The beneficial effect of nicardipine on the healing of myocardial infarcts in dogs.

The effect of 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-[2-(N-benzyl-N-methyl amino)] ethyl ester 5-methyl ester hydrochloride (nicardipine, RS-69216, YC-93), on the healing of myocardial infarcts has been examined in dogs surviving for 3 months after ligation of the left anterior descending coronary artery (LAD). Three groups of 12-14 dogs were subjected to the following treatments: a) Group X received one-month oral pretreatment (1-2 mg/kg/d) with post-ligation i.v. treatment delayed for 1 h (10 micrograms/kg followed by 2 micrograms/kg/15 min for 5 h) and oral treatment (1-2 mg/kg/d) for 3 months (n = 9 survivors). b) Group Y received oral placebo for one month, i.v. saline vehicle every 15 min for 5 h commencing 1 h postligation, and oral placebo for 3 months (n = 8 survivors). c) Group Z received oral placebo for one month as in group Y, i.v. and oral drug treatment post-ligation as for group X (n = 10 survivors). Recordings were made of general haemodynamics and at post mortem, each heart was X-rayed and sliced transversely to give 14 sections from which detailed observations were made on left ventricular (LV) geometry. Comparative morphological measurements were available from filed data for 11 normal dog hearts (designated group C) of similar type. Nicardipine treatment significantly modified the general haemodynamic responses to LAD ligation particularly in maintaining a low LV systolic pressure and inhibiting elevation of LV end diastolic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)