Blade and balloon atrial septostomy for creation of an adequate interatrial communication.

During a 7 year period from 1984 to 1991, 100 infants underwent either balloon atrial septostomy (BAS) (n = 92) or blade septostomy (BLS) (n = 8). The indication was complete transposition of the great arteries in all the patients. The mean age in the BAS group was 1.8 +/- 1.5 months while that in the infants requiring BLS due to a thick septum was 3.03 +/- 2.29 months. The degree of improvement in arterial oxygen saturation in both groups was satisfactory -27.16 +/- 14.06% in the BAS group vs 23.5 +/- 12.18% in the BLS group. There were no procedure related deaths in the BLS group, through only monoplane fluoroscopy was used in 6/8 patients. Three patients however died following balloon septostomy. We conclude that BLS is a safe and effective alternative to surgical septostomy when performed with due care. Two dimensional echocardiography during BAS enhances the speed and safety of the procedure and helps to identify patients who may require BLS due to a thick interatrial septum.

Primary pulmonary hypertension: natural history and prognostic factors.

A retrospective cohort study was carried out in 61 patients (30 males, 31 females, age 24.6 +/- 11.8 years) with primary pulmonary hypertension diagnosed by strict clinical and hemodynamic criteria, to obtain an understanding of the natural history and prognostic markers. While 15 patients were alive, 46 patients (76%) had expired during the follow up period. Two, five and ten years survivals were 48%, 32% and 12% respectively. Median survival duration from time of diagnosis was 22 months. The survivors had significantly higher age of onset, cardiac index and significantly lower right atrial mean pressure, right ventricular end diastolic pressure, cardiothoracic ratio from chest rontgenogram and calculated pulmonary vascular resistance as compared to non survivors. While pulmonary artery systolic pressure was not significantly different, pulmonary artery diastolic and pulmonary artery mean pressures were significantly lower in survivors than in non-survivors. Lower New York Heart Association class, right atrial mean pressure < or = 7 mm Hg, right ventricular end diastolic pressure < or = 10 mmHg, cardiac index > 2.5 L/min/m2, pulmonary arterial oxygen saturation > 60%, were associated with significantly longer survival. The degree of pulmonary arterial hypertension had an indirect prognostic effect through the above parameters. Vasodilator therapy did not significantly alter the outcome of patients with primary pulmonary hypertension.

Thrombolytic therapy for prosthetic cardiac valve thrombosis.

During 1992-93 12 patients (5 males, 7 females) with thrombosed prosthetic cardiac valves were treated with streptokinase on 13 occasions (one patient with prosthetic tricuspid valve had two thrombotic episodes). Their age ranged from 14 to 52 years (median 39). Two valves were in aortic position, six in mitral and four in tricuspid position. Eight were Bjork-Shiley prosthesis, three were Medtronic Hall valves and one was a St. Jude Valve. Timing of prosthetic valve thrombosis ranged from 3 months to 12 years after valve replacement surgery. Duration of symptoms due to valve thrombosis ranged from 1-4 months with tricuspid valve thrombosis and 1-14 days with left sided valve thrombosis. Five were in functional class II and four each were in functional class III and class IV. All patients were evaluated by echo Doppler and cine fluoroscopy. Loading dose of streptokinase was 2.5 lakh units in 4 patients and 1 lakh units in 9 patients. Maintenance infusion was at 1000 units/Kg/hour in 11 patients and 1 lakh units/hour in 2 patients. Duration of streptokinase infusion ranged from 3 hr to 38 hr. Thrombolytic therapy was successful (clinical, echo Doppler and fluoroscopy) in 12 out of 13 cases (92%). It was unsuccessful in a patient with valve at tricuspid position in whom infusion had to be stopped after 24 hour due to bleeding gums. One patient developed intracerebral bleed and expired. In conclusion streptokinase therapy is useful for prosthetic cardiac valve thrombosis.

Two dimensional and Doppler echocardiographic evaluation of double chambered right ventricle.

Two-dimensional and Doppler echocardiographic findings in 20 patients with double chambered right ventricle are described. All patients had the diagnosis established by cardiac catheterisation and confirmed at operation. Echocardiographic evaluation was done prior to surgical correction. Anomalous muscle bands in right ventricular cavity were detected in 16 patients. Doppler flow velocities in the right ventricular cavity suggested infundibular obstruction to blood flow at a low level in all 17 patients studied by Doppler echocardiography. Ventricular septal defects (11 patients), pulmonary stenosis (3 patients), and aortic regurgitation (3 patients) were detected accurately before operation by echocardiographic examination. Failure to detect the anomalous muscles in right ventricular cavity may occur in adult patients with poor anterior resolution and in those with severe right ventricular outflow obstruction and myocardial hypertrophy. Two dimensional echocardiography with Doppler flow analysis is useful in the evaluation and differential diagnosis of right ventricular outflow obstructions prior to invasive studies and surgical intervention.

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.

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.

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.