RESUMEN
Objetivo: Comparar o comportamento clínico-evolutivo de portadores de CDI por taquicardia ventricular (TV) sincopal ou parada cardíaca (PC) por TV/FV. Método: 585 pacientes foram submetidos a implante de CDI entre jan/2000 e jul/2005 para prevenção secundária de morte súbita cardíaca (MSC). Foram selecionados 415 pacientes de um banco de dados prospectivo, distribuídos em dois grupos: G1, com TV sincopal (n=318) e G2, com PC por TV/FV (n=97). As variáveis analisadas foram: idade, sexo, fração de ejeção do ventrículo esquerdo(FEVE), classe funcional de insuficiência cardíaca (CF IC), medicamentos, terapias de choque apropriadas (TCA) pelo CDI e óbitos. Para análise estatística...
Asunto(s)
Humanos , Masculino , Femenino , Persona de Mediana Edad , Desfibriladores Implantables , Muerte Súbita Cardíaca/prevención & control , Síncope/complicaciones , Taquicardia Ventricular/inducido químicamenteRESUMEN
This case shows the improvement promoted by cardiac resynchronization therapy (CRT) on myocardial perfusion and left ventricular (LV) performance assessed by gated myocardial perfusion scintigraphy. The patient had idiopathic dilated cardiomyopathy, left bundle branch block and severe heart failure despite optimized medical treatment. After CRT, clinical improvement, QRS reduction and improvement of previously hypoperfused anterior and septal walls were observed. There was also decrease in LV end-diastolic and systolic volumes and increase in LV ejection fraction.
Asunto(s)
Estimulación Cardíaca Artificial , Cardiomiopatía Dilatada , Radiofármacos , Tecnecio Tc 99m Sestamibi , Función Ventricular Izquierda/fisiología , Bloqueo de Rama/diagnóstico por imagen , Bloqueo de Rama/fisiopatología , Bloqueo de Rama/terapia , Cardiomiopatía Dilatada/diagnóstico por imagen , Cardiomiopatía Dilatada/fisiopatología , Cardiomiopatía Dilatada/terapia , Femenino , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Humanos , Persona de Mediana Edad , Cintigrafía , Volumen Sistólico/fisiología , Factores de TiempoRESUMEN
Este caso mostra a melhora proporcionada pela terapia de ressincronização cardíaca (TRC) sobre a perfusão miocárdica e o desempenho do ventrículo esquerdo (VE) avaliados pela cintilografia de perfusão miocárdica com MIBI-99mTc sincronizada ao eletrocardiograma. Paciente portadora de miocardiopatia dilatada idiopática, bloqueio de ramo esquerdo e insuficiência cardíaca refratária ao tratamento medicamentoso otimizado. Após TRC, foi observada melhora clínica, redução da duração do QRS e melhora na perfusão das paredes anterior e ântero-septal que se encontravam previamente hipoperfundidas. Houve também redução dos volumes diastólico e sistólico finais e aumento da fração de ejeção do VE.
This case shows the improvement promoted by cardiac resynchronization therapy (CRT) on myocardial perfusion and left ventricular (LV) performance assessed by gated myocardial perfusion scintigraphy. The patient had idiopathic dilated cardiomyopathy, left bundle branch block and severe heart failure despite optimized medical treatment. After CRT, clinical improvement, QRS reduction and improvement of previously hypoperfused anterior and septal walls were observed. There was also decrease in LV end-diastolic and systolic volumes and increase in LV ejection fraction.
Asunto(s)
Femenino , Humanos , Persona de Mediana Edad , Estimulación Cardíaca Artificial , Cardiomiopatía Dilatada , Radiofármacos , Función Ventricular Izquierda/fisiología , Bloqueo de Rama/fisiopatología , Bloqueo de Rama , Bloqueo de Rama/terapia , Cardiomiopatía Dilatada/fisiopatología , Cardiomiopatía Dilatada , Cardiomiopatía Dilatada/terapia , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca , Insuficiencia Cardíaca/terapia , Volumen Sistólico/fisiología , Factores de TiempoRESUMEN
OBJECTIVE: Cardiac resynchronization therapy (CRT) is an adjunct treatment for heart failure (HF) which associates with left bundle-branch block (LBBB) and is refractory to medical therapy. However, nearly 1/3 of the patients still do not respond, the reasons for which have yet to be determined. Additionally, experimental studies proved that epicardial left ventricle (LV) pacing yields reversed electrical activation sequence, increasing QT interval duration and dispersion of the ventricular repolarization, and leaving patients at greater risk for ventricular arrhythmias. METHODS: In this study, a series of 60 patients (61.7% male, mean age 59.2+/-11.54 years) in NYHA functional class III-IV heart failure and LBBB, who received CRT through implantation of atrial-biventricular pacemakers, were assessed by 87-lead body surface potential mapping (BSPM). The BSPM, noninvasive technique with semi-automatic readings, allowed analysis of variables associated with the cardiac ventricular repolarization QT intervals, maximal, minimum and mean Tpeak-end, and QT dispersion (QTmax - min), in addition to transmural dispersion of repolarization (Tpeak-end max - Tpeak-end min), in two different moments: baseline rhythm and during atrial-biventricular pacing. RESULTS: QT dispersion showed a significant 19.6% reduction (p=0.0009) under CRT, as compared with baseline measurements (85.58+/-26.63 msec vs. 68.83+/-25.16 msec). The transmural dispersion of repolarization (Tpeak-end max - Tpeak-end min) showed smaller statistical significance (p=0.0343); however, its values were similarly decreased (55.50+/-15.45 msec vs 49.41+/-14.11 msec) during CRT. CONCLUSION: These results may corroborate findings from major randomized clinical trials. We consider that the electrocardiographic variables obtained with the use of the BSPM, namely, the QT and Tpeak-end intervals, are appropriate for analysis and study of the effects of cardiac resynchronization therapy on the improved electrical dispersion as characterizing the improvement of homogeneity of cardiac ventricular repolarization.
Asunto(s)
Mapeo del Potencial de Superficie Corporal , Disfunción Ventricular/diagnóstico , Bloqueo de Rama/complicaciones , Bloqueo de Rama/terapia , Estimulación Cardíaca Artificial , Desfibriladores Implantables , Femenino , Sistema de Conducción Cardíaco/fisiopatología , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/terapia , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Disfunción Ventricular/fisiopatologíaRESUMEN
OBJECTIVE: To establish the parameters of intra- and interventricular synchrony in normal individuals and to compare them with patients with dilated cardiomyopathy with and without conduction disorders shown in the electrocardiogram (ECG) examination. METHODS: Three groups of patients were included in this study: 18 individuals (G1) with no cardiomyopathy and with a normal ECG (52+/-12 years, 29% male); 50 patients with dilated cardiomyopathy and severe left ventricular dysfunction, with 20 patients (G2) presenting QRS <120 ms (51+/-10 years, 75% male) and 30 patients (G3) with QRS >120 ms (57+/-12 years, 60% male). All patients underwent RV. Evaluation of left intraventricular dyssynchrony was carried out with the measurement of the phase histogram width and interventricular dyssynchrony was evaluated by the difference of the mean phase angle between the right and left ventricles (RLDif). RESULTS: Left ventricle ejection fractions (LVEF)s were: 62 +/- 6% (G1), 27 +/- 7% (G2) and 22 +/- 8% (G3) and right ventricle ejection fractions were: 46 +/- 5% (G1), 41 +/- 6%(G2) and 38 +/- 8% (G3). Evaluation of the phase histogram width was: 89 +/- 18 ms (G1), 203 +/- 54 ms (G2) and 312 +/- 130 ms (G3), p<0.0001. The measurement of RLDif was: 14 +/- 11 ms (G1), 39 +/- 40 ms (G2) and 87 +/- 49 ms (G3); comparing G1 vs. G2 and G1 vs. G3, p<0.0001 and G2 vs. G3, p=0.0007. CONCLUSION: The parameters analyzed discriminate the three groups of patients according to the ventricular synchrony degree. Patients with dilated cardiomyopathy and with no branch block in ECG (QRS <120 ms) may present dyssynchrony, but at a lower degree than patients with widened QRS.
Asunto(s)
Cardiomiopatía Dilatada/complicaciones , Ventriculografía con Radionúclidos , Disfunción Ventricular Izquierda/etiología , Anciano , Cardiomiopatía Dilatada/fisiopatología , Estudios de Casos y Controles , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
Objetivo: Avaliar a importância clínica da presença de marcapasso definitivo (MPD) previamente ao implante de CDI de nossa instituição, foram selecionados 275 submetidos a implante de CDI para prevenção secundária de morte súbita cardíaca (MSC), agrupados de acordo com a cardiomiopatia de base e a presença de MPD prévio ao implante de CDI. As variáveis analisadas foram: sexo, idade, CF-NYHAA, medicações, ritmo cardíaco, FEVE e TVNS. Para análise estatística, utilizou-se o método de Kaplan Meier e o teste de log-rank. Resultados: A amostra reduzida de pacientes com consistentes...
Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Enfermedad de Chagas/complicaciones , Enfermedad de Chagas/diagnóstico , Muerte Súbita/prevención & control , Marcapaso Artificial/efectos adversos , Marcapaso ArtificialRESUMEN
The femoral vein has been used as an alternative conduit to implant pacemakers in children of any weight. Such method associates endocardial pacing and good cosmetics. The aim of this study was to evaluate prospectively, since 1981, the long-term follow-up of 99 children, from newborn to 13 years old (average = 4.1 +/- 3.6 years, 56 girls), who underwent the implantation of pacemakers via the femoral vein. Atrioventricular block was present in 88% of patients, of congenital etiology in 39% and postoperative in 54%. Single chamber pacemakers were implanted in 92% of patients. During a mean follow-up of 5.3 +/- 5.0 years (maximum = 18.2 years), 5 patients died of cardiac causes, 4 of infection, 2 suddenly, and 3 of unknown causes. The 5-, 10- and 15-year actuarial survival rates were 83.7%, 75.7%, and 75.7%, respectively. Transfemoral leads were used for a mean of 48.9 +/- 44.0 months. Reasons for lead explantations were pacing failure in five patients, infection in eight, and elective in nine. The 2-, 5- and 10-year actuarial survivals of transfemoral leads were 87.6%, 73.8%, and 31.8%, respectively. The mean lead survival was 97 months. Overall, 105 reoperations were performed, 38 for battery depletion, 24 for body growth, 14 for infection or pocket revisions, and 27 for miscellaneous reasons. In conclusion, the durability and overall long-term performance of transfemoral leads were excellent.