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Biomedical subjects

J F Brymer

Publications and source records attributed to J F Brymer.

At least 19 recordsLinked to original sources
PubMed1991

Left ventricular shape as a determinant of functional mitral regurgitation in patients with severe heart failure secondary to either coronary artery disease or idiopathic dilated cardiomyopathy.

The relation between left ventricular (LV) shape and functional mitral regurgitation (MR) was evaluated in 39 patients with congestive heart failure. Heart failure was due to coronary artery disease in 23 patients (group I) and to idiopathic dilated cardiomyopathy in 16 (group II). LV shape was quantitated based on the ratio of LV major-to-minor axis and LV sphericity index calculated at end-systole and end-diastole. In group I, 9 patients had angiographic evidence of MR and 14 did not. In group II, 10 patients had MR and 6 did not. Within each group, there were no differences between patients with and without MR with regard to LV chamber volume and regional segmental wall motion abnormalities. In both groups, however, a significant difference was observed between patients with and without MR with respect to end-systolic and end-diastolic LV shape indexes. In group I, the end-systolic major-to-minor axis ratio was lower in patients with (1.42 +/- 0.04) than without (1.72 +/- 0.05) MR (p less than 0.001). Similar differences were observed in group II (1.41 +/- 0.06 vs 1.69 +/- 0.04) (p less than 0.01). In group I, the end-systolic sphericity index was also greater in patients with (0.32 +/- 0.02) than without (0.25 +/- 0.01) MR (p less than 0.02). Similar differences were observed in group II (0.37 +/- 0.03 vs 0.26 +/- 0.01) (p less than 0.02). These data indicate that in patients with severe heart failure, functional MR is present in those who manifest a more spherical LV cavity.

Cardiomyopathy, Dilated↗
PubMed1991

Angioplasty of long or tandem coronary artery lesions using a new longer balloon dilatation catheter: a comparative study.

To determine whether or not a new 3 cm long angioplasty balloon was more effective in treatment of long (15-25 mm) or tandem (less than 25 mm overall length) coronary lesions, 44 consecutive patients with suitable lesions were alternately assigned to treatment with shorter, standard, 2 cm length, or long, 3 cm balloons. Primary success of PTCA was achieved in 95%. Those treated with long balloons required fewer inflations (3.3 +/- 1.5 vs. 5.7 +/- 2.1, P = .0001) and showed fewer moderate or severe intimal dissections of the lesions (4/22 vs. 12/22, p = .028). The use of 3 cm PTCA balloons in long or tandem lesions appears to be efficacious and less likely to cause dissections than shorter, 2 cm length devices.

Angioplasty, Balloon, Coronary↗
PubMed1989

Color Doppler features of left ventricular pseudoaneurysm.

A patient had left ventricular pseudoaneurysm after mitral valve replacement surgery. The diagnosis was made by color flow Doppler demonstration of systolic flow between the left ventricular chamber and an echo-free space posterior to the heart which was initially interpreted as localized pleural effusion. Color Doppler features of this entity have not been previously described. Color flow cardiac Doppler enhances echocardiographic and pulsed Doppler diagnosis of left ventricular pseudoaneurysms.

Adult↗
PubMed1988

Left ventricular function after successful percutaneous transluminal coronary angioplasty for postinfarction angina pectoris.

The purpose of this study was to determine if coronary revascularization by balloon angioplasty (PTCA) in patients with postinfarction angina can elicit an improvement of global systolic left ventricular (LV) function. LV function was evaluated in 18 patients with postinfarction angina based on peak aortic blood acceleration measured noninvasively with a continuous wave Doppler velocimeter. Initial Doppler measurements were made 4 +/- 1 days after infarction and just before PTCA and were repeated 24 to 48 hours after PTCA. Patients were divided into 2 groups. Group I (n = 10) had successful PTCA (reperfusion). Group II (n = 8) either had an unsuccessful PTCA or did not undergo PTCA or thrombolytic therapy (no reperfusion). In group I patients, peak acceleration increased from 16 +/- 1 m/s/s just before PTCA to 24 +/- 2 m/s/s 24 to 48 hours after successful PTCA (p less than 0.001). In group II patients, peak acceleration was 17 +/- 2 m/s/s just before PTCA and remained relatively unchanged (18 +/- 2 m/s/s) 24 to 48 hours later. These data indicate that revascularization of coronary arteries in patients with postinfarction angina can elicit considerable improvement of global LV systolic function.

Adult↗
PubMed1988

Influence of coronary collaterals on left ventricular function in patients undergoing coronary angioplasty.

The purpose of this study was to determine the role of coronary collaterals on global left ventricular function during transient coronary occlusion. Left ventricular systolic function was evaluated noninvasively in 37 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) by means of peak aortic blood acceleration measured with a continuous-wave Doppler velocity meter placed suprasternally. Doppler measurements were made before, during, and immediately after balloon inflation. Nineteen patients underwent PTCA of the left anterior descending coronary artery, 15 of the right coronary artery, and three of the circumflex coronary artery. All patients had a subtotal coronary occlusion. Among the 37 patients 23 had no angiographic evidence of collaterals supplying the vessel undergoing PTCA and 14 had collaterals. In patients without collaterals peak acceleration was 16.0 +/- 3.0 m/sec/sec before balloon occlusion and decreased to 11.8 /+- 3.6 m/sec/sec within 30 to 40 seconds of coronary occlusion (p less than 0.001). After 30 to 40 seconds of reperfusion (balloon deflated), peak acceleration returned to near- preocclusion levels (17.3 +/- 7.5 m/sec/sec). Among patients with collaterals peak acceleration remained unchanged during balloon occlusion and reperfusion relative to preocclusion levels (NS). These data indicate that collaterals can preserve left ventricular function during transient coronary occlusion in humans.

Angioplasty, Balloon↗
PubMed1987

Eigenimage filtration of intravenous digital subtraction angiograms of the heart. Work in progress.

The authors developed a postprocessing technique, eigenimage filtering, to extract phase-dependent information from digital subtraction angiograms of the heart. This technique suppresses the interference from the right ventricle and left atrium and produces an image of the left ventricle and aorta that is substantially free of these overlap artifacts. The resultant eigenimages of the heart appear more like conventional ventriculograms than do digital subtraction angiograms and matched filtered images.

Cardiac Catheterization↗
PubMed1986

Relation of atherosclerosis to arterial wall shear in the left anterior descending coronary artery of man.

Low fluid dynamic shear acting on the vascular endothelium has been suggested as a factor in atherogenesis. This study describes qualitatively differences of wall shear rate in the left anterior descending coronary artery (LAD) of man and relates the distribution of wall shear to that of atheromatous plaques. Selective coronary arteriograms of 21 patients without obstructive LAD diseases were reviewed. Blood velocity, and therefore wall shear in the LAD, was assessed qualitatively based upon the rate of clearance of contrast material. There was a rapid clearing of contrast material along the outer wall of the LAD as it curved around the border of the heart. A much slower clearing occurred along the inner wall, bordering the myocardium, which persisted two to six cardiac cycles after the outer wall had cleared. This suggests that velocity, and therefore shear rate, is lower along the inner wall of the LAD than along the outer wall. In 27 patients who died of noncardiac disease, an uneven distribution of atheromatous plaques in the LAD was observed histologically, with greater involvement of the inner wall. These observations demonstrate an association between the lower shear rate along the inner wall of the LAD and the site of higher concentration of atherosclerosis.

Adult↗
PubMed1986

Noninvasive evaluation of left ventricular performance based on peak aortic blood acceleration measured with a continuous-wave Doppler velocity meter.

Peak aortic blood acceleration is recognized to be a sensitive index of global left ventricular performance. In the present study peak acceleration was assessed noninvasively in patients with a continuous-wave Doppler velocity meter. Peak aortic blood velocity and peak blood acceleration were measured by placing the ultrasonic transducer at the suprasternal notch. Measurements were obtained in 36 patients undergoing diagnostic cardiac catheterization. Peak velocity and acceleration were measured at rest just before left ventriculography. In patients with ejection fractions greater than 60%, peak acceleration was 19 +/- 5 m/sec/sec. In patients with ejection fractions of 41% to 60%, peak acceleration was lower, at 12 +/- 2 m/sec/sec (p less than .001). In patients with ejection fractions of 40% or less, peak acceleration (8 +/- 2 m/sec/sec) was markedly lower than in patients with ejection fractions greater than 60% (p less than .001). Peak acceleration showed a good linear correlation with ejection fraction (r = .90), and a better power fit (r = .93). These results indicate that peak acceleration, measured noninvasively with a continuous-wave Doppler velocity meter, is a useful indicator of global left ventricular performance.

Aorta↗
PubMed1985

Regional left ventricular systolic function in patients with segmental early relaxation and single-vessel coronary artery disease.

The purpose of this study was to determine whether systolic function is compromised in segments of the left ventricle that manifest early relaxation and are supplied by a diseased coronary artery. Regional fractional area of shortening (FAS) was evaluated from resting ventriculograms of 24 patients. Nine patients had no cardiac disease or segmental early relaxation (SER) and served as controls. Fifteen patients had single-vessel coronary artery disease (60% to 95% diameter stenosis of the left anterior descending coronary artery). Among these 15 patients, seven had no evidence of SER and eight had SER localized to the anterior wall. In patients with coronary disease and SER, and FAS of the anterolateral segment, 1.30 +/- 0.08, was greater than either controls, 1.07 +/- 0.12 (p less than 0.01) or patients with coronary disease but no SER, 1.03 +/- 0.19 (p less than 0.01). Among patients with coronary disease and SER, the FAS of the anterolateral segment was greater than the corresponding diaphragmatic segment (1.30 +/- 0.08 vs 0.97 +/- 0.12) (p less than 0.001). There was no difference in the FAS between these two segments in either controls or in patients with coronary disease, but without SER. These results indicate that SER of the anterior wall in patients with disease of the left anterior descending coronary artery is associated with enhanced systolic function of the anterolateral region. This observation is incompatible with the concept that ischemia is an underlying mechanism of SER.

Adult↗
PubMed1985

"Ischemia at a distance" during intermittent coronary artery occlusion: a coronary anatomic explanation.

The mechanism of electrocardiographic ST segment changes during acute coronary occlusion was evaluated in 28 consecutive patients with single vessel coronary artery disease undergoing coronary angioplasty. Patients were continuously monitored with a six lead electrocardiogram. Twenty-three patients showed ST changes in the primary zone of occlusion, and 13 of these had additional ST changes in a remote zone. Ten of these 13 had unusually extensive arteries supplying the remote zone. The balloon occluded two adjacent normal arteries in two patients, and no coronary anatomic explanation was evident in one patient. Ten patients with striking primary zone ST changes showed no remote change. Seven had nonextensive primary zone arteries, and three others had abundant collateral vessels. Five patients showed no electrocardiographic changes in primary or remote zones. Four had collateral vessels, and one had left ventricular hypertrophy on the baseline electrocardiogram. It was concluded that remote electrocardiographic changes are probably due to occlusion of unusually extensive coronary arteries and are not simply reciprocal.

Angioplasty, Balloon↗
PubMed1984

Blood velocity in the right coronary artery: relation to the distribution of atherosclerotic lesions.

Vascular endothelial injury by high shear stresses and adverse effects of low shear rates on mass transfer across the arterial wall have been suggested as factors in atherogenesis. This study describes differences in blood velocity, and therefore differences of shear rate, across the lumen of the right coronary artery (RCA) of man. Selective coronary arteriograms of 30 patients without obstructive RCA disease were reviewed. Velocity was assessed qualitatively based on the rate of clearance of contrast material. There was a rapid clearing of contrast material along the outer wall of the RCA as it curved around the border of the heart. A much slower clearing occurred along the inner wall, bordering the myocardium, which persisted 2 to 6 cardiac cycles after the outer wall had cleared. This suggests that velocity, and therefore shear rate, is much lower along the inner wall of the RCA. To determine the relation of the distribution of atherosclerotic plaques in the RCA to local blood velocity, the RCA in 17 randomly selected human subjects who died of noncardiac disease were studied histologically. There was an uneven distribution of atherosclerotic plaques in the RCA with greater involvement of the inner wall. These observations demonstrate an association between the lower shear rate along the inner wall of the RCA and the site of higher concentration of atherosclerosis.

Adult↗
PubMed1984

Regional left ventricular systolic function in patients with segmental early relaxation and normal coronary arteries.

The purpose of the study was to determine whether regional differences of left ventricular systolic function exist in patients with normal coronary arteries who manifest segmental early relaxation. The presence or absence of segmental early relaxation was determined angiographically in 16 patients with normal coronary arteries who underwent diagnostic cardiac catheterization because of chest pain. Seven patients had early relaxation localized to the left ventricular anterior wall and nine patients had no evidence of segmental early relaxation. Regional function was assessed from ventriculograms obtained in the right anterior oblique projection using the area method to calculate the regional fractional area of shortening. The fractional area of shortening of the anterolateral region was greater in patients with than in those without segmental early relaxation (69 +/- 4 versus 55 +/- 11%; p less than 0.01). In addition, in patients with segmental early relaxation, this variable exceeded the fractional area of shortening of the diaphragmatic region (69 +/- 4 versus 53 +/- 9%; p less than 0.01). There was no difference in the fractional area of shortening between these two regions in patients who did not manifest segmental early relaxation. These results suggest that regional differences in systolic function are present in patients with but not in those without segmental early relaxation. Augmented regional systolic function was observed in patients with segmental early relaxation and was limited to regions that manifested early relaxation.

Adult↗