Atrial flutter and embolic risk: The relationship between atrial flutter cycle length and left atrial appendage function.

BACKGROUND: The potential for thromboembolism in atrial flutter (AFL) is different from atrial fibrillation. AFL cycle length (AFL-CL) may be related to reduced left atrial appendage (LAA) function. Very rapid AFL-CL can lead to mechanical and electrophysiological disorders that contribute to lower LAA emptying velocity (LAEV). The aim of this study is to relate atrial flutter cycle length with LAEV and its role in thrombogenesis. METHODS: Cross-sectional study of patients with atrial flutter AFL who underwent transoesophageal echocardiography (TEE) before catheter ablation or electric cardioversion. AFL-CL in milliseconds was measured with a 12-lead EKG or in intracardiac records. RESULTS: We included 123 patients. There was correlation between AFL-CL and LAEV (r = 0.34; p = 0.003) in typical AFL. Cycle length, LA size and atypical flutter were predictors of low LAEV on multivariate analysis. An index multiplying atrial rate (bpm) during the arrhythmia versus left atrial size(mm) >11,728 was associated with spontaneous echogenic contrast and/or left atrial thrombus on TEE (C-statistic = 0.71; CI95%0.60-0.81). CONCLUSIONS: There was a significant relationship between the AFL-CL and LAEV. The LAEV was affected by the LA size, the type of atrial flutter and the AFL-CL. A new index, relating the atrial rate with the left atrial size, was able to identify a higher occurrence of spontaneous echogenic contrast and/or left atrial thrombus.

Late Outcome and Predictors of Adverse Events Related to the Implantation of a Permanent Pacemaker in Patients with Isolated Congenital Atrioventricular Block.

Isolated congenital atrioventricular block (ICAVB) is a rare, and pacemaker implantation is the only effective treatment. We sought to identify the predictive factors of adverse events related to pacemaker implantation in ICAVB. This is a cohort study of patients diagnosed with ICAVB who underwent pacemaker implantation from 1980 to 2014 in a single center. During the studied period, a total of 647 patients underwent implantation of their first permanent cardiac pacemaker before 30 years of age. Of these, only 62 (9.5 %) were diagnosed with ICAVB. This condition was diagnosed in utero in 15 (24.2 %) cases, 5 (8.1 %) in the neonatal period, 32 (51.6 %) during childhood, and 10 (16.1 %) during adolescence and young adulthood. The presence of autoantibodies (anti-Ro/SSA) was observed in 41 % of mothers who underwent serological evaluation. Age at the time of the initial pacemaker implant was 9.8 ± 9 years. During a mean follow-up time of 15 years, 1 (1.7 %) death occurred due to infectious endocarditis. Complications related to pacemaker implant were reported in 24 patients (38.7 %). The number of complications was significantly higher in the group with an epimyocardial implantation site (HR 6; CI 2.45-14.95). Ventricular dysfunction occurred in 6 (11.7 %) patients; however, we were not able to identify any predictors of it. Our results showed a low mortality rate after permanent therapy. However, these patients exhibited high morbidity related to the pacemaker system, and the epimyocardial implant site was an independent predictor of complications. Predictors of left ventricular dysfunction were not found in the present study.

Percutaneous Intervention in ST-Elevation Myocardial Infarction: Culprit-only or Complete Revascularization?

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.

Analysis of Dyssynchrony and Ventricular Function in Right Univentricular Stimulation at Different Positions.

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.

Percutaneous Intervention in ST-Elevation Myocardial Infarction: Culprit-only or Complete Revascularization? / Intervenção Percutânea no Infarto com Supradesnivelamento do Segmento ST: Revascularização Completa ou Tratamento apenas da Artéria Culpada?

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.

Analysis of dyssynchrony and ventricular function in right univentricular stimulation at different positions

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.