Jose A. Ettedgui

Complications of endomyocardial biopsy in children

OBJECTIVES To evaluate the incidence of, and risk factors for, complications of endomyocardial biopsy in children. BACKGROUND Endomyocardial biopsy (EMB) is a low risk procedure in adults, but there is a paucity of data with regard to performing this procedure in children. METHODS Retrospective review of the morbidity and mortality of 1,000 consecutive EMB procedures. RESULTS One thousand EMB procedures (right ventricle 986, left ventricle 14) were performed on 194 patients from July 1987 through March 1996. Indications for EMB included heart transplant rejection surveillance (846) and the evaluation of cardiomyopathy or arrhythmia for possible myocarditis (154). Thirty-seven (4%) procedures were performed on patients receiving intravenous inotropic support. There was one biopsy related death, secondary to cardiac perforation, in a two-week-old infant with dilated cardiomyopathy. There were nine perforations of the right ventricle, eight occurring in patients with dilated cardiomyopathy and one in a transplant recipient. The transplant patient did not require immediate intervention; two patients required pericardiocentesis alone, and six underwent pericardiocentesis and surgical intervention. All nine perforations were from the femoral venous approach (p < 0.01). Multivariate analysis demonstrated that the greatest risk of perforation occurred in children being evaluated for possible myocarditis (p = 0.01) and in those requiring inotropic support (p < 0.01). Other complications included arrhythmia (5) and single cases of coronary-cardiac fistula, flail tricuspid leaflet, pneumothorax, hemothorax, endocardial stripping and seizure. CONCLUSIONS Risk of endomyocardial biopsy is highest in sick children with suspected myocarditis on inotropic support. However, EMB can be performed safely with very low morbidity in pediatric heart transplant recipients.

Coarctation and hypoplasia of the aortic arch: Will the arch grow?

Hypoplasia of the transverse aortic arch of various degrees of severity is commonly seen in infants who have coarctation of the aorta. It is more often present when the coarctation is associated with intracardiac lesions that diminish or limit forward flow in the ascending aorta and promote right to left flow through an arterial duct. The increased frequency of surgical treatment of infants with complex coarctation, which is in part related to the ability to stabilize their condition with prostaglandin E1, has posed the question of the potential for growth and development of the originally hypoplastic aortic arch after conventional repair of aortic coarctation. Review of our experience with transverse aortic arch hypoplasia, found in 33 (32%) of 102 infants undergoing coarctation repair by subclavian flap aortoplasty or classic resection and end-to-end anastomosis, revealed excellent growth of the transverse arch after repair in all patients available for linear follow-up. The currently proposed extended arch repair should be reserved for the small group of infants with transverse aortic arch to ascending aorta diameter ratios (arch indices) of less than 0.25.

Absent pulmonary valve syndrome with ventricular septal defect: Role of the arterial duct

Absent pulmonary valve syndrome is usually associated with tetralogy of Fallot, but it also has been described in the presence of a ventricular septal defect or an intact ventricular septum.1–8 The pulmonary valve is represented by rudimentary nodules without identifiable leaflets and it is associated with aneurysmal dilation of the pulmonary trunk and one or both of its branches. It has been postulated that closure of the arterial duct in early intrauterine life plays an important etiologic role in the genesis of this syndrome.3,6 The anatomic and hemodynamic features of absent pulmonary valve syndrome are readily recognized prenatally using cross-sectional and Doppler echocardiography.9 We present the prenatal echocardiographic findings in 5 fetuses with absent pulmonary valve syndrome and a ventricular septal defect, 2 with a patent arterial duct, and speculate on the possible role of the arterial duct in this condition.

The value of angiography in the follow-up of coronary involvement in mucocutaneous lymph node syndrome (Kawasaki disease)☆

From September 1976 to August 1988, 205 patients with mucocutaneous lymph node syndrome (Kawasaki disease) were evaluated; 29 were suspected of having coronary artery abnormalities because of either abnormalities on echocardiography (n = 21), congestive heart failure (n = 3), prolonged fever (n = 3) or cardiac arrest (n = 2). All 29 underwent cardiac catheterization and 22 were found to have coronary artery abnormalities. An additional 4 patients were diagnosed solely by autopsy; therefore, 26 patients (12%) in this series had coronary artery abnormalities. The clearance of contrast medium from the coronary arteries after aortography was significantly prolonged in patients with coronary artery aneurysms as compared with that in a control group (p less than 0.001). All patients exhibited delayed clearance of contrast medium on the initial aortogram as compared with that on follow-up studies (p less than 0.01). Of the 22 patients with angiographically documented coronary artery abnormalities, 19 had right and 20 had left coronary artery involvement; the majority had diffuse involvement of both vessels. In 15 patients who underwent follow-up catheterization 6 months to 7 years after initial study, complete resolution was observed in only 37% of affected coronary artery segments. In four patients, three of whom were asymptomatic, severely stenotic or occluded coronary artery segments were found on late catheterization. Coronary artery bypass surgery was performed in two of these patients. Echocardiography did not detect any of these stenoses. Although echocardiography is important for initial diagnosis and serial evaluation, angiography is essential to fully define the nature and extent of coronary artery lesions, particularly if stenosis is present.

A quantitative evaluation of aortic regurgitation after anatomic correction of transposition of the great arteries.

Twenty patients who had undergone anatomic correction of transposition of the great arteries were assessed by Doppler echocardiography or cardiac catheterization, or both, to identify the presence of aortic regurgitation. The severity of aortic regurgitation was evaluated by radionuclide angiographic measurement of the stroke volume index a mean of 47.1 months postoperatively. The stroke volume index was defined as the ratio of the stroke counts between the left and right ventricles. A value greater than 1.8 was considered to indicate significant left ventricular volume overload. Eight patients (40%) were shown to have various degrees of aortic regurgitation by Doppler echocardiography or cardiac catheterization, or both. The mean (+/- SD) stroke volume index was 1.03 +/- 0.15 in these patients and 1.01 +/- 0.21 in the 12 patients without aortic regurgitation (p = NS). The stroke volume index was not above the normal range in any patient, indicating that the degree of aortic regurgitation present was trivial. This medium-term study indicates that trivial or mild aortic regurgitation is a frequent finding after anatomic correction of transposition of the great arteries. However, it rarely results in an audible cardiac murmur or significant left ventricular volume overload. Long-term evaluation is required to determine its importance.

Balloon aortic valvotomy through a carotid cutdown in infants with severe aortic stenosis: Results of the multi-centric registry

OBJECTIVES The purpose of this study was to evaluate the short and intermediate term results of infants who have undergone balloon aortic valvotomy from the carotid arterial approach, and to identify risk factors in those infants who had a poor outcome. METHODS Between 1988 and 1999, balloon aortic valvotomy was attempted at four centres in 95 infants with severe aortic stenosis. Echocardiographic and hemodynamic data, and outcome, were analysed retrospectively. RESULTS Valvotomy was accomplished in 92 of the 95 infants, with a median age of 5 days, a range from 0 to 191 days, and weighing 3.4 kg, with a range from 1.0 to 6.5 kg. Major procedural complications occurred in 10 infants. Post-procedural aortic regurgitation was severe in 5 patients. There were 13 early deaths, and 4 late deaths. The period of mean follow-up has been 2.1 years, with a range from 0 to 9.3 years. The actuarial survival at 3 years was 76 +/- 6%. Further interventions were needed in 19 patients, giving a 3-year freedom from reintervention of 67 +/- 6%. The 51 infants who were duct-dependent were further analyzed, and found to have a higher mortality (38%) compared to those infants not dependent on the arterial duct (5%). Risk factors for a poor outcome in the duct-dependent infants were mitral stenosis (p<0.005), a left ventricle which did not form the cardiac apex (p<0.005), and an aortic valve with a diameter of less than 6 mm (p<0.05). CONCLUSIONS This multi-centric registry shows good results in the intermediate term for treating infants with severe aortic valvar stenosis with balloon valvotomy through a carotid arterial cutdown. Infants dependent on prostaglandin had a worse outcome, especially if they had any of the identified risk factors.

Pulmonary artery growth fails to match the increase in body surface area after the Fontan operation

Objective: To evaluate the growth of the pulmonary arteries after a Fontan procedure. Design: Retrospective review. Setting: Two paediatric cardiology tertiary care centres. Patients: 61 children who underwent a modified Fontan operation and had angiography suitable for assessment of pulmonary artery size before the Fontan procedure and during long term follow up. An atriopulmonary connection (APC) was present in 23 patients (37.7%) and a total cavopulmonary connection (TCPC) was present in 38 (62.3%). Postoperative angiograms were performed 0.5–121 months (median 19 months) after the Fontan operation. Main outcome measure: Growth of each pulmonary artery measured just before the first branching point. The diameter was expressed as a z score with established nomograms used to standardise for body surface area. Results: The mean change in the preoperative to postoperative z scores of the right pulmonary artery was −1.06 (p  =  0.004). The mean change in the preoperative to postoperative z scores of the left pulmonary artery was −0.88 (p  =  0.003). Changes in the preoperative to postoperative z scores were more pronounced in the patients undergoing APC than TCPC, especially for the right pulmonary artery. Conclusion: After the Fontan operation, growth of the pulmonary arteries often fails to match the increase in body surface area.

Use of terbutaline in the treatment of complete heart block in the fetus

Between 1989 and 2000, 21 fetuses were diagnosed with complete atrioventricular block. Seven women with fetal ventricular rates of less than 60 were given oral terbutaline, and 6 of these had an initial increase in the fetal ventricular rate. Four fetuses (57%) maintained an increased average rate of 60 beats per minute and survived. Two fetuses returned to rates below 55 and died. The final fetus, with hypertrophic cardiomyopathy, was unresponsive. Terbutaline, therefore, is initially effective in raising the fetal ventricular rate, but this effect may be transient.

Transatrial lead placement for endocardial pacing in children.

Transvenous placement of endocardial leads in children may be difficult due to restrictions and complications of vascular access. We have placed endocardial leads from a transatrial approach in 5 children with various cardiac malformations. The usual surgical approach involved an anterolateral thoracotomy and, under fluoroscopic guidance, passage of the lead tip directly through the right atrial wall and across the tricuspid valve to the apex of the right ventricle. At a mean follow-up time of 23.2 months (range, 12.0 to 27.9 months), all patients have low thresholds for myocardial capture, and there have been no complications. We conclude that placement of endocardial leads by a transatrial approach provides an excellent alternative to an epicardial system in children destined for lifelong pacing.

Echocardiographic-morphologic correlations in tricuspid atresia

OBJECTIVES Our aim was to clarify the anatomic substrate in hearts diagnosed as having tricuspid atresia by studying autopsy specimens and comparing the findings with those in two-dimensional echocardiograms. BACKGROUND Traditionally, tricuspid atresia was thought, and is still believed by some, to be due to an imperforate valvular membrane interposed between the floor of the blind-ending right atrium and the hypoplastic right ventricle. Others argued that the dimple, when present, pointed to the outflow tract of the left ventricle rather than to the right ventricle, making the lesion more akin to double-inlet left ventricle. METHODS We examined 39 autopsy specimens catalogued as having tricuspid atresia. We then studied 24 two-dimensional echocardiograms from patients with a primary diagnosis of tricuspid atresia. RESULTS Of the 39 specimens, 37 had a completely muscular floor to the right atrium (absent right atrioventricular [AV] connection). The dimple, when identified, was (except in one case) directed to the left ventricular outflow tract. Only two hearts had an imperforate tricuspid valve. Two-dimensional echocardiograms in all cases showed an echo-dense band, produced by the fibrofatty tissue of the AV groove and representing absence of the right AV connection, between the muscular floor of the morphologically right atrium and the ventricular mass. CONCLUSIONS Tricuspid atresia is usually, but not always, due to morphologic absence of one AV connection. In most cases, the ventricular mass then comprises a dominant left ventricle together with a rudimentary and incomplete right ventricle.