Implantable cardioverter-defibrillators in lamin A/C mutation carriers with cardiac conduction disorders

Abstract

Background: Sudden cardiac death is frequent in patients with lamin A/C gene (LMNA) mutations and may be related to ventricular arrhythmias (VA).

Objective: To evaluate a strategy of prophylactic implantable cardioverter-defibrillator (ICD) implantation in LMNA mutation carriers with significant cardiac conduction disorders.

Methods: Forty-seven consecutive patients (mean age 38 ± 11 years; 26 men) were prospectively enrolled between March 1999 and April 2009. Prophylactic ICD implantation was performed in patients with significant cardiac conduction disorders: patients requiring permanent pacing for bradycardia or already implanted with a pacemaker at the initial presentation, or patients with a PR interval of >0.24 seconds and either complete left bundle branch block or nonsustained ventricular tachycardia.

Results: Twenty-one (45%) patients had significant conduction disorders and received a prophylactic ICD. Among ICD recipients, no patient died suddenly and 11 (52%) patients required appropriate ICD therapy during a median follow-up of 62 months. Left ventricular ejection fraction was ≥45% in 9 patients at the time of the event. Among the 10 patients without malignant VA, device memory recorded nonsustained ventricular tachycardia in 8 (80%). The presence of significant conduction disorders was the only factor related to the occurrence of malignant VA (hazard ratio 5.20; 95% confidence interval 1.14-23.53; P = .03).

Conclusions: Life-threatening VAs are common in patients with LMNA mutations and significant cardiac conduction disorders, even if left ventricular ejection fraction is preserved. ICD is an effective treatment and should be considered in this patient population.

Keywords: ATP; AVB; Conduction disturbances; DCM; ICD; Implantable cardioverter-defibrillator; LBBB; LMNA; LVEF; Lamin A/C gene; NSVT; SCD; Sudden cardiac death; VA; VF; VT; Ventricular arrhythmias; antitachycardia pacing; atrioventricular block; dilated cardiomyopathy; implantable cardioverter-defibrillator; lamin A/C gene; left bundle branch block; left ventricular ejection fraction; nonsustained ventricular tachycardia; sudden cardiac death; ventricular arrhythmias; ventricular fibrillation; ventricular tachycardia.