Paroxysmal ventricular standstill.

Among the various rhythms reported in the course of a Stokes-Adams attack, one of the rarest is standstill of the ventricle as an episode during normal rhythm. Such a condition may be called paroxysmal ventricular standstill, and is to be distinguished from the condition of alternating complete block and normal rhythm to which the term paroxysmal heart block may be applied. Three cases of paroxysmal ventricular standstill have been observed, in two of which there was paroxysmal heart block also, and ventricular standstill was also provoked by carotid sinus pressure. Weiss and Baker (1933) described several cases of total cardiac standstill, auricular standstlil, or extreme sinus bradycardia, and one of complete block in auricular fibrillation as a result of carotid sinus pressure: all of these had cardiovascular disease. Starling (1921) reported ventricular standstill on* swallowing but no cardiographic records were made of the attacks. Yater and Williams (1928-29) described a case of complete cardiac and ventricular standstill with slow irregular P waves. The case of Lewis (1920) showed ventricular standstill with auricular rhythm preserved; this patient later developed a complete block. A case recorded by Alexander and Bauerlein (1936) had variations in the degree of heart block with changes of posture but not with carotid sinus pressure. Holmes and Weill (1945) recorded mild grades of heart block in healthy men when they lay down; carotid sinus pressure caused a decrease in the P-R interval. Turner (1948) recorded the case of a man of 61 with cardiac asystole with pressure on either carotid sinus, whose attacks ceased after bilateral carotid sinus denervation. Parkinson et. al. (1941) recorded 5 examples of ventricular standstill, and collected 28 others that had been reported. Among all these there was only one in which the standstill was immediately followed by normal rhythm with unimpaired A-V conduction; this patient showed complete heart block on another day. Isolated cases of ventricular standstill are mentioned in two or three textbooks.