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Biomedical subjects

W L Winters

Publications and source records attributed to W L Winters.

At least 55 records · Page 3Linked to original sources
PubMed1983

Detection of coronary artery disease with exercise two-dimensional echocardiography. Description of a clinically applicable method and comparison with radionuclide ventriculography.

Two-dimensional echocardiography (2-D echo) was performed in 73 patients evaluated for coronary artery disease (CAD) and in four normal volunteers before and immediately after a maximal treadmill exercise test. Diagnostic images were obtained from the apical and parasternal windows. In 17 patients with normal coronary arteriograms, ejection fraction (EF) increased from 66 +/- 9% (+/- SD) at rest to 73 +/- 8% after exercise (p less than 0.001), while in 56 patients with proved CAD, EF fell from 56 +/- 13% at rest to 53 +/- 16% after exercise (p less than 0.01). The sensitivity of postexercise 2-D echo for detecting CAD (based on abnormal EF response and/or regional dyssynergy) was 91% (51 of 56 patients) and the specificity was 88% (15 of 17). Sensitivity for one-, two- and three-vessel disease was 64% (seven of 11), 95% (20 of 21) and 100%, respectively. Patients with multivessel disease showed a significant fall in a wall motion score index, from 0.79 +/- 0.25 to 0.63 +/- 0.26. Exercise radionuclide ventriculography (RNV) was also performed in 41 of the subjects (17 normals and 24 CAD patients) on a bicycle ergometer. The overall sensitivity of 2-D echo in this subgroup was 92%, compared with 71% for RNV. The sensitivity of 2-D echo for one-vessel disease (n = 4) was 50%, that for two-vessel disease (n = 12) was 100% and that for three-vessel disease (n = 12) was 100%. Respective values for RNV were 0%, 80% and 90%. The specificity of 2-D echo was 88% and that of RNV was 82%. A significantly higher peak heart rate response was observed on the treadmill than on the bicycle ergometer in both CAD patients and normal subjects. We conclude that postexercise 2-D echo is a clinically applicable technique for the diagnosis and evaluation of CAD patients and compares favorably with exercise RNV.

Adult↗
PubMed1981

A new, simplified and accurate method for determining ejection fraction with two-dimensional echocardiography.

A new method to determine left ventricular (LV) ejection fraction (EF) with wide-angle, two-dimensional echocardiography (2-D echo) has been developed using the parasternal long-axis, apical four-chamber and apical long-axis views. End-diastolic and end-systolic measurements of LV short axes at the base and mid-LV cavity in the parasternal long-axis view and at the upper, middle and lower thirds of the cavity in the apical views are made, from which an averaged minor axis at end-diastolic and at end-systole is calculated. Fractional shortening of the LV long axis (delta L) is estimated from apical contraction. Satisfactory 2-D echoes were obtained in 55 of 58 nonselected patients (all three views in 32 patients, two views in 22 and one view in one); 42 of 55 patients had coronary artery disease. EF by 2-D echo was compared with EF by gated cardiac blood pool imaging in all patients (r = 0.927, SEE = 6.7%) and to EF by single-plane cineangiography (angio) in 35 of 55 patients (r = 0.913, SEE = 7.4%). LV dyssynergy was frequently present and involved the apex in 29 of 55 patients. Using angio as the standard for evaluating wall motion at the apex, 2-D echo was 100% sensitive and specific in detecting abnormal apical wall motion. We conclude that EF can be determined accurately with 2-D echo in a large group of patients with and without dyssynergy by a simple method that eliminates the need for planimetry or computer assistance.

Adult↗
PubMed1980

Echo-phonocardiographic evaluation of obstruction of prosthetic mitral valve.

Echo-phonocardiograms of 64 patients with multiple types of prosthetic mitral valves (PMV) were evaluated. Six patients demonstrated findings suggesting valve obstruction: four had surgical confirmation of prosthetic obstruction, one reduced cardiac output and pulmonary hypertension but no prosthetic dysfunction at surgery, and one is asymptomatic. Three of four patients with confirmed obstruction had variable second sound to opening click intervals (A2-MO) with interrupted disc opening; two had interrupted disc closure with split closing clicks and three of four had reduced diastolic closure rate. In 58 clinically well patients with PMV, cycle-to-cycle A2-MO varied little: 0-10 msec in sinus rhythm and 10-25 msec in atrial fibrillation. Diastolic closure rates of five different types of PMV were similar: 21.6 mm/sec, (range 14-49). No patient had interrupted opening, closing or multiple closing clicks. Thus, delayed PMV opening or closure, altered A2-MO interval and double closing clicks are highly useful in detecting patients with obstruction of a variety of mitral prostheses.

Adolescent↗
PubMed1977

Patterns of patency of 596 vein grafts up to seven years after aorta-coronary bypass.

The long-term behavior of vein grafts and their effect on the native circulation were studied by examining 596 vein grafts in 343 patients at a mean follow-up of 15.4 months, range zero to 84 months. Serial studies were performed on 27 patients with 38 grafts. The over-all graft patency rate was 84 per cent, and the rate after more than 5 years was 89 per cent. The patency rate in asymptomatic patients was 91 per cent compared with 81 per cent in the remainder. The patency of grafts attached distal to total occlusions was 82 per cent (78/82). The angle of origin of the grafts from the aorta did not appear to influence patency or the severity of intimal proliferative changes. In 76 patients with 126 grafts, pre- and postoperative cineangiograms were compared, and changes in the graft and underlying coronary artery classified as Groups 1 to to 6: Group 1, patent graft, bidirectional flow in the grafted vessel, proximal lesion unchanged; Group 2, patent graft, bidirectional flow, proximal lesion progressed to occlusion locally; Group 3; patent graft, distal flow only, occlusion of lesion and segment between graft and lesion; Group 4, graft occluded, native artery unaltered; Group 5, graft occluded, native artery now occluded at lesion and region of anastomosis; Group 6, new distal lesion. Results were as follows; Group 1, 58 per cent; Group 2, 21.2 per cent; Group 3, 5 per cent, Group 4, 12.5 per cent; Group 5, 2.5 per cent; and Group 6, 0.8 per cent. Native coronary arteries undergoing closure (Group 2) had lesions 95 per cent or greater in 93 per cent of patients. The rate of closure of ungrafted lesions was 2 per cent. We believe these results encourage the continued used of vein bypass grafts.

Coronary Artery Bypass↗
PubMed1976

Aortocoronary saphenous vein autograft accidentally attached to a coronary vein: follow-up angiography and surgical correction of the resultant arteriovenous fistula.

The fate of aortocoronary saphenous vein bypass graft to the left anterior descending (LAD) coronary vein is reported. The vein graft communicated with the coronary sinus through the proximal LAD vein, producing a functional coronary arteriovenous fistula. The LAD vein was totally occluded distally at follow-up four months after operation. The natural history of congenital fistulas between coronary arteries and the coronary sinus suggested that bacterial endocarditis, pulmonary hypertension, and cardiac failure were all possible future complications in this patient. Operation was performed to revascularize the LAD artery to relieve persistent angina, and to close the fistula. Postoperative angiography showed a patent graft to the LAD artery with complete obliteration of the fistula. The patient is asymptomatic ten months after operation.

Adult↗