A 2 1/2-year-old girl with bradycardia and left bundle branch block at birth began to experience "night cries" when deeply asleep. Electrophysiological study demonstrated congenital diffuse atrioventricular conduction disease with concealed paroxysmal atrioventricular block, nonpropagated His bundle depolarizations, severe sinus node abnormality, and a low atrioventricular junctional escape rhy...

Univentricular heart of left ventricular type is defined as the condition in which the entirety of atrial inputs is committed to a main chamber exhibiting trabecular pattern of left ventricular type, usually in the presence of another chamber in the ventricular mass which has a right ventricular trabecular pattern. This condition can occur with two atrioventricular valves, a common atrioventric...

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...

INTRODUCTION AND OBJECTIVES Permanent His-bundle pacing is effective in patients with supra-Hisian atrioventricular block. We report our experience in patients with infra-Hisian atrioventricular block. METHODS The study involved selected patients referred for syncope and intraventricular conduction disturbance, infra-Hisian atrioventricular block, with left ventricular dyssynchrony and no cor...

Symptomatic bradycardia-independent atrioventricular block occurred in a patient with right bundle-branch block, left anterior hemiblock, and prolonged HV interval. The arrhythmia, triggered by a spontaneous or induced premature beats, appeared when the post-extrasystolic PP and HH intervals increased to a critical value. Reinitiation of atrioventricular conduction required the presence of vent...

We describe a 73-year-old woman with a history of breast cancer and metastatic disease diagnosed in January 2002 (stable when we saw her) who was admitted for sudden dyspnea and presyncope. Complete atrioventricular block was documented, and a temporary pacemaker was implanted. Eight hours after admission she recovered sinus rhythm with left bundle branch block as seen in previous recordings. C...

We report a critical role for the T-box transcription factor Tbx5 in development and maturation of the cardiac conduction system. We find that Tbx5 is expressed throughout the central conduction system, including the atrioventricular bundle and bundle branch conduction system. Tbx5 haploinsufficiency in mice (Tbx5(del/+)), a model of human Holt-Oram syndrome, caused distinct morphological and f...

We have studied the disposition of the cardiac conducting tissues in four hearts from situs solitus individuals possessing primitive ventricles without outlet chambers. These hearts correspond to the type of univentricular heart defined as common ventricle by Lev. All the hearts studied possessed normally positioned great arteries. Two groups, each consisting of two hearts, could be distinguish...

Eighty patients with clinical indications for cardiac pacing had atrioventricular conduction analysed by His bundle study. The indications for cardiac pacing included high grade atrioventricular block, sick sinus node syndrome without tachycardia, bradycardia-tachycardia syndrome, unstable bilateral bundle-branch block, and uncontrolled ventricular irritability. Complete heart block, Wenckeback...

was common (49%), and evidence is produced which suggests that it is probably the result of the ventriculotomy rather than direct trauma to the right bundle. Right bundle-branch block with left anterior hemiblock was less common (II%). Right bundle-branch block with left anterior hemiblock, especially if associated with a prolonged PR interval (trifascicular block), may predispose to complete a...