Effects of pulse excimer laser irradiation on the human left ventricular wall.

Abstract

This study was to assess the potential application of excimer lasers in the ablation of myocardium in vitro for the treatment of constant ventricular tachycardia or hypertrophic cardiomyopathy. A fresh human heart and EMG model 103 XeCl pulse excimer laser machine were used. The pulse repetition rate varied from 1 to 7 Hz. Irradiation directly on the left endocardial and epicardial walls lasted for 10 seconds and was repeated 3 times, creating 3 craters. The histological changes were examined by light microscope. Results showed very close relations between the depth or volume of vaporized craters and the pulse repetition rate on the endocardial (r = 0.9674, P less than 0.001 and r = 0.8962, P less than 0.01, respectively) and epicardial walls (r = 0.9602, P less than 0.001 and r = 0.9612, P less than 0.001, respectively). A sharp, clear border without debris or coagulating necrosis was seen under the microscope. We concluded that the pulse excimer laser, differing from Ar+ or Nd:YAG lasers, might be a powerful tool for manipulating the human ventricular wall, but more work needs to be done before it can be widely applied in the treatment of cardiovascular disease.