A case of severe diphtheria complicated by myocarditis and neurorespiratory paralysis is reported. The myocarditis manifested with severe conduction disturbances including left bundle-branch block and high grade second degree atrioventricular block leading to Adams-Stokes attacks. Temporary transvenous electrical pacing for.3 days was successful in the management of this complication, but posit...

Trifascicular block, which consists of impaired conduction in the three main fascicles of the ventricular conduction system, may progress to high-grade or complete atrioventricular block. Exceptionally, it is possible to register in the same patient paroxysmal alternating atrioventricular block and bilateral bundle branch block. This is the electrocardiogram of a male, 60 year-old patient comin...

A 76-year-old patient with a medical history of hypertension, type 2 diabetes mellitus and moderate valvular aortic stenosis underwent cephalic DDD pacemaker implantation because of fatigue and a 3rd degree atrioventricular block with a ventricular escape rhythm of 45 beats per minute. After implantation, he complained about stabbing chest pains. A chest radiograph did not reveal any signs of a...

A proportion of patients with atrial fibrillation and other supraventricular arrhythmias remain refractory to medical therapy and require definitive treatment. In some cases, the arrythmia may be cured by catheter or surgical ablation. Techniques have recently been developed for disruption of the substrate for atrioventricular nodal reentry tachycardia'-3 and atrial flutter,4'5 and a potential ...

The effects of phentolamine, 0-3 mg/min given intravenously for 15 minutes, on His bundle electrograms were studied in 11 patients with heart disease. Recordings were made at varied heart rates, using atrial pacing. Phentolamine significantly reduced the AH interval in every patient but it had no effect on the HV interval. Functional and effective refractory periods were measured with the use o...

Two cases with a concealed left-sided accessory atrioventricular bypass tract are described. In both, functional longitudinal dissociation of the atrioventricular node narrowed the range of atrial premature beat coupling intervals which could initiate re-entry using the accessory pathway. In case 1 early premature atrial beats were followed by an atrioventricular nodal re-entrant echo. The atri...

BACKGROUND Two catheter electrode systems were compared for delivering radiofrequency current for ablation of the atrioventricular junction. Seventeen patients with drug-resistant supraventricular tachyarrhythmias were studied. METHODS AND RESULTS A 6F or 7F catheter with six or eight standard electrodes (1.25 mm wide, 2.5-mm spacing) was used in the first seven patients (group 1). A 7F quadr...

The beneficial effects of cardiac resynchronization therapy (CRT) have been evaluated in several trials, and different degrees of response to CRT have been reported; indeed, the optimization of pacing sites and stimulation timing seems to be a major determinant of the hemodynamic response. For standard CRT delivery, the atrioventricular pacing interval is shortened to ensure consistent left ven...