[Ischemia tolerance of the heart in percutaneous transluminal coronary angioplasty. Controlled study of the effect of isosorbide dinitrate and nifedipine].

In a randomized controlled study, influence of sublingual isosorbide dinitrate (ISDN) and nifedipine on ischemic tolerance of the heart during percutaneous transluminal coronary angioplasty (PTCA) was examined. After dilations without premedication except heparin ten patients received 10 mg ISDN sublingually and dilations after one, five, and ten minutes were repeated, then 20 mg nifedipine sublingually was administered followed by dilations at one, five, ten, and 15 minutes intervals (group A). First 20 mg nifedipine and then 10 mg ISDN were given sublingually with the same repeated dilations in ten patients forming group B. Mean arterial pressure decreased from 111 +/- 11 to 97 +/- 14 mmHg after ISDN (p less than 0.001) in group A and to 86 +/- 12 mmHg after nifedipine (p less than 0.001). In group B arterial pressure remained constant after nifedipine and decreased to 84 +/- 15 mmHg after ISDN (p less than 0.05). Coronary perfusion pressure in group A remained constant at about 27 +/- 11 mmHg and increased in group B from 27 +/- 14 to 31 +/- 20 mmHg after nifedipine and decreased to 20 +/- 16 mmHg after ISDN (n.s.). Dilation period increased in group A from 33 +/- 15 s to 69 +/- 25 s after ISDN (p less than 0.001) and remained constant after nifedipine 67 +/- 23 s. Dilation time in group B increased from 31 +/- 8 s to 49 +/- 17 s after nifedipine (p less than 0.001) and to 81 +/- 46 s after ISDN (p less than 0.001). Time until ST segment depression of greater than 0.1 mV increased from 14 +/- 5 s to 37 +/- 19 s by ISDN in group A and to 33 +/- 16 s after nifedipine (p less than 0.001). Times in group B measured 16 +/- 5 s and 24 +/- 8 s after nifedipine and 39 +/- 24 s after ISDN (p less than 0.05). In groups A and B arrhythmias could be suppressed despite prolonged dilation times only by application of both drugs.(ABSTRACT TRUNCATED AT 250 WORDS)