ABSTRACT
Abstract Introduction: Chronic stimulation of the right ventricle with pacemaker is associated with ventricular dyssynchrony and loss of contractility, even in subjects without previous dysfunction. In these patients, there is a debate of which pacing site is less associated with loss of ventricular function. Objective: To compare pacemaker-induced dyssynchrony among different pacing sites in right ventricular stimulation. Methods: Cross-sectional study of outpatients with right ventricle stimulation higher than 80% and preserved left ventricular ejection fraction. Pacing lead position (apical, medial septum or free wall) was assessed through chest X-rays. Every patient underwent echocardiogram to evaluate for dyssynchrony according to CARE-HF criteria: aortic pre-ejection time, interventricular delay and septum/posterior wall delay on M mode. Results: Forty patients were included. Fifty-two percent had apical electrode position, 42% mid septum and 6% free wall. Mean QRS time 148.97±15.52 milliseconds. A weak correlation between the mean QRS width and pre-aortic ejection time (r=0.32; P=0.04) was found. No difference in QRS width among the positions could be noted. Intraventricular delay was lower in apical patients against mid septal (34.4±17.2 vs. 54.3±19.1 P<0.05) - no difference with those electrode on the free wall. No difference was noted in the pre-aortic ejection time (P=0.9). Conclusion: Apical pacing showed a lower interventricular conduction delay when compared to medial septum site. Our findings suggest that apical pacing dyssynchrony is not ubiquitous, as previously thought, and that it should remain an option for lead placement.
Subject(s)
Humans , Male , Female , Aged , Pacemaker, Artificial/adverse effects , Cardiac Pacing, Artificial/adverse effects , Ventricular Dysfunction, Right/etiology , Arrhythmias, Cardiac/physiopathology , Stroke Volume , Echocardiography , Cardiac Pacing, Artificial/methods , Cross-Sectional Studies , Ventricular Function, Right , Ventricular Dysfunction, Right/diagnostic imaging , Ventricular Dysfunction, Left/etiology , Electrocardiography , Heart Ventricles , Myocardial ContractionABSTRACT
Abstract The best approach of multivessel coronary artery disease in the context of acute myocardial infarction with ST segment elevation and primary percutaneous coronary intervention is one of the main reasons for controversy in cardiology. Although the main global guidelines do not recommend routine complete revascularization in these patients, recent randomized clinical trials have demonstrated benefit of this approach in reducing cardiovascular outcomes. For this reason, an adequate review of this evidence is essential in order to establish scientifically based strategy and achieve better outcomes for these patients who present with acute myocardial infarction. This review aims to present objectively the most recent evidence available on this topic.
Resumo O adequado manejo da doença arterial coronariana (DAC) multivascular, no contexto do infarto agudo do miocárdio com supradesnivelamento do segmento ST e da intervenção coronariana percutânea primária, é um dos grandes motivos de controvérsia em Cardiologia. Embora as principais diretrizes mundiais não recomendem a revascularização completa de forma rotineira nesses pacientes, recentes ensaios clínicos randomizados (ECRs) têm demonstrado benefício dessa abordagem na redução de desfechos cardiovasculares. Por esse motivo, torna-se imprescindível uma adequada revisão dessas evidências, a fim de que se possa estabelecer uma conduta cientificamente embasada e capaz de trazer benefícios aos pacientes que se apresentam no contexto agudo do infarto do miocárdio. Esta revisão objetivou apresentar de forma objetiva as evidências mais recentes disponíveis a respeito desse tema.