Cardiac arrhythmias in hypertrophic cardiomyopathy

Area of Science:

• Cardiology
• Genetics
• Diagnostic Imaging

Background:

• Hypertrophic cardiomyopathy (HCM) is a genetic heart condition with variable presentation.
• Early detection of HCM in relatives of affected individuals is crucial for timely intervention.
• Diagnostic criteria for HCM, particularly in family screening, require validation.

Purpose of the Study:

• To determine the prevalence of cardiac arrhythmias in relatives of patients with confirmed hypertrophic cardiomyopathy.
• To evaluate the diagnostic accuracy of interventricular septal thickness (≥1.3 cm) via echocardiography for identifying HCM in relatives.
• To compare arrhythmia profiles between relatives with and without echocardiographically diagnosed HCM and healthy controls.

Main Methods:

• Echocardiography was used to measure interventricular septal thickness in 50 close relatives of deceased HCM patients.
• Twenty-four-hour ambulatory electrocardiographic monitoring was performed on relatives and 40 healthy controls.
• Statistical analysis compared arrhythmia prevalence and types across groups: HCM relatives, non-HCM relatives, and controls.

Main Results:

• Twenty-two relatives met the echocardiographic criterion for HCM (interventricular septal thickness ≥1.3 cm).
• Relatives with HCM showed significantly higher rates of supraventricular extrasystoles, supraventricular arrhythmias, and high-grade ventricular arrhythmias compared to other groups.
• No significant differences in arrhythmias were observed between non-HCM relatives and healthy controls.

Conclusions:

• Echocardiographic measurement of interventricular septal thickness ≥1.3 cm is a valid criterion for diagnosing HCM in relatives.
• Relatives with HCM exhibit a distinct and increased prevalence of cardiac arrhythmias.
• Screening of close relatives of HCM cases using echocardiography, followed by ambulatory electrocardiographic monitoring if indicated, is recommended.