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Biomedical subjects

T Colman

Publications and source records attributed to T Colman.

At least 37 records · Page 2Linked to original sources
PubMed1991

Differences in response to single dose and steady-state therapy with verapamil in stable angina.

Ten patients with stable effort angina were studied in a randomized double-blind and placebo-controlled trial to compare the antianginal efficacy of "acute" and "chronic" (after reaching a steady-state level) treatment with verapamil. Efficacy was assessed by exercise testing after a 120 mg single-dose and at the end of a seven-dose course of 120 mg of verapamil given thrice daily. Three daily exercise tests were performed the first, second and fifth day of the study protocol at 8, 12 and 16 hours. Eight hours after the last dose was given, exercise time increased by 54 +/- 30 sec after a single-dose of verapamil and by 156 +/- 31 sec after seven-doses of verapamil (P less than 0.05 as compared to single-dose verapamil). The time to 1 mm depression of the ST segment increased by 30 +/- 20 sec after a single-dose of verapamil and by 66 +/- 28 sec after seven-doses of verapamil (P less than 0.01 as compared to single dose verapamil). Six of the ten patients became free from angina on treadmill exercise after a seven-dose course of verapamil, but only one patient became free from angina after acute testing with a single-dose of verapamil. It is concluded that several doses of verapamil are required to achieve an optimal anti-ischemic effect, as suggested by the pharmacodynamic properties of this drug. Once steady-state is achieved, the effects of verapamil remain for at least 8 hours, so that an administration schedule of three times daily protects the patient for a 24-hour period.

Administration, Oral↗
PubMed1990

[Factors affecting early graft patency after coronary grafts].

From June 1984 to December 1987, an early postoperative angiographic study was performed in 247 patients who underwent isolated coronary artery bypass surgery. The average age of these patients was 58.6 years, range 31 to 75 years. Preoperatively 50.8% of patients had myocardial infarction and 43.2% of them had unstable angina before surgery. Early coronary artery bypass angiogram was performed in 683 grafts (2.76 grafts per patient): 74 internal mammary artery grafts and 609 saphenous vein grafts. The distribution, location and type of the stenosis, distal coronary artery diameter, segmental myocardial contractility, and distal angiographic coronary filling are analyzed with a matching statistical method. Multivariate analysis showed significant predictors of early graft occlusion to be right coronary and circumflex artery, poor or non visible distal angiographic filling, coronary arteries smaller than 1.5 mm. The univariate analysis associates as risk factors hypokinetic or akinetic territories and multiple stenosis coronary arteries. It can be concluded that the early angiographic study demonstrate that coronary arteries with multiple stenosis, poor distal angiographic filling, smaller than 1.5 mm in diameter, coronary arteries perfusing hypokinetic or akinetic territories and the right coronary and left circumflex artery grafts have significantly lower early cumulative patency rates.

Adult↗
PubMed1989

Mitral valve rupture during percutaneous dilation of aortic valve stenosis.

A 62-year-old patient underwent catheter balloon valvuloplasty for aortic valve stenosis. During the procedure, iatrogenic severe mitral regurgitation was induced, requiring emergency surgery. At operation, extensive laceration of the septal mitral leaflet was found; chordae tendinae were intact. Retrospective examination of the cineangiogram revealed the presence of balloon indentation at the chordal level during inflation, which disappeared at full inflation. Mitral valve rupture was probably related to balloon entrapment in chordae tendinae, severe chordal stretching at inflation, and subsequent valve laceration. This severe complication or aortic valvuloplasty in adults has not been reported previously and probably could be avoided by careful observation of guidewire and balloon position before inflation.

Aortic Valve Insufficiency↗
PubMed1989

[Evaluation using serial exercise tests of verapamil alone and combined with isosorbide dinitrate in exertional angina].

The response to verapamil alone and combined with isosorbide dinitrate in a group of 12 patients with severe ischemic heart disease and stable effort angina was assessed by means of serial treadmill testing. The study was randomized, of a square latin design and double-blind. The tested drugs and dosages were 120 mg of verapamil, 120 mg of verapamil plus 20 mg of isosorbide dinitrate and placebo. Patients were serially tested (Bruce protocol) over three consecutive days at 8-9-12 and 16 hours. A significative improvement was observed in several ischemic parameters both with verapamil alone and combined with isosorbide dinitrate, but this improvement was remarkably enhanced with the combination of drugs. The mean exercise time to produce angina improved from 268 +/- 18 sec (basal) to 379 +/- 19 sec (verapamil plus isosorbide dinitrate) and the time for 1 mm ST segment depression from 163 +/- 22 sec (basal) to 257 +/- 19 sec (verapamil plus isosorbide dinitrate) when measured at the last daily test (8 hours after drug administration). It is concluded that both verapamil alone and combined with isosorbide dinitrate at the chosen doses are clinically efficient, significantly improving the ischemic parameters. The combination of verapamil and isosorbide dinitrate resulted in a remarkably better improvement in this group of patients with stable effort angina.

Adult↗
PubMed1988

An assessment of single doses of 8 mg sustained-release molsidomine using serial exercise tests.

The effectiveness and duration of the anti-anginal action of two sustained-release preparations, molsidomine (8 mg) and isosorbide dinitrate (20 mg), were assessed by means of serial exercise tests in 12 patients with angina of effort. The tests, which were limited by the symptoms, were carried out on three consecutive days using the Bruce protocol. Each patient was tested four times each day: the first test was performed before treatment and the others were carried out 1, 4 and 8 h after administration of the drug or placebo. One hour after administration of molsidomine, the appearance of signs of ischaemia in the ECG were considerably delayed and they were reduced in magnitude. Furthermore, the length of time during which the patients were free of angina increased. After 4 h both drugs significantly delayed the onset of angina and depression of the ST segment by 1 mm. The conclusion is that at the doses used both drugs prolong the length of time in which there is no angina, but that they have no significant effect at 8 h.

Aged↗
PubMed1983

Analysis of the amount of tricuspid valve anular dilatation required to produce functional tricuspid regurgitation.

To determine the critical anular dilatation required for functional tricuspid regurgitation (TR) and the role of systolic anular shortening in the severity of TR, 67 patients in whom right ventriculography had been performed were studied. These patients were classified into group I, control (n = 12), and the group II, patients with rheumatic valvular disease (n = 55). Group II patients were subclassified as follows: IIa, without TR (n = 19); IIb, with mild TR (n = 22); and IIc, with moderate to severe TR (n = 14). The angiographic maximal early systolic and minimal end-systolic diameters were measured. The shortening of the tricuspid anulus was expressed as percent reduction of the maximal diameter. The average maximal diameter (mm/m2) was: group I, 21 +/- 2; group IIa, 24 +/- 2; group IIb, 31 +/- 4; and group IIc, 37 +/- 4. The average minimal diameter (mm/m2) was: group I, 15 +/- 2; group IIa, 18 +/- 2; group IIb, 23 +/- 2; and group IIc, 31 +/- 3. The average percent shortening was: group I, 30 +/- 7%; group IIa, 25 +/- 7%; group IIb, 26 +/- 5%; and group IIc, 15 +/- 3%. The rheumatic patients had a larger maximal diameter than did those in the control group. Anular shortening was reduced only in the group with moderate to severe TR and preserved in the other groups, including those with mild TR. The critical diameter was determined to be between the maximal diameter in the rheumatic patients without TR and the minimal diameter in the patients with moderate to severe TR, or 27 mm/m2. Thus this easily measured parameter can determine the presence and significance of functional TR, adding objectivity to the angiographic diagnosis of TR.

Adolescent↗
PubMed1981

Right ventriculography as a valid method for the diagnosis of tricuspid insufficiency.

The value of right ventriculography in the diagnosis of tricuspid insufficiency (TI) is often questioned because of 1) the high incidence of premature ventricular contractions (PVCs) during injections and 2) interference of the catheter in the valve closure mechanism. In 168 patients a commercially available, not preshaped, balloon-tipped catheter was used for right ventriculography. To avoid the induction of PVCs, the catheter tip was placed in the middle third of the diafragmatic wall of the right ventricle, and the balloon was inflated, becoming trapped by the trabeculae. In this position the catheter's side holes should be located in the inflow chamber. To ensure this correct position, and therefore lack of ectopic beats during angiography, a saline test injection was performed previously in every case. With this technique the incidence of PVCs during ventriculography was only 7.7%. In all but one case, such beats were isolated. The 168 patients were divided into three groups according to their likelihood of experiencing tricuspid interference by the catheter: group 1 included 41 patients with a normal heart or with coronary artery disease. No one from this group had TI. Of group II, 28 patients with right ventricular pressure or volume overload or cardiomyopathy, only 2 had TI, both with a previous clinical diagnosis of regurgitation. Group III contained 99 patients with rheumatic heart disease. Thirty-five of them showed angiographic TI, and 24 of these had this diagnosis confirmed either clinically or at surgery. It is felt that this technique of right ventriculography, with its low incidence of PVCs and slight interference with tricuspid closure, is a valid method for the objective study of the tricuspid valve.

Adolescent↗
PubMed1981

Coronary arteriography and atrial thrombosis in mitral valve disease.

The arteriographic findings of neovascularity and fistula formation from the coronary arteries to the left atrium have occasionally been reported in association with atrial thrombosis in patients with mitral valve disease. To establish the diagnostic value of these findings, the preoperative coronary angiograms of 507 patients who underwent open mitral valve surgery were reviewed. Atrial thrombosis was present in 76 patients (14.9 percent). In the 30 patients with angiographic neovascularity and fistula formation, the thrombi were always observed to arise from the circumflex coronary artery. None of these 30 patients had atherosclerotic coronary lesions. In 25 of these patients an atrial thrombus was found at operation. These coronary arteriographic findings, in this selected group of patients, had a predictive accuracy of 83.3 percent, a specificity of 98.8 percent and a sensitivity of 32.8 percent for the diagnosis of the presence of thrombus in the left atrium. No relation was found between these signs and the size and histologic age of the thrombi examined.

Adult↗
PubMed1981

Open mitral commissurotomy.

We analyzed the results obtained in 163 consecutive patients with "pure" mitral stenosis who underwent operation by the open approach exclusively. Calcification was found in the mitral valve leaflets in 11% of the patients and left atrial thrombus, in 13.2%. A statistically significant relationship was discovered between history of previous systemic embolism and cardiac rhythm (p less than 0.005). The subvalvular apparatus was affected in 66.6% of patients; most of them were in New York Heart Association Functional Class III (p less than 0.005). The frequency with which annuloplasty had to be performed because of mitral insufficiency after commissurotomy was statistically higher (p less than 0.025) among patients in Functional Class III. Early mortality was 1.2% and late mortality, 0.2% per patient-year. Two patients required late reoperation (0.4% per patient-year). One was in Functional Class III and the other, Functional Class IV before the first operation. Three patients sustained a late systemic embolism (0.6% per patient-year). All survivors but 1 are in Functional Class I (84.4%) or II (14.9%).

Adolescent↗
PubMed1980

The surgical management of left atrial thrombosis.

A series of 122 consecutive patients with left atrial thrombosis is reviewed. Positive diagnosis was achieved in only 40 cases (36%) based on the angiographic findings and the presence of coronary fistula. The main cause of mortality and morbidity was cerebrovascular embolism. A change in our surgical technique, including the occlusion of the mitral orifice, has so far eliminated this problem.

Adult↗
PubMed1980

Hemodynamic factors that affect calculated orifice areas in the mitral hancock xenograft valve.

From June 1974 to December 1978, 714 Hancock valves have been placed in 605 patients. One hundred seventy-five patients with a mitral xenograft have been restudied. The results were questionable due to the wide scatter and disparity between the calculated and the theoretical orifice of each valve size. To elucidate these differences, the hemodynamic data of 40 isolated, normal functioning mitral Hancock valves were reviewed. Early, middle and late diastolic mitral valve gradients were measured by planimetry and their corresponding flows were estimated by angiography. The paired data were fitted to exponential functions and specific lines for each Hancock valve size were obtained. By superimposing Gorlin's pressure and flow curves on these lines, the instantaneous effective orifice for each Hancock valve can be determined. We concluded that 1) the Hancock valve effective orifice is flow related and always lower than its theoretical opening; 2) normal function frequently cannot be firmly established by the mean effective area; and 3) the nomogram described may help in determining the time-related variations of a particular valve.

Adult↗
PubMed1980

Is tricuspid valve repair necessary?

In an attempt to clarify the indications for tricuspid valve operations, we studied 150 patients who had preoperative and postoperative full catheterization including biventriculography. Seventy-eight patients had organic and 72 had functional tricuspid insufficiency (TI). One hundred nineteen underwent tricuspid repair (46 commissurotomies and 115 annulopasties), and in 31 the tricuspid disease was surgically ignored. Ninety seven percent of all patients with hemodynamically correct left-side repair were in Class I or II, regardless of the state of the tricuspid valve. Repair of lesions on the left side determined the postoperative cardiac index. In the "repaired group," 38% had residual gradients and 30% residual TI. Eighty percent of patients with low postoperative pulmonary resistance had no TI, compared with 53% with high pulmonary resistance. In the "ignored group," all 14 patients with organic disease had residual TI, as did nine of 17 with functional disease but with elevated pulmonary resistance. The right ventricular end-diastolic volume (RVEDV) decreased 37% in the "repaired" (p < 0.001) and 36% in the "ignored" group (p < 0.01) if tricuspid competence was achieved, but remained high if TI persisted. Because of these data, which emphasize the need for an early and correct repair of the left-side lesions, we believe that (1) functional TI can be ignored only in patients with predictable and significant reduction in pulmonary resistance and (2) organic disease must be repaired.

Adolescent↗