We report a case of a 62-year-old male with Steinert's disease who presented with progressive intermittent episodes of lightheadedness five years after he was diagnosed with the disease. On evaluation, he developed a new onset trifascicular block (first degree atrioventricular block, new onset right bundle branch block, and left anterior fascicular block). A dual chamber pacemaker was inserted ...

The pattern of complete right bundle-branch block (RBBB) combined with abnormal left axis deviation is shown to be the predominant conduction abnormality during orthograde (antegrade) conduction in patients who have experienced transient or permanent complete heart block (59% of a series of 44 patients). Sequential records on the same patient are presented showing progressive development of the...

Atrial and ventricular pacemaker function was studied in 20 patients with idiopathic chronic complete heart block using the rate response to an intravenous bolus dose of isoprenaline (5 mug/70 kg bodyweight). Pacemaker responses were compared with those of 16 normal control subjects. None of the patients was having syncopal attacks at the time of admission and they were therefore selected in th...

Bundle branch block is a common cause of a widened QRS complex, and, as indicated in Table 1, different mechanisms may be responsible. Three are rate related and one is based upon retrograde invasion into the bundle branch. Those four mechanisms lead to the intermittent appearance of a bundle branch block pattern. Most commonly, bundle branch block is continuously present, so-called fixed bundl...

His bundle (H) electrograms were recorded in three patients with Mobitz type II block and narrow QRS. Block was secondary to digitalis intoxication in one patient. In the second patient, who had first-degree A-V block, type II block occurred with atrial pacing at a slightly increased heart rate. In the third patient, who had corrected transposition of the great vessels, type II block occurred s...

In 1909 Eppinger and Rothberger showed that characteristic changes in the electrocardiogram arose after section of the right and left branches of the bundle of His in dogs, and the following year these experimental results were applied to human pathology, so that bundle branch block became a clinical concept. Since that time the electrocardiogram originally designated right branch block has com...