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Biomedical subjects

T B Tri

Publications and source records attributed to T B Tri.

13 recordsLinked to original sources
PubMed1984

Amiodarone-digoxin interaction. Clinical and experimental observations.

Twenty-two patients were given amiodarone for refractory cardiac arrhythmias, and pre- and post-amiodarone serum digoxin levels were studied. The interval between pre- and post-amiodarone serum digoxin levels ranged from five days to nine months (mean interval, seven weeks). The mean (+/- SD) pre-amiodarone serum digoxin level was 1.0 +/- 0.4 ng/ml, and the post-amiodarone serum digoxin level was 1.9 +/- 0.8 ng/ml (p less than .001). To develop an animal model for study of the digoxin-amiodarone interaction, 18 pigs were given digoxin for a four-week period. Half of the animals were given amiodarone as well as digoxin for the last two weeks of the study. At the end of the initial two-week period, there was no difference in serum digoxin levels between the two groups. At the end of the second two-week period, the serum digoxin level in the group receiving digoxin alone was 0.6 +/- 0.2 ng/ml, and the serum digoxin level in the group receiving the digoxin and amiodarone was 1.2 +/- 0.6 ng/ml (p less than .01). These data confirm the presence of an amiodarone-digoxin interaction in man and show that the pig is an appropriate model for study of this clinical phenomenon in the animal laboratory.

Adolescent↗
PubMed1981

Echocardiographic evaluation of the St. Jude medical prosthetic valve.

M-mode and two-dimensional echocardiographic studies were performed on 19 patients with 25 normally functioning St. Jude Medical prosthetic cardiac valves, in an attempt to define the normal echocardiographic appearance of this new cardiac prosthesis. Satisfactory M-mode echocardiograms were obtained in 17 of the 19 patients, and satisfactory two-dimensional studies were obtained in all. M-mode measurements included the diameter of the orifice ring, leaflet separation, and the opening and closing slopes of the leaflets. The values obtained compared favorably with direct measurements from the prosthesis and were reasonably reproducible. Two-dimensional imaging revealed characteristic systolic and diastolic patterns and provided direct visualization of valvular motion. Echocardiographic evaluation of the prosthesis can be facilitated if it is positioned at implantation so that the open leaflets are perpendicular to the echocardiographic plane of the long axis of the ventricle.

Adolescent↗
PubMed1981

Hemodynamic evaluation of the St. Jude Medical valve prosthesis in the small aortic anulus.

The hemodynamic function of the 19 mm and 21 mm St. Jude Medical valve prostheses in the aortic position was evaluated in seven patients who had valve replacement for either severe aortic stenosis or regurgitation an average of 4 months after operation. Cardiac output and simultaneous transvalvular gradient were recorded at rest and during moderate supine arm exercise. The average peak systolic gradient was 14 mm Hg (range 0 to 25 mm Hg) at rest and 32 mm Hg (range 23 to 56 mm Hg) with exercise. The average mean systolic gradient was 20 mm Hg (range 10 to 28 mm Hg) at rest and 38 mm Hg (range 30 to 48 mm Hg) with exercise. The mean effective orifice area was 1.2 cm2 (range 0.9 to 1.4 cm2) at rest and 1.1 cm2 (range of 0.9 to 1.3 cm2) with exercise. Mean cardiac output at rest was 4.4 L/min, and, with exercise, 7.4 L/min. Of the five valves evaluated with root aortography, four demonstrated trivial and one mild aortic insufficiency. We conclude that the St. Jude Medical valve prostheses in the aortic position has favorable hemodynamic function which is particularly evident in the 19 mm and 21 mm sizes when compared with other currently available aortic valve prostheses.

Adolescent↗
PubMed1981

Thrombosis of a St. Jude Medical tricuspid prosthesis. Case report.

Thrombosis of both valve leaflets of a St. Jude Medical tricuspid cardiac prosthesis, resulting in valvular dysfunction, was detected by systolic and diastolic tricuspid murmurs and confirmed by M-mode and two-dimensional echocardiograms. Thrombus formation at both hinge points of the bileaflet valve caused one leaflet to stick in the nearly closed position and the other to have severely impeded motion. Thrombotic involvement of both valve leaflets, not previously reported, occurred in a 17-year-old boy who has undergone six prosthetic cardiac valvular replacements in the past 2 years. Failure to achieve adequate anticoagulation in the early postoperative period appears to be related to the thrombosis in this case.

Adolescent↗