Changes in systolic time intervals - a non-invasive marker for the haemodynamic effects of sumatriptan

Aims This study assessed the use of systolic time intervals (STI) as a pote ntial noninvasive marker of the haemodynamic effects of sumatriptan, a 5HT( 1) receptor agonist. Methods Twenty-six patients undergoing diagnostic cardiac catheterization p articipated. STIs were derived from haemodynamic pressure tracings at basel ine, following placebo injection and following either subcutaneous (n=18) o r intravenous injection (n = 8) of sumatriptan. Results Sumatriptan (i.v. or s.c.) was associated with significant increase s in mean arterial pressure (95% C.I. 9,14mmHg, P=0.0001), total electromec hanical systole (95% C.I.8,36ms, P<0.0001), pre-ejection period (95%C.I. 8, 21 ms, P=0.0001) and left ventricular ejection time (95% C.I. 2,12ms, P=0.0 03). Conclusion STI responses were consistent with sumatriptan-induced changes i n afterload. In summary, the measurement of STIs is a potential non-invasiv e method of investigating the influence of serotonergic compounds on the ca rdiovascular system.