Alterations in contrast medium-induced coronary reactive hyperemia after bepridil in patients with coronary artery disease.

The acute effects of an intravenous infusion of bepridil (BEP) (4 mg . kg-1) on left ventricular (LV) hemodynamics, coronary sinus blood flow (CSBF), and myocardial metabolism were studied in eight patients with coronary artery disease. In contrast with data previously reported with calcium channel blockers, BEP induced an elevation in LV end-diastolic pressure from 12.0 +/- 7.1 to 20.1 +/- 7.2 mm Hg (mean +/- SD, p less than 0.001) and a fall in LV dp/dt max from 1339 +/- 302 to 1177 +/- 251 mm Hg . sec-1 (p less than 0.01). This significant alteration in LV function is likely to be explained by the lack of effect on heart rate and aortic pressure observed after an acute intravenous infusion of BEP. Myocardial oxygen consumption (MVO2) increased from 448 +/- 272 to 498 +/- 273 mumol . min-1/100 g LV (p less than 0.05) as did CSBF from 79.5 +/- 42.7 to 92.1 +/- 45.1 ml X min-1/100 g LV (p less than 0.01). Lactate extraction fell from 0.33 +/- 0.17 to 0.15 +/- 0.17 (p less than 0.05). A contrast medium-induced coronary reactive hyperemia (HPR) evidenced an increased hyperemic volume from 9.5 +/- 3.6 to 12.1 +/- 4.5 ml/100 g LV (p less than 0.01) and HPR duration from 23.3 +/- 6.9 to 32.3 +/- 15.4 sec (p less than 0.05) after BEP. However, the peak/resting CSBF ratio was blunted after BEP from 1.74 +/- 0.18 to 1.61 +/- 0.12 (p less than 0.05), evidencing a net effect of BEP on HPR.(ABSTRACT TRUNCATED AT 250 WORDS)