The His bundle electrogram was recorded in I9 cases with P mitrale simultaneously with standard lead II, and compared with 30 cases with normal P waves. Internodal conduction time (P1A) interval did not differ in P mitralefrom the controlgroup, confirming that prolonged atrial activation in P mitrale represents a specific 'left atrial block'. The importance of this observation is discussed with...

The findings in a patient with complete atrioventricular block and normal morphology and duration of the QRS complex are presented. A His bundle electrogram was obtained, which led to the location of the atrioventricular block within the His bundle. A careful review of the electrocardiograms obtained during the seven years preceding the onset of complete atrioventricular block showed a QRS comp...

Traditional right ventricular pacing prolongs the electrical and mechanical activation of the heart, which reduces the pump function, and in selected patients may lead to pacing-induced heart failure. Pacing the His bundle preserves the normal or near-normal activation pattern of the ventricles that prevents the detrimental effects of right ventricular pacing. This review discusses the techniqu...

Introduction Cardiac resynchronization therapy (CRT) has shown a significant clinical benefit over right ventricular pacing in patients with left ventricular dysfunction and a high ventricular pacing requirement. Traditionally, CRT has relied on coronary sinus (CS) lead placement through the use of fluoroscopy and venography. Three-dimensional (3D) electroanatomic mapping has been used as an al...

Idiopathic premature ventricular contractions (PVCs) are a common arrhythmia, sometimes presenting as highly symptomatic and drug-resistant ectopy and more rarely as a reduction in left ventricular function. Common sites of PVCs include the right and left ventricular outflow tracts, the mitral annulus, and the aortic cusps. In addition, the right ventricular septum in the vicinity of the His bu...

A case of type B Wolff-Parkinson-White syndrome, with intractable atrial fibrillation, underwent surgical division of a right-sided accessory atrioventricular bundle of Kent. Pre-excitation and complicating tachyarrhythmias were henceforth abolished for 6 weeks, when the patient died of infective endocarditis. Histological examination showed a divided Kent's accessory atrioventricular pathway a...