Diurnal changes and reproducibility of corrected sinus node recovery time

Abstract

Corrected sinus node recovery time (CSRT) has been found unreliable in identifying all cases of sick sinus syndrome. Since other factors than sinus node dysfunction might add to the pathologic significance of the CSRT, we assessed it in 15 patients (nine group I patients with "prolonged" CSRT max = 3,196 + 2,740 msec and six group II patients with "short" CSRT max = 367 + 79 msec) at 0800, 1100, 1400, 1700, 2000, and 2300 hours with atrial overdrive stimulation rates (AST) of 90, 110, 140, 170, and 200 bpm on three consecutive days using a loop-mounted stable atrial electrode. Only with AST greater than or equal to 140 beats per minute (bpm) did all CSRTI values prove prolonged (greater than or equal to 560 msec). CSRTI values at corresponding time intervals were reproducible with AST greater than or equal to 140 bpm (day 1 vs 2 vs 3, P greater than .05), but not at AST 90 bpm and 110 bpm (P less than .05); CSRTII results, however, varied from day to day (less than .05) due to less scatter of single results. CSRTI results increased progressively with AST 90, 110, and 140 bpm from 301 + 256 msec by 60% for each pacing rate up to 785 + 848 msec. With AST greater than or equal to 140 bpm, the pattern of CSRT changes was inconsistent; this was also reflected by the distribution of the mean maxima of CSRTI: For 0800 hours at AST 140 bpm = 822 + 937 msec; for 1100 hours at AST 200 bpm = 824 + 1446 msec; for 1400 hours at AST 140 bpm = 780 + 814 msec; for 1700 hours at AST 170 bpm = 1,099 + 1,008 msec; for 2000 hours at AST 200 bpm = 1,156 + 1,280 msec; and for 2300 hours at AST 170 bpm = 1,021 + 1,102 msec. We conclude therefore that the optimal diagnostic yield for sick sinus syndrome testing is influenced by the time of the day and the AST used for CSRT testing.

Arrhythmias And Thromboembolic Complications After The Extracardiac Fontan Operation

“…The noninvasive assessment of sinus node function is generally considered to be as reliable as more invasive diagnostic tools. 25,26 Several other series have also used 24-hour Holter monitoring as a component of intermediate and late-term follow-up and have demonstrated a variety of arrhythmias, in particular sinus node dysfunction and atrial arrhythmias. 23,24 Given the avoidance of suture lines in the region of the sinoatrial node, the finding of sinus node dysfunction may appear surprising, but it is not unprecedented.…”

Modifications to the cavopulmonary anastomosis do not eliminate early sinus node dysfunction

“…8,16 The noninvasive assessment of sinus node function is generally considered to be as reliable as more invasive diagnostic tools. 17,18 Furthermore, because the incidence of sinus node dysfunction increases with time from surgery, any comparison of surgical modifications from different eras must be adjusted for duration of follow-up. In an attempt to address these multiple variables, this prospective study compared the early incidence of sinus node dysfunction between the hemi-Fontan/lateral tunnel approach and the bidirectional Glenn/extracardiac conduit Fontan with the use of routine ECGs and ambulatory Holter monitors at each surgical step.…”

Light-dark dependence of electrocardiographic changes during asphyxia and reoxygenation in a rat model

“…Acute systemic asphyxia causes profound electrophysiologic dysfunction in the conductive system of the myocardium, which affects sinus node function, the atrioventricular (AV) node refractory period [14][15][16], PQ interval [17][18][19], distribution of refractory periods [19], and changes in heart rate [20,21], as well as the threshold for ventricular arrhythmias [22].…”