Heart murmurs, valvular regurgitation and electrical disturbances in copper-deficient genetically hypertensive, hypertrophic cardiomyopathic rats

Objective: Rats with a genetic tendency to develop hypertensive, hypertroph ic cardiomyopathy were fed copper-deficient diets and their cardiac respons es were investigated. Methods: Five male weanling rats of the Long-Evans and SHHF/Mcc-fa(cp) stra ins were randomly selected to receive diets containing either adequate quan tities of copper (94.5 mu mol Cu/kg diet) or reduced quantities of copper ( <15.8 mu mol Cu/kg diet) for 6 weeks, (n=5 within each group). Echocardiogr ams and electrocardiograms were recorded and analyzed at the end of the 6-w eek interval. Results: Electrocardiograms from copper deficient groups showed longer Q-T intervals and increased QRS amplitudes than controls. Both the copper defic ient and control SHHF groups demonstrated significant QRS complex prolongat ion compared to Long-Evans rats. Echocardiography analysis showed significa nt increases in left ventricular area, free wall dimension, and myocardial cross-sectional areas in rats fed a copper deficient diet. The frequency of systolic cardiac murmurs increased in copper deficient rats and were relat ed to the presence of valvular regurgitation as determined from echocardiog raphy. Discussion: However, the data do not suggest that a copper-deficient diet f ed to a strain of rats genetically susceptible to heart disease later in li fe, hastens or worsens the onset of cardiac disease. The genetic predisposi tion and copper-deficient states exert independent effects upon the heart.