Obstruction within the right ventricular body: two-dimensional echocardiographic features

Real-time 2-dimensional (2-D) echocardiograms were performed in 4 patients, all with considerable obstruction within the right ventricular (RV) body, in 3 patients due to muscle bundles and in 1 due to hypertrophic cardiomyopathy (HC). None had obstruction at the pulmonic valve level or immediately below. Echocardiographically, obstruction presented in 3 patients as localized bulging of the RV free wall in the subinfundibular region such that the RV cavity presented a typical "hourglass" appearance. Associated ventricular septal defect (VSD) was detected in 2 patients by echocardiography. In the fourth case, a patient with HC, RV obstruction was associated with a prominent bulge of the ventricular septum into the right ventricle. In 3 patients, the obstruction was convincingly demonstrated only in the subcostal RV inflow-apex-outflow plane, rather than in the standard echocardiographic planes. Pulse Doppler studies in 2 patients demonstrated disturbed RV flow. Obstruction within the RV body is a potentially serious condition which has been overlooked both at cardiac catheterization and at surgery. Demonstration of this lesion by 2-D echocardiography appears feasible and would greatly improve diagnostic accuracy.     

Differentiation of left ventricular pseudoaneurysm from true aneurysm with two dimensional echocardiography

Real time two dimensional echocardiographic findings in four patients with a pathologically proved left ventricular pseudoaneurysm were compared with those in seven patients with a similarly proved true aneurysm of the left ventricle. Pseudoaneurysms produced a bounded echo-free space with a narrow neck that communicated with the left ventricular cavity. The maximal internal width of this neck (O_max) was much smaller than the maximal parallel internal diameter (D_max) of the aneurysmal sac, and the ratio O_max/D_max never exceeded 0.5. In all cases the pseudoaneurysm could be seen extending behind the intact portion of the involved left ventricular wall, and this finding produced a characteristic beak-like configuration in the studies of two patients. In contrast, true aneurysm resulted in local bulging and dilatation of the left ventricular wall so that the maximal internal width of the mouth (O_max) was nearly equal to, or actually represented, the maximal internal diameter (D_max) of the aneurysm so that the ratio O_max/D_max ranged from 0.9 to 1.0. Our preliminary study indicates that real time two dimensional echocardiography is useful in differentiating pseudoaneurysm from true aneurysm of the left ventricle.     

Myocardial texture characterization by two-dimensional echocardiography

Twenty-four normal subjects and 181 patients with various cardiac disorders (36 autopsies) were studied by 2-dimensional echocardiography. In vitro echocardiographic studies were performed on 26 of 36 autopsied hearts utilizing an ultrasonically visible metallic probe to correlate myocardial echo patterns with histopathologic features. All normal subjects and the majority of patients with ventricular hypertrophy due to valvular or hypertensive lesions showed a uniformly speckled or an echolucent appearance of the myocardium (type I texture). No autopsied heart with this texture had gross fibrosis (visible to the naked eye) or infiltrative disease. All patients with infiltrative disorders (amyloidosis, 7 of 7; Pompe's disease, 4 of 4) had multiple, discrete, and small (3 to 5 mm) highly refractile echoes (HREs) in the myocardium involving the ventricle or ventricles completely (type IIA texture) or partly (type IIB texture). However, this finding was non-specific and was observed in many other conditions such as left heart hypoplastic syndrome (10 of 10), hypertrophic cardiomyopathy (19 of 26), and chronic renal failure (4 of 9). In the noninfiltrative group, HREs in the autopsied cases were shown to result from gross fibrosis or endocardiofibroelastosis utilizing in vitro echocardiographic studies and metallic probe-guided biopsies, while HREs in the autopsied cases with cardiac amyloidosis could be correlated only with amyloid deposits since fibrosis was absent. Larger HREs (greater than 5 mm) presenting as broad patches or long linear echoes in the myocardium (type IIC texture) was seen in old myocardial infarctions (9 of 21) and congestive cardiomyopathy (4 of 26) and were correlated with large areas of myocardial fibrosis. Two-dimensional echocardiographic studies of myocardial texture help identify various infiltrative and degenerative processes in the heart.     

Two-dimensional and Doppler echocardiographic evaluation of aortic aneurysm and dissection

Ten patients with nondissecting aortic aneurysm and 10 with aortic dissection proved by angiography, surgery or both, were studied by real-time, 2-dimensional echocardiography. Multiple transducer positions were used to visualize various aortic segments so that a composite image of the aorta could be formulated. Using this comprehensive approach, the site, size and extent of all nondissecting aneurysms were correctly delineated (2 ascending aorta, 3 ascending aorta plus aortic root and 5 aortic arch with brachiocephalic involvement). In all patients with aortic dissection, the condition was identified by the presence of prominent, flap-like, undulating motion of the inner dissected wall or marked parallel wall widening (greater than or equal to 15 mm) and correctly categorized into DeBakey type I (4 cases), II (2 cases) or III (4 cases). Pulsed Doppler studies were useful in diagnosing reopening of dissection in a patient with previous surgical obliteration of the false channel.     

Two dimensional echocardiographic evaluation of exercise-induced left and right ventricular asynergy: Correlation with thallium scanning

Adequate real time two dimensional echocardiograms were prospectively obtained before and immediately after graded treadmill exercise testing in 41 of 48 patients who underwent cardiac catheterization for suspected coronary artery disease. Findings were correlated with thallium perfusion scans performed 5 to 10 minutes and 3 hours after the same exercise test. Exercise-induced wall motion abnormalities were detected in 19 of 23 patients with significant coronary artery disease and no prior myocardial infarction as well as in all 5 patients with known previous infarction. Three patients with coronary artery disease experienced new isolated right ventricular asynergy with exercise that would have been missed if only the left ventricle had been evaluated. Exercise-induced thallium perfusion defects showed good correlation with exercise-induced asynergy as detected with echocardiography. Two dimensional echocardiography performed immediately after treadmill stress testing is a feasible and rewarding technique in the evaluation of patients suspected to have coronary artery disease.     

Two-dimensional echocardiographic identification of pulmonary artery branch stenosis

Pulmonary artery branch stenosis is a not uncommon congenital lesion, noted in approximately 4% of children at the time of cardiac catheterization. Real-time 2-dimensional echocardiography was used to examine 10 patients with angiographically documented pulmonary branch stenosis. Five cases of pulmonary artery branch narrowing were identified by echocardiography without prior knowledge of angiographic findings. In 5 other patients whose angiographic results were known, the narrowings were identified in 4 of 5 cases. These results demonstrate the feasibility of evaluating pulmonary branch stenosis with the nonionizing, noninvasive method of 2-dimensional echocardiography.     

Noninvasive diagnosis of mitral prosthesis malfunction

We describe the utilization of echocardiography and phonocardiography in the diagnosis of malfunction of the Smeloff-Cutter mitral prosthesis in a patient in whom corrective surgery was subsequently performed without the necessity of cardiac catheterization studies. The noninvasive studies also delineated prosthesis malfunction as the etiology of pulsus alternans, noted clinically in this patient.     

Nitroprusside infusion in experimental acute myocardial infarction with systemic hypertension: effects on systemic hemodynamics and regional myocardial blood flows

The effects of graded doses of nitroprusside on regional myocardial blood flow were studied in awake, acutely hypertensive dogs with acute myocardial infarction. Acute systemic hypertension was produced by infusing a mixture of norepinephrine and epinephrine for 80 minutes after coronary artery occlusion. The increase in aortic pressure produced by catecholamine infusion was accompanied by increases in heart rate, left ventricular (LV) end-diastolic pressure, first derivative of LV pressure (dP/dt), dP/dt at an LV developed pressure of 50 mm Hg (dP/dt/P) and pressure-rate product, but total peripheral vascular resistance did not change significantly. Two graded doses of nitroprusside were then infused, each for 25 minutes, beginning 30 minutes after the onset of coronary artery occlusion. The smaller dose of nitroprusside returned aortic pressure to control levels and significantly reduced total peripheral vascular resistance and LV end-diastolic pressure, but did not affect cardiac output, heart rate, LV dP/dt, dP/dt/P and pressure-rate product. Regional blood flow increased to both the ischemic and normal myocardium. The larger dose of nitroprusside further reduced aortic pressure and total peripheral vascular resistance and LV end-diastolic pressure and significantly increased heart rate and cardiac output. However, LV dP/dt, dP/dt/P and pressure-rate product remained unchanged. Regional blood flow to normal myocardium increased, but the increase in ischemic endocardial blood flow produced by the smaller dose of nitroprusside was no longer significant when the larger dose was administered. These changes were not produced by administration of normal saline solution.(ABSTRACT TRUNCATED AT 250 WORDS)     

Postextrasystolic Potentiation as a Predictor of Potential Myocardial Viability: Preoperative Analyses Compared With Studies After Coronary Bypass Surgery

The ability to predict reversibility of ventricular dysfunction should be important in determining operability. This study examined the usefulness of postextrasystolic potentiation as such a predictor. Left ventricular wall motion was studied using cineventriculography in 31 patients before and after revascularization surgery. Preoperative ejection fraction and wall motion were analyzed during a sinus beat and after a random ventricular extrasystole, whereas postoperative ejection fraction and wall motion were examined only during a sinus beat. Changes in ventricular motion were correlated with changes in vascular supply achieved by operation. Of the 7 patients whose ejection fraction was improved postoperatively, 6 had shown postextrasystolic potentiation compared with only 10 of the 24 patients without such improvement (P less than 0.05). Regional wall motion analysis also showed a significant association between postextrasystolic potentiation and postoperative improvement in wall motion. Of 26 zones judged to have an increased vascular supply after operation, 11 showed increased motion postoperatively. All 11 had shown postextrasystolic potentiation, compared with only 5 of 15 zones with increased vascular supply but without increased postoperative motion (P less than 0.001). Thus, postextrasystolic potentiation seems to be a useful predictor of the ability of asynergic myocardium to respond to successful revascularization surgery.     

Nifedipine in chronic stable angina: a double-blind placebo-controlled crossover trial

Thirty patients with chronic stable angina pectoris were randomized in a double-blind prospective placebo-controlled crossover trial to assess the efficacy of nifedipine (30 to 60 mg/day orally) in controlling symptoms and objective signs of myocardial ischemia using a symptom-limited treadmill exercise test. Adverse effects that occurred during both nifedipine and placebo treatment were minor and generally well tolerated. Twenty-three patients were analyzed from the crossover phase of the study. Nifedipine significantly reduced the frequency of angina by 55% and nitroglycerin consumption by 59%, and increased exercise time by 34%. These changes were significantly greater than those in the placebo group. Hemodynamic evaluation during exercise revealed a significant reduction in systolic and diastolic blood pressures in the nifedipine group at the onset of angina and at maximal exercise without significant differences in heart rate responses in the nifedipine and placebo groups. The pressure-rate product during submaximal exercise was significantly smaller in the nifedipine group than in the placebo group, but did not differ significantly in the 2 groups at the onset of angina or on maximal exercise. Furthermore, S-T segment depressions that occurred during exercise at the same pressure-rate products were smaller in the nifedipine period than in the placebo period. Thus, it appears that the antianginal effects of nifedipine are caused by a reduced myocardial oxygen demand for a specific work load and possibly by an increased blood supply to ischemic myocardium.     

Cold pressor test during two-dimensional echocardiography: usefulness in detection of patients with coronary disease

We assessed the feasibility and value of the cold pressor test (CPT) during real-time two-dimensional echocardiography (2DE) in patients with suspected coronary artery disease and normal resting left ventricular wall motion. Twenty patients were studied without knowledge of angiographic findings that demonstrated no significant coronary artery disease in seven (group 1) and significant coronary lesions in 13 (group 2). The increments in physiologic parameters (heart rate, systolic blood pressure, and double product) were not significantly different in both groups. CPT-induced wall motion abnormalities were identified echocardiographically in nine patients in group 2 and in one patient in group 1 (sensitivity 69% and specificity 86%). None of the patients in our study developed chest pain, ST changes, or ectopy during the test. It is concluded that 2DE combined with the CPT is valuable in identifying patients with coronary artery disease who show no left ventricular asynergy at rest.     

Effect of furosemide on hemodynamics and lung water in acute pulmonary edema secondary to myocardial infarction

Hemodynamic studies were carried out in 19 patients with left ventricular failure complicating acute myocardial infarction. Fourteen patients were studied before and after the intravenous administration of 0.5 mg/kg of furosemide, and five patients served as a control group. Serial measurements included intracardiac pressures, cardiac output and lung water by a double isotope technique. A significant reduction was noted in right atrial (P < 0.005), pulmonary arterial (P < 0.0005) and pulmonary wedge pressures (P < 0.0005) after administration of furosemide. Only the change in right atrial pressure was significantly different from that in the control group (P < 0.05). Lung water was not changed in 4 patients studied 2 hours after administration of furosemide but was significantly changed in the remaining 10 patients studied 4 to 24 hours after furosemide (P = 0.0001). This change was also significantly different from values in the control group (P < 0.05). The patients with no reduction in excess lung water also had a smaller reduction in pulmonary wedge pressure and a lower pretreatment stroke work index than the other patients.The mobilization of excess lung water in patients with acute myocardial infarction complicated by left ventricular failure has several features. Despite a prompt diuresis, the reduction in lung water is delayed for at least several hours after the administration of furosemide and may be related to the degree of left ventricular dysfunction. Venodilation may be a major result of treatment with furosemide.     

Age and prior caffeine use alter the cardiovascular and adrenomedullary responses to oral caffeine

The effects of age and chronic caffeine use (approximately 300 mg/day) on the cardiovascular and humoral responses to 250 mg of oral caffeine (the equivalent of 2 to 3 cups of coffee) were examined. Older subjects had greater increases in blood pressure than younger subjects (p less than 0.03), and caffeine nonusers had greater blood pressure increases than caffeine users, regardless of age (p less than 0.05). Caffeine increased the product of systolic blood pressure and heart rate (an estimate of myocardial oxygen demand) in older caffeine nonusers, but this effect was absent in older caffeine users (p less than 0.01). Cardiovascular effects of caffeine could not be related temporally to changes in plasma epinephrine, which were greater in caffeine nonusers and younger subjects, or to plasma norepinephrine, renin activity or vasopressin, which did not change. Thus, age accentuates and moderate prior caffeine use attenuates the cardiovascular effects of oral caffeine; these effects are not mediated solely through the sympathoadrenal system.     

Echocardiography in chronic alcoholics following prolonged periods of abstinence

Left ventricular function was analyzed using standard echocardiographic techniques in 26 chronic asymptomatic alcoholics without clinical evidence of cardiovascular disease. All were studied following a long period of abstinence (mean 3.1 years; range 3 months to 17 years). Seven asymptomatic children (mean age 14.1 years; range 4 to 19 years) whose mothers had been actively drinking throughout their pregnancies were also studied. The calculated fractional shortening of the left ventricle (per cent ΔS), ejection fraction, mean velocity of circumferential fiber shortening (mean V_CF), excursions and maximal systolic velocites of the ventricular septum and left ventricular posterior wall, preejection period/left ventricular ejection time ratios, mitral valve EF slopes, and thicknesses of the left ventricular posterior wall and ventricular septum were obtained in all. Normal left ventricular function was found in all but one adult alcoholic. In this patient, the per cent ΔS, ejection fraction, and mean V_CF were reduced. One additional adult alcoholic had a minimally thickened ventricular septum. Our results differ from other studies which have shown significant left ventricular dysfunction in asymptomatic chronic alcoholics. A possible explanation is the much longer period of abstinence of our chronic alcoholics at the time of their examinations. It also appears that left ventricular function in children born of alcoholic mothers is not affected when assessed after the long interval following prolonged exposure to alcohol in utero.