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Biomedical subjects

K Subramanyan

Publications and source records attributed to K Subramanyan.

15 recordsLinked to original sources

Profile of female patients undergoing coronary angiogram at a tertiary centre.

OBJECTIVE: To study clinical profile, risk factors and pattern of coronary artery involvement in females. MATERIAL AND METHOD: Female patients undergoing coronary angiography at Apollo Hospitals, Chennai during 1996-1998 for angina were analysed for risk factors. RESULTS: Out of 5997 angiograms, 660 (11%) were females of which 574 (88%) post-menopausal. 48% had atypical chest pain, 11% had unstable angina, 1% had acute myocardial infarction (MI). Past history of MI was present in 48%. Risks factors were hypertension in 60%, diabetes in 52%, obesity in 41%, dyslipidemia in 32%, family history in 36%. 71% patients used oral contraceptive. None of the patients were smoker, 34.8% pre-menopausal and 72.2% post-menopausal had coronary artery disease. Single vessel disease 33% vs 22.1% two vessel disease 43.3 vs 31.2%. Triple vessel 22.3 vs 46.6% and diffuse disease 10% vs 38.7% was seen in pre-menopausal vs post-menopausal females, respectively. CONCLUSIONS: Family history was the predominant risk factor in pre-menopausal and diabetes mellitus and hypertension in post-menopausal females. Diffuse and triple vessel disease were significantly common in post-menopausal females.

Adult↗

Adenosine myocardial SPECT--its efficacy and safety and correlation with coronary angiogram.

OBJECTIVE: The aim of this study was to determine the safety and efficacy of adenosine Tc99m sestamibi myocardial perfusion study under controlled conditions and to correlate the adenosine Tc99m sestamibi perfusion defects and the coronary angiography in patients investigated for coronary artery disease. METHODS: This prospective study included 122 consecutive patients who underwent adenosine Tc99m sestamibi single photon emission computed tomography (SPECT) myocardial perfusion study. Seventy two patients had coronary angiographic correlation. All the patients who were referred by the cardiologists for stress myocardial perfusion scan who could not be stressed physiologically for one reason or the other were included in the study. RESULTS: Among the coronary angiography group the overall sensitivity, specificity, positive predictive value and negative predictive value of adenosine Tc99m sestamibi single photon emission computed tomography myocardial perfusion study for detecting significant coronary obstruction (diameter > or = 50%) were 94.4%, 79%, 85% and 92% respectively. The side effects were transient and required no treatment. CONCLUSION: We conclude adenosine Tc99m sestamibi single photon emission computed tomogram myocardial perfusion study is a reliable test with high sensitivity and specificity for the detection of coronary artery disease.

Adenosine↗

Percutaneous transluminal septal myocardial ablation in drug-resistant hypertrophic obstructive cardiomyopathy: 18-month follow-up results.

OBJECTIVE: Surgery has been the only therapeutic option in patients with hypertrophic obstructive cardiomyopathy (HOCM) who are resistant to standard treatment. Percutaneous transluminal septal myocardial ablation (PTSMA) by alcohol-induced occlusion of the septal artery for the reduction of left ventricular outflow tract (LVOT) gradient is a novel method. However, long-term clinical follow-up is insufficient. This study reports the acute and mid-term results after PTSMA in symptomatic patients with HOCM. METHODS: Six patients (4 men and 2 women) with symptomatic HOCM and inadequate response to pharmacologic therapy had their major septal branches ablated with alcohol. Mean duration of follow-up was 1.5 years. RESULTS: There was reduction in LVOT gradient in all patients (100%) with a mean reduction of 50 mmHg. Two patients developed complete heart block (CHB) and 3 patients developed bifascicular block. CHB persisted in 1 patient. Two patients died within 8 days of the procedure; one due to cerebrovascular accident and 1 due to asystole. The patient who died of asystole had CHB but refused permanent pacemaker implantation. CHB reverted in 1 patient and bifascicular blocks persisted in 3 patients. Clinical and echocardiographic follow-up was achieved in the 4 surviving patients after 1.5 years. All surviving patients had LVOT gradient reduction and clinical improvement. CONCLUSION: PTSMA for HOCM is a non-surgical technique for reducing LVOT gradient. Heart blocks are one potential complication, and may require pacemaker implantation. Long-term follow-up and a larger series of patients are required to determine conclusive therapeutic significance.

Adult↗

Three-dimensional Bolton-Brush Growth Study landmark data: ontogeny and sexual dimorphism of the Bolton standards cohort.

OBJECTIVE: The treatment of craniofacial reconstructive surgery patients may benefit from comparison to average referent three-dimensional landmark data. These data may be useful for diagnosis, treatment planning, prosthetic design, or outcomes assessment. With regard to subadult patients, we hypothesize that the pattern of ontogenetic shape change of same sex, same ethnicity, referent populations will show gross uniformity. We present a preliminary shape analysis of 50 three-dimensional landmarks derived from 317 Bolton-Brush Growth Study biorthogonal image pairs. We determine which landmarks can be collected from scanned radiographs reliably by four operators for the precisely locatable points, ontogenetic trends in landmark configuration shape change, and patterns of sexual dimorphism. PARTICIPANTS: Participants were Bolton standards individuals (16 male and 16 female) who contributed biplane cephalograms seven or more times with annual or greater spacing between ages 3 and 18 years. DESIGN: After removing outliers, we searched for ontogenetic heterogeneity, including sexual dimorphism and within sex-specific Procrustes coordinate shape spaces. RESULTS: A cut-off of 4.3-mm interoperator error left 32 landmarks in our analysis. Three different approaches (principal component analysis, age-trend analysis, and principal components of age residuals) all found no patterns of individual variation around sex-specific average trends of shape change. Male shape change peaks at age 15, a correlate of the growth spurt. CONCLUSIONS: Simultaneous frontal and lateral anatomic landmark identification improves three-dimensional localization reliability. Three-dimensional craniodental shape change from ages 8 to 18 within the Bolton standards presents little heterogeneity. Considerations of ethnicity aside, these may be initial grounds for use of these data as a normative referent.

Adolescent↗

Severity of rheumatic mitral regurgitation.

Thirty patients below the age of 15 years (range 8-1/2 to 15 years, mean 11.8 years) have been studied for the severity of rheumatic mitral regurgitation. Moderately severe to severe pulmonary venous hypertension was found in 76.6% and pulmonary arterial hypertension in 60%. Left ventricular volumes could be calculated in 13 patients. The end-diastolic volume was elevated in 11 and the endsystolic volume in 12 cases. The regurgitant fraction, calculated in nine patients was 0.6 or more in seven cases. The clinical and hemodynamic severity of mitral regurgitation in children was identical to that seen in adults in the absence of active rheumatic carditis. Children with dominant rheumatic mitral regurgitation can develop congestive failure on the basis of valvar damage per se.

Adolescent↗

Percutaneous transluminal coronary angioplasty in patients over the age of 65 years.

PTCA performed in 672 patients (646 patients < 65 years and 26 patients > or = 65 years) from March 1986 to September 1990 consisting of 619 males and 53 females are being discussed for the purpose of comparison of the results between patients in the < 65 years and > or = 65 years age groups. It was found that diabetes mellitus (50 vs 24.4.%, P < 0.01), obesity (46.1 vs 26%, P < 0.05), and hyperlipidaemia (66 vs 37.1%, p < 0.01) had a higher incidence among the elderly. Of the total 1047 lesions observed, 662 lesions in the < 65 years age group and 37 lesions in the > or = 65 years age group were dilated by PTCA (1.02 lesions/patient and 1.4 lesions/patient respectively). The lesion morphology showed higher degree of irregular contour in the < 65 years age group (23.6 vs 8.1%, p < 0.05), though the number of lesions with PTCA attempted in all age groups were almost similar. Major complications included one MI (3.8%) and two deaths (7.6%) in the > or = 65 years age group. During followup (mean duration: 8.2 months > or = 65 years and 13.5 months < 65 years age group) significantly higher percentage of patients < 65 years were asymptomatic when compared to elderly (50.2 vs 15.4% p < 0.05). Angina status was same more often in the elderly (23.1 vs 2.8% p < 0.01). The cumulative rate for repeat PTCA was similar for elderly and younger patients.

Age Factors↗

Balloon valvuloplasty of stenosed Carpentier-Edwards bioprosthesis at pulmonary position.

Bioprostheses frequently become calcified and stenosed, especially when implanted in younger patients. The general recommendation in such cases is to repeat surgery. Balloon valvuloplasty has hitherto been attempted with mixed success. Calcification and limitation of the balloon size due to the valve ring can lead to suboptimal long-term results. We report a case where balloon dilation of the stenosed bioprosthesis at pulmonary position was successfully performed with good immediate result. Cardiac catheterization after 3 years showed only a minimal increase (5 mmHg) in the gradient.

Abnormalities, Multiple↗

Significance of ST alternans during percutaneous transluminal coronary angioplasty.

Repolarisation ST alternans was observed during percutaneous transluminal coronary angioplasty (PTCA) in nine patients. Six had ST alternans on surface electrocardiogram (ECG) while three patients developed ST alternans only on intracoronary ECG recordings. The pattern of occurrence of ST alternans in successive inflations varied. Ventricular arrhythmias occurred in 6 of 28 (21.42%) of inflations associated with ST alternans while in a control group of 50 patients undergoing PTCA who did not have ST alternans, ventricular arrhythmias were noted in only 6 of 342 inflations (1.75%; p < 0.001). It is suggested that ST alternans is a regional ischemic phenomenon.

Adult↗