HOMOGENEOUSLY REDUCED VERSUS REGIONALLY IMPAIRED MYOCARDIAL BLOOD-FLOW IN HYPERTENSIVE PATIENTS - 2 DIFFERENT PATTERNS OF MYOCARDIAL PERFUSION ASSOCIATED WITH DEGREE OF HYPERTROPHY

Objectives, The aim of this study was to quantitatively measure region al and global myocardial blood flow and coronary reserve in hypertensi ve patients without coronary artery disease and to assess the correlat ion with left ventricular mass. Background. The effect of left ventric ular hypertrophy on regional vasodilating coronary capability in arter ial hypertension is controversial, and no quantitative method has been applied to assess a possible correlation. Methods. Positron emission tomography was performed in 50 untreated hypertensive patients and 13 normotensive subjects. Blood flow at baseline and after dipyridamole w as globally and regionally measured by using nitrogen-13 ammonia; coro nary reserve and resistance were calculated. Left ventricular mass was assessed by two-dimensional echocardiography. Results. In hypertensiv e patients, flow at baseline was similar to that of normotensive subje cts (p = 0.21), but values were reduced after pharmacologic vasodilati on (p < 0.05). This impairment of maximal coronary flow was not correl ated with left ventricular mass (p = 0.13). Among hypertensive patient s, we identified a group with a homogeneous distribution of perfusion and a group with a heterogeneous flow pattern, Flow was globally reduc ed in the former group, but it was abnormal only at the site of perfus ion defects in the latter, Patients with regional defects showed the h ighest likelihood of having an increased left ventricular mass. (C) 19 98 by the American College of Cardiology.