Effects of intracoronary nicardipine, diltiazem and verapamil on coronary blood flow

Background. Intracoronary OC) calcium channel blockers (CCB) such as diltia zem and verapamil are frequently utilized during percutaneous coronary inte rventions to maximize coronary blood flow. Their use, however, may be Limit ed by systemic side effects such as hypotension and bradyarrhythmias. The v asoselective dihydropyridines, such as nicardipine, may be more effective a t increasing coronary blood flow with fewer systemic side effects. This stu dy compares the effects of nicardipine, diltiazem and verapamil on coronary blood flow, heart rate and blood pressure. Methods. IC nicardipine (200 meg), diltiazem (1 mg) and verapamil (200 meg) were serially administered in a randomized, double-blinded fashion in mini mally diseased (( 30% stenosis) left anterior descending or left circumflex arteries in nine patients, Epicardial coronary artery diameter (ECAD) was determined by quantitative coronary angiography and coronary blood flow vel ocity (CBFV) was measured by Doppler Flowire in each patient before and aft er each medication. Results, Nicardipine significantly increased CBFV (p < 0.05) and had a long er duration of effect (p < 0.05), but had no difference in ECAD compared wi th diltiazem and verapamil, No differences were noted between CCB in change s in heart rate or mean arterial blood pressure. However, two patients had transient episodes of Type I second degree AV block after receiving diltiaz em, Conclusions. When compared with diltiazem and verapamil, nicardipine appear s to offer more potent and more prolonged vasodilatation with less risk of serious systemic side effects. Future studies are needed to assess the effi cacy of IC nicardipine in patients with no-reflow.