Symptoms and ECG changes precede sudden cardiac death in hypertrophic cardiomyopathy—A nationwide study among the young in Sweden

Abstract

Background Hypertrophic cardiomyopathy (HCM) is a major cause of sudden cardiac death (SCD) in the young. We aimed to characterize detailed family history, symptoms, hospital utilization and ECG changes before SCD. Methods We extracted all cases suffering SCD with HCM from the SUDDY cohort, which includes all cases of SCD between 2000–2010 in Sweden among individuals aged 0–35 years along with their controls. We gathered data from mandatory national registries, autopsy reports, medical records, ECGs (including military conscripts), and detailed family history from an interview-based questionnaire (with relatives, post-mortem). Results Thirty-eight cases (7 female), mean age 22 years, with HCM were identified. Among these, 71% presented with possible cardiac symptoms (chest pain [26%], syncope [22%], palpitations [37%]), before death; 69% received medical care (vs 21% in controls) within 180 days before death. The majority (68%) died during recreational activity (n = 14) or exercise/competitive sports (n = 12). Fifteen (39%) had a known cardiac disorder prior to death, with HCM being diagnosed pre-mortem in nine cases. 58% presented with abnormal ECG recordings pre-mortem, and 50% had a positive family history (1st-3rd generation) for heart disease. Conclusion In this comprehensive, nationwide study of SCD due to HCM, 87% (33/38) of cases had one or more abnormality prior to death, including cardiac symptoms, a positive family history, known cardiac disease or ECG abnormalities. They sought medical care prior death, to a larger extent than controls. These findings suggest that cardiac screening should be expanded beyond competitive athletes to aid SCD prevention in the young population with HCM.

The Majority of Participants With Suspected Hypertrophic Cardiomyopathy Documented During Screening Echocardiography Have a Normal Electrocardiogram

“…20 Identifying high-risk patients is crucial to lowering the risk of SCD in young individuals with HCM, as effective treatment has the potential to significantly reduce HCM mortality and morbidity. [22][23][24] The HCM diagnosis is based on imaging techniques, such as echocardiography or cardiovascular magnetic resonance (CMR), that reveal increasing LV wall thickness. 21 Thorough investigation has led to a better comprehension of risk categorization for patients with HCM.…”

“…20 Identifying high-risk patients is crucial to lowering the risk of SCD in young individuals with HCM, as effective treatment has the potential to significantly reduce HCM mortality and morbidity. 22–24…”

An overview of the electrocardiographic monitoring devices in sports cardiology: Between present and future

“…Hence, when an athlete spontaneously refers palpitations or other symptoms to the team personnel including doctors, suggesting an underlying arrhythmic event, it is imperative to carefully integrate the clinical and instrumental investigations. Nevertheless, some arrhythmic disturbances might also be totally asymptomatic and only identified during the medical examination or SCD might be the first symptom 2,4 . Therefore large‐scale epidemiological studies reporting its prevalence, etiology or prognosis in athletes are missing.…”

“…Therefore large‐scale epidemiological studies reporting its prevalence, etiology or prognosis in athletes are missing. Palpitations are frequently referred symptoms in the general population, described as an abnormal perception (irregular, accelerated, intense) of the cardiac pulse; most palpitations occur during sinus rhythm are benign in nature, but also malignant arrhythmias can be the cause of palpitations 4 . In the literature, the prevalence of palpitations appears to be more common in highly trained or in master athletes, rather than in infants or adolescents 5,6 .…”

“…Nevertheless, some arrhythmic disturbances might also be totally asymptomatic and only identified during the medical examination or SCD might be the first symptom . 2 , 4 Therefore large‐scale epidemiological studies reporting its prevalence, etiology or prognosis in athletes are missing. Palpitations are frequently referred symptoms in the general population, described as an abnormal perception (irregular, accelerated, intense) of the cardiac pulse; most palpitations occur during sinus rhythm are benign in nature, but also malignant arrhythmias can be the cause of palpitations.…”