Hypertrophic cardiomyopathy

QT interval

Tachycardia

Sinus bradycardia

Cardiology

Heart rate

Environmental health

Ambulatory

Heart failure

Blood pressure

Ventricular tachycardia

Supraventricular tachycardia

Population

Internal medicine

Implantable cardioverter-defibrillator

Bradycardia

Odds ratio

Left bundle branch block

Sudden cardiac death

Medicine

Ventricular fibrillation

Atrial fibrillation

Acta Cardiologica

Introduction: Risk assessment for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) remains complex. The goal of this study was to assess electrocardiogram (ECG)-derived risk factors on SCD in a large HCM populationMethods: Retrospective review of adults with HCM evaluated at Mayo Clinic, Rochester, MN from 1 December 2002 to 31 December 2012 was performed. Data inclusive of ECG and 24-hour ambulatory Holter monitor were assessed. SCD events were documented by ventricular fibrillation (VF) noted on implantable cardioverter defibrillator (ICD), or appropriate VT or VF-terminating ICD shock.Results: Overall, 1615 patients (mean age 53.7 ± 15.2 years; 943 males, 58.4%) were assessed, with mean follow-up 2.46 years and 110 SCD events. Via logistic regression (n = 820), the odds of SCD increased with increasing number of conventional risk factors. With one risk factor the OR was 4.88 (p < .0001; CI 2.22–10.74), two risk factors the OR was 6.922 (p < .0001; CI 2.94–16.28) and three or more risk factors, the OR was 13.997 (p < .0001; CI 5.649–34.68). Adding QTc > 450 to this logistic regression model had OR 1.722 (p = .04, CI 1.01–2.937) to predict SCD. QTc ≥ 450 was a significant predictor for death (HR 1.88, p = .021, CI 1.10–3.20). There was no correlation between sinus bradycardia, sinus tachycardia, first degree AV block, atrial fibrillation, left bundle branch block, right bundle branch block, premature atrial complexes, premature ventricular complexes, supraventricular tachycardia, PR interval, QRS interval and SCD.Conclusions: Prolonged QTc was a risk factor for SCD and death even when controlling for typical risk factors.

QT prolongation and sudden cardiac death risk in hypertrophic cardiomyopathy