Paroxysmal supraventricular tachycardia most commonly arises from reentry within the atrioventricular (AV) node. Although ablation of the His bundle has gained popularity for treating patients with AV node reentrant tachycardia refractory to medical therapy, undesirable sequelae include complete heart block and the necessity for a permanent pacemaker. To obviate this limitation, we have develop...

The mechanisms of atrial fibrillation relate to the presence of random reentry involving multiple interatrial circuits. Triggers for development of atrial fibrillation include rapidly discharging atrial foci (mainly from pulmonary veins) or degeneration of atrial flutter or atrial tachycardia into fibrillation. Therapy for control of atrial fibrillation includes drugs, atrial pacing for those w...

OBJECT Atrial fibrillation is associated with excess mortality. This analysis was performed to determine the magnitude of the excess mortality risk. METHODS Life table analysis of a published study of 350 patients undergoing radiofrequency ablation of the atrioventricular node and permanent pacemaker implantation for symptomatic paroxysmal or chronic atrial fibrillation. A substantial proport...

We reported a case of a 72-year-old male, known diabetic on insulin, referred because of complete atrioventricular block. He was found to have acute hepatitis during which he developed transient atrial arrhythmia, and sinus node dysfunction. His cardiac symptoms disappeared completely after hepatitis improvement. All of his cardiac investigations were normal including electrocardiogram, echocar...

Hemochromatosis is a clinical syndrome caused by abnormal accumulation of iron in parenchymal organs leading to organ toxicity and dysfunction. Cardiac hemochromatosis is a cardiomyopathy due to primary iron-overload cardiomyopathy which causes congestive heart failure. Patients with cardiac hemochromatosis may be asymptomatic early in the disease. Once heart failure develops, there is rapid de...

The actions of 2-methylhistamine (H1 agonists), 4-methylhistamine (H2 agonist), and histamine were studied by selective perfusion of the sinus node artery and atrioventricular node artery in 75 dogs anesthetized with pentobarbital sodium. 2-Methylhistamine and histamine had variable and inconsistent effects on the sinus rate. 4-Methylhistamine (100 microgram/ml) produced acceleration of the sin...

The electrocardiograms of 100 patients with rapid and regular PP intervals during atrial arrhythmias (because of atrial tachycardia or flutter, or pacing) were examined for periods of irregular atrioventricular conduction. This irregular conduction corresponds to an alternating Wenckebach phenomenon, of a type that can be determined from simple rules. The different types of conduction encounter...

An 18-year-old man whose sister has classic Kartagener's syndrome was found to have sinusitis, bronchiectasis, and corrected transposition with normal visceral situs. Congenital complete heart block was secondary to absence of conducting-system pathways between a small posterior atrioventricular node and the transposed His bundle and bundle branches. No anterior atrioventricular node was presen...

Modification of atrioventricular node is a usual and necessary operation to cure atrioventricular nodal reentrant tachycardia (AVNRT). In this operation, atrioventricular block is the most severe complication and its prevention is of our great concern. This complication always occurs under some special circumstances with potential risk. So, it is very important to realize such conditions, as in...

The cardiac specialized conduction tissue was studied by serial sectioning in 13 cases of situs ambiguus. In four cases of right isomerism, we found paired sinus nodes in relation to a crista terminalis, and in each case a sling of conduction tissue between two atrioventricular nodes was present regardless of the ventricular morphology or cardiac position. In the cases with left isomerism, the ...