Ischemia and left ventricular dysfunction: A reciprocal relation?

There is convincing evidence that (prolonged) episodes of myocardial ischemia lead to impairment of left ventricular (LV) function and ultimately to chronic congestive hear? failure (CHF), but whether the opposite is also true has not been well established. We studied this issue in two groups of CHF patients with positron emission tomography (PET)by using [N-13]ammonia ((NH3)-N-13) as a tracer. In the first protocol we compared 12 patients with idiopathic dilated cardiomyopathy (who have normal coronary arteries) with 12 healthy controls, In the second protocol we studied a group of 24 patients with documented coronary artery disease (CAD). In this protocol, we compared patients with normal LV function to those with LV dysfunction and CHF. In patients with cardiomyopathy, myocardial blood flow at rest was normal but flow reserve (after dipyridamole infusion) was significantly impaired (1.7 +/- 0.08) compared with normal subjects (2.7 +/- 0.01;