The efficacy of retrograde coronary venous delivery of
procainamide for the management of spontaneous and inducible sustained
ventricular tachycardia was evaluated and compared with systemic intravenous
procainamide administration in 22 conscious dogs with permanent left anterior descending coronary artery occlusion. Selective retrograde injection of
procainamide was achieved through an autoinflatable balloon
catheter placed in the great cardiac vein, with the tip positioned in the vicinity of the site of left anterior descending
coronary occlusion. Great cardiac vein retroinfusion of
procainamide was significantly (p less than 0.05) more effective than systemic
intravenous injection against spontaneous
ventricular tachycardia 1 day after coronary artery occlusion (13 dogs) and against electrically induced sustained
ventricular tachycardia in the 3 to 12 day postocclusion period (9 dogs). Significantly lower doses of
procainamide were used with retroinfusion as compared with systemic administration, that is, 19.6 +/- 8.8 versus 35 +/- 0 mg/kg
body weight during spontaneous
tachycardia and 13.4 +/- 4.1 versus 32.1 +/- 2 mg/kg during induced
tachycardia (p less than 0.01). Retroinfusion of
saline solution through the great cardiac vein had no effect on either type of
tachycardia. Myocardial tissue
procainamide levels measured in infarcted and ischemic zones of the left anterior ventricular wall were 9 to 100 times higher after great cardiac vein retroinfusion than after systemic injection. Great cardiac vein
dye injection studies demonstrated a preferential distribution in left ventricular regions supplied by the occluded coronary artery. It is concluded that regional coronary venous
procainamide retroinfusion in dogs with
myocardial infarction is more effective than systemic
intravenous injection against both spontaneous and inducible sustained
ventricular tachycardia. The greater efficacy of great cardiac vein treatment appears to be primarily related to selectively increased delivery of
procainamide to ischemic myocardial sites.