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Biomedical subjects

R L Popp

Publications and source records attributed to R L Popp.

At least 127 records · Page 7Linked to original sources
PubMed1983

Reproducibility of left ventricular volumes by two-dimensional echocardiography.

Reproducibility may be as important as absolute accuracy in assessing the utility of an echocardiographic method of left ventricular volume estimation for epidemiologic or physiologic studies. The magnitude of differences between measurements in the same subjects from day to day must be defined before any quantitative technique can be used reliably to document "real" changes in heart volume over time. Two-dimensional echocardiograms were performed serveral days apart in 30 subjects, including 20 normal subjects and 10 patients with stable coronary heart disease. Analyses of light-pen tracings provided measurements of end-diastolic volume, endsystolic volume and derived ejection fraction on both days, and differences in individual subjects between days were quantitated. Beat to beat, interobserver and intraobserver variability also were assessed. Although group values changed little from day to day, individual volume changes were substantial in some cases. Confidence limits for individual measurements were derived from analyses of intrasubject variability and were as follows: end-diastolic volume +/- 15%, end-systolic volume +/- 25%, ejection fraction +/- 10%. Confidence limits in a larger group of subjects were narrower; in a group of 30 subjects, changes of greater than 2% in end-diastolic volume, 5% in end-systolic volume and 2% in ejection fraction most likely represent real change. Intraobserver variability was minimal, but interobserver and beat to beat variability were of sufficient magnitude to suggest that serial measurements on a given subject be made ideally by a single person and that several cycles be averaged for a given measurement.

Adult↗
PubMed1983

Two-dimensional echocardiographic assessment of bioprosthetic valve dysfunction and infective endocarditis.

Two-dimensional echocardiography of Hancock porcine heterograft valves was evaluated by correlation with clinical, hemodynamic, angiographic and pathologic findings in 80 patients. Ninety-five aortic and mitral bioprostheses were categorized by the type of valvular abnormality: group I, dysfunction due to primary tissue failure (41 valves); group II, dysfunction due to paravalvular leakage without infection (5 valves); group III, infective endocarditis with or without hemodynamic dysfunction (28 valves); and group IV, control cases without dysfunction or infection (21 valves). Increased size of a bioprosthetic leaflet image (minimal dimensions 3 x 5 mm) was observed in 46% (19 of 41) of cases with primary tissue failure and in 62% (10 of 16) of cases with leaflet vegetations due to endocarditis. Prolapse of leaflet echoes to below the level of the bioprosthetic sewing ring occurred in 76% (28 of 37) of cases with torn leaflets and also in 46% (6 of 13) of valves with vegetations on intact leaflets. Antegrade extension of leaflet echoes to beyond the level of the stents, observed in 4 of 16 cases with leaflet vegetations, was the only echocardiographic sign distinguishing leaflet infection from leaflet degeneration. Aortic bioprostheses with ring dehiscence affecting 40 to 90% of the anular circumference showed motion discordant with the motion of the adjacent aortic root and native anulus. Although echocardiographic abnormalities are frequently observed with bioprosthetic leaflet degeneration or infection, the echocardiographic appearance often does not distinguish between these two major complications and is best interpreted concurrently with other clinical and laboratory assessment.

Adolescent↗
PubMed1982

Mitral and aortic valve orifice area in normal subjects and in patients with congestive cardiomyopathy: determination by two dimensional echocardiography.

Previous determinations of normal valve orifice areas have been mainly from postmortem studies. In this study mitral and aortic valve orifice area were determined from two dimensional echocardiograms in 20 normal subjects and 20 patients with congestive cardiomyopathy. Mitral valve orifice area was larger than quoted in standard textbooks. Both mitral and aortic valve orifice area were reduced in patients with cardiomyopathy. Valve opening was assessed relative to left ventricular and aortic root size. The ratio of mitral valve orifice area to left ventricular cross-sectional area was markedly reduced in patients with cardiomyopathy compared with normal subjects. The ratio of aortic valve orifice area to aortic root size also was reduced in patients with cardiomyopathy. Anterior mitral leaflet E point-septal separation was similar to that in previous reports contrasting normal subjects with patients with myopathy. Among patients with cardiomyopathy, mitral E point-septal separation was primarily a function of left ventricular size and was not significantly correlated with fractional shortening or ejection fraction within this group having uniformly poor systolic function.

Adolescent↗
PubMed1982

Cardiovascular physiology in a case of heterotopic cardiac transplantation.

Successful heterotopic cardiac transplantation in a 24 year old man with end stage cardiomyopathy provided an opportunity to study cardiovascular physiology. The donor and native hearts, functioning independently in parallel, were studied by serial physical examination, electrocardiography, echocardiography, nuclear angiography and cardiac catheterization. Results indicated that the donor left heart assumed the predominant role in supplying systemic output, possibly contributing to decreasing function of the patient's own (native) heart. Analysis of serial nuclear angiograms revealed an initial postoperative ejection fraction of 52 and 21 percent in the donor and the native left ventricle, respectively; repeat studies 3 months postoperatively showed values of 50 and 9 percent, respectively, indicating significant deterioration in native left ventricular cardiac function. Observation of valve motion of the native heart showed major irregularities of the aortic valve in contrast to seemingly normal, regular mitral valve motion. These data rise interesting questions regarding interpretation of valve motion as an indicator of ventricular function.

Adult↗
PubMed1982

Aortitis in ankylosing spondylitis: early detection of aortic root abnormalities with two dimensional echocardiography.

Mild aortic root dilatation, cusp thickening and subvalvular fibrous ridges have been reported as characteristic in patients with ankylosing spondylitis and aortic regurgitation. Thirty-five patients with ankylosing spondylitis (10 also had Reiter's syndrome) without clinically apparent cardiac involvement were studied using phased array two dimensional and sector-directed M mode echocardiography to determine the prevalence of aortic abnormalities. Aortic root dimensions were measured at the aortic anulus, at the tip of the cusps and 0.5 to 1.5 cm above the cusps. The two dimensional echocardiographic study was also analyzed for qualitative abnormalities. The dimensions were compared with those in 20 normal men and among patient subgroups separated according to age, duration and severity of ankylosing spondylitis and presence of qualitative abnormalities. With one exception, no abnormally increased aortic dimensions suggestive of aortic dilatation were found in any group. However, two patients had aortic dimensions greater than 4.2 cm at the valve (normal 4.0 cm or less). Also, six patients had discrete areas of increased bright echoes below the left or noncoronary cusps suggestive of a subaortic "bump" and two of the six patients had increased aortic cusp echoes suggestive of thickening or fibrosis, or both. These changes tended to occur more commonly in older patients and those with more severe disease. It is concluded that aortic root changes suggestive of inflammation or fibrosis, or both, occur in asymptomatic patients with ankylosing spondylitis and are detectable on two dimensional echocardiography. Dilatation usually does not occur without aortic regurgitation.

Adult↗
PubMed1982

Relation of P-S4 interval to left ventricular end-diastolic pressure.

Reports have suggested that the interval between P wave onset and the fourth heart sound (P-S4 interval) reflects changes in left ventricular myocardial stiffness. We made simultaneous measurements of the P-S4 or atrial electrogram to S4 (A-S4) interval and left ventricular pressure in 19 patients with coronary artery disease who were studied before and after atrial pacing. Thirteen patients developed angina accompanied by significant rises in their end-diastolic pressure and a consistent decrease in P-S4 or A-S4 interval; whereas the six patients who had atrial pacing without the development of angina had no change in end-diastolic pressure, P-S4, or A-S4 interval. The resting data showed in inverse correlation between left ventricular end-diastolic pressure and the P-S4 interval. In addition, the P-S4 interval let us discriminate between patients with normal and abnormal end-diastolic pressure (greater than 15 mmHg).

Adult↗
PubMed1982

The cardiac effects of d- and l-disopyramide in normal subjects: a noninvasive study.

Commercially available disopyramide is a racemic mixture of equal parts of dextrorotatory (d-) and levorotatory (l-) optical isomers. We studied the cardiac effects of i.v. administration of each isomer and the racemic mixture (dl-) in six normal males by digitized echocardiography, systolic time intervals and ECG. Both isomers and the racemic mixture produced equally marked dose-dependent negative inotropic effects (28.1 +/- 11.8% mean maximal reduction in fractional shortening of left ventricular dimension) and diastolic effects (28.6 +/- 24.1% mean maximal reduction in peak left ventricular filling rate). However, only the d-isomer prolonged QTc duration (by 13.6 +/- 5.2% at maximum, p less than 0.001 vs l-isomer). We conclude that disopyramide, in the doses used, produces marked adverse effects on left ventricle systolic and diastolic function in normal subjects independent of optical rotation. The production of these effects by the l-isomer without affecting QTc duration suggests different subcellular mechanisms for the myocardial depressant effects and some of the electrophysiologic effects of disopyramide.

Adult↗
PubMed1982

Two-dimensional echocardiographic analysis of segmental left ventricular wall motion before and after coronary artery bypass surgery.

Twenty patients with coronary artery disease were studied with two-dimensional echocardiography the day before saphenous vein bypass graft surgery. Serial studies were obtained 7.4 +/- 2.5 (+/- SD) and 43.4 +/- 13.1 days postoperatively to qualitatively assess the effect of bypass surgery on regional wall motion. Changes in segmental wall motion were assessed semiquantitatively by assigning a segmental wall motion score to each of nine echocardiographically defined segments. Preoperatively, 18% of the segments moved abnormally. The mean overall segmental wall motion score did not change significantly, as shown by comparing the postoperative studies with the preoperative study. However, there was a significant worsening in the septal motion (apical and basal) and a significant improvement in posterior wall motion (apical and basal) after bypass surgery. Anterior and lateral wall motion were not significantly changed. Nonseptal segments that were normal preoperatively usually remained normal; abnormal nonseptal segments usually improved or were unchanged by surgery. The motion of septal segments, however, generally worsened postoperatively whether they were normal or abnormal preoperatively. We conclude that segmental wall motion assessed by two-dimensional echocardiography may improve after revascularization surgery, but the interventricular septum shows impaired motion. This effect of coronary artery bypass on wall motion is better demonstrated relatively late after operation than early in the postoperative course, as has been done in some previous studies.

Aged↗
PubMed1982

Optimal resources for ultrasonic examination of the heart. Echocardiography study group.

This paper provides guidelines for the optimal, rather than minimal, performance of ultrasonic examination of the heart for current clinical applications using conventional echocardiographic equipment. Since the original report of this Inter-Society Commission on Heart Disease Resources Committee in 1975, M-mode echocardiography has continued to be a valuable clinical tool, and two-dimensional echocardiography has been developed. Guidelines are presented for optimal physician and cardiac sonographer training, case loads, space and support systems, equipment design features and performance testing, and administrative considerations. The developing area of Doppler ultrasound and the competitive technologies are noted.

Cardiology↗