Association of variants in MYH7, MYBPC3 and TNNT2 with sudden cardiac death-related risk factors in Brazilian patients with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is characterized by unexplained left ventricular hypertrophy (LVH) and is one of the major causes of sudden cardiac death (SCD). An exon-targeted gene sequencing strategy was used to investigate the association of functional variants in sarcomeric genes (MYBPC3, MYH7 and TNNT2) with severe LVH and other SCD-related risk factors in Brazilian HCM patients. Clinical data of 55 HCM patients attending a Cardiology Hospital (Sao Paulo city, Brazil) were recorded.

Evaluation of super-responders to cardiac resynchronization therapy in the presence of left bundle branch block and absence of scar in the posterolateral wall of the left ventricle.

Patients with heart failure (HF) undergoing cardiac resynchronization therapy (CRT) who exhibit above-expected improvement are known as super-responders. We assessed the rate of super-responders in a population with left bundle branch block (LBBB) > 150 ms in the absence of scar tissue in the left ventricular posterolateral wall as well as prognostic variables. In this prospective observational cohort study (n=20) an electrocardiogram (ECG) was performed pre- and post-CRT.

Relation of Fractionated Atrial Potentials With the Vagal Innervation Evaluated by Extracardiac Vagal Stimulation During Cardioneuroablation.

Background: Vagal hyperactivity is directly related to several clinical conditions as reflex/functional bradyarrhythmias and vagal atrial fibrillation (AF). Cardioneuroablation provides therapeutic vagal denervation through endocardial radiofrequency ablation for these cases. The main challenges are neuromyocardium interface identification and the denervation control and validation.

Pacemaker Implants in Children and Adolescents with Chagas Disease in Brazil: 18-Year Incidence.

Background:: Chagas disease continues to be a serious public health problem, and accounts for 25-30% of the indications for cardiac stimulation in Brazil.

Objective:: To assess clinical and epidemiological characteristics of patients with Chagas disease, younger than 18 years, who had undergone pacemaker implantation in Brazil between 1994 and 2011, and its temporal trend.

Methods:: This was a cross-sectional analysis of data from the Brazilian Pacemaker Registry database.

Simplified method for esophagus protection during radiofrequency catheter ablation of atrial fibrillation--prospective study of 704 cases.

Introduction: Although rare, the atrioesophageal fistula is one of the most feared complications in radiofrequency catheter ablation of atrial fibrillation due to the high risk of mortality.

Objective: This is a prospective controlled study, performed during regular radiofrequency catheter ablation of atrial fibrillation, to test whether esophageal displacement by handling the transesophageal echocardiography transducer could be used for esophageal protection.

Methods: Seven hundred and four patients (158 F/546M [22.

Comparison of electrophysiological parameters of septal and apical endocardial cardiac stimulation.

Background: The conventional right ventricle (RV) endocardial pacing leads QRS widening and desynchronization myocardial compromising ventricular function. With the need for stimulation less deleterious, RV septal pacing has been used more. Eventually have been reported higher thresholds and smaller R waves in the septal stimulation.

Right ventricular apical pacing: the unwanted model of cardiac stimulation?

Despite having a huge benefit in enabling heart rate control, cardiac pacing by stimulating the right ventricular apex causes an artificial iatrogenic left bundle-branch block-like syndrome. As a result, QRS widening and cardiac wall desynchronization occurs. The problems caused by this undesirable pacemaker side effect have been ignored, as they are counteracted by the great benefit of cardiac rate correction.

Radiofrequency catheter ablation of atrial fibrillation guided by spectral mapping of atrial fibrillation nests in sinus rhythm.

Background: Two types of myocardia can be observed through the endocardial spectral mapping (SM) in sinus rhythm: the compact type with a smooth spectrum and the fibrillar type with a segmented spectrum (atrial fibrillation nests). During the atrial fibrillation (AF), the compact type has an organized activation and low frequency (passive), whereas the fibrillar type has a rather disorganized activation and high frequency (active/resonant), with both being activated by high-frequency sustained tachycardia--the background tachycardia (BT).

Objective: To describe the treatment of AF by the ablation of the AF nests and BT.