Nodular thickening of the atrio-ventricular valves may be conspicuous in the hearts of the elderly. Usually described as senile sclerosis, it is assumed to be an involutional or degenerative process associated with advanced age. The difficulty of distinguishing such changes from the results of other pathological conditions which may have been present earlier in life is well recognized (Gould, 1...

Effective cardiac resynchronization therapy (CRT) requires an accurate atrio-biventricular pacing system. The innovative Quartet lead is a quadripolar, over-the-wire left ventricular lead with four electrodes and has recently been designed to provide more options and greater control in pacing vector selection. A lead with multiple pacing electrodes is a potential alternative to physical adjustm...

In subclinical hyperthyroidism, thyroid-stimulating hormone (TSH) levels are suppressed below normal range but serum-free thyroxine and free triiodothyronine levels are within normal range. The clinical manifestations can be highly variable and patients mostly remain undiagnosed. Sinus tachycardia, atrial premature beats and atrial fibrillation are the reported tachyarrhythmias in such patients...

We report a patient with a systemic vasculitis and heart involvement with complete atrio-ventricular block. After pacemaker implantation, the stimulation threshold significantly increased resulting in exit block. Two adjunctive ventricular leads were implanted with temporary threshold improvement. Oral glucocorticoids decreased the stimulation threshold with a transient, dose-dependent efficacy...

To determine the presence and distribution of cardiac myosin isozymes in the human conduction system, we performed an immunohistochemical study using monoclonal antibodies CMA19 and HMC14, which are specific for myosin heavy chains of human atrial type (alpha-type) and ventricular type (beta-type), respectively. Serial frozen sections of human hearts were obtained from autopsy samples and exami...

Invasive electrophysiological studies were performed in 2 symptomatic patients with recurrent arrhythmias in which impulse formation presumably occured within atrioventricular nodal bypass tracts. Case 1 had ectopic beats arising within, or close to, the upper end of a left-sided atrioventricular nodal bypass tract of the type described by Brechenmacher. In addition, this conduction was 'concea...

BACKGROUND Atrio-esophageal fistula formation following radiofrequency ablation of left atrial tachyarrhythmias is a rare but devastating complication. Esophageal injuries are believed to be precursors of fistula formation and reported to occur in up to 47% of patients. This study investigates the incidence of esophageal lesions when real time esophageal temperature monitoring and temperature l...

BACKGROUND The aim of this study was to investigate the effect of cardiac resynchronization therapy (CRT) with right ventricular (RV) sense triggered left ventricular (LV) pacing for chronic heart failure (CHF). METHODS Thirty patients who were eligible for the Class I indication of CRT were enrolled and the informed consents were signed. Left ventricular ejection fraction (LVEF), diastolic m...

Complete atrio-ventricular septal defects (CAVSD) are present in about 3% of children born with congenital heart pathologies. They usually require early surgical correction, mostly in infancy, and surgery is considered to be the gold standard. It is unlikely that anyone would survive beyond the first years without severe morbidity. However, we report a case of a Pakistani girl who underwent suc...

STJMMARY A case is described with clinical and electrocardiographic findings of incessant junctional reciprocating tachycardia. Electrophysiological study showed that longitudinal dissociation of the atrioventricular node into two pathways was responsible for the maintenance of the arrhythmia. The two intranodal pathways had different refractory periods but reciprocally related and overlapping ...