Study of atrial contraction in sick sinus syndrome using conventional and esophageal echocardiography

To evaluate the active systolic function of both atria in sick sinus syndrome (SSS), conventional and esophageal echocardiograms were recorded in 22 normal subjects (Normal), 5 patients (pts) with sinus bradycardia (Group I), 9 with sinoatrial block or sinus arrest (Group II), 10 with bradycardia-tachycardia syndrome (BTS, Group III) and 6 with transient atrial fibrillation (Group IV). Two pts in Group II and 8 in Group III had a history of syncope. Atrial filling fraction obtained by the left ventricular echogram (AFF by LV echo) and posterior wall excursion of the aorta during atrial contraction (Ea) were determined by the conventional echocardiogram. The excursion of the interatrial septum during atrial contraction (Eb) and the dimensional shortening of the right atrium during atrial contraction (Ec) were determined by the esophageal echocardiogram. Results were as follows: AFF was almost the same in Normal, and Group I, II and IV, but it was significantly lower in Group III. AFF was also decreased in 2 pts in Group II who had a history of syncope. Both Ea and Eb in Group III were significantly lower than those in the other groups. Ec was not significantly different among all groups, although one patient in Group III had markedly decreased Ec. There was a significant correlation between Ea and AFF (r = 0.638, p less than 0.001). We conclude that in a number of cases with SSS, especially BTS, left atrial active contraction is significantly impaired in addition to the electrophysiological abnormality.