IS CORONARY PLOW RESERVE IN RESPONSE TO PAPAVERINE REALLY NORMAL IN SYNDROME-X

Background An impaired coronary flow reserve in syndrome X has been de monstrated by many studies. Recently, however, a normal coronary flow reserve in response to papaverine was reported, but the number of pati ents in these studies was small. The aim of this study was to investig ate whether coronary how reserve in response to intracoronary papaveri ne is really impaired in syndrome X. Methods and Results We investigat ed 53 syndrome X patients (typical angina, a positive exercise test, a nd completely normal coronary arteries on angiography) and 26 heart tr ansplant patients with normal coronary arteries (control group). All a ntianginal medications were stopped 48 hours before the study. A 3.6F intracoronary Doppler catheter was positioned in the proximal left ant erior descending coronary artery and was connected to a Millar velocim eter. The coronary blood flow velocity at rest and in response to a hy peremic dose of papaverine was measured. Coronary flow reserve was def ined as the ratio of hyperemic coronary blood flow velocity in respons e to papaverine and resting coronary blood flow velocity. The coronary flow reserve (mean+/-SDS) in the syndrome X group was 2.72+/-1.39. Th e coronary flow reserve in the control group was significantly higher at 5.22+/-1.26 (P<.01). In both grops there was no significant differe nces in the heart rate or the mean arterial pressure during the study. Conclusions Our study shows that coronary flow reserve in response to intracoronary papaverine is impaired in syndrome X patients.