PERSISTENT ATRIAL STANDSTILL IN A FAMILY WITH MYOCARDIAL DISEASE

Three siblings with slow heart rates and mild congestive heart failure are described. Their electrocardiograms showed normal QRS complexes but no P waves. Intra-atrial electrocardiograms confirmed the absence of atrial activity. In one patient Adams-Stokes' attacks developed for which he required an artificial pacemaker. A biopsy specimen of his right atrium showed interstitial and perivascular deposits of amyloid. Atrial standstill may be suspected when P or fibrillary waves are absent from the electrocardiogram. It may be confirmed by intracardiac electrocardiograms. Inability to stimulate the atria, using the internal pacemaker, indicates that the myocardium, rather than the sinus node, is responsible for the atrial standstill. © 1969.