John P. Kovalchin

Left ventricular non-compaction cardiomyopathy in children: characterisation of clinical status using tissue Doppler-derived indices of left ventricular diastolic relaxation

Background: Left ventricular non-compaction (LVNC) may manifest an undulating phenotype ranging from dilated to hypertrophic appearance. It is unknown whether tissue Doppler (TD) velocities can predict adverse clinical outcomes including death and need for transplantation in children with LVNC. Methods and results: 56 children (median age 4.5 years, median follow-up 26 months) with LVNC evaluated at one hospital from January 1999 to May 2004 were compared with 56 age/sex-matched controls. Children with LVNC had significantly decreased early diastolic TD velocities (Ea) at the lateral mitral (11.0 vs 17.0 cm/s) and septal (8.9 vs 11.0 cm/s) annuli compared with normal controls (p<0.001 for each comparison). Using receiver operator characteristic curves, the lateral mitral Ea velocity proved the most sensitive and specific predictor for meeting the primary end point (PEP) at 1 year after diagnosis (area under the curve = 0.888, SE = 0.048, 95% CI 0.775 to 0.956). A lateral mitral Ea cut-off velocity of 7.8 cm/s had a sensitivity of 87% and a specificity of 79% for the PEP. Freedom from death or transplantation was 85% at 1 year and 77% at 2 years. Conclusions: TD velocities are significantly reduced in patients with LVNC compared with normal controls. Reduced lateral mitral Ea velocity helps predict children with LVNC who are at risk of adverse clinical outcomes including death and need for cardiac transplantation.

The Impact of Fetal Echocardiography

Fetal echocardiography has impacted the fetus with congenital heart disease in many important ways. Advances in fetal echocardiography have allowed for more accurate and earlier detection of cardiac abnormalities. In turn, the prenatal diagnosis of cardiac abnormalities has improved the care and outcome of selected fetuses with severe cardiac malformations or arrhythmias. Fetal echocardiography has improved the understanding of the development and evolution of congenital heart disease in utero, and it may serve a role in identifying candidates for prenatal intervention. The prenatal diagnosis of congenital heart disease has allowed for better counseling and preparation of families regarding the anticipated prenatal development of the fetus as well as the expected postnatal management plans and prognosis. This article reviews the impact of fetal echocardiography in these and other areas.

Echocardiographic hemodynamic and morphometric predictors of survival after two-ventricle repair in infants with critical aortic stenosis

OBJECTIVES The purpose of this study was to identify echocardiographic hemodynamic and morphometric factors that would predict which infants with critical aortic stenosis could undergo relief of left ventricular outflow obstruction as opposed to the Norwood procedure. BACKGROUND Echocardiographic predictors of survival in infants with critical aortic stenosis after two-ventricle repair have been mainly limited to morphometric factors, which have limitations. Echocardiographic hemodynamic predictors of survival in these patients have not previously been studied. METHODS Doppler color flow mapping and pulsed Doppler techniques were used to obtain hemodynamic measurements of flow in the ascending, transverse and descending aorta, the ductus arteriosus, and across the aortic and mitral valves in infants with critical aortic stenosis. Morphometric measurements of the left heart structures were obtained, and comparisons were made between survivors and nonsurvivors for the hemodynamic and morphometric factors. RESULTS Twenty-eight infants (mean age 1 +/- .6 days, mean weight 3.6 +/- .6 kg) with critical aortic stenosis were evaluated. Nineteen had a two-ventricle repair initially attempted, and nine had a Norwood operation. Among the patients with a two-ventricle repair, the hemodynamic factors associated with survival after two-ventricle repair included predominant or total antegrade flow in the ascending (p < 0.01) and transverse aorta (p < 0.05). Aortic valve gradient, mitral valve inflow and direction of flow in the ductus arteriosus and descending aorta were unrelated to outcome. The morphometric factors associated with survival after two-ventricle repair included the indexed aortic annulus (p < 0.0002), aortic root (p < 0.003), ascending aorta (p < 0.008) and left ventricular long-axis length (p < 0.01). Left ventricular volume, mass, ejection fraction and mitral valve area were not related to outcome after two-ventricle repair. CONCLUSIONS In infants with critical aortic stenosis, predominant or total antegrade flow in the ascending and transverse aorta was associated with survival after two-ventricle repair. Determination of a one- versus two-ventricle repair remains a complex issue in infants with critical aortic stenosis. In addition to established morphometric predictors, hemodynamic information on the direction of flow in the aorta may help to define candidates for the Norwood operation.

Outcomes and Predictors of Perinatal Mortality in Fetuses With Ebstein Anomaly or Tricuspid Valve Dysplasia in the Current Era A Multicenter Study

Background— Ebstein anomaly and tricuspid valve dysplasia are rare congenital tricuspid valve malformations associated with high perinatal mortality. The literature consists of small, single-center case series spanning several decades. We performed a multicenter study to assess the outcomes and factors associated with mortality after fetal diagnosis in the current era. Methods and Results— Fetuses diagnosed with Ebstein anomaly and tricuspid valve dysplasia from 2005 to 2011 were included from 23 centers. The primary outcome was perinatal mortality, defined as fetal demise or death before neonatal discharge. Of 243 fetuses diagnosed at a mean gestational age of 27±6 weeks, there were 11 lost to follow-up (5%), 15 terminations (6%), and 41 demises (17%). In the live-born cohort of 176 live-born patients, 56 (32%) died before discharge, yielding an overall perinatal mortality of 45%. Independent predictors of mortality at the time of diagnosis were gestational age <32 weeks (odds ratio, 8.6; 95% confidence interval, 3.5–21.0; P<0.001), tricuspid valve annulus diameter z-score (odds ratio, 1.3; 95% confidence interval, 1.1–1.5; P<0.001), pulmonary regurgitation (odds ratio, 2.9; 95% confidence interval, 1.4–6.2; P<0.001), and a pericardial effusion (odds ratio, 2.5; 95% confidence interval, 1.1–6.0; P=0.04). Nonsurvivors were more likely to have pulmonary regurgitation at any gestational age (61% versus 34%; P<0.001), and lower gestational age and weight at birth (35 versus 37 weeks; 2.5 versus 3.0 kg; both P<0.001). Conclusion— In this large, contemporary series of fetuses with Ebstein anomaly and tricuspid valve dysplasia, perinatal mortality remained high. Fetuses with pulmonary regurgitation, indicating circular shunt physiology, are a high-risk cohort and may benefit from more innovative therapeutic approaches to improve survival.

Nitric Oxide in the Evaluation of Congenital Heart Disease with Pulmonary Hypertension: Factors Related to Nitric Oxide Response

Inhaled nitric oxide (NO) has been used in the preoperative evaluation of patients with congenital heart disease and pulmonary hypertension. The purpose of this study was to characterize responses in pulmonary vascular resistance (PVR) to oxygen and increasing doses of NO during cardiac catheterization and to determine if any related factors affect the response of the pulmonary vascular bed to NO. A prospective analysis of 42 patients (median age, 3.0 years) with congenital heart disease and pulmonary hypertension who underwent NO testing was performed. Systemic vascular resistance (SVR) and PVR were assessed in room air, 100% oxygen, and oxygen plus 20, 40, and 80 parts per million (ppm) NO. Changes in pulmonary artery pressure, PVR, and SVR were assessed. The response to NO was then correlated to individual patient’s age, gender, type of heart defect, the presence of trisomy 21, and baseline PVR/SVR. There was a greater decrease in PVR and PVR/SVR with 20 ppm NO than with oxygen alone. There was no additional decrease at 40 or 80 ppm NO. There was no correlation between age, gender, type of congenital heart disease, and baseline PVR/SVR ratio with the degree of response to NO. Patients with trisomy 21 had less of a response to NO (p = 0.017) than patients without trisomy 21. There is no difference in determining PVR response with doses of NO beyond 20 ppm during cardiac catheterization. Age, gender, and baseline PVR/SVR ratio are not associated with responsiveness to NO. Patients with trisomy 21 may be less responsive to NO.

Echocardiographic Determinants of Clinical Course in Infants With Critical and Severe Pulmonary Valve Stenosis

OBJECTIVES The purposes of this study were to determine the growth pattern of the pulmonary valve (PV) annulus and right heart structures in patients with critical and severe pulmonary stenosis (PS) after balloon dilation, and to determine any morphometric or hemodynamic differences between cyanotic infants with critical PS and asymptomatic infants with severe PS that may account for their varied clinical presentations. BACKGROUND Growth of the PV annulus and right heart structures in patients with critical PS after balloon valvuloplasty has not clearly been defined. In addition, the anatomic and hemodynamic factors that determine whether an infant with severe PS will present with cyanosis or without symptoms are not well understood. METHODS Measurements of the PV annulus, tricuspid valve (TV) annulus and main, right and left pulmonary arteries were obtained from initial and follow-up echocardiograms, and Z values were calculated. Hemodynamic data and balloon pulmonary valvuloplasty techniques were reviewed. Right ventricular (RV) volumes were measured from angiograms. RESULTS Fourteen patients with critical PS (mean [+/- SD] age 0.21 +/- 0.37 months) and 20 patients with severe PS (mean age 2.6 +/- 2.9 months) were evaluated at presentation and at 32 +/- 33 and 42 +/- 32 months of follow-up, respectively. Balloon pulmonary valvuloplasty was successful in 64% of patients with critical PS and in 90% of patients with severe PS. The PV, TV and pulmonary arteries increased in size after balloon pulmonary valvuloplasty in both groups at a rate that paralleled or exceeded the rate of somatic growth. The initial TV diameter and RV volume were smaller in patients with critical PS than in those with severe PS (p < 0.05 and p < 0.0008, respectively). CONCLUSIONS After balloon pulmonary valvuloplasty in infants with critical and severe PS, right heart structures increase in size at a rate that parallels or exceeds the rate of somatic growth. The primary morphometric differences between these groups are a smaller TV diameter and RV volume in infants with critical PS. This may contribute to increased right to left atrial shunting and account for the variations in clinical presentation.

Safety and efficacy of intravenous contrast imaging in pediatric echocardiography

This study was performed to determine the safety and efficacy of intravenous contrast echocardiography in children attending a tertiary cardiac center. This was a prospective study to evaluate the use of Optison contrast agent in children with severely limited transthoracic echocardiographic windows. Twenty children (median age, 15 years; range, 9–18) underwent fundamental imaging (FI), harmonic imaging (HI), and HI with intravenous contrast (Optison FS-069). Endocardial border delineation was determined based on a visual qualitative scoring system (0, none: 4, excellent). Endocardial border definition was significantly improved in all patients using contrast echocardiography (FI vs Optison, p < 0.001 for each). Improved border definition was most dramatic in the apical and left ventricular (LV) free wall regions. Left ventricular ejection fraction (LVEF) was measurable in 20 patients (100%) using contrast compared to 11 (55%) with FI or HI (p < 0.05). The echocardiographic diagnosis was correctly delineated in 1 patient with a severely dyskinetic LV segment only with use of intravenous contrast and HI. No patients suffered adverse hemodynamic effects, changes in taste, or flushing episodes. Three patients experienced transient headaches. Intravenous contrast echocardiography offers an additional tool in evaluating children with very poor transthoracic echocardiographic windows. Such a strategy increases diagnostic accuracy and allows accurate LVEF determination. Adverse hemodynamic effects related to intravenous contrast are exceedingly rare.

Is cardiac catheterization a prerequisite in all patients undergoing bidirectional cavopulmonary anastomosis

Traditionally, all patients undergo cardiac catheterization before bidirectional cavopulmonary anastomosis (BCPA). The purpose of this study was to determine if preoperative catheterization is necessary when echocardiographic parameters appear favorable. A retrospective review was performed of all patients who underwent BCPA (n = 142) between February 1996 and May 2001. Echocardiographic criteria defining a favorable BCPA candidate included good ventricular function, moderate or less atrioventricular and semilunar valve regurgitation, absence of ventricular outflow tract obstruction, normal proximal branch pulmonary artery (PA) size, and low PA pressures estimated by PA band gradient or systemic PA shunt velocity. The median age at operation was 7 months (range: 2-11) and weight was 6.2 kg (range: 2.7-7.1). There were 73 unfavorable candidates. Patients with hypoplastic left heart syndrome (n = 23) and pulmonary atresia with intact septum (n = 15) predominated among the unfavorable group. All patients were catheterized. This provided additional information on PA pressures in 3 patients in the favorable group but did not defer operation or influence outcome (no mortality, prolonged pleural drainage, or longer intensive care department stay). All 3 patients are alive at a mean follow-up of 51 months. The 30-day mortality was 2% (4 of 151 patients), all in the unfavorable group. Overall, 20 patients (13%) required arterioplasty of PAs at the time of BCPA. BCPA can be performed with a low risk of morbidity and mortality in a wide range of patients. By using commonly acquired echocardiographic parameters, a low-risk subgroup of patients can be identified who can safely avoid preoperative cardiac catheterization.

Anomalous Right Coronary Artery from the Pulmonary Artery: Noninvasive Diagnosis and Serial Evaluation

Isolated anomalous origin of the right coronary artery from the main pulmonary artery (ARCAPA) is a rare congenital cardiac malformation. We reviewed the current literature and found only 31 patients with ARCAPA. We report the first case that was diagnosed and followed on a noninvasive basis with cardiovascular magnetic resonance after surgical re-implantation. This report of a patient with ARCAPA showed resolving coronary artery sizes secondary to decreased pulmonary steal. Cardiovascular magnetic resonance is an accurate and reliable imaging modality that allows serial noninvasive follow up in patients with coronary artery anomalies.

Fetal cardiac malposition: incidence and outcome of associated cardiac and extracardiac malformations.

Cardiac malposition is a rare but important finding when detected on fetal ultrasound. The purpose of this study was to evaluate the incidence of fetal cardiac malposition, associated abnormalities, and clinical outcome in a tertiary-care medical center. Records of fetuses (1993 to 2006) with dextroposition, dextrocardia, mesocardia, ectopia cordis, or heterotaxy were reviewed. The presence of congenital heart disease (CHD), extracardiac anomalies, and outcome were noted. Cardiac malposition was present in 101 fetuses among a total of 3313 (3%) pregnancies. In 78 (78%) patients, the heart was positioned in the right hemithorax. Of those, 26 (33%) had dextrocardia (CHD = 21), and 52 (67%) had dextroposition (CHD = 14). Sixteen (16%) patients had mesocardia (CHD = 8), and 7 (7%) had ectopia cordis (CHD = 6). The majority (58%) of fetal cardiac malposition was caused by intrathoracic masses. Concomitant CHD occurred in 50%. Outcome was available in 97%. The perinatal and neonatal mortality rate was 30%; the elective termination rate was 4%. Patients with CHD had higher mortality rates. The highest mortality rates occurred in ectopia cordis and combined disease of diaphragmatic hernia and CHD.