Effects of early intravenous low-dose of metoprolol on cardiac sympathetic activities and electrophysiological properties in myocardial infarction heart.

This study observed the effects of early intravenous low-doses of metoprolol on cardiac sympathetic activities and electrophysiological properties in myocardial infarction (MI) dogs. Thirty two mongrel dogs with the first diagonal branch of the left anterior descending coronary artery ligated were randomly divided into three groups: The low-dose group was given metoprolol 0.6 mg/kg immediately by intravenous injection (n=12); the target-dose group was given metoprolol 1.

Outcomes of percutaneous coronary intervention in patients ≥ 75 years: one-center study in a Chinese patient group.

Objective: To investigate the clinical and perioperative characteristics of patients ≥ 75 who undergoing percutaneous coronary intervention (PCI) and to evaluate the risk factors related to short-term post-PCI mortality in this specific patients group.

Methods: 1,035 consecutive subjects who underwent PCI from December 2011 to November 2013 were divided into four categories: (1) patients with stable angina (SA) ≥ 75 years (n = 58); (2) patients with SA < 75 years (n = 218); (3) patients with acute coronary syndrome (ACS) ≥ 75 years (n = 155); (4) patients with ACS < 75 years (n = 604). A multivariable logistic regression analysis was conducted to detect risk factors of six-month mortality in patients ≥ 75 years who had undergone PCI.

In vivo effects of mid-myocardial pacing on transmural dispersion of repolarization and conduction in canines.

Objective: In our previous in vitro study mid-myocardial relative to epicardial pacing decreased transmural dispersion of depolarization (TDR) and prevented ventricular arrhythmia. We therefore hypothesized that in vivo mid-myocardial pacing in canines has a similar effect.

Methods And Results: Using custom-made electrodes, monophasic action potentials were simultaneously recorded in vivo from left ventricular epicardial (Epi), mid-myocardial (Mid) and endocardial (Endo) layers of canines (n = 12).

A novel NKX2-5 loss-of-function mutation predisposes to familial dilated cardiomyopathy and arrhythmias.

Dilated cardiomyopathy (DCM) is the most prevalent type of primary myocardial disease, which is the third most common cause of heart failure and the most frequent reason for heart transplantation. Aggregating evidence demonstrates that genetic risk factors are involved in the pathogenesis of idiopathic DCM. Nevertheless, DCM is of remarkable genetic heterogeneity and the genetic defects underpinning DCM in an overwhelming majority of patients remain unknown.

Pulmonary antrum radial-linear ablation for paroxysmal atrial fibrillation: interim analysis of a multicenter trial.

Background: Substrate abnormality in pulmonary vein (PV) antrum plays a critical role in mechanism of atrial fibrillation (AF). The present study compares the strategy of PV antrum radial-linear (PAR) ablation to encircling PV isolation for paroxysmal AF.

Methods And Results: A total of 86 patients with paroxysmal AF were randomly assigned to PAR ablation group or PV isolation group.

Effects of mid-myocardial pacing on transmural dispersion of repolarization and arrhythmogenesis.

Introduction: Epicardial (Epi) activation of the left ventricular (LV) wall increases transmural dispersion of repolarization (TDR), which creates a substrate for the development of ventricular arrhythmia. We hypothesize that pacing from the LV mid-myocardium may decrease the TDR and occurrence of arrhythmias.

Methods And Results: A transmural electrocardiogram and transmembrane action potentials were simultaneously recorded from Epi, mid-myocardial (M), and endocardial (Endo) layers of the arterially perfused canine LV wedge preparations (n= 8).

Selective atrial vagal denervation guided by evoked vagal reflex to treat refractory vasovagal syncope.

A 57-year-old woman with refractory vasovagal syncope and a sinus pause of 6.8 seconds during tilt-table test accepted the suggestion of atrial vagal denervation. Radiofrequency pulses were delivered on positive vagal reflex sites according to the standard of heart rate (HR) drop ≥20% after high frequency stimulation (HFS).

Catheter ablation of cardiac fat pads attenuates Bezold-Jarisch reflex in dogs.

Background: Bezold-Jarisch reflex (BJR) plays an important role in the pathophysiology of several cardiovascular disorders. Radiofrequency catheter ablation (RFCA) of the vagal ganglia in cardiac fat pads (FPs) may attenuate BJR. The purpose of this study was to examine the effects of RFCA of the cardiac FPs on veratridine-induced BJR in dogs.

Transcatheter closure of perimembranous ventricular septal defect using a modified double-disk occluder.

This multicenter study assessed the efficacy and safety of transcatheter closure of perimembranous ventricular septal defect (VSD) using a modified double-disk occluder. In 5 different centers in China, 412 patients with VSD, including 202 men and 210 women, underwent attempted transcatheter closure. The age range was 3 to 65 years (mean 16.