settings will be instrumental in designing contextually relevant behavior change communication strategies.

This study highlights critical deficiencies in public knowledge and preparedness regarding sudden cardiac death (SCD) and arrhythmias in India, particularly in practical life-saving skills such as CPR and AED use. While conceptual awareness of risk factors and warning signs was moderate, significant misconceptions and low confidence in emergency response persist, especially among rural, low-income, and less-educated populations. Education, socio-economic status, prior CPR training, and AED awareness emerged as key determinants of knowledge, underscoring the urgent need for targeted interventions. Integrating CPR/AED training into schools, workplaces, and community programs, expanding public access to AEDs, and leveraging mass media for culturally appropriate awareness campaigns are critical steps to bridge the knowledge-to-action gap. These measures, aligned with national non-communicable disease control strategies, can strengthen community response systems and ultimately reduce preventable deaths from SCD in India.

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