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Biomedical subjects

M L Bhatia

Publications and source records attributed to M L Bhatia.

At least 37 records · Page 2Linked to original sources
PubMed1989

Clinical significance of high frequency QRS potentials in myocardial infarction: analysis based on power spectrum of lead III.

Power spectrum analysis of ECG lead III QRS potentials using the Fast Fourier Transform technique was performed in 10 normal subjects and nine patients with inferior wall myocardial infarction (IWMI). A relative lowering in both low and high frequency QRS potentials was observed in the infarct group, in agreement with previous studies on power spectrum of lead II. However, contrary to earlier conclusions, the lowering was independent of a general attenuation in QRS voltages. Discriminant analysis of the frequency components showed that the high frequency components (190-310 Hz) were able to discriminate better between the two groups than the low frequency components (10-120 Hz).

Action Potentials↗
PubMed1989

HLA-DR/DQ antigens and reactivity to B cell alloantigen D8/17 in Indian patients with rheumatic heart disease.

D8/17, a B cell alloantigen, and its occurrence with DR/DQ antigens was examined in 54 patients with rheumatic heart disease and matched North Indian controls. Thirty-four patients (62.9%) carried D8/17 as compared with a frequency of 12.5% in controls (chi 2 by Yates', 18.75; p less than 0.0001). A marginally increased frequency of human leukocyte antigen (HLA)-DR3 (44.2% vs. 28.8%) and a significantly reduced frequency of HLA-DR2 (21.1% vs. 46.6%; p less than 0.005) was observed in patients as compared with controls. However, the most significant positive association was observed with HLA-DQw2 (63.4% in patients and 31.5% in controls; chi 2 by Yates', 9.85; p less than 0.005). The DQw2 association was significant only in the D8/17-positive patients. These observations suggest that the disease susceptibility gene in rheumatic heart disease may be nearer to the HLA-DQ locus than to the HLA-DR.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1989

Experience with activity sensing rate responsive ventricular pacing. A study based upon assessment of exercise tolerance.

Fourteen patients (mean age 41 years) who received rate responsive activity sensing VVI pacemakers were studied to evaluate the relationship between the rate response and exercise tolerance by analysing the symptom limited maximum treadmill time both during fixed rate VVI oacubg abd dyrubg VVI + activity mode pacing (RRP). The proper functioning of RRP mode was confirmed by Holter monitoring in all. The indications for pacing were, sino-atrial block with high grade AV block, tachybrady syndrome, atrial fibrillation with complete heart block, congenital complete heart block and persistent slow junctional rhythm. Basic rate was programmed to 70 PPM in both pacing modes; rate response and activity threshold were programmed to 5 and medium respectively. The order in which two pacing modes were tested was chosen randomly. The maximum treadmill time (MTT) was 25.4% longer in the RRP than in VVI mode with a mean of 11.4 minutes in RRP and 8.5 mins in VVI(p less than 0.01). for the subgroup of patients who demonstrated paced only rhythm the average increase in MTT was 31.4% with a mean of 11.8 minutes in RRP and 8.1 mins in VVI (p less than 0.01). Five patients who showed intermittent spontaneous rhythm, increased their average MTT by 22.3% with a mean of 11.2 minutes in RRP and 8.7 mins in VVI mode (p less than 0.05). During RRP a significance positive correlationship was seen between MTT and the increase in heart rate (N = 14, r = 0.85, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

Surgical experience with intracardiac myxomas.

Eighteen patients underwent surgery for intracardiac myxoma (16 left atrial and 2 right atrial) during the last 10 years. Seventeen patients had tumour stalk attached to the oval fossa. The myxoma was excised along with a cuff of the atrial septum, which was reconstructed using a Dacron patch in 15 patients and by direct suture in 2 patients. In the remaining case the myxoma was attached to the left atrial wall and adjacent atrioventricular junction. There was only one early death in a patient who underwent a concomitant lobectomy for lung abscess and one late death due to a noncardiac cause. During the follow-up period of 3-96 months (average 36 months) all the survivors were in New York Heart Association Class I. Scanning electron microscopy of tumour tissue was done in 8 cases. The morphological findings did not help in categorizing the tumours into any pathological subgroups. Postoperative cardiac catheterization done in 3 patients (30-50 months postoperatively) showed return of haemodynamics to normal. Echocardiographic studies done postoperatively have not revealed recurrence of tumour in any patient. Surgical excision of myxomas is possible with very gratifying long-term results.

Adolescent↗
PubMed1988

Myocardial involvement and its response to immunosuppressive therapy in nonspecific aortoarteritis (Takayasu's disease)--a study by endomyocardial biopsy.

Myocardial involvement in nonspecific aortoarteritis was evaluated in 16 patients (age 7-37 years, 2 males, 14 females) with the help of endomyocardial biopsy obtained from the right ventricle using the Cordis bioptome introduced from the right femoral vein. Morphological features of myocarditis were present in 8, endocardial thickening in 2, mild to moderate myofibre hypertrophy in 11, and a normal biopsy in 3 patients. Myocarditis was present in 8/11 cases with active disease and in none with inactive disease. Five of the 8 patients with myocarditis presented with congestive cardiac failure with 3 of them having no associated hypertension or valvar involvement to account for it. Immunosuppressive therapy was given to all patients with myocarditis. Serial studies (ongoing) showed clinical, haemodynamic and morphological improvement. Myocarditis appears to occur commonly in nonspecific aortoarteritis during the acute phase of the disease and may precipitate congestive cardiac failure in some patients. Immunosuppressive therapy shows promise and merits further evaluation.

Adolescent↗
PubMed1988

Spatial quantitative vectorcardiography in aortic stenosis: correlation with hemodynamic findings.

Thirty-four patients with hemodynamically documented valvar aortic stenosis without congestive heart failure were studied by the corrected Frank lead system vectorcardiography, with special emphasis on the angular characteristics of spatial R max to define the severity of the lesion. Spatial QRS-T angle demonstrated a highly significant correlation with the peak left ventricular systolic pressure (r = 0.72, P less than 0.001) and a significant correlation with peak transvalvar aortic gradient (r = 0.49, P less than 0.01). Furthermore, all patients with a QRS-T angle of more than 90 degrees had significant aortic stenosis (TVG greater than or equal to 50 mm Hg). The peak left ventricular systolic pressure and transvalvar aortic gradient also demonstrated a significant negative correlation with azimuth angle (r = -0.36 and -0.34, respectively; P less than 0.05) and a positive correlation with spatial R max magnitude (r = 0.38 and 0.41, respectively; P less than 0.05). There was no correlation between elevation angle of spatial R max and left ventricle systolic pressure or transvalvar aortic gradient. Our study indicates that spatial quantitative vectorcardiographic angular characteristics, particularly spatial QRS-T angle, may be a useful adjunct to other noninvasive techniques to assess the severity of valvar aortic stenosis.

Adolescent↗
PubMed1988

Doppler echocardiographic evaluation of normal and thrombosed Björk-Shiley mitral prosthetic valves.

Doppler echocardiographic characteristics of 75 normally functioning Björk-Shiley mitral prostheses were studied in patients whose valvar function was considered normal by clinical and fluoroscopic evaluation. The mean Doppler peak and end-diastolic gradients were 9.01 +/- 3.23 mm Hg, and 2.36 +/- 1.0 mm Hg, respectively. The mean area of the mitral valve calculated by the half-time method was 2.58 +/- 0.38 cm2. No significant difference between the various Doppler parameters was found for the two different valve sizes (25 and 27 mm) studied. Trivial mitral regurgitation was detected in 21 (28%) cases. Doppler echocardiography was performed in six patients with suspected malfunction of the Björk-Shiley mitral prosthesis subsequently confirmed at operation. The end-diastolic gradients in the six patients were 16, 20, 10, 14, 16, and 24 mm Hg, respectively. The calculated areas of the mitral valve were 1.57, 1.37, 1.3, 1.5, 1.46, and 1.3 cm2, respectively. The values of the gradient and calculated areas in malfunctioning valves were very different from those found in normally functioning Björk-Shiley mitral prostheses. It is concluded that Doppler echocardiography is a very useful noninvasive technique for the study of the function of the Björk-Shiley mitral prosthesis and provides quantitative information regarding pressure gradients and valvar area.

Adult↗
PubMed1988

Immunohistochemical characterisation of Aschoff nodules and endomyocardial inflammatory infiltrates in left atrial appendages from patients with chronic rheumatic heart disease.

Fifty left atrial appendages collected fresh during closed mitral valvotomy in patients with chronic rheumatic heart disease, were analysed to determine the frequency of Aschoff nodules and characteristics of mononuclear inflammatory infiltration. Fifty-six percent of specimens demonstrated Aschoff nodules with no clinical or laboratory evidence of acute rheumatic activity in the patients undergoing surgery. Endomyocardial infiltration contained predominantly T cells and occasionally B cells. The relative proportions of T helper-inducer, T suppressor-cytotoxic lymphocytes and macrophages were 45.1 +/- 7.6, 23.5 +/- 4.8 and 29.3 +/- 9.6%, respectively. Frequent presence of Aschoff nodules and heavy mononuclear infiltrates in chronic rheumatic heart disease suggests a possibility of subclinical ongoing carditis.

Adolescent↗
PubMed1988

Sudden bradyarrhythmic death in dilated cardiomyopathy: a case report.

An 18-year-old male presented with biventricular failure and atrial fibrillation. Detailed investigations revealed the diagnosis of dilated cardiomyopathy. He was put on medical treatment which resulted in symptomatic improvement. One year later he presented with 2 episodes of syncope, with no change in the routine electrocardiogram. A 24-hour ambulatory monitoring was done. The patient died suddenly while on the monitor. Analysis of the terminal event revealed a sudden complete heart block followed by asystole, an event described very rarely in the published literature.

Adolescent↗
PubMed1988

Evaluation of patients with bundle branch block and "unexplained" syncope: a study based on comprehensive electrophysiologic testing and ajmaline stress.

Thirty-five patients with bundle branch block (BBB) and unexplained syncope underwent electrophysiologic study (EPS) including programmed ventricular stimulation and ajmaline administration (1 mg/kg, IV) to induce infra-His block. A prolonged HV interval (greater than 55 ms) was present in 16 of the 35 patients. Ajmaline-induced HV block occurred in 12 patients (complete HV block in 10, and 2:1 HV block in two). Monomorphic ventricular tachycardia (VT) was inducible in nine (25.7%) and polymorphic VT in two patients (5.7%). Left ventricular ejection fraction (LVEF) was less than 40% in five patients (45.5%) with inducible VT. Two patients had an unexpected co-existence of inducible HV block and VT. The remaining 14 patients (40%) had no detectable abnormality. The incidence of inducible VT was higher (45% vs 13.3%), and the presence of negative studies was lower (30% vs 53.3%) in patients with structural heart disease (n = 20), when compared to those with no significant heart disease (n = 15) (differences not significant [NS]). During a mean follow-up period of 16.5 +/- 9.2 months, all the patients with inducible HV block have been asymptomatic after having received permanent pacemakers. Patients with inducible monomorphic VT (except one with poor left ventricular function who died suddenly) have also been asymptomatic on antiarrhythmic drugs. Of the remaining patients, seven with normal EPS, two with prolonged HV intervals but no inducible HV block (despite being given permanent pacemakers) and one patient with polymorphic VT on antiarrhythmic drugs continue to have recurrent syncope. Approximately 60% of patients with BBB and unexplained syncope have clinically significant electrophysiologic abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Closed mitral valvotomy during pregnancy. A 20-year experience.

Closed mitral valvotomy for rheumatic mitral stenosis was performed on 126 pregnant women (average duration of pregnancy c. 21 weeks), 91% of whom were in NYHA functional class III or IV. Associated functional tricuspid regurgitation was present in 47 (37%) of the women, and 102 (81%) had critical mitral stenosis (digitally assessed valve area less than 1 cm2). There was no surgical mortality. Postoperatively 84% of the women were in NYHA class I. Clinical evidence of pulmonary artery hypertension and tricuspid regurgitation regressed postoperatively in most patients. Full-term normal delivery was achieved in 82% of the pregnancies, with total fetal mortality 6%. There were no congenital abnormalities and the infants' progress was normal. At 5-year follow-up 86% of the women were in NYHA class I or II and at 10 years the figure was 60%. The restenosis rate was 2%/year and the late mortality 3.3%. Closed mitral valvotomy during pregnancy thus was safe and reliable, giving significant functional and clinical improvement without adversely affecting the fetus.

Adult↗
PubMed1988

Pregnancy in patients with prosthetic cardiac valve. A 10-year experience.

Pregnancy after valve replacement has been considered hazardous because of maternal and fetal complications secondary to anticoagulant medication, in addition to basic myocardial problems. Of 229 females aged 15-45 years with prosthetic valve replacement, 37 (including 34 with Björk-Shiley valve and anticoagulants) subsequently had a total of 47 pregnancies. Fullterm delivery of a normal infant was achieved in 40 cases. There were three premature births, two spontaneous abortions, one stillbirth and one ectopic pregnancy. The fetal mortality was 8.5%. Valve thrombosis developed in two cases, but surgical treatment was successful. Oral anticoagulants (acenocoumarin and dipyridamole) were continued throughout pregnancy. Heparin was substituted before labour began, but discontinued after delivery, when effective oral anticoagulation was resumed. Our experience showed that pregnancy in women with mechanical heart valve prosthesis and continued oral intake of anticoagulants is safe and successful in most cases.

Acenocoumarol↗