SUMMARY Myocardial blood flow/unit mass (MBF) and the determinants of myocardial oxygen consumption were measured in seven control subjects (group I) and 15 patients (pts) with cardiomyopathy (CM), group II (group Ila-congestive CM: 10 pts; group Ilb-hypertrophic CM: 5 pts). In group I left ventricular (LV) MBF was 64±8 (SD) ml/lOg -min; it was significantly lower in Ila (45 ± 15 ml/lOOg. min, P < 0.01) and IIb (39±7 ml/100g min, P < 0.01). However, calculated total LV flow (LV mass X MBF) was increased in the two CM groups. In nine CM pts, LV MBF increased in response to atrial pacing from 41±7 to 63±13 ml/lOOg * min.PATIENTS WITH CARDIOMYOPATHY frequently complain of chest pain suggestive of ischemic heart disease despite the presence of widely patent coronary arteries.' In addition, these patients often manifest varying degrees of myocardial hypertrophy and impaired ventricular performance. The relationship between these abnormalities and myocardial perfusion is largely unknown. There have been only a few studies, each involving small numbers of patients, of the myocardial circulation in cardiomyopathies and these studies have yielded conflicting results.4The first purpose of this study was to measure average left ventricular as well as regional myocardial perfusion at rest in patients with cardiomyopathy and to compare the values obtained with those in a control group of patients with normal coronary arteriograms and normal ventricular performance. For the study, patients with cardiomyopathy were divided into two functional categories, congestive cardiomyopathy and hypertrophic cardiomyopathy, by criteria developed by Goodwin.8 In nine of the cardiomyopathy patients, myocardial blood flow was also measured during right atrial pacing in order to evaluate the circulatory response to an increase in myocardial oxygen consumption.The second purpose of this study was to investigate in man the relationship between myocardial blood flow and three of the major determinants of myocardial oxygen consumption: heart rate, myocardial contractility, and wall stress. '-12 For this purpose, heart rate, mean velocity of circumferential fiber shortening (MVcf), and peak left ventricular (LV) systolic wall stress were measured in the control sub- 484In group Ila, calculated peak wall stress was normal (4.39±0.77 dynes/cm' X 106) but mean velocity of circumferential fiber shortening (MVcf) was significantly reduced (0.53±0.18 vs 1.26±0.12 circum/sec, P < 0.01). In llb, MVcf was normal but peak stress was significantly reduced (2.80±0.75 vs 4.51±1.10 dynes/cm' X 106, P < 0.05). Multiple regression analysis based on all pts yielded, MBF = 16.9 MVcf + 9.30 Stress + 0.26 Heart Rate -26.4, (r = 0.79). The data indicate that MBF is reduced in CM patients and the regression analysis suggests that MBF in these 22 pts with normal coronary arteriograms was determined largely by heart rate, peak stress, and ventricular performance.jects and in the patients with congestive and hypertrophic cardiomyopathy. The aim of this part of the stu...

Ultrasonic angioplasty may be a useful clinical method for recanalization of total occlusions in patients with peripheral vascular disease. Ultrasonic energy appears to cause controlled injury to the atherosclerotic intima by selectively disrupting the ultrasound-sensitive occlusion.

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The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.

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