RESUMO
OBJECTIVES: We hypothesized that deceleration capacity (DC), a novel marker of cardiac autonomic modulation, is an independent predictor for mortality in patients with non-ischemic dilated cardiomyopathy (NICM). BACKGROUND: NICM is associated with a high risk for sudden cardiac death (SCD). However there are no clinically established parameters available for risk stratification beyond LVEF. DC has been previously shown to be a strong independent predictor for total mortality in patients after myocardial infarction. METHODS: Holter-ECG recordings of 201 patients NICM (83.1% male, mean age: 61.4years, mean LVEF: 33.3%) were analyzed by the method of phase-rectified-signal-averaging (PRSA) to obtain DC. RESULTS: During a minimum follow-up of 40month 59 patients died. Kaplan Meyer Analysis showed a significantly higher mortality in patients with a DC below 4.5ms (log rank p=0.012) irrespective to the presence of atrial fibrillation. CONCLUSIONS: Impaired DC is a powerful independent predictor for mortality in patients with NICM.
Assuntos
Cardiomiopatia Dilatada/diagnóstico , Cardiomiopatia Dilatada/mortalidade , Desaceleração , Idoso , Cardiomiopatia Dilatada/fisiopatologia , Eletrocardiografia Ambulatorial/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Valor Preditivo dos Testes , Volume Sistólico/fisiologiaRESUMO
BACKGROUND: Nonischemic dilated cardiomyopathies (DCM) are the most common reason for heart failure in developed countries after ischemic disease. They often lead to device therapy. Left ventricular ejection fraction as a single parameter to identify patients at risk for sudden cardiac death revealed inconclusive data in patients with DCM. METHODS: Autonomic tone, measured by classical and innovative parameters of heart rate variability (HRV), heart rate turbulence or baroreceptor reflex, was demonstrated to give valuable prognostic information especially in patients with ischemic disease and after acute myocardial infarction. In patients with DCM, classical parameters of HRV showed inhomogeneous data in a heterogeneous patient collective caused by unsystematic measurement of single parameters in various patient collectives. RESULTS: Innovative parameters of HRV are promising in patients with DCM and showed prognostic relevance although patient numbers are limited and prospective data are missing. Further studies are needed in this field. CONCLUSION: Despite the in part convincing evidence for the relevance of autonomic tone as a prognostic marker in patients with DCM, their evaluation is still not part of clinical routine. Additional parameters to estimate the risk of sudden cardiac death are urgently needed.