Roxy N.S. Lo

Management evolution of pulmonary atresia and intact ventricular septum

To examine the impact on survival and clinical course of incorporating the morphologic classification of the right ventricle into the evolving management strategy for babies with pulmonary atresia and intact ventricular septum, the surgical results and follow-up status of the first 62 consecutive patients managed in this hospital between 1979 and 1990 were reviewed. Before 1984, all 23 babies from group I underwent primary right ventricular outflow reconstruction irrespective of right ventricular morphology and size. Since 1984, depending on the morphology and size of the right ventricle, 39 babies from group II had either closed transventricular pulmonary valvotomy (n = 31) or a shunt operation (n = 8). There were 10 hospital (43%) and 2 late deaths (total mortality 52%) in our group I patients. Three of the 11 long-term survivors had cyanosis at rest but none had any residual pressure gradient across the pulmonary outflow. Group II had 6 hospital (15%) and 4 late deaths (total mortality = 26%). Of the 29 long-term survivors, 9 had a second-stage right ventricular outflow reconstruction, 8 had balloon valvuloplasty and 2 had successful Fontan operation. At the latest follow-up, 5 children from this group have cyanosis at rest, 1 has a residual gradient (55 mm Hg) across the infundibulum, and 3 have right ventricular dysfunction. The hospital and total mortality for babies in group II was significantly lower than that in group I (p < 0.01). These data suggest that tailoring the treatment to the right ventricular anatomy results in a lower overall mortality although long term postoperative hemodynamic abnormalities are observed in both groups.

The management of symptomatic neonates with suspected congenital heart disease using combined cross-sectional echocardiography and pulsed Doppler flow study as the definitive investigations

We studied prospectively 140 consecutive symptomatic neonates with suspected congenital heart disease by combined cross-sectional and pulsed Doppler echocardiography. Using the sequential segmental approach, the anatomy at all cardiovascular junctions was clearly defined in 89 (64%) babies. Based on the non-invasive investigations, 47 went to surgery while 42 babies were treated medically. The other 51 babies underwent further cardiac catheterisation. Of these, only 23 (16%) required diagnostic catheterisation prior to their management decision. The remaining 28 babies were catheterised for (1) angiographic measurement of anatomical structures (n = 12), (2) haemodynamic measurement (n = 1), and (3) balloon atrial septostomy (n = 15). One hundred and two babies had ultimate verification of their echocardiographic diagnoses. A total of 612 cardiovascular segments were identified. There were 33 (5%) echocardiographic errors, 23 of missed or uncertain diagnosis and 10 wrong interpretations. The diagnostic sensitivity and specificity for the combined non-invasive technique were thus 96 and 98%, respectively. Only one death was attributed directly to an echocardiographic error. Hence when the clinical outcome was taken into consideration, 88 of the 89 neonates without an initial catheterisation were judged to be appropriately managed for their presentation.

Balloon valvuloplasty after pulmonary valvotomy for babies with pulmonary atresia and intact ventricular septum

During a 2 1/2-year period, staged procedures of transventricular closed pulmonary valvotomy followed by balloon valvuloplasty were attempted in 12 babies with pulmonary atresia and an intact ventricular septum. All babies immediately underwent valvotomy when echocardiography revealed a tripartite right ventricle with adequate inflow and outflow dimensions and without sinusoidal-coronary arterial fistulas. After valvotomy, the overall mortality rate was 25% (3/12), but the only surgical death (1/12, 8%) was due to failure to establish continuity between the right ventricular cavity and the pulmonary trunk. The other 2 babies died of neonatal complications after successful valvotomy. Angiocardiography performed 5 to 18 months after valvotomy documented substantial growth of the right ventricular inflow and outflow dimensions in the 9 survivors. Twelve balloon dilation procedures were then performed in 7 babies. All except 1 achieved a significant drop in the right ventricular to left ventricular peak systolic pressure ratio (0.96 +/- 0.40 to 0.56 +/- 0.28; p less than 0.01). Balloon valvuloplasty was not required in 1 baby and failed in the other, who then underwent successful right ventricular outflow tract reconstruction. After these staged procedures, follow-up at 1 month to 20 months (mean follow-up, 14.8 months) revealed resting cyanosis in 3 babies, which was related to severe residual infundibular stenosis (55 mm Hg) in 1 and a subnormal tricuspid valve annulus in 2. The remaining 5 babies (including 1 who required no valvuloplasty) were active and pink (saturation greater than 97%) and had a mean Doppler estimated gradient of 19 mm Hg (range, 8 to 36 mm Hg) across the pulmonary valve.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross-sectional and pulsed Doppler echocardiography of the atrioventricular junction of hearts with univentricular atrioventricular connexion

The atrioventricular junction of 52 consecutive patients with univentricular atrioventricular connexion was examined by cross-sectional and pulsed Doppler echocardiography. The echocardiographic features were then compared with catheterisation and cineangiographic findings. In the diagnosis of the mode of atrioventricular connexion, cross-sectional echocardiography was superior to cineangiography in differentiating single inlet with absence of one atrioventricular connexion from double inlet with a common atrioventricular valve. Straddling atrioventricular valves were diagnosed by echocardiography alone. Using pulsed Doppler echocardiography, the diagnostic sensitivity of atrioventricular valvar regurgitation was 92.6% and the specificity 100%. By mapping the regurgitant jet with pulsed Doppler echocardiography, an index was derived to evaluate the severity of atrioventricular valvar regurgitation. The indices obtained correlated well with cineangiographic grading on a three-point scale (Spearman rank correlation coefficient: rs = 0.9). Thus, cross-sectional echocardiography coupled with a range-gated Doppler system provide accurate anatomical details of the atrioventricular junction and reliable assessment of atrioventricular valvar regurgitation in patients with univentricular atrioventricular connexion.

The changes in right ventricular diastolic indices in babies with pulmonary atresia and intact ventricular septum undergoing corrective surgery: a pulsed Doppler echocardiographic study

We used pulsed Doppler echocardiography to study the right ventricular diastolic function of29 normal babies and 12 neonates with pulmonary atresia and intact ventricular septum. Eleven patients underwent staged operations of closed pulmonaryvalvotomy followed by either rightventricular outflow reconstruction (n=5) or balloon angioplasty of the pulmonary valve (n=3). In normal babies, the Doppler wave form showed dominant early (E) and separate late active (A) waves of activity, when the heart rate was slow ( area ); the time of diastolic filling relative to the cardiac cycle (TIRR); and the peak diastolic filling velocity relative to the mean filling velocity over the cardiac cycle (Velocity Index). Profiles of the indices against heart rate for both normal controls and patients indicated that only the index of the time of diastolic filling (T/RR) and the Velocity Index were appropriate for our serial comparisons. Thus, for neonates with pulmonary atresia, the index of the time (TIRR) was significantly lower (0.29±0.03 vs 0.43±0.04, p 0.05) of the index of time (T/RR=0.29±0.05) or velocity (5.88±1.17). Babies who underwent a second stage procedure and achieved a final good result had predominantly biphasic right ventricular diastolic filling waves with significant progression (p

Demonstration of ascending aorta in hypoplastic left heart syndrome with aortic atresia by balloon occlusion aortography

Balloon occlusion angiography in the descending aorta produced clear retrograde visualization of the hypoplastic ascending aorta and related structures in eighteen neonates with aortic atresia. Transient bradycardia was the only complication observed. It is technically simpler than retrograde cannulation of the aorta via an arteriotomy and should be the method of choice when cardiac catheterization is required in patients with the hypoplastic left heart syndrome.

Retrograde transfemoral catheterization of the left ventricle in children with aortic valve stenosis.

SummaryIn 19 consecutive children with aortic valve stenosis, the left ventricle was entered retrogradely with a Gensini catheter guided by a tip-deflector guidewire which could produce any desirable degree of curvature at its tip. In all patients, the aortic valve was retrogradely traversed for measurement of the pressure gradient (mean gradient=53 mmHg, mean valve area=0.36 cm2), and left ventriculography. No complications were encountered. This technique is safe, simple, and effective in retrograde catheterization of the left ventricle in children with aortic stenosis.

Variability of the diameter of the pulmonary outflow tract and its relation to balloon valvoplasty for congenital pulmonary valvar stenosis

The diameter of the pulmonary outflow tract was measured from the right ventricular cineangiogram at different phases of the cardiac cycle prior to balloon valvoplasty in 54 patients with congenital pulmonary valvar stenosis. Measured at the level of the hinge point of the valvar leaflets, the pulmonary outflow tract was found to be largest at end-diastole and smallest at end-systole. The mean increase in diameter from systole to diastole was 25.3% (range 6–53%) for 47 patients with typical valvar stenosis, and 24.3% (range 14–41%) for seven patients with dysplastic valvar leaflets (p>0.5). Dilatation using balloons less than 1.2 times the size of the maximal end-diastolic diameter produced a mean reduction in the pressure gradient from right ventricle to pulmonary trunk of 71.1%, compared to 76.2% with bigger balloons (p>0.3). Two patients with an initial ratio between balloon and outflow tract of 0.9 required a second dilatation. The timing of measurement of the diameter of the pulmonary outflow tract should be standardized. Oversized balloons probably are not necessary for pulmonary valvoplasty.

Axillary artery counter-current aortography in the newborn with aortic arch obstruction.

Abstract13 newborn infants with aortic coarctation were evaluated by counter-current aortographic technique. The right radial or brachial artery approach (2 cases in each group) did not give successful aortic arch imaging while the right axillary artery approach resulted in adequate imaging in each of 9 cases investigated. In 2, the axillary artery was transiently weakened but returned to normal within 24 h. No other complications were encountered. Axillary artery counter-current aortography is a safe and relatively non-invasive procedure which can be used to image the aortic arch in the newborn babies when other non-invasive diagnosis of aortic arch obstruction is tentative.

Atrioventricular septal defect after surgical resection of a subaortic shelf

SummaryLeft ventricular to right atrial (LV-RA) communications are rare septal defects. The majority of them are congenital in origin and acquired defects are exceedingly rare. The causes of acquired LV-RA communications include chest trauma [3, 4, 7], infective endocarditis [1, 2, 15], and valvar replacement [5, 6, 9, 12–14]. This report describes a case of direct LV-RA and interventricular communications occurring three months after excision of a subaortic shelf.