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Biomedical subjects

S Radhakrishnan

Publications and source records attributed to S Radhakrishnan.

At least 37 records · Page 2Linked to original sources
PubMed1993

Analysis of hand forces in health and disease during maximum isometric grasping of cylinders.

An analysis of force distribution in the hand during maximum isometric grasping actions is reported in a detailed and accurate manner. A microcomputer-controlled instrument which measures all 12 phalangeal forces of fingers simultaneously, in a single attempt at squeezing a cylindrical object, is described. The study involved 20 normal subjects of different weights and age groups grasping tubes of 50 mm, 75 mm, 90 mm and 110 mm diameters. Normal grasp forces decreased significantly with the increase in tube diameter, with the force being concentrated more on the distal segments of the fingers on the proximal and middle segments. The mean percentage contributions of finger forces to total grip strength, from index to little fingers, were 31, 33, 22 and 14 per cent, respectively. The study was extended to cover leprotic and paralytic hands to assess their functional capabilities. In the case of leprosy subjects, the grip strength decreased with the severity of the disease and was only about 50 per cent of that of normal subjects. In hemiplegics, the grip strength was only about one-eighth of the normal values. The above assessment procedure provides baseline data which could serve as guidelines to a clinician in assessing the severity of the disease and observing the patient's recovery following the treatment. It would also be useful in the design of hand-operated controls and prosthetic arms.

Fingers↗
PubMed1993

Atrio-ventricular regurgitations in constrictive pericarditis: incidence and post-operative outcome.

We studied 33 surgically proven cases of constrictive pericarditis during the period 1989-1991 by color Doppler echocardiography and angiography to look for incidence and postoperative outcome of atrioventricular regurgitation. The mean age was 27.2 + 16.5 years (21 males, 12 females). There was a very high incidence of mitral (79%, trivial in 13, mild in 11 and moderate in 2) and tricuspid (73%, trivial in 7, mild and moderate in 6 each and severe in 5) regurgitation. There was good correlation between 'color Doppler' and angiography for detection and quantification of these regurgitations (r = 0.89 for mitral and 0.76 for tricuspid regurgitation, respectively). There were no preoperative clinical or hemodynamic predictors for the incidence or severity of these regurgitations. Immediate postoperative (7-10 days) evaluation by color Doppler did not show any change in these regurgitations. A follow-up study (by color Doppler and angiography) in 18 patients at a mean period of 229 + 105 days revealed regression of these regurgitations by at least 1 grade in 50% of patients. Patients with persisting regurgitations had persisting hemodynamic abnormality and relatively longer duration of symptoms. The presence of atrio-ventricular regurgitations should not be taken as evidence favoring diagnosis of restrictive cardiomyopathy and against that of constrictive pericarditis. The mechanism of these regurgitations is not clear to us.

Adult↗
PubMed1993

Helicobacter pylori-associated gastritis in Kuwait: endoscopy-based study in symptomatic and asymptomatic children.

Information is limited concerning the prevalence of Helicobacter pylori infection in asymptomatic children. Since January 1989, we have endoscoped 60 children for recurrent abdominal pain or for obtaining small-intestinal biopsy (their ages were a mean of 6.6 (range 9 months-13 years); there were 37 boys and 23 girls. Antral biopsies were obtained from all subjects and these were studied for the presence of gastritis and stained for H. pylori using modified Gram's stain. All biopsies were cultured for H. pylori. Children endoscoped for small-intestinal biopsy (n = 18) were used for comparison. Of the 42 children who had abdominal pain, 24 showed histological gastritis and 13 had H. pylori on microscopy (31% H. pylori-associated gastritis). In the compared group, five showed histological gastritis, and all had H. pylori on microscopy (27.7%). Culture was positive in 15; sensitivity was 85.7%. Six children, three pairs of siblings, had H. pylori gastritis supporting environmental etiology. Two had coinfection with intestinal giardiasis. Seven children were treated with daily oral amoxycillin (50 mg/kg) and tinidazole (20 mg/kg) for 6 weeks. In 3 (42.3%) H. pylori colonization cleared with healing of gastritis and resolution of symptoms. These results indicate that H. pylori gastritis is equally prevalent in symptomatic and asymptomatic children (31 and 27.7%, respectively; p > 0.05) in our population. It seems that the combination of oral amoxycillin and tinidazole is a poor choice in the treatment of H. pylori-associated gastritis in Kuwaiti children.

Abdominal Pain↗
PubMed1992

Echocardiographic variables affecting surgical outcome in patients undergoing closed mitral commissurotomy.

We studied, by transthoracic cross-sectional echocardiography, the influence of subvalvar pathology on the early hemodynamic result of closed mitral commissurotomy in 132 patients with severe rheumatic mitral stenosis (56 males, 76 females, mean age 25.2 yr, range 10-55) in our tertiary care hospital in North India from July 89 to December 91. The mitral subdistance ratio was calculated by dividing the distance between the papillary muscle tip and mitral valve in systole (apical 4-chamber view) by left ventricular diastolic length (apical long axis view). Nineteen patients with mild subvalvar pathology (mitral subdistance ratio > 0.18) and 71 patients with moderate, achieved a larger valve area (2.26 cm2 SD 0.54) than 42 patients with severe subvalvar pathology (mitral subdistance ratio < 0.12, postoperative valve area 2.09 cm2 SD 0.6, p < 0.05). In addition, 9 of these 42 patients (21%) developed significant mitral regurgitation (4 deaths), in contrast to 1/19 with mild and 6/71 with moderate subvalvar pathology. We conclude that echocardiography identifies patients with severe subvalvar pathology who fare poorly after closed mitral commissurotomy. However, this procedure would still be practised in developing countries like ours due to financial constraints.

Adolescent↗
PubMed1992

Hypoplastic right ventricle with mild pulmonary stenosis in an adult.

A rare cyanotic heart disease surviving to adulthood with minimal symptoms is presented. The final diagnosis was hypoplastic right ventricle with mild pulmonary stenosis, where the latter was not responsible for the right-to-left shunting across a large atrial septal defect. The differences from cases reported in the literature are highlighted.

Adult↗
PubMed1992

Discordance between abdominal and atrial arrangement in a case of complex congenital heart disease.

The report describes a rare case of a complex congenital heart disease wherein the splenic status and the relationship of the suprarenal abdominal great vessels strongly suggested right isomerism, but atrial morphology demonstrated usual atrial arrangement. It emphasises the increasing recognition that the arrangement of the abdominal organs need not accurately reflect atrial arrangement.

Abnormalities, Multiple↗
PubMed1991

Aneurysm of the left sinus of Valsalva causing severe mitral regurgitation.

A 24-year-old male presented with exertional dyspnoea of one year's duration. Echocardiography revealed an unruptured aneurysm of the left sinus of Valsalva distorting the mitral valvar apparatus and producing severe regurgitation in the absence of myocardial ischemia or infarction. We propose an alternate mechanism for the mitral regurgitation.

Adult↗
PubMed1991

Persistent atrial standstill--clinical, electrophysiological, and morphological study.

Persistent atrial standstill (PAS) is a rare disorder characterized by absence of atrial activity on the surface and intracavity electrograms, absence of atrial mechanical activity, and inability to electrically stimulate the atria. Four patients (ages 18-60 years) with PAS were evaluated. One of these (no. 3) only had right atrial (RA) standstill, whereas left atrium (LA) showed spontaneous activity and could be stimulated electrically. As RA biopsy is not possible, right ventricular (RV) endomyocardial biopsy (EMB) was obtained to identify possible atrial pathology that revealed inflammatory myocarditis, 2; amyloidosis, 1; and myocardial hypertrophy with fibrosis, 1. Three patients were given permanent pacemakers. One of these with amyloidosis died suddenly. One is lost to follow-up. The others cases are persisting with PAS.

Adolescent↗
PubMed1990

Doppler assessment of interventricular pressure gradient across isolated ventricular septal defect.

Continuous wave Doppler ultrasound was used to estimate the pressure gradient between the right and left ventricle for assessment of pulmonary arterial systolic pressure in 30 patients with isolated ventricular septal defect and for subsequent comparison with similar data obtained on cardiac catheterization. The age of the patients ranged from 8 months to 45 years (6.8 +/- 8.6 years). No patient had right or left ventricular outflow tract obstruction. Doppler measurements were done within 24 h of cardiac catheterization. Pressure gradient across ventricular septal defect on cardiac catheterization ranged from 7 to 95 mmHg (48 +/- 24 mmHg) and that on Doppler assessment ranged from 8 to 78 mmHg (42 +/- 20 mmHg). Doppler measurements of interventricular pressure gradient correlated well with those obtained on cardiac catheterization (r = 0.90, p less than 0.001). Correlation was better in patients with pressure gradient across ventricular septal defect less than 75 mmHg (r = 0.96). Correlation was poor in three of five patients with very small ventricular septal defects (interventricular pressure gradient greater than 75 mmHg) because the jet used was not ideal. Thus continuous wave Doppler ultrasound is an accurate noninvasive means of measuring pressure gradient across ventricular septal defect, which is a useful parameter for assessment of pulmonary artery systolic pressure in patients with isolated ventricular septal defect without right and left ventricular outflow tract obstruction.

Adolescent↗
PubMed1990

Echocardiographic demonstration of resolving intrapericardial mass in tuberculous pericardial effusion.

A patient with tuberculous pericardial effusion is described who presented with cardiac tamponade. Subsequent to pericardiocentesis, a large echodense intrapericardial mass was observed which disappeared completely with antituberculous chemotherapy. The resolution of the mass suggests that it was a conglomeration of fibrinous exudates deposited in the pericardial cavity. Presence of such exudates should not be considered an indication for surgical intervention.

Echocardiography↗
PubMed1990

Epidemiological study of coronary heart disease in urban population of Delhi.

A community based survey of coronary heart disease (CHD) was carried out on a random urban sample of 13,723 adults in the age group 25-64 yr in Delhi, India. CHD was diagnosed either on the basis of clinical history supported by documentary evidence of treatment in a hospital or at home; or on ECG evidence in accordance with the Minnesota Code. The overall prevalence of CHD based on clinical history, was 31.9 (39.5 in males and 25.3 in females) per 1000 adults in this age group. The number of patients with CHD increased with advancing age in both sexes. The total prevalence rate based on both clinical history and ECG criteria (asymptomatic patients with ECG changes of definite myocardial infarction and ST-T changes suggestive of CHD) was estimated as 96.7/1000 adults in this age group. Analysis of information on socio-economic status, family history of CHD, obesity, hypertension and smoking obtained from this sample of 13,723 adults suggested that hypertension had the strongest association with CHD. Obesity, diabetes and family history were also found to be associated with CHD. It should, however, be noted that risk factor assessments in CHD can be done satisfactorily only through incidence studies.

Adult↗
PubMed1990

Prevalence, awareness & treatment status of hypertension in urban population of Delhi.

A community based survey for the prevalence of hypertension was carried out on a random urban sample of 13,723 adults in the age group 25-64 yr from the Union Territory of Delhi (India). Hypertension was defined as systolic pressure greater than 160 mm Hg and/or a diastolic pressure greater than 90 mm Hg or a history of current antihypertensive medication. The overall prevalence rate/1000 adults was 127.5 (116.6 in males and 136.8 in females). Mild hypertension (diastolic pressure between 91-104 mm Hg) predominated in the whole group, the proportion decreasing with increasing age in both sexes. Fifty per cent of the hypertensives were aware of their problem, the awareness being slightly higher in females (51.8% versus 46.5%). Approximately 30 per cent of the hypertensives were on medication for high blood pressure. The status control of blood pressure was low in the population, being only 9 per cent, with little difference between the two sexes. The study emphasises the enormity of the problem of hypertension in an urban population in India and poor control of blood pressure achieved in the community.

Adult↗