Incidence of acute myocardial infarction in patients with exercise-induced silent myocardial ischemia.

Fifty-five patients with angiographically proved coronary artery disease (CAD) underwent Bruce protocol exercise stress testing with thallium-201 imaging. Twenty-seven patients (group I) showed myocardial hypoperfusion without angina pectoris during stress, which normalized at rest, and 28 patients (group II) had a similar pattern of reversible myocardial hypoperfusion but also had angina during stress. Patients were followed for at least 30 months.

Cardiac mechanics and function in obese normotensive persons with normal coronary arteries.

Obesity is associated with several cardiac abnormalities, but its effects on cardiac loading conditions and contractile function are controversial. The frequent coexistence of obesity with systemic hypertension and coronary artery disease further complicates evaluation of cardiac function in obese persons. Therefore, cardiac mechanics and contractile function were examined at cardiac catheterization in 14 obese persons (50 +/- 5% overweight) who were free of systemic hypertension and angiographic coronary narrowing.

Hemodynamic predictors of outcome in patients undergoing valve replacement.

The afterload-corrected end-systolic volume index (ratio of end-systolic stress to end-systolic volume index [ESS/ESVI]) was previously useful in predicting outcome in patients with mitral regurgitation undergoing valve replacement. Therefore we tested ESS/ESVI together with standard hemodynamic variables as possible predictors of outcome in 39 patients with various valvular lesions who underwent valve replacement. Thirteen patients had preoperative mitral regurgitation, 16 had aortic stenosis, nine had aortic regurgitation, and one had mitral stenosis.

Left ventricular wall stress and function in childhood coarctation of the aorta.

Unlike most adults with compensated pressure overload of the left ventricle, children with moderate to severe aortic stenosis exhibit pronounced left ventricular muscle hypertrophy, enhanced ejection performance and diminished wall stress. To determine whether these findings are present in other forms of left ventricular pressure overload in children, left ventricular mechanics were studied by catheterization in 14 children with coarctation of the aorta (average peak gradient 39 +/- 17 mm Hg) and in 10 normal children. Ejection fraction and mean velocity of circumferential fiber shortening in the coarctation group (0.

Variant angina in an 11 year old boy.

Variant angina is a syndrome in which ischemic cardiac pain occurs with ST segment elevation. The syndrome is due at least in part to coronary vasospasm. Although well documented in adults, there are no known reports of this syndrome in children.

Electrocardiographic ST-T wave patterns, extent of coronary artery disease, and left ventricular performance following non-Q-wave myocardial infarction.

Subendocardial, nontransmural, or non-Q-wave myocardial infarction (NQM) carries a serious prognosis. Many previous studies of NQMI include only patients without new Q waves at the time of infarction. Since the site of transmural MI (by Q waves) has implications concerning extent of coronary disease (CAD) and left ventricular (LV) dysfunction, we wondered what the extent of CAD and LV dysfunction is among acute MI patients who have neither new nor old Q waves.

Assessment of systolic ventricular muscle function in man: the end systolic index.

Accurate assessment of ventricular muscle contractile function in patients with heart disease is impaired by alterations in afterload, preload and wall thickness which often accompany the disease. The relationship between pressure and volume at end systole is considered to provide a contractile index which is independent of preload and which accounts for afterload. Use of the index prerequisites determinations of the left ventricular end systolic pressure, wall thickness as well as the dimensions or volumes, respectively, which may be assessed with either invasive or noninvasive methods.

Absolute left ventricular volume by an iterative build-up factor analysis of gated radionuclide images.

A method for determining absolute left ventricular (LV) volumes from radionuclide gated blood-pool (GBP) images was validated in 34 patients. The technique is nongeometric, corrects for tissue attenuation, and uses an experimentally determined set of build-up factors to account for the effects of scatter. Only four parameters are needed to determine LV volumes: the LV count rates from a left anterior oblique (LAO) and a right posterior oblique (RPO) image (180 degrees opposed to the LAO), a venous blood sample, and a patient thickness measurement.

Differences in myocardial performance and load between patients with similar amounts of chronic aortic versus chronic mitral regurgitation.

It is not known if the favorable changes in preload and afterload that augment ejection performance in acute experimental aortic and mitral regurgitation are also present in patients with chronic regurgitation. Additionally, observations that patients with mitral versus aortic regurgitation respond differently to valve replacement suggest that differences exist preoperatively between these two types of volume overload. Therefore, ventricular mechanics were compared in nine patients with severe aortic regurgitation, eight patients with severe mitral regurgitation and seven normal subjects.

Coronary thrombolysis by intravenous streptokinase in acute myocardial infarction: acute and follow-up studies.

Coronary arteriography was performed before, immediately after, and 9 to 14 days after administering i.v. streptokinase (850,000 to 1,500,000 IU) to 43 patients within 6 hours of myocardial infarction.

Left ventricular performance in patients with coexistent mitral stenosis and aortic insufficiency.

Isolated mitral stenosis and isolated aortic insufficiency impose unique and opposite loading conditions on the left ventricle. To assess these combined effects, hemodynamic and angiographic factors were compared among normal subjects and patients with isolated mitral stenosis, isolated aortic insufficiency or combined mitral stenosis and aortic insufficiency. Left ventricular end-diastolic volume index was lower in patients with combined lesions and severe or moderate aortic insufficiency than in patients with isolated severe or moderate aortic insufficiency (138 +/- 19 versus 206 +/- 20 cc/m2 and 87 +/- 5 versus 145 +/- 22 cc/m2, respectively) (p less than 0.

Improved prediction of peak left ventricular pressure by echocardiography in children with aortic stenosis.

Prediction of peak left ventricular pressure by echocardiography in children with aortic stenosis assumes that wall stress is normal. The recent finding that stress is subnormal in many children with aortic stenosis and elevated ejection performance requires reevaluation of this noninvasive technique. By using M-mode echocardiography, left ventricular end-diastolic dimension and wall thickness and left ventricular shortening fraction were measured in 27 children with aortic stenosis undergoing left ventricular pressure measurement by cardiac catheterization.

Acute and long-term hemodynamic effects of oral pirbuterol in patients with chronic severe congestive heart failure: randomized double-blind trial.

In 20 patients with severe congestive heart failure (CHF), we studied the effects of the beta-adrenergic agonist pirbuterol compared to placebo in both an acute double-blind randomized trial and after long-term treatment. Acutely, pirbuterol patients (n = 10) demonstrated a significant rise in cardiac index (2.2 +/- 0.

Contractile function, myosin ATPase activity and isozymes in the hypertrophied pig left ventricle after a chronic progressive pressure overload.

Experimental right ventricular pressure-overload hypertrophy in small mammals is associated with early muscle dysfunction, even before the onset of overt pump failure. Experimental results are quite heterogeneous regarding muscle function of the pressure hypertrophied left ventricle. Muscle dysfunction of the right or left ventricle, when found, may be causally related to alterations of myosin ATPase activity and isozyme type.

Relation of therapeutic response to nifedipine to coronary anatomy and motion of S-T segment during unstable angina pectoris.

Of 77 patients hospitalized for unstable angina pectoris and failure of oral, dermal, or intravenous nitrates and/or beta blockade, 81 percent with negligible or single-vessel disease and 55 percent with two- or three-vessel disease showed response (p less than 0.05) to nifedipine therapy. Patients with either S-T elevation or no change during pain responded better (31 of 45) than those with any S-T depression (16 of 32; p less than 0.

Left ventricular function in peripartum cardiomyopathy.

Although many cases of peripartum cardiomyopathy have been reported in the literature, detailed data from left heart catheterization and contrast ventriculography are unavailable. A patient with peripartum cardiomyopathy had catheterization performed to clarify the diagnosis. Hemodynamics at rest and with exercise, angiographic volumes, and indices of left ventricular function are presented.

Left ventricular wall stress in compensated aortic stenosis in children.

It is known that children with aortic stenosis (AS) frequently have supernormal indexes of left ventricular (LV) pump function and remain compensated for many years. Factors causing this increase in pump performance have not been elucidated. A study was done on LV mechanics in 11 children with AS (aortic valve area 0.

Absolute left ventricular volume from gated blood pool imaging with use of esophageal transmission measurement.

A new method for determining absolute left ventricular (LV) volume from equilibrium gated blood pool images was validated in 36 patients by comparing gated blood pool (GBP) imaging with contrast ventriculography (CV) using both Simpson's rule (SR) and area-length (AL) calculations. The technique is geometry-independent and is the first to correct for tissue attenuation with use of an in vivo point source. An orally administered capsule containing 1 to 2 mCi of technetium-99m (Tc-99m) sulfur colloid is used for this purpose.

Coexistent mitral stenosis and dynamic left ventricular outflow obstruction.

A 66-year-old female with known mitral stenosis presented with symptoms of progressive pulmonary congestion. Concomitantly, subvalvular left ventricular outflow obstruction was suspected clinically and both lesions were confirmed at cardiac catheterization. At operation, marked septal hypertrophy and rheumatic mitral stenosis were observed, the mitral valve was replaced, and a septal myomectomy was performed.

Provocative ergonovine testing in patients without obstructive coronary disease.

Ergonovine administration during coronary angiography is frequently used to rule out coronary spasm as a cause of chest pain. We performed this study to determine which electrocardiographic variables (other than ST segment elevation with pain) and which chest pain characteristics might be predictive of ergonovine test outcome in patients without obstructive coronary disease. Thirty-one patients had an electrocardiogram recorded during chest pain.