Ambient particulate matter (PM) exposure is linked to cardiovascular complications and death— especially for individuals with preexisting heart failure. A model of heart failure was developed in Spontaneously Hypertensive Heart Failure (SHHF) rats. Four-week isoproterenol infusion (ISO;2.5mg/kg/day) induced mid- treatment tachycardia and hypotension and post-treatment heartrate (HR), blood pressure, pulse pressure (PP) and contractility decrements suggesting heart failure. ISO induced cardiac hypertrophy and fibrotic cardiomyopathy. PP, HR, and HR variability (HRV) alterations post-ISO indicated parasympathetic dominance and sympathetic desensitization. Cardiac insufficiency dissipated before PM inhalation at 3 weeks post- ISO. After saline but not ISO infusion, PM slightly decreased HRV, possibly because of adrenergic responsiveness differences. ISO potentiated PM-induced pulmonary injury and atrioventricular conduction interference. The ISO regimen was repeated in non- telemetered SHHFs. At 2 weeks, rats received high-salt diets for 6 weeks. The data suggest co-exposure to ISO+8% salt more effectively elicits a heart failure-like state.Master of Science in Public Healt
