Computer-enhanced digital angiography: correlation of clinical assessment of left ventricular ejection fraction and regional wall motion.

We compared computer-enhanced digital angiography (CEDA) following pulmonary injection of 20 ml Renografin-76 (5 ml/sec) to conventional directly injected left ventriculography (LV) in 13 patients undergoing routine diagnostic catheterization. Left ventricular ejection fraction (LVEF) was determined by planimetry from end-diastolic and end-systolic images by two independent angiographers. The correlation coefficient for LVEF (CEDA vs. LV) was r = 0.75 (p less than 0.005) for observer 1 and r = 0.85 (p less than 0.0005) for observer 2. The interobserver variability for LVEF was very low, resulting in a high correlation coefficient (r = 0.91, p less than 0.0005). Three angiographers independently reviewed both the conventional and CEDA images in a random order for assessment of anterior, apical, and inferior regional wall motion, using a 6-point subjective grading system (198 determinations). The interobserver correlation for subjective assessment of regional wall motion by both LV and CEDA was poor (49% for LV and 59% for CEDA, p = NS). These poor correlations were not improved by excluding any region or angiographer from the analysis. The agreement of regional motion assessments between the two techniques was only 40%. To improve reproducibility of wall motion interpretation, an automated analysis program was developed. First the range of normal contraction was defined from pooled literature data. The movement of any segment of the left ventricular wall could then be determined in millimeters and referenced to the normal range. This method eliminated interobserver variability. In the absence of an acceptable standard of segmental wall motion to which this measurement can be compared, the accuracy of this objective format could not be determined. We conclude that CEDA images allow accurate determination of ejection fraction and that the large interobserver variability of subjective regional wall motion analysis can be overcome by employing more objective formats.

Computer enhanced digital angiography.

A new computer image enhancement technique was employed on cardiac images of 10 dogs and 7 patients to demonstrate the feasibility of an on-line automatic delineation of the left ventricular endocardial silhouette with a peripheral venous injection of contrast material while simultaneously reducing the x-ray dosage. This technique employs a very fast analog-to-digital conversion system capable of digitizing on-line video frames. By storing and continuously updating the first 30 video frames and then subtracting each incoming frame from this memory, most of the background is eliminated leaving only the contrast filled ventricle. Using calibrated densitometric measurements, we found that iodine concentrations in the human left ventricle following venous injection of 40 ml Renografin-76 (25 ml/s), peaked at 4.3 +/- 0.3 mg/ml (mean +/- SD) compared to 14.8 +/- 0.8 mg/ml following direct injection of 40 ml at 13 ml/s (p less than 0.001). The computer enhanced venous-injected images had an optical contrast 14 times greater than that of the unenhanced direct left ventriculogram. This increase in optical contrast provided unambiguous subjective definition of the endocardial borders. This technique is applicable to both central and peripheral contrast injection whereby high quality images can be obtained at approximately 98% reduction in radiation (5 mA, 65-85 kV), allowing performance of serial studies.

Cardiac effects of acute ethanol ingestion unmasked by autonomic blockade.

We assessed the effects of ethanol and autonomic blockade on left ventricular function in nine normal subjects, age 20--35 years, using M-mode echocardiography and systolic time intervals. On day 1, measurements were made of heart rate, mean velocity of circumferential fiber shortening, and left ventricular pre-ejection period and left ventricular ejection time ratio (PEP/LVET), during a control period and after autonomic blockade. Autonomic blockade was produced with intravenous propranolol (0.2 mg/kg body weight) and atropine (0.04 mg/kg body weight). On day two, measurements were again made during a control period, then with ethanol alone, followed by addition of autonomic blockade to ethanol. One hundred eighty milliliters of ethanol were ingested over 60 minutes, resulting in a mean blood ethanol level of 110 mg/dl (range 77--135 mg/dl) at 60 minutes post-ingestion. There were no significant differences between the control data on days 1 and 2. Blood pressure was unchanged throughout the study. study. On day 1, autonomic blockade alone resulted in the expected increase in heart rate (p less than 0.001), with a proportional increase in mean velocity of circumferential fibr shortening (p less than 0.01), and an increase in PEP/LVET (p less than 0.01). On day 2, ethanol alone resulted in no significant changes except for a slight increase in PEP/LVET (p less than 0.02). Ethanol plus autonomic blockade, (day 2), compared with autonomic blockade alone (day 1), revealed a decrease in mean velocity of circumferential fiber shortening (p less than 0.05), and an increase in PEP/LVET (p less than 0.01), with a decrease in intrinsic heart rate (p less than 0.001). We conclude that in normal subjects: 1) autonomic blockade does not directly affect contractility; 2) acute ethanol ingestion alone does not produce important changes in cardiac function; and, 3) ethanol in the autonomic blockaded heart causes a significant decrease in contractility. Thus, we infer that ethanol has a negative inotropic effect which is masked by catecholamines and/or autonomic nervous system discharge.

Short-term effects of smoked marihuana on left ventricular function in man.

The short-term effects of smoking one to three marihuana cigarettes (900 mg of marihuana per cigarette; 2.2% delta9-tetrahydrocannabinol) on left ventricular performance were evaluated in 21 experienced users of cannabis at different times during a 94-day in-hospital study of the biologic effect of daily heavy smoking of marihuana. In six subjects, cardiac output was determined using the indocyanine-green dye-dilution technique; and in two of these individuals and 15 additional subjects, cardiac output, ejection fraction, preejection period (PEP), left ventricular ejection time (LVET), and the velocity of circumferential fiber shortening (Vcf) were determined using echocardiograms, phonocardiograms, and carotid pulse recordings. Following the smoking of one to three marihuana cigarettes, the heart rate rose 16 to 53 percent, cardiac output rose 4 to 9 percent, stroke volume did not change or fell slightly, and ejection fraction, PEP/LVET, and did not change, except for a slight increase in Vcf (15%) after three marihuana cigarettes, which could be accounted for by the associated increase in heart rate (53%). These findings suggest that in long-term heavy users of cannabis, marihuana has no significant effect on myocardial contractility independent of its effect on heart rate.

Echocardiographic diagnosis of mitral regurgitation in congestive cardiomyopathy.

Eighteen patients with congestive cardiomyopathy were studied by echocardiography and cardiac catheterization. Patients with coronary disease on angiography or primary valvular disease were excluded. Six patients showed mild or no mitral regurgitation; in 12 others the degree of mitral regurgitation was moderate or severe. The echocardiographic features in these patients were: (1) a dilated left ventricle (LV), (2) normal LV wall thickness, (3) reduced LV posterior wall motion, and (4) reduced or absent systolic thickening of the interventricular septum (IVS). IVS motion was reduced in 10 patients, and appeared "normal" or increased in another eight, all of whom showed moderate or severe mitral regurgitation on angiography. It is concluded that an apparent normal or increased motion of the IVS with reduced or absent systolic thickening in congestive cardiomyopathy is evidence for coexistence of significant mitral regurgitation. Reduced or absent systolic thickening can distinguish these patients from those with segmental myocardial disease and normal septa or dilated LV's due to volume overload.

Long-term survival in preductal atresia of the aortic arch.

Atresia of the aortic arch is distinguished from complete interruption of the aorta by the presence of a fibrotic strand bridging the 2 discontinuous segments of aorta. Most patients with aortic arch atresia have associated intracardiac defects. There is a high neonatal mortality in this condition, with 95% of the patients dying in the first year of life. The case described herein is the first long-term survivor with atresia of the aortic arch, a patent ductus arteriosus, and an atrial septal defect to reach adulthood. In this patient an extensive collateral network existed in spite of the presence of a patent ductus arteriosus.

Echocardiographic manifestations of infiltrative cardiomyopathy. A report of seven cases due to amyloid.

Echocardiography has been useful in the evaluation of congestive and hypertrophic cardiomyopathies. We present echocardiographic findings in seven patients with infiltrative cardiomyopathy due to amyloid. Cardiac amyloidosis was documented at autopsy in two patients, and the diagnosis was suggested by clinical, echocardiographic, tissue, or hemodynamic findings in the other five. Hemodynamic findings in three patients mimicked constrictive pericarditis; and autopsy was performed on one of the three and showed a normal pericardium. Underlying disorders were multiple myeloma (five patients), ankylosing spondylitis (one patient), and an unknown disorder (one patient). The basic echocardiographic findings in infiltrative cardiomyopathy due to amyloid were (1) symmetrically increased left ventricular wall thickness (in the absence of hypertension or aortic valvular disease), (2) hypokinesia and decreased systolic thickening of the interventricular septum and left ventricular posterior wall, and (3) small to normal size of the left ventricular cavity. Two patients also had small pericardial effusions. Thus, in a patient with congestive heart failure, these echocardiographic findings should suggest infiltrative cardiomyopathy.

Hemodynamic consequences of femoral arteriovenous bovine shunts.

Seventeen patients with femoral arteriovenous bovine shunts (FAVBS) were evaluated to delineate the cardiovascular consequences of the procedure. The resting cardiac index (CI), as estimated by echocardiography, was increased in 8 patients (47%). Twelve of the 17 patients (71%) had more than a 20% reduction in CI after 5 minutes of shunt occlusion. In 6 of these, the CI returned to normal from an abnormally high value. As a group, the decrease in CI was significant (P = 0.001). This was accomplished mainly by a significant decrease in stroke volume (P less than or equal to 0.004). Signs and symptoms of congestive heart failure developed in 10 of the 17 patients during the year following FAVBS. Because of the marginal cardiac reverse in patients with renal failure and the significant increase in cardiac index resulting from FAVBS, alternative forms of vascular access should be used whenever possible.

High-output congestive failure from femoral arteriovenous shunts for vascular access.

Femoral arteriovenous bovine shunts (FAVBS) represent an accepted method of vascular access for patients requiring chronic hemodialysis. The authors present 4 patients who required corrective surgery for high-putput congestive heart failure (HOCHF) secondary to high flow rates through the shunt. In order to avoid this serious complication, intraoperative graft flow rates should not exceed 900 cc/min. HOCHF secondary to FAVBS may be refractory to conservative therapy and require either banding of the shunt or its removal.

Abnormal motion of the mitral valve with pericardial effusion: Pseudo-prolapse of the mitral valve.

The echocardiograms of seven patients with large pericardial effusions were found to show posterior motion of the mitral leaflets in systole as seen in prolapse of the mitral valve. Repeat echocardiograms after resolution of the effusion revealed normal mitral valve motion. None of the patients had clinical evidence of prolapsed mitral valve. We postulate that a posterior swing of the heart within the pericardial fluid occurring in late systole causes posterior displacement of the mitral valve simulating a prolapsed valve.

Echocardiographic diagnosis of a mobile, pedunculated tumor in the left ventricular cavity.

A mobile left ventricular tumor was detected by echocardiography. The tracing showed a cluster of echoes in the left ventricular cavity corresponding to the location of the tumor as seen in angiograms. At surgery the tumor was attached to the interventricular septum by a thin fibrous stalk.

Posterior mitral leaflet motion in mitral stenosis.

A reduced rate of diastolic closure of the anterior mitral leaflet has been shown to occur in mitral stenosis, primary pulmonary hypertension, and in cases with reduced left ventricular compliance. Posterior notion of the posterior mitral leaflet in diastole has been the distinguishing feature to rule out the diagnosis of mitral stenosis. We have analyzed echocardiograms of 167 patients with mitral stenosis and have found 16 cases where the posterior mitral leaflet moved posteriorly, that is, in an opposite direction from the anterior mitral leaflet. Two other features were found that were helpful in establishing the diagnosis of mitral stenosis in these atypical cases, namely, thickening of the mitral leaflets and reduction or absence of the artrial wave.