Assuntos
Morte Súbita Cardíaca/prevenção & controle , Algoritmos , Estenose da Valva Aórtica/etiologia , Estenose da Valva Aórtica/terapia , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/terapia , Displasia Arritmogênica Ventricular Direita/etiologia , Displasia Arritmogênica Ventricular Direita/terapia , Cardiomiopatia Dilatada/etiologia , Cardiomiopatia Dilatada/terapia , Cardiomiopatia Hipertrófica/etiologia , Cardiomiopatia Hipertrófica/terapia , Morte Súbita Cardíaca/etiologia , Insuficiência Cardíaca/complicações , Humanos , Síndrome do QT Longo/etiologia , Síndrome do QT Longo/terapia , Prolapso da Valva Mitral/etiologia , Prolapso da Valva Mitral/terapia , Infarto do Miocárdio/complicações , Ensaios Clínicos Controlados Aleatórios como Assunto , Ressuscitação , Fatores de Risco , Torsades de Pointes/induzido quimicamente , Torsades de Pointes/mortalidade , Síndrome de Wolff-Parkinson-White/etiologia , Síndrome de Wolff-Parkinson-White/terapiaRESUMO
Heart rate variability (HRV) assesses the electrical stability of the heart and can identify patients at risk of sudden cardiac death (SCD). The value of 10 HRV parameters from 24 hour ECG (in both time and frequency domain) to predict serious arrhythmic events (SAE) in a group of 56 patients with ventricular tachycardia and/or ventricular fibrillation of different etiologies not due to acute myocardial infarction was explored. Eighteen patients had low left ventricular ejection fractions (LVEF). During follow-up (6-46 months, mean = 24) 8 SCD and 12 recurrences of malignant ventricular arrhythmias or ICD discharges were recorded. Proportional hazard analysis (Cox model) for SAE revealed that the mean of all 5 minute standard deviation of RR intervals (SD) and the amplitude of low frequency spectrum (L) were independent risk factors of SAE (P < 0.05). The best models were: SD+EF and L+EF where predictive values were high (sensitivity approximately 60%, specificity over 95%, positive predictive value over 90% and negative predictive value approximately 80%). Event-free survival curves revealed a significantly shorter survival in patients with EF < 40%: 47% vs. 92%, SD < 43 ms; 56% vs. 92% and L < 16 ms; 56% vs. 89% (all P < 0.001) after 2 years. The subgroup with low EF and SD < 43 ms revealed a significantly shortened survival (27% vs 83% at 2 years, P < 0.01). Some HRV parameters, SD from the time and L from the frequency domain, were predictive of a fatal outcome in VT/VF patients. Combined SD+EF and L+EF values are powerful predictors of serious arrhythmic events.
Assuntos
Arritmias Cardíacas/fisiopatologia , Frequência Cardíaca , Disfunção Ventricular/fisiopatologia , Adulto , Idoso , Arritmias Cardíacas/complicações , Arritmias Cardíacas/terapia , Baixo Débito Cardíaco/fisiopatologia , Morte Súbita Cardíaca/etiologia , Desfibriladores Implantáveis , Eletrocardiografia Ambulatorial , Eletrofisiologia , Feminino , Seguimentos , Previsões , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Recidiva , Fatores de Risco , Sensibilidade e Especificidade , Processamento de Sinais Assistido por Computador , Volume Sistólico , Taxa de Sobrevida , Taquicardia Ventricular/fisiopatologia , Disfunção Ventricular/complicações , Disfunção Ventricular/terapia , Fibrilação Ventricular/fisiopatologiaRESUMO
In 126 patients with clinical ventricular tachycardia and/or fibrillation, ischemic heart disease and repetitive and/or frequent ventricular ectopic beats long-term therapy guided by Holter ecg was assessed. Criteria for efficacy of antiarrhythmic drugs were following: 1) > 75% decrease in ectopic beats, 2) elimination of salvos, 3) > 90% reduction of couples and R/T and 4) reduction of multiformity up to 2 forms. They were fulfilled in 71% of patients (responders). During follow-up 1-49 months, mean 20, rate of sudden death was lower in responders as compared with nonresponders (p < 0.05). However, suppression of ventricular ectopic beats was not predictive for a favorable outcome, because the incidence of arrhythmic events and total cardiac death was similar in the two groups.