Nicotine-modified postinfarction left ventricular remodeling.

Cigarette smoking has been noted to impair wound healing in tissues such as skin, bone, and gut. This study was designed to examine whether nicotine adversely affects postinfarction cardiac wound healing and remodeling in an experimental model of myocardial infarction. For this purpose, two groups of rats were studied. The control group received a simple bandage, and the nicotine group had a section (1.75 mg/day) of a nicotine patch attached on their backs. After a 7-day treatment period, an anterior wall infarction was induced. A bandage-free 7-day healing period followed, after which hearts were isolated for mechanical tests. Nicotine-treated rats developed significantly enlarged left ventricles with thin, infarcted walls and a rightward shift in the passive pressure-volume relationship. Pressure-strain analysis also indicated possible changes in the material properties of the wound for nicotine-treated rats. In conclusion, nicotine has significant adverse effects on postinfarction healing and left ventricular remodeling. These observations have important clinical implications because of the enhanced risk for development of heart failure.