Multiple Autonomic and Repolarization Investigation of Sudden Cardiac Death in Dilated Cardiomyopathy and Controls

作者：Pezawas Thomas^*; Diedrich Andre; Winker Robert; Robertson David; Richter Bernhard; Wang Li; Byrne Daniel W; Schmidinger Herwig

来源：Circulation-Arrhythmia and Electrophysiology, 2014, 7(6): 1101-1108.

DOI：10.1161/CIRCEP.114.001745

• cardiomyopathy, dilated
• implantable cardioverter defibrillator
• (non-invasive) risk stratification
• sudden cardiac death or arrhythmic death

Background-Prophylactic defibrillator implantation is recommended in dilated, nonischemic heart disease and left ventricular ejection fraction of %26lt;= 0.30 to 0.35. Noninvasive testing should improve accuracy in decision making of prophylactic defibrillator implantation. %26lt;br%26gt;Methods and Results-We enrolled 60 patients (median age, 57 years) with dilated cardiomyopathy and left ventricular ejection fraction %26lt;= 0.50, and 30 control subjects (median age, 59 years) with left ventricular ejection fraction %26gt;0.50. The protocol included an initial assessment, a second assessment after 3 years, and a final follow-up: pharmacological baroreflex testing (baroreceptor reflex sensitivity), short-term spectral analysis of heart rate variability (low frequency/high frequency), and long-term time domain analysis (SD of all normal-to-normal R-R intervals), exercise microvolt T wave alternans, and signal-averaged ECG, and corrected QT-time. The median follow-up was 7 years. End points were cardiac death, resuscitated cardiac arrest, and arrhythmic death. Cardiac death was observed in 21 patients. Resuscitated cardiac arrest and arrhythmic death caused by ventricular tachyarrhythmias %26gt;= 240 per minute was observed in 7 and 10 patients, respectively. In the single time point analysis, microvolt T wave alternans, baroreceptor reflex sensitivity, and SD of all normal-to-normal R-R intervals at initial testing added significant information regarding cardiac death. Microvolt T wave alternans added information on resuscitated cardiac arrest or arrhythmic death at multiple time points (P%26lt;0.001). False-negative microvolt T wave alternans results were seen in 8% of patients. %26lt;br%26gt;Conclusions-Noninvasive testing and left ventricular ejection fraction could not reliably identify patients with dilated cardiomyopathy at risk of fatal ventricular tachyarrhythmias. Therefore, the strategy to confine prophylactic implantable cardioverter-defibrillator implantation to patients with dilated cardiomyopathy and severely reduced LV function should be reconsidered.

• 出版日期2014-12