Effects of Ozone Inhalation during Exercise on Selected Heart Disease Patients

摘要

Heart patients are considered at greater risk during episodes of significant oxidant pollution and, although there are no quantitative laboratory data available, are advised to curtail physical activity. In this investigation, six male volunteers, ages 46-64 years, with clinically documented coronary artery disease and well defined symptomatic angina pectoris threshold on physical exertion, served as subjects. Each patient was exposed on three occasions for 40 minutes to either filtered air or ozone at concentrations of 0.20 or 0.30 ppm while walking on a treadmill at workloads simulating their regularly prescribed symptom limited exercise training regimen. Standard pulmonary function tests and periodic observations of exercise ventilation, respiratory metabolism, electrocardiographic changes, hemodynamic response, and clinical signs and symptoms were noted. Analysis of variance revealed that none of the patients' physiologic responses to ozone exposure were statistically significant. Furthermore, neither onset of angina pain or ischemic changes were related to ozone exposure in a dose dependent fashion. Hence, the patients not only failed to exhibit any unexpected cardiovascular strain while exposed to ozone, but also evidenced no significant pulmonary function impairment or exercise ventilatory pattern alteration as has been observed in clinically normal subjects exercising at similar ozone concentration levels.