A THREE-YEAR-OLD GIRL WITH MYOCARDIAL TOXICITY AND CONGESTIVE HEART FAILURE DURING CONTINUOUS l-BODY ISOPROTERENOL INHALATION THERAPY

The case is a three-year-old girl. She was admitted to our hospital for status asthmaticus. Because her respiratory failure was worseninig, continuous l-body isoproterenol inhalation therapy was administered. Fourteen hours later, the T-wave on the electrocardiogram changed, despite bradycardia. Isoproterenol inhalation therapy was discontinued, but her asthma attack worsened again. There was no reliable evidence to substantiate a diagnosis of myocardial toxicity on examination, so isoproterenol inhalation therapy was re-started. Forty-eight hours later, a chest X-ray showed cardiomegaly, and an electrocardiogram showed ST-segment depressions. We made a diagnosis of congestive heart failure due to myocardial toxicity, and discontinued the isoproterenol inhalation therapy. The signs and symptoms of congestive heart failure subsided soon after discontinuation. We call attention to the fact that continuous l-body isoproterenol inhalation therapy may induce myocardial toxicity without tachycardia.