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SUMMARY We evaluated the ability of ST-segment analysis during submaximal exercise tolerance testing (85% predicted age-adjusted heart rate) to diagnose the presence of significant coronary artery stenosis (2 75% cross sectional area narrowing) in a group of 85 men and 92 women with chest pain syndromes and no previously documented myocardial infarctions. Disease prevalence by selective coronary angiography was 36% for men and 33% for women (NS). Predictive value of a positive exercise test (PV(+ET)) as defined by 1 mm ST-segment depression 0.08 second after the J point was significantly higher for men than for women (77% vs 47%, p < 0.05). Predictive value of a negative test (PV(-ET)) was not significantly different for men (81%) and women (78%). Analysis of the 66 men and 66 women not taking digitalis preparations again showed that PV(+ET) was significantly higher for men than for women (90% vs 45%, p < 0.01).Multivariate analysis showed that patients with angiographically significant coronary disease had significantly lower attained heart rates and shorter exercise duration than those without significant stenosis, independent of ST-segment responses. A discriminant function using ST-segment response, attained heart rate and a sex-dependent ST-segment response factor was developed. Duration of exercise was not an independent predictor by our analysis. This function improved the PV(+ET) and PV(-ET) for the total group and for the women; for men, the PV(-ET) improved, while the PV(+ET) fell slightly. This function has not yet been used prospectively.In patients with chest pain and no previously documented myocardial infarction, men have a significantly higher PV( + ET) than women, which cannot be accounted for simply by a difference in disease prevalence (i.e., Bayes' theorem).EXERCISE TESTING has been a commonly used tool for the evaluation of cardiac status for over 20 years. Despite its extensive use as a screening test for asymptomatic patients, a diagnostic test for patients with symptoms of ischemic heart disease, and as a functional test for patients with known cardiac disease, the usefulness, accuracy, and even basic methods for interpretation of the test remain controversial.Proper use of any test involves definition of the patient populations in which the diagnostic yield will be greatest. The use of exercise testing for diagnosis of coronary atherosclerotic heart disease in women with chest pain has also been controversial. Some authors '-5 Hospital from 1971-1977 were reviewed, and all patients evaluated for chest pain who had both coronary angiography and acceptable exercise tests within 6 months were identified. Patients with valvular heart disease, including mitral valve prolapse, congenital heart disease, idiopathic hypertrophic subaortic stenosis, left bundle branch block on the ECG, a history of chest surgery, or a previously documented myocardial infarction were excluded from the study. The diagnosis of a previous myocardial infarction was based on the finding of at least two of the followin...

SUMMARYSystolic time intervals (STI) and serum digoxin concentrations (SDC) were measured in eight patients with compensated atherosclerotic and/or hypertensive heart disease who received oral digoxin 0.25 mg/day or 0.5 mg/day for alternate two-week periods without a loading dose. Control data were obtained both before and after the four weeks of treatment. After 13 days treatment with digoxin, 0.5 mg/day, there was a significant decrease in total electromechanical systole corrected for heart rate (QS2i), pre-ejection period (PEP), pre-ejection period corrected for heart rate (PEP,) Methods Eight patients, all in normal sinus rhythm, with compensated atherosclerotic and/or hypertensive heart disease were studied. Four patients were male and four patients were female. Ages ranged from 35 years to 68 years. Five patients were receiving maintenance doses of digoxin, orally, at the time of selection for the study. Digoxin was discontinued at least two weeks prior to the first control observation. In all patients, SDC at the time of the first control observation was less than 0.4 ng/ml. Diuretics, antihypertensive agents, and sedatives were continued in unchanged doses. Patients taking diuretics received supplemental oral potassium chloride. The purpose of the study was fully explained to each patient and written informed consent was obtained.The initial evaluation of each patient included determinations of blood urea nitrogen, serum creatinine, sodium, potassium, chloride, carbon dioxide combining power, calcium, carotene, and thyroxine. The results of these studies were all within the normal range. Chest X-rays and 12-lead electrocardiograms were compatible with the clinical diagnoses.Two sets of control observations (Cl and C2) were obtained two weeks before starting digoxin. Four of the patients then received digoxin 0.25 mg/day for two weeks

Left ventricular structure, function, and the coronary circulation were studied in a subset of patients with mitral valve leaflet prolapse. This group of 26 patients (21 females, five males, with mean age of 46 years), had the syndrome identified as idiopathic mitral valve prolapse (IMVP), which was characterized by a systolic click-murmur, clinical symptoms that were highly variable in duration and intensity, angiographically-documented mitral prolapse, and no obvious associated systemic or cardiovascular disease. Mitral regurgitation was of moderate degree in four, mild in 14, and absent in eight. The left ventricular (LV) end-diastolic volume index was elevated in ten of 25 (40%), the LV mass index was elevated in six of 17 (35%), but the LV anterior wall thickness was increase in only one of 17. Three major patterns of ventricular contraction were identified: 1) normal in seven; 2) abnormal, usually an inferior deformity and/or anterior asynergy, in eight; and 3) hyperkinetic in 11. Normal resting left ventricular function, assessed as an ejection fraction greater than 55%, was present in 17 of 25 (68%). Selective coronary arteriography was essentially normal in all 25 patients studied. An ischemic ECG response was detected during only one of 12 maximal treadmill exercise tests and in none of ten atrial pacing stress tests (AP). Myocardial lactate extraction did not change significantly during AP in six patients. We conclude that cardiomyopathy does not appear to be a primary cause or an important associated component of the IMVP syndrome. Abnormalities of the coronary circulation or of myocardial metabolism were not demonstrated by available methods. A proposed pathophysiological mechanism to explain the clinical and angiographic findings in IMVP is discussed.

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The cardiovascular effects of a new antihypertensive drug, bupicomide, were compared with those of hydralazine in 6 patients with mild to moderate hypertension. The mean supine arterial pressure of patients was reduced 15.2 mm Hg by bupicomide (900 to 2,000 mg/day) and 15.7 mm Hg by hydralazine (300 to 600 mg/day). Heart rate increased an average of 11.3 bpm during bupicomide and 14.5 bpm by hydralazine. Neither drug was associated with a postural decrease in mean arterial pressure. The heart rate response during maximum tolerated treadmill exercise was not diminished by either drug. Cardiac index was increased during administration of both drugs. Bupicomide and hydralazine reduced forearm vascular resistance, while renal blood flow and renal vascular resistance were not significantly modified. Evidence of equivalent augmentation of sympathetic nervous activity during administration of both drugs consisted of equal and significant increases in heart rate and urinary norepinephrine excretion, and decreases in duration of the pre-ejection period. The absolute values of these parameters were correlated with mean arterial pressure, which may indicate that the increase in sympathetic nervous activity was mediated by baroreceptor reflexes. Although bupicomide inhibits dopamine beta-hydroxylase, our results suggest that it is acting as a direct vasodilator.

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