Ventricular endocardial right bifocal stimulation in the treatment of severe dilated cardiomyopathy heart failure with wide QRS.

The QRS widening by ventricular conventional pacing impairs the systolic and diastolic functions and increases mitral regurgitation. The aim of this study was to compare conventional pacing to an alternative stimulation mode with a narrower QRS using two leads in the RV. Thirty-nine (25 men, 14 women; mean age 60.1 +/- 15.1 years) dilated cardiomyopathy patients (Chagas' disease [n = 17], coronariopathy [n = 9], AV ablation for tachycardiomyopathy [n = 3], and other [n = 10]) with cardiac failure (NYHA 3.1 +/- 0.8), pacemaker indication, and chronic AV block (22 AF) had endocardial pacemaker implantations (27 Biotronik, 12 Guidant). Two RV leads (one septal, one conventional [RV apex] were connected, respectively, to the atrial and ventricular pacemaker plugs. After clinical stabilization they were studied under three stimulation modes in the same session: AAI (septal), VVI (conventional), and ventricular endocardial right bifocal stimulation (VERBS) (DDT/DVI/DDD = AV interval = 15/10 ms). In comparison to conventional pacing, VERBS increased ejection fraction (0.124), cardiac output (19.5%), and peak filling rate (31.0%), and decreased QRS duration (24.7%), left atrium area (11.9%), mitral regurgitation area (32.3%), the diastolic transmitral flow (E/A relation) (19.3%), and the propagation flow time (18.0%) from the mitral valve to the left ventricular apex (tE_col), (P < 0.05). The quality-of-life showed an impressive score reduction of 50.4%. The septal stimulation alone showed a less expressive benefit. In severe dilated cardiomyopathy with classic pacemaker indication, VERBS showed significantly better performance than the septal or the conventional stimulation alone. There was a good systolic and a remarkable diastolic improvement causing an important reduction in the quality-of-life score.

Cardioestimulaçäo transesofágica: método atraumático simplificado / Transesophageal cardiostimulation: simplified atraumatic method

A estimulaçäo cardíaca elétrica artificial tem importantes aplicaçöes diagnósticas e terapêuticas. Normalmente, mesmo para investigaçäo, é realizada de forma invasiva através do posicionamento de eletrodos nos átrios e ventrículos, sob radioscopia ou durante cirurgia cardíaca. Em 1983, Pachón e cols. idealizaram e construíram um estimulador de alta energia, especialmente dimensionado para comando do coraçäo através do esôfago. O procedimento é realizado utilizando-se um eletrodo bipolar, convencional, do tipo usado para implante endocavitário definitivo, posicionado no interior do esôfago. A estimulaçäo das câmaras atriais, desta forma, mostrou-se muito bem tolerada pela maioria dos pacientes sendo desnecessário o uso de sedaçäo ou analgesia, podendo ser realizada a nível ambulatorial ou à beira do leito. Baseados neste recurso, após estudo de 216 pacientes, propöe-se uma metodologia näo-invasiva para estudo da doença do nó sinusal, da síndrome de pré-excitaçäo ventricular, além de detecçäo e reversäo de taquiarritmias supraventriculares