Optimal Pacing Mode for Sick Sinus Syndrome

To the Editor: I read with interest the article on the treatment of patients who have sick sinus syndrome (SSS) with single-chamber atrial pacing by Anderson et al.1 However, their finding of the annual risk of second- or third-degree atrioventricular (AV) block of only 0.6% per year contrasts somewhat with the reported findings that abnormal AV conduction was demonstrated in 57% to 67% of patients with SSS using invasive electrophysiologic techniques.2 3 4 Therefore, although Anderson et al1 demonstrated that abnormalities of AV conduction cause clinical problems only infrequently, it should be clear that a significant number of patients with SSS cannot be treated with atrial pacing alone. In these …