Cardiopulmonary toxicity of tetrachloroethylene

Tetrachloroethylene (1,1,2,2-tetrachloroethene) is a widely used organic solvent capable of producing adverse renal, hepatic, and central nervous system effects. The cardiac effects of tetrachloroethylene, thus far unexplored, were studied in several species. To standardize the dosimetry, tetrachloroethylene was prepared for intravenous injection in solutions of Tween 80, which had no demonstrable cardiotoxicity. In rabbits under urethane and in cats and dogs under pentobarbital, tetrachloroethylene increased the vulnerability of the ventricles to epinephrine-induced extra-systoles, bigeminal rhythms, and tachycardia. The mean threshold doses of tetrachloroethylene were 10 mg/kg in rabbits, 24 mg/kg in cats, and 13 mg/kg in dogs. In rabbits this threshold dose for cardiac arrhythmias correspond to blood levels between 2.2 and 3.6 microgram/ml. Animals demonstrating a reflex bradycardia to vasopressor doses of epinephrine were relatively resistant to the arrhythmogenic action of tetrachloroethylene. Ventricular arrhythmias occurred in less than 30% of the animals after tetrachloroethylene alone. In cats higher doses of tetrachloroethylene (40 mg/kg) produced acute pulmonary edema. Tetrachloroethylene (30-40 mg/kg) decreased left intraventricular dP/dt (max) in dogs, without significantly increasing left intraventricular end-diastolic pressure, although there was a transient decrease in arterial blood pressure that accompanied the early phase of myocardial depression. These results are being used as the basis for studies of the chronic effects of tetrachloroethylene on cardiac performance.