Coronary flow reserve of nonischemic heart failure

Coronary flow reserve (CFR) provides essential information about the coronary microvascular bed in the absence of narrowings of epicardial coronary arteries. Experimental and human data suggest chronic heart failure is associated with a reduction of CFR in the absence of coronary artery disease. Dipyridamole, papaverine, or adenosine administration intravenously or intracoronary achieve maximal vasodilation of coronary arteries in human studies, however, systemic administration of vasodilator (dipyridamole) resulted in conflicting effects on systemic blood pressure. Various mechanisms including the nitric oxide pathway, neurohumoral alterations, and microvascular spasm among others, may contribute to the decrease in CFR in nonischemic heart failure. Notably, there is no study which describes the correlation between subjective symptoms of heart failure and the severity of the decrease in CFR. Further investigation of this area may be beneficial in determining the appropriate level of exercise training for heart failure patients and understanding mechanisms of the progression of heart failure.