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Biomedical subjects

H S Wasir

Publications and source records attributed to H S Wasir.

At least 73 records · Page 4Linked to original sources

Thrombolytic therapy for prosthetic valve thrombosis: a study based on serial Doppler echocardiographic evaluation.

Sixteen patients with echocardiographic and cinefluoroscopic evidence of Björk-Shiley prosthetic valve obstruction (13 mitral valves and 3 aortic valves) were treated with intravenous streptokinase. Streptokinase was administered as an initial bolus of 250,000 units for 30 minutes, followed by an infusion of 100,000 units/hr. Serial cinefluoroscopy and echocardiography (M-mode, two-dimensional, and Doppler) were performed at 0, 24, 48, and 72 hours of treatment. The end point of treatment was defined as near normalization of clinical, echocardiographic, and fluoroscopic parameters. Successful thrombolysis was achieved in all patients. The average duration of streptokinase therapy was 43 hours (range 2 to 72 hours). Two of 16 patients had minor systemic embolism during therapy. Short-term follow-up has shown sustained benefit in 14 of 16 patients. Two patients have had rethrombosis of the mitral prosthetic valves and have undergone thrombectomy. Our study demonstrates the feasibility, safety, and efficacy of thrombolytic therapy in the treatment of prosthetic valve thrombosis. It also emphasizes the role of serial Doppler echocardiography in guiding the duration of therapy and assessing its efficacy.

Adult↗

A comparison of dobutamine infusion and exercise during radionuclide ventriculography in the evaluation of coronary arterial disease.

Twenty-six patients with "chest pain" syndrome were subjected to radionuclide ventriculography during exercise and dobutamine infusion. All 10 patients with normal coronaries were identified correctly by normal ventriculographic responses to both tests. Of 16 patients with significant coronary arterial disease, dobutamine stress identified 15 patients correctly, whereas only 12 of these had an abnormal exercise response. Three patients with one-vessel disease with a normal exercise response had an abnormal dobutamine stress response. Dobutamine radionuclide stress testing is an acceptable alternative to exercise testing in patients who cannot exercise and its incremental diagnostic yield in patients with one-vessel disease requires further evaluation.

Coronary Disease↗

Fish oil supplements for prevention of restenosis after coronary angioplasty.

We have evaluated the effect of fish oil supplementation in the prevention of restenosis after percutaneous transluminal coronary angioplasty by a randomised trial conducted in 107 patients. The treatment group (n = 58, 96 significant coronary narrowings) received 10 capsules of fish oil (1.8 g eicosapentaenoic acid, 1.2 g docosahexaenoic acid) besides aspirin and calcium blockers, beginning 4.3 (SD 2.9) days before coronary angioplasty. The conventional medical treatment group (n = 49, 81 significant coronary narrowings) received only aspirin and calcium blockers. Enrollment required the presence of angina pectoris and successful dilatation of all significant coronary narrowings. All patients were followed-up for at least 6 months. Restenosis was identified by symptoms and exercise testing and confirmed by angiography. The incidence of angiographic restenosis was 32% in the fish oil group and 27% in the conventional treatment group. Biochemical investigations showed a greater decrease in serum triglyceride levels in fish oil group as compared to the conventional treatment group. There was no significant difference in the cholesterol levels over the treatment period. Administration of fish oil in a dose of 3 g per day did not reduce the incidence of early restenosis after coronary angioplasty.

Angioplasty, Balloon, Coronary↗

Myopotential inhibition of unipolar demand pacemakers: utility of provocative manoeuvres in assessment and management.

Fifty patients with permanent unipolar pacemakers (48 multiprogrammable, 2 non programmable) with protective insulating sheath placed against the muscular side of the pacemaker pocket were studied to determine the occurrence of inhibition of pacing by sensing of the myopotentials. All the patients were subjected to a combination of different provocative manoeuvres at their nominal R wave sensitivity settings. Myopotential inhibition was exhibited in 35 (70%) patients. Only 3 patients however had reported symptoms suggesting loss of pacing. The most useful provocative manoeuvre was shoulder flexion with adduction against resistance (94.3% positivity). Appropriate sensitivity adjustments resulted in amelioration of the problem in 86% of the patients while still retaining R wave sensing. Myopotential interference continues to be a frequently observed problem even in the present generation of unipolar pacemakers. Provocative tests and appropriate reprogramming should be done in all such patients as a routine.

Action Potentials↗

Significance of ventricular late potentials in patients with myocardial infarction.

Fifty six patients (52 males, 4 females, mean age 53.6 +/- 8 years, range 35-75 years) were studied to determine the influence of clinical variables, site of myocardial infarction, thrombolytic therapy, documented arrhythmias and left ventricular ejection fraction (LVEF) on the incidence of ventricular late potentials (LP's). LP's were detected in 17 (30.3%) patients; in 6 (26%) patients with acute and in 11 (33.3%) patients with old healed myocardial infarction. 87.5% of the patients in whom LPs were detected had low LVEF. The presence of low LVEF correlated significantly with the presence of LP's (p = .02). LP's were also present in all patients with documented sustained ventricular tachycardia. Clinical variables (Killip and NYHA class), site of myocardial infarction, Q wave versus non-Q wave myocardial infarction and thrombolytic therapy did not relate to the presence of LP's (p > 0.5) Patients of myocardial infarction with low LVEF and a history of ventricular tachyarrhythmias should undergo signal averaged electrocardiography for LP detection. LP presence would identify patients at higher risk of future arrhythmic events within this subgroup.

Adult↗

Cardiac involvement in nonspecific aortoarteritis (Takayasu's arteritis).

Fifty-four patients (18 males and 36 females, ages 2 to 37 years) with nonspecific aortoarteritis (NSAA) were studied. Evaluation revealed hypertension in 35, congestive heart failure (CHF) in 24, mild to moderate mitral regurgitation in six, and mild aortic regurgitation in two. Erythrocyte sedimentation rate was raised (greater than 35 mm in the first hour) in 38 patients. The arterial lesions included type I in seven, type II in eight, and type III in 34. Pulmonary artery involvement was present in 4 (type IV) of the 20 patients in whom it was studied. Selective coronary angiography was done in 11 patients and revealed 90% left main stenosis in one patient. Hemodynamic data revealed raised (greater than 7 mm Hg) mean right atrial pressure in nine, raised mean pulmonary artery pressure (greater than 20 mm Hg) in 29, and raised left ventricular filling pressure (greater than 12 mm Hg) in 27 patients. Radionuclide ventriculography revealed reduced (less than 45%) left ventricular ejection fraction (LVEF) in 27 patients. The myocardial morphology as evaluated on right ventricular endomyocardial biopsy revealed normal histology in nine, features of inflammatory myocarditis in 24, and nonspecific changes suggestive of dilated cardiomyopathy in six patients. Marked right ventricular endocardial thickening was present in three. All patients with CHF had some histologic abnormality. We emphasize that myocardial involvement including myocarditis is common in NSAA and may precipitate CHF in these patients.

Adolescent↗

Profile of coronary arterial disease in diabetic patients undergoing coronary arterial bypass grafting.

Diabetics are believed to have more extensive and diffuse lesions of the coronary arteries in presence of coronary arterial disease. We studied prospectively 52 diabetics with coronary arterial disease who underwent coronary arterial bypass grafting and evaluated their pre-operative symptomatology, angiographic appearance of coronary arteries, coronary arterial dimensions as assessed at surgery, and the post-operative complications. These were compared to 52 age and sex matched non-diabetic controls undergoing surgery during the same period. There was no statistically significant difference in the incidence of pre-operative symptomatology or frequency of myocardial infarction in the two groups. Left ventricular angiographic findings were also comparable, as was the observation on the extent and severity of coronary arterial disease as assessed by angiography and at surgery. Hence, we recommend coronary arterial bypass grafting to diabetics with the same criteria as are applied to non-diabetics, confident that there will be no added morbidity and mortality.

Adult↗

Silent myocardial ischemia after percutaneous transluminal coronary angioplasty and its prognostic significance.

A cohort of 175 patients who underwent successful percutaneous transluminal coronary angioplasty (PTCA) were subjected to a treadmill exercise test to determine the prognostic significance of silent and symptomatic myocardial ischemia during the follow-up (average 11.7 months). The cardiac events during the follow-up were defined as cardiac death, nonfatal myocardial infarction, class III angina, and need for repeat angioplasty or coronary artery bypass surgery. During exercise, 39 patients (22%) had abnormal exercise-induced ST depression without chest pain (Group I). A group of 22 patients (13%) had both exercise-induced chest pain and ST-segment depression (Group II), and 114 patients (65%) had normal exercise test and no chest pain (Group III). The groups were similar in sex distribution, history of previous myocardial infarction, distribution of vessel disease, and presence of left ventricular dysfunction. Group III included more patients with complete revascularization. Follow-up data revealed that cardiac event rates in Groups I and II were significantly higher than in Group III (41%, 41%, vs. 16%) (p less than 0.01). The event rates in Groups I and II with multivessel angioplasty also were significantly higher than in Group III (58%, 61%, vs. 21%) (p less than 0.01). Exercise-induced silent myocardial ischemia is frequently seen early after successful PTCA and is more prevalent in patients undergoing multivessel angioplasty and incomplete revascularization. Both silent and symptomatic ischemia early after PTCA are predictors of an unfavorable prognosis.

Angioplasty, Balloon, Coronary↗

Value of analysis of the evolution of the pattern of the ST segment in exercise electrocardiograms.

We analysed retrospectively the exercise electrocardiogram records of all patients with positive exercise tests which, on subsequent coronary angiography, proved to be "false positives". The exercise records of 10 "false positive" patients were compared with the records of 10 patients with true positive tests in the setting of single vessel disease and 20 patients with true positive tests and multivessel disease. Patients proving to be false positives did not differ from those with true positive tests in respect to either the slope of the ST segment, the number and site of leads showing shift of the ST segment, or the peak exercise double product. The total duration of exercise, however, was significantly longer in patients having false positive tests (7.93 minutes SD 1.34) as compared to true positive results (5.95 minutes SD 1.9 in single vessel disease, and 4.4 minutes SD 2.2 in multivessel disease, P = less than 0.05). Eight of 10 patients having a false positive test showed an atypical evolution of the pattern of the ST segment. Seven had rapid normalization of depression of the ST segment immediately after cessation of exercise, while one showed shift of the ST segment only during the period of recovery. In contrast, 28 of 30 patients with true positive tests showed gradual normalization of the depressed ST segment during the period of recovery. We conclude that shifts in the ST segment that normalize rapidly on cessation of exercise are frequently a false positive finding.

Adult↗

Quantitative grading of exercise stress test for patients with coronary artery disease using multivariate discriminant analysis.

A group of 111 male patients who had undergone maximal or symptom-limited maximal exercise stress testing for evaluation of coronary artery disease (CAD) were subjected to coronary angiography. Group I comprised 33 patients with normal or single-vessel disease (SVD), while 78 patients with double-vessel disease (DVD) or triple-vessel disease (TVD) formed Group II. On univariate analysis of the exercise test, the following variables were found to be of significance in discriminating between the two groups: age, exercise duration, double product (heart rate X systolic blood pressure) at peak exercise, duration of ST-segment depression, number of leads showing ST depression, ST depression of 1 mm or more, configuration of the depressed ST segment, and diastolic blood pressure response to exercise. Multivariate analysis however revealed that only the following five variables had significant discriminant power: number of leads showing ST depression, exercise duration, double product, diastolic pressure response, and ST-segment configuration. On the basis of their relative importance, a regression equation was developed to give a quantitative score to individual patients. A score of less than zero detected multivessel disease (MVD) with high specificity (94%) and sensitivity (70%), while a score of 15 or more almost excluded MVD (sensitivity 87%). The scoring system as reported here improved the exercise stress test interpretation when compared with the conventional reporting system.

Adult↗

Association of coronary calcification with obstructive disease in coronary arteries in Indian patients.

A total of 1150 consecutive patients (1052 males and 98 females; age 51.2 +/- 10.1 years) with suspected coronary artery disease (Group I) were subjected to fluoroscopy for detection of coronary artery calcification (CAC) and coronary angiography. Another group (Group II) of 120 patients (95 males and 25 females; age 51.4 +/- 9.4 years) catheterized for cardiac diseases other than coronary artery disease (CAD) were subjected to the same protocol of fluoroscopy and coronary angiography to exclude incidental CAD in view of their age. CAC was present in 240 patients (20.0%) in Group I. Of these, 200 (83.4%) had triple-vessel disease (TVD); 20 (8.3%) had double-vessel disease (DVD); 19 (7.9%) had single-vessel disease (SVD); and 37 (15.4%) patients had left main coronary disease (LMCAD). Only one of these patients had insignificant CAD considered as "normal" coronary arteries (NC). Incidence of LMCAD, TVD, DVD, SVD, and NC in patients without CAC was 4.4%, 56.3%, 18.2%, 14.0%, and 11.5%, respectively. Incidence of CAC in patients with LMCAD, TVD, DVD, SVD, and NC was 48.1%, 28.1%, 10.8%, 13.0%, and 1.0% respectively. In Group II (n = 120), 24 patients (20%) had CAD, CAC was present in 5 patients with CAD (20.9%), and in two patients without CAD (2%). CAC is relatively uncommon in Indian CAD patients. Its presence, however, indicates severe multivessel disease.

Adult↗