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Biomedical subjects

K G Balakrishnan

Publications and source records attributed to K G Balakrishnan.

At least 55 records · Page 3Linked to original sources
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Assessment of severity of aortic stenosis by continuous wave Doppler echocardiography.

Fifty consecutive patients with aortic stenosis were evaluated by continuous wave Doppler echocardiography for assessment of the transaortic gradient. The Doppler derived gradients were compared with the gradients measured at cardiac catheterisation. Excellent correlation was found between the Doppler and catheterisation findings for the maximum instantaneous gradient (r = 0.92) and the mean systolic gradient (r = 0.84). The maximum, midsystolic and late systolic Doppler gradients also showed a good correlation with the peak to peak catheter gradient. The maximum Doppler velocity however, showed overestimation of the peak to peak gradient in the presence of mild aortic stenosis (predictive accuracy 86%). The midsystolic Doppler velocity showed the highest predictive accuracy (94%) for the detection of severe aortic stenosis. No case of severe aortic stenosis was missed by Doppler using either the maximum or midsystolic Doppler velocity. These findings indicate that continuous wave Doppler ultrasound provides a reliable estimate of the gradient in patients with aortic stenosis.

Adolescent↗
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Coxsackie viral myocarditis: a clinical and echocardiographic study.

Thirty two patients with acute onset of cardiac symptoms following an episode suggestive of viral infection, were studied. 11 patients had Coxsackie viral myocarditis. All had 4 fold rise of neutralising Coxsackie viral antibody titres on paired sera tested. Coxsackie B virus types 2 and 4 were commonly detected. Among the eleven patients, 8 presented with congestive heart failure, 2 with ventricular arrhythmias and one with chest pain and S3 gallop. All had ECG changes. Echocardiographic examination showed global left ventricular dysfunction in 7, regional wall motion abnormalities in 2 and normal left ventricular function in one. Serial echocardiographic examination showed progressive myocardial dysfunction in 3 and improvement in myocardial function in two patients. Two patients died during the follow up period. Echocardiography helped in assessing the course of patients with viral myocarditis.

Adolescent↗
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Two-dimensional and Doppler echocardiographic study of coronary arteriovenous fistulas.

Sixteen patients with coronary arteriovenous fistula (CAVF) were studied by two-dimensional echocardiography (2DE). Of these 12 had Doppler studies. In all, the diagnosis of CAVF was confirmed by aortic root or selective coronary angiography. In 8 patients, the 2DE findings suggested CAVF. Five patients had dilated main coronary arteries and in 4 patients abnormal fistulous channels were identified. Two had diastolic flutter of the tricuspid valve and one had spontaneous contrast in the right atrium. In 11 out of 12 patients, Doppler analysis picked up a continuous flow (to the right atrium in 5, right ventricle in 4 and to both ventricles in 2 patients) prior to the cardiac catheterisation. We conclude that noninvasive diagnosis of CAVF can be made with the combined use of two-dimensional and Doppler echocardiography in most of the patients.

Adolescent↗
PubMedDate not supplied

Accuracy of continuous wave Doppler predicted gradient in patients undergoing balloon pulmonary valvoplasty.

14 patients who underwent balloon valvoplasty had trans-pulmonic gradient evaluated by continuous wave Doppler echocardiography. Maximum systolic gradients measured from Doppler flow velocities were correlated with peak to peak gradient obtained at cardiac catheterisation. Prior to valvoplasty, there was good correlation between the Doppler maximum gradient (92.85 +/- 34.7mm Hg) and the peak to peak catheter gradient (105.57 +/- 56.60 mm Hg), (r = 0.91, p = less than 0.001). Immediately after balloon valvoplasty, the maximum Doppler gradient did not correlate with the peak to peak catheter gradient (r = 0.33, p = NS). Exclusion of patients with infundibular gradients improved the correlation coefficient between the Doppler maximum and peak to peak catheter gradient to 0.69. At late restudy following valvoplasty, when regression of infundibular stenosis was noted in 6 out of 8 patients, the Doppler maximum and catheter peak to peak gradient had excellent correlation (r = 0.97, p = less than 0.001). In patients with lone valvular gradient immediately following valvoplasty and at late restudy, maximum Doppler gradients correlated well with catheter gradients in 14 estimations (r = 0.66, p = less than 0.01). This study shows that the non-invasive quantification of pulmonary valve stenosis can be reliably undertaken, using continuous wave Doppler echocardiography before balloon valvoplasty and during follow-up, after the procedure when the infundibular stenosis has regressed. The presence of an infundibular gradient immediately after balloon dilatation makes the Doppler prediction less reliable.

Adolescent↗