Low-voltage direct-current stimulation is safe and promotes angiogenesis in rabbits with myocardial infarction

This study evaluates safety and efficacy of low-voltage direct-current (DC) electrical stimulation of angiogenesis in rabbits with myocardial infarction (MI). Thirty Japanese rabbits were divided into treatment and control groups, and MI was induced by ligation of the left circumflex (LCX) artery. Two platinum electrodes were placed directly on the epicardium on either side of LCX artery. Low-voltage DC stimulation (4.0 V/cm, 30 min/day) was performed in the treatment group immediately after surgery until fourth week post-operatively. Cardio-electrophysiological, respiratory, hematological, blood biochemical, histopathological, immunohistochemical parameters, as well as capillary density at the marginal zone of myocardial infarct were compared between treatment and control groups. Capillary density in the treatment group (63.1 ± 2.2) was significantly higher (P < 0.01) than that in controls (45.4 ± 3.9). Overall mortality was 6.7%, and the prevalences of pneumothorax and intraoperative arrhythmia were 3.3 and 6.7%, respectively. Transient hypotension, anemia, leukocytosis, hypoxemia, and a slight increase in myocardial enzymes levels were observed in both groups. Regarding electrical stimulation, no adverse reactions except a minor infiltration of inflammatory cells and mild degeneration were observed in the myocardium. It was, therefore, concluded that low-voltage DC stimulation in the MI rabbits was not only safe but also effective in promoting angiogenesis in the myocardium.