Background: Testing for sick sinus syndrome (SSS) requires invasive stimulation protocols for sinus node recovery time (SNRT) and corrected sinus node recovery time (CSNRT).
Methods and results: We compared the CSNRT with the lengthening of the sinus cycle length (ADO:SCL) corrected to the basic cycle length (ADO:CSNRT) after administration of an intravenous bolus of adenosine (0.15 mg/kg) in 10 patients with clinical SSS (group 1) and 67 control patients (group 2). With 550 ms as an abnormal result for the ADO:CSNRT (and for the CSNRT) as an indicator of sinus node dysfunction, the ADO:CSNRT had a sensitivity of 80% and specificity of 97% for detection of SSS compared with sensitivity and specificity of 70% and 95% for invasive CSNRT. When combined, the 2 tests had a sensitivity of 100%. There was significant difference in the CSNRT between group 1 (1848 +/- 1825 ms) and group 2 (355 +/- 169 ms, P <. 0001) and a significant difference in ADO:CSNRT between group 1 (1168 +/- 1002 ms) and group 2 (272 +/- 592 ms, P <.0001).
Conclusions: We conclude that the ADO:CSNRT is a sensitive and specific test for SSS that equals invasive testing and should be considered as an alternative to invasive testing in patients with suspected SSS.