Differences in the morphology and duration between premature P waves and the preceding sinus complexes in patients with a history of paroxysmal atrial fibrillation.

Background: Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Experimental and human mapping studies have demonstrated that perpetuation of AF is due to the presence of multiple reentrant wavelets with various sizes in the right and left atria.

Hypothesis: Atrial fibrillation may be induced by atrial ectopic beats originating in the pulmonary veins, and premature P-wave (PPW) patterns may help to identify the source of firing.

Temporary cardiac pacing using a new, steerable, balloon-tipped pacing catheter.

A new balloon-tipped, flow-directed, steerable pacing catheter for unipolar temporary ventricular pacing is presented. It was successfully and uneventfully tested in 25 patients with acute myocardial infarction in the coronary care unit. The main advantage of the new catheter is the ease with which a stable contact may be achieved between the pacing electrode and the endocardium.

Single coronary artery associated with annuloaortic ectasia and ventricular septal defect.

A 60-year-old man with a single left coronary artery associated with an annuloaortic ectasia and a ventricular septal defect is described. He presented with severe heart failure and underwent open-heart surgery during which all these entities were confirmed.