Regional myocardial blood flow in patients with chest pain syndromes and normal coronary arteriograms.

Abstract

To evaluate possible disorders of regional myocardial blood flow in patients with chest pain syndromes and normal coronary arteriograms, we studied 21 patients with intracoronary injections of Xenon-133. Thirteen patients were restudied during an intervention: 6 patients received glyceryl trinitrate and 7 patients had contrast agent-induced hyperaemia. Patients were divided into 3 clinical groups: 7 patients had classic angina, 7 patients had a mixture of typical and atypical chest pain, and 7 patients had entirely atypical pain. A wide range of normal values for regional myocardial blood flow at rest was noted (41 to 128 ml/min per 100 g, with an average regional myocardial blood flow of 77 ml/min per 100 g ± 7 (mean ± SEM)). There were no significant differences between the 3 groups.With contrast hyperaemia, regional myocardial blood flow increased 164 per cent, while with glyceryl trinitrate, it decreased 31 per cent. Again, there was no statistical difference among the groups. Regional abnormalities offlow (> 15% difference between distal quadrants) were noted in 3 of 34 measurements. Two patients had heterogeneity of flow at rest by quadrant analysis but no focal perfusion abnormalities detected by functional imaging. Interestingly, both patients had positive exercise tests. Another patient had regional differences only during contrast-induced hyperaemia. Our findings suggest that most patients with chest pain syndromes and normal coronary arteriograms-even those with classic angina-do not have significant measurable myocardial perfusion abnormalities.The pathophysiology of angina pectoris is usually related to myocardial ischaemia secondary to significant luminal obstruction of the proximal coronary arteries (Zoll et al., 1951). Occasionally, however, patients will present with the typical or quasi-typical symptoms of angina, yet have entirely normal coronary arteriograms and no other recognised cause of myocardial ischaemia (valvular heart disease, hypertension, arteritides, etc.). Some patients with typical (and even atypical) angina may also have evidence of abnormal myocardial function compatible with ischaemia-such as myocardial lactate production with stress (Arbogast and Bourassa, 1972;Boudoulas et al., 1974) and electrocardiographic ST segment depression on exercise testing (Dwyer et al., 1969;Kemp et al., 1973)-others show abnormal left ventricular performance-such as a rise in left 'Supported by USPHS Grants.

Coronary vasodilator reserve, pain perception, and sex in patients with syndrome X.

“…Recently coronary vasodilator reserve (CVR) in syndrome X has been the object of many studies. [2][3][4][5][6][7][8][9] Positron emission tomography (PET), in particular, has permitted the noninvasive quantifica-tion of regional MBF and CVR.79 However, in none of these studies were syndrome X patients compared directly with matched normal control subjects. Generally, the control groups have consisted of patients with "atypical" chest pain or patients with chest pain but no changes on the stress ECG.…”

Thallium-201 stress imaging in hypertensive patients.

“…14 " 16 The abnormal thallium-201 perfusion study results may have been related to undetected coronary artery disease in hypertensive patients, increased oxygen demand caused by increased left ventricular mass, 17 inadequate coronary reserve, 18 ' 19 altered hemodynamics, 20 ' 21 or to a combination of these or other, as yet unrecognized, factors. 22 " 24 The increased incidence of abnormal stress test results in hypertensive patients in the absence of angiographic coronary artery disease noted in earlier radionuclide ventriculographic studies 4 and the trends observed in the present study of thallium perfusion may reflect supply-demand imbalance independent of coronary anatomy.…”