RESUMEN
Chronic right ventricular (RV) pacing might elicit unpredictably deleterious effects on left ventricular (LV) function similar to that of native left bundle branch block (LBBB). The objective of the present study was to evaluate the clinical and echocardiographic response to cardiac resynchronization therapy after years of chronic RV pacing. In this prospective observational study of 284 consecutive patients, cardiac resynchronization therapy was performed in 194 patients (68%) with a native LBBB and in 90 patients (32%) with a pacing-induced LBBB after chronic RV pacing (upgraded group). Echocardiographic and clinical parameters were evaluated in both groups at baseline and during 2 years of follow-up. The clinical response was defined as survival with improvement of > or =1 in the New York Heart Association class without heart failure hospitalization. Reverse LV remodeling was defined as LV end-systolic volume reduction of > or =15%. At baseline, the New York Heart Association class, quality of life, and exercise capacity were comparable but the LV ejection fraction was significant greater and the LV volumes were significant smaller in the upgraded group. Changes with time in the clinical parameters, echocardiographic parameters, and clinical response were not significantly different between the 2 groups. Reverse LV remodeling was observed in 86% in the upgraded group versus 78% of the native LBBB group after 1 year (p = 0.39). Survival was not significantly different between the 2 groups. In conclusion, comparable clinical and echocardiographic improvement was seen when resynchronization therapy was applied in patients with preceding chronic RV pacing compared with patients with a native LBBB.
Asunto(s)
Bloqueo de Rama/fisiopatología , Estimulación Cardíaca Artificial , Ventrículos Cardíacos/fisiopatología , Anciano , Bloqueo de Rama/diagnóstico por imagen , Bloqueo de Rama/mortalidad , Ecocardiografía Doppler , Femenino , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/inervación , Humanos , Masculino , Estudios Prospectivos , Calidad de Vida , Sistema de Registros , Análisis de Regresión , Encuestas y Cuestionarios , Análisis de Supervivencia , Factores de TiempoRESUMEN
AIMS: To evaluate the clinical utility of pressure-volume loop analyses during pacemaker/implantable cardioverter defibrillator (ICD) implantations to assess the optimal right ventricular (RV) and/or left ventricular (LV) lead position. METHODS AND RESULTS: 29 patients with heart failure and chronic RV apical pacing were studied. Stroke work (SW), LV ejection fraction (LVEF), cardiac output (CO), and LV dP/dt(max) were assessed using a conductance catheter in the LV during RV apical, RV outflow tract, single-site LV, and biventricular pacing at different left-sided pacing locations. Left ventricular ejection fraction was 34.3 +/- 9.8%. Compared with baseline, RV outflow tract pacing showed a small increase of 4.0 +/- 6.4% in LV dP/dt(max) and no improvement in SW, LVEF, or CO. In the optimal biventricular configuration, SW increased 39 +/- 41%, LVEF increased 22 +/- 13%, CO increased 16 +/- 16%, and LV dP/dt(max) increased 10 +/- 11% (all P < 0.05). In 45% of the patients, the optimal LV lead position was found at a different location as the 'first choice' postero-lateral or lateral target vein. CONCLUSION: Pressure-volume loop analysis during pacemaker/ICD implantations facilitates to determine the optimal LV pacing site. Patients with chronic RV pacing showed a significant acute improvement in LV function when LV pacing or biventricular pacing is applied.
Asunto(s)
Arritmias Cardíacas/terapia , Estimulación Cardíaca Artificial/métodos , Insuficiencia Cardíaca/terapia , Marcapaso Artificial , Anciano , Arritmias Cardíacas/fisiopatología , Femenino , Insuficiencia Cardíaca/fisiopatología , Hemodinámica , Humanos , Masculino , Estudios Prospectivos , Volumen Sistólico/fisiología , Resultado del Tratamiento , Función Ventricular Izquierda/fisiología , Función Ventricular Derecha/fisiologíaRESUMEN
BACKGROUND: Although prevalence of heart failure increases with age, in most clinical trials of cardiac resynchronization therapy (CRT), older patients are not included. Observational studies of effects of CRT in older patients had a small sample size. In the present study, the clinical and echocardiographic response to CRT in a larger group of elderly (age > 75 years) patients was evaluated. METHODS: In this prospective observational study of 266 consecutive patients, CRT was performed in 107 elderly patients (40%) and 159 (60%) younger patients (age < or = 75 years). Echocardiographic and clinical parameters were evaluated at baseline and at 3, 12, and 24 months. RESULTS: In the elderly group, mean age was 79 years compared with 67 years in patients aged < or = 75 years. Clinical baseline characteristics between the 2 groups were comparable. During follow-up, there was a comparable and sustained improvement in both groups according to New York Heart Association (NYHA) class, quality of life score, and left ventricular (LV) ejection fraction. Clinical response, defined as survival with improvement (> or = 1 score) of NYHA class without hospital admittance for heart failure, was seen in 67% and 69% (group aged < or = 75 years) versus 65% and 60% (group aged > 75 years) after 3 months and 1 year, respectively. Reverse LV remodeling defined as LV end-systolic volume reduction > or = 10% was seen in 79% and 87% (group aged < or = 75 years) versus 71% and 79% (group aged > 75 years) after 3 months and 1 year, respectively. Hospitalization for heart failure decreased significantly in both groups in the year after CRT. A subgroup analysis of 39 octogenarians (> 80 years) also showed a significant improvement in NYHA class and LV ejection fraction in this subgroup. Also, LV reverse remodeling occurred in a similar extent (75% and 84%) after 3 months and 1 year, respectively. CONCLUSIONS: This study shows a clinical and echocardiographic improvement of CRT in patients aged > 75 years and even so in octogenarians.
Asunto(s)
Estimulación Cardíaca Artificial , Insuficiencia Cardíaca/terapia , Factores de Edad , Anciano , Anciano de 80 o más Años , Ecocardiografía Doppler , Femenino , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Observación , Estudios Prospectivos , Calidad de Vida , Volumen Sistólico , Resultado del Tratamiento , Remodelación VentricularRESUMEN
The prevalence of atrial fibrillation (AF) in patients with heart failure is high, but data about the effects of cardiac resynchronization therapy (CRT) in patients with chronic AF are scarce. In this prospective observational study of 263 consecutive patients, CRT was performed in 96 patients (37%) with chronic AF and 167 patients (63%) with sinus rhythm (SR). Echocardiographic and clinical parameters were evaluated at baseline and 3 and 12 months. Reverse left ventricular (LV) remodeling is defined as LV end-systolic volume decrease > or =10%. Hospitalization rates for heart failure in the year before and after implantation were compared. Baseline characteristics between patients with and without AF were similar, but the AF group had smaller LV end-systolic and end-diastolic volumes and larger left atrial dimensions. New York Heart Association class, 6-minute walking distance, quality-of-life score, LV ejection fraction, and mitral regurgitation improved significantly at 3 and 12 months in both groups, and the changes were similar. Reverse LV remodeling after 3 and 12 months was 74% and 82% (AF group) versus 77% and 83%, respectively (SR group, p = 0.79). After 1 year, cardioversion had occurred in 25% of patients with AF. In the year after implantation, significant decreases in hospitalizations for heart failure in both groups (84% and 90%) were documented. Long-term mortality was almost equal in both groups. In conclusion, this large-scale study shows that the benefit of CRT in patients with chronic AF and heart failure is similar to that in patients with SR. Patients with chronic AF and heart failure should be considered candidates for CRT.
Asunto(s)
Fibrilación Atrial/complicaciones , Fibrilación Atrial/terapia , Estimulación Cardíaca Artificial , Insuficiencia Cardíaca/complicaciones , Insuficiencia Cardíaca/terapia , Anciano , Fibrilación Atrial/mortalidad , Electrocardiografía , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/mortalidad , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
INTRODUCTION: Most data on cardiac resynchronization therapy (CRT) are from trials with highly selected patients, with limited long-term echocardiographic data. This study was performed to evaluate long-term echocardiographic remodeling after CRT in daily practice. METHODS AND RESULTS: A biventricular pacemaker was implanted in 130 patients with advanced heart failure who met the general accepted criteria for CRT or in heart failure patients with a conventional pacemaker indication. Two years echocardiographic follow-up was available. Mean age (73 years) was higher than in the randomized trials. Forty-one patients (32%) died during the 2 year follow-up period. Mortality was higher in males, in patients with increased NT-proBNP, renal dysfunction, or left atrial dilatation before implantation. Echocardiographic response (LVEF improvement of 5% or more) was documented in 69, 88, and 91% of the survivors, after 3 months, 1 year, and 2 years, respectively. Echocardiographic response after 3 months was associated with a significantly higher long-term survival (P = 0.04). Mean LVEF was 22% at baseline compared to 31.8, 38.3, and 39.7% after 3 months, 1 year, and 2 years, respectively (P < 0.01). Reverse remodeling (a reduction of LV end systolic volume of more than 10%) was observed in 70.7, 81.0, and 91.7% of the survivors after 3 months, 1 year, and 2 years, respectively. Long-term LV improvement was more pronounced in patients with nonischemic cardiomyopathy. CONCLUSION: LV reverse remodeling and beneficial echocardiographic changes were sustained during 2 years follow-up. A 5% or more increase in LVEF after 3 months was associated with a better long-term survival.
Asunto(s)
Estimulación Cardíaca Artificial/estadística & datos numéricos , Insuficiencia Cardíaca/terapia , Anciano , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/diagnóstico por imagen , Humanos , Estudios Longitudinales , Masculino , Estudios Prospectivos , Análisis de Supervivencia , Resultado del Tratamiento , Ultrasonografía , Remodelación VentricularRESUMEN
BACKGROUND: recent short-term observations have shown an improvement in cardiac function and heart failure symptoms from atrio-biventricular pacing. This study was designed to assess the safety and feasibility of an atrio-biventricular transvenous pacing system, and examine the long-term effects of cardiac resynchronization in patients with advanced heart failure and ventricular conduction abnormalities. METHODS AND RESULTS: between August, 1997 and November, 1998, 103 patients received a cardiac resynchronization system (CRS) consisting of a pulse generator interfaced with an atrio-biventricular lead system, including a lead designed for left ventricular (LV) pacing via cardiac veins. Baseline evaluation included 12-lead electrocardiogram, estimation of New York Heart Association (NYHA) functional class, assessment of quality of life (QOL), and distance covered during a 6-min walk (6-MW). Detailed echocardiographic data were also collected in a subset of 46 patients. Measurements were repeated in all surviving patients at 1, 3, 6 and 12 months after implantation of the CRS. A single, self-limiting procedure-related complication occurred. Over a follow-up of 12 months, 21 patients died. The 12-month actuarial survival was 78% (CI 70-87%). Nine surviving patients were withdrawn from the study during long-term follow-up for miscellaneous reasons. At each point of follow-up, a significant shortening of QRS duration was measured. In addition, significant improvements were observed in mean NYHA functional class, 6-MW and QOL score. In the 46 patients with complete echocardiographic data, LV ejection fraction increased from 21.7+/-6.4% at baseline to 26.1+/-9.0% at last follow-up (P = 0.006), LV end diastolic dimension decreased from 72.7+/-9.2 to 71.6+/-9.1 mm (P = 0.233), interventricular mechanical delay decreased from 27.5+/-32.1 to 20.3+/-25.5 ms (P = 0.243), mitral regurgitation apical four-chamber area decreased from 7.66+/-5.5 to 6.69+/-5.9 cm(2) (P = 0.197), and left ventricular filling time increased from 363+/-127 to 408+/-111 ms (P = 0.002). CONCLUSIONS: long-term cardiac resynchronization can be safely and reliably achieved by transvenous atrial synchronized right and left ventricular pacing. These changes were accompanied by clinically relevant improvements in functional status and QOL, as well as a measurable increase in LV performance. The outcome of randomised controlled trials is awaited.