216-59: Arrhythmias and sudden cardiac death in fifty adult patients with left ventricular noncompaction syndrome

Abstract

Purpose: To study the spectrum of rhythm and conduction disturbances in adults with the syndrome of noncompact myocardium (NCM). Methods: The study included 50 patients, 42.8 ± 14.9 years, 28 male, who according to visual criteria CCM diagnosed: 12 patients using 3 methods (echocardiography, CT, MRI), 30 using 2 methods. Morphological study of myocardium were also undergone (n = 14) asa well as coronary angiography (n = 16) and electrophysiological (EP) study (n = 5). The mean follow-up was 10.5 [3.5; 22.5] months. Results: The following arrhythmias were detected: 1. Atrial fibrillation in 15 (30%, initially paroxysmal in 7 patients, persistent in 3 and constant in 3). 2. Ventricular premature beats, PVCs (more than 200 per day) in 28 (56%), 979 [29.25; 3669] PVCs per day. 3. The unstable ventricular tachycardia (VT) in 32 (64%), in the absence of significant PVCs in 7 patients, "torsade de pointes" in 1 patient. 4. Sustained VT in 7 (14%) patient. 5. Ventricular fibrillation (VF( in 5 patients (10%, in one case VF was induced during EP study). 6. Complete left bundle branch block, LBBB, in 8 (16%) patients. 7. Sick Sinus Syndrome in 4 (8%) patients. 8. AV block II-III degree in 3 (6%) patients. Heart failure was present in 43 (86%) patients, 2 [1; 3] NYHA class, average ejection fraction was 34.6 ± 14.0%. Isolated arrhythmias were the manifestation of the NCM in 9 (18%) patients without systolic dysfunction (mask arrhythmic syndrome). Most malignant ventricular arrhythmias observed in patients with combination NCM and ARVD (n = 2) and / or active myocarditis. Pacemakers are implanted in 3 patients, CRT in 1 patient and ICD / CRT-D in 14/4 (36%) patients), including for primary prevention of sudden cardiac death (SCD) in 14 of them. Appropriate shocks observed in 5 (28%) cases, inappropriate shocks in 2 (11%). SCD has developed only in patients without ICDs. Overall mortality was 10%. RFA in two patients (with PVCs and sustained VT) had no effect. Intracardiac thrombosis was detected in 11 patients, thromboembolism in 5 patients. Heart transplantation performed in 3 patients. Conclusions: Noncompaction syndrome should be excluded in all patients with arrhythmias of unknown origin. Arrhythmias in NCM associated with myocardial dysfunction in some extent, as well as with presence of systolic dysfunction and myocarditis. They have life-threatening nature (sick sinus syndrome, AV block II-III degree, stable VT, SCD) in 24% of patients.