Measures of dyssynchrony in the left ventricle of healthy children and young patients with dilated cardiomyopathy.

BACKGROUND: Doppler tissue imaging may help identify children with dyssynchrony who could benefit from resynchronization therapy. However, few studies have quantified dyssynchrony measures in children; no study has investigated the relationship among age, heart rate, and dyssynchrony measures in children; and no study has quantified cross-correlation delay in children. The aim of this study was to test the hypotheses that measures of left ventricular dyssynchrony would correlate with age, primarily because of the correlation between heart rate and age, and that children with cardiomyopathy would have left ventricular dyssynchrony. METHODS: Sixty healthy children and 11 children with dilated cardiomyopathy were prospectively enrolled. Seven dyssynchrony measures were quantified: septal-to-lateral delay, peak velocity difference, the standard deviations of times to peak in 12 segments in systole and diastole, and cross-correlation delay in systole, diastole, and the whole cycle. RESULTS: The seven dyssynchrony measures were either not correlated with age or only weakly correlated with age after correcting for heart rate using Bazett's formula. Septal-to-lateral delay, peak velocity difference, and the standard deviation of times to peak in 12 segments in systole showed dyssynchrony in 57% to 85% of normal controls, compared with 20% for cross-correlation delay in the whole cycle and 3% for the standard deviation of times to peak in 12 segments in diastole. Cross-correlation delay in systole, cross-correlation delay in diastole, cross-correlation delay in the whole cycle, and the standard deviation of times to peak in 12 segments in diastole were elevated in children with dilated cardiomyopathy compared with controls. CONCLUSIONS: Echocardiographic dyssynchrony measures should be corrected for heart rate using Bazett's formula in children. Time-to-peak Doppler tissue imaging dyssynchrony measures classify many healthy children as having abnormalities with the timing of left ventricular contraction, which suggests that the methodology is not accurate in children. In preliminary studies, cross-correlation dyssynchrony measures show elevated systolic and diastolic measures of dyssynchrony in children with dilated cardiomyopathy compared with controls, which deserves further investigation to help identify children who may benefit from resynchronization therapy.

A juvenile murine heart failure model of pressure overload.

Persistent pressure overload can cause cardiac hypertrophy and progressive heart failure (HF). The authors developed a pressure-overload HF model of juvenile mice to study the cardiac response to pressure overload that may be applicable to clinical processes in children. Severe thoracic aortic banding (sTAB) was performed using a 28-gauge needle for 40 juvenile (age, 3 weeks) and 47 adult (age, 6 weeks) C57BL/6 male mice. To monitor the structural and functional changes, M-mode echocardiography was performed for conscious mice that had undergone sTAB and sham operation. Cardiac hypertrophy, dilation, and HF occurred in both juvenile and adult mice after sTAB. Compared with adults, juvenile HF is characterized by greater impairment of ventricular contractility and less hypertrophy. In addition, juvenile mice had significantly higher rates of survival than adult mice during the early postoperative weeks. Consistent with clinical HF seen in children, juvenile banded mice demonstrated a lower growth rate than either adult banded mice or juvenile control mice that had sham operations. The authors first developed a juvenile murine model of pressure-overload HF. Learning the unique characteristics of pressure-overload HF in juveniles should aid in understanding age-specific pathologic changes for HF development in children.

Agreement is poor among current criteria used to define response to cardiac resynchronization therapy.

BACKGROUND: Numerous criteria believed to define a positive response to cardiac resynchronization therapy have been used in the literature. No study has investigated agreement among these response criteria. We hypothesized that the agreement among the various response criteria would be poor. METHODS AND RESULTS: A literature search was conducted with the keywords "cardiac resynchronization" and "response." The 50 publications with the most citations were reviewed. After the exclusion of editorials and reviews, 17 different primary response criteria were identified from 26 relevant articles. The agreement among 15 of these 17 response criteria was assessed in 426 patients from the Predictors of Response to Cardiac Resynchronization Therapy (PROSPECT) study with Cohen's kappa-coefficient (2 response criteria were not calculable from PROSPECT data). The overall response rate ranged from 32% to 91% for the 15 response criteria. Ninety-nine percent of patients showed a positive response according to at least 1 of the 15 criteria, whereas 94% were classified as a nonresponder by at least 1 criterion. kappa-Values were calculated for all 105 possible comparisons among the 15 response criteria and classified into standard ranges: Poor agreement (kappa< or =0.4), moderate agreement (0.4 or =0.75). Seventy-five percent of the comparisons showed poor agreement, 21% showed moderate agreement, and only 4% showed strong agreement. CONCLUSIONS: The 26 most-cited publications on predicting response to cardiac resynchronization therapy define response using 17 different criteria. Agreement between different methods to define response to cardiac resynchronization therapy is poor 75% of the time and strong only 4% of the time, which severely limits the ability to generalize results over multiple studies.

Aorto-right atrial tunnel: fetal heart failure, diagnosis, and treatment.

Aorto-right atrial tunnel (ARAT) is a rare clinical entity. Although it is a benign finding in most cases; it can present with significant right ventricular volume overload and congestive heart failure. This report describes the first fetal diagnosis of congenital aorto-right atrial tunnel and successful management of the heart failure by surgical intervention.

Variability in tissue Doppler echocardiographic measures of dyssynchrony is reduced with use of a larger region of interest.

BACKGROUND: Doppler tissue imaging (DTI)-based dyssynchrony parameters failed to predict response to cardiac resynchronization therapy (CRT) in the multicenter Predictors of Response to Cardiac Resynchronization Therapy (PROSPECT) trial. Large variability during the interpretation of DTI data was one of several factors thought to contribute to this failure. In this study, the authors hypothesized that using larger regions of interest (ROIs) to generate velocity curves from Doppler tissue images would significantly reduce the variability of DTI dyssynchrony parameters. METHODS: The variability of 3 ROI sizes (6 x 6, 18 x 6, and 30 x 6 mm) was compared in 30 patients undergoing CRT. Variability due to manual ROI placement was determined for each ROI size by placing 3 ROIs in each myocardial segment, 6mm apart from one another. Thus, 3 velocity curves were generated for each segment and each ROI size. Four published dyssynchrony parameters were calculated from all permutations of the 3 ROI positions per segment. A mean modified coefficient of variation was calculated for each parameter and ROI size. RESULTS: The 6 x 6 mm ROI had a mean coefficient of variation of 27%. The 18 x 6 and 30 x 6 mm ROIs had significantly lower coefficients of variation (17% and 14%, respectively) than the 6 x 6 mm ROI (P < .01 for both). The 30 x 6 mm ROI also reduced the diagnostic inconsistency of dyssynchrony parameters by 44% (P = .024) compared with the 6 x 6 mm ROI. CONCLUSION: Using a 30 x 6 mm ROI instead of a 6 x 6 mm ROI to quantify tissue Doppler dyssynchrony reduces variability by 47% and diagnostic inconsistency by 44%. The authors recommend using a 30 x 6 mm ROI in future trials to minimize variability.

Acute pacing-induced dyssynchronous activation of the left ventricle creates systolic dyssynchrony with preserved diastolic synchrony.

INTRODUCTION: Patients with heart block have conventionally received a pacemaker that stimulates the right ventricular apex (RVA) to restore heart rate control. While RVA pacing has been shown to create systolic dyssynchrony acutely, dyssynchrony can also occur in diastole. The effects of acute RVA pacing on diastolic synchrony have not been investigated. RVA pacing acutely impairs diastolic function by increasing the time constant of relaxation, decreasing the peak lengthening rate and decreasing peak negative dP/dt. We therefore hypothesized that acute RVA pacing would cause diastolic dyssynchrony in addition to creating systolic dyssynchrony. METHODS AND RESULTS: Fourteen patients (13 +/- 4 years old) with non-preexcited supraventricular tachycardia underwent ablation therapy with subsequent testing to confirm elimination of the tachycardia substrate. Normal cardiac structure and function were then documented on two-dimensional echocardiography and 12-lead electrocardiography prior to enrollment. Tissue Doppler images were collected during normal sinus rhythm (NSR), right atrial appendage pacing (AAI), and VVI-RVA pacing during the postablation waiting interval. Systolic and diastolic dyssynchrony were quantified using cross-correlation analysis of tissue Doppler velocity curves. Systolic dyssynchrony increased 81% during RVA pacing relative to AAI and NSR (P < 0.01). Diastolic synchrony was not affected by the different pacing modes (P = 0.375). CONCLUSION: Acute dyssynchronous activation of the LV created by RVA pacing resulted in systolic dyssynchrony with preserved diastolic synchrony in pediatric patients following catheter ablation for treatment of supraventricular tachycardia. Our results suggest that systolic and diastolic dyssynchrony are not tightly coupled and may develop through separate mechanisms.

Effects of region of interest tracking on the diagnosis of left ventricular dyssynchrony from Doppler tissue images.

BACKGROUND: Left ventricular dyssynchrony is often diagnosed by comparing velocity curves from Doppler tissue images of two or more myocardial regions. Velocity curves are generated by placing sample volumes or regions of interest (ROIs) within the myocardium. ROIs need to be manually relocated to maintain a midmyocardial location as the heart moves, but are frequently left in a stationary position. The error caused by use of a stationary ROI may affect the diagnosis of dyssynchrony, but this has not been quantified. OBJECTIVE: We hypothesized that using a stationary ROI to quantify dyssynchrony from Doppler tissue images would affect the diagnosis of dyssynchrony in patients with heart failure. METHODS: We quantified dyssynchrony in 18 patients with heart failure using 4 published dyssynchrony parameters: septal-to-lateral delay, maximum difference in the basal 2- or 4-chamber times to peak, SD of the 12 basal and midwall times to peak, and cross-correlation delay (XCD). Each dyssynchrony parameter was measured using both tracked and stationary ROIs. RESULTS: Use of a stationary ROI did not change the diagnosis of dyssynchrony when using XCD. However, ROI tracking changed the diagnosis of dyssynchrony in 17%, 11%, and 17% of patients when using septal-to-lateral delay, maximum difference in the basal 2- or 4-chamber times to peak, and SD of the 12 basal and midwall times to peak, respectively. XCD showed the lowest percent difference between tracked and stationary ROIs (4 +/- 9% vs 22 +/- 53%, 50 +/- 167%, and 12 +/- 30%, respectively, for septal-to-lateral delay, maximum difference in the basal 2- or 4-chamber times to peak, and SD of the 12 basal and midwall times to peak). CONCLUSION: Manual ROI tracking is required when using conventional time-to-peak parameters to diagnose dyssynchrony. XCD diagnosis of dyssynchrony can be performed accurately with a stationary ROI.

Real-time three-dimensional echocardiographic acquisition and quantification of left ventricular indices in children and young adults with congenital heart disease: comparison with magnetic resonance imaging.

BACKGROUND: Echocardiographic assessment of left ventricular (LV) contractility and dimensions is important in the management of patients with congenital heart disease. Conventional two-dimensional measures are limited because of volume or pressure-overloaded right ventricles that may distort the septal planes. Real-time three-dimensional echocardiography (RT3DE) has overcome these limitations; however, postprocessing image reconstruction and analysis are required. We compared LV indices calculated by new online RT3DE software with those obtained by magnetic resonance imaging (MRI) in patients with congenital heart disease. METHODS: Twelve patients (ages 1-33 years, median age = 15.9 years) with congenital heart disease underwent RT3DE and cardiac MRI. End-diastolic and end-systolic LV volumes, stroke volume, ejection fraction, and mass were calculated online using biplane method-of-discs and semiautomated border detection echocardiographic techniques. RESULTS: All RT3DE volumes correlated strongly with MRI (r = 0.93-0.99, P < .001). Ejection fraction had a lower correlation (r = 0.69, P = .013). There was no significant underestimation or overestimation of MRI values by RT3DE. Both biplane method-of-discs and semiautomated border detection echocardiographic techniques had excellent volume correlation (r = 0.94-0.99, P < .001). Interobserver variability was 7%. CONCLUSIONS: Combined RT3DE acquisition and analysis machines can accurately assess the LV in patients with congenital heart disease, thus impacting clinical management and perhaps obviating the need for MRI in some cases.

Cross-correlation quantification of dyssynchrony: a new method for quantifying the synchrony of contraction and relaxation in the heart.

BACKGROUND: Quantification of left ventricular dyssynchrony using Doppler tissue imaging may improve selection of patients who will benefit from cardiac resynchronization therapy. Most methods used to quantify dyssynchrony use a time-to-peak analysis, which is quantitatively simplistic and requires manual identification of systole and selection of peak velocities. METHODS: We developed and tested a new, highly automatable dyssynchrony parameter, cross-correlation delay (XCD), that does not require identification of systole or manual selection of peak systolic velocities. XCD uses all velocity data points from 3 consecutive beats (approximately 420 points). We tested XCD on 11 members of a positive control group (responders to cardiac resynchronization therapy with a >or=15% reduction in left ventricular end-systolic volume) and 12 members of a negative control group (normal 12-lead electrocardiogram and 2-dimensional echocardiogram findings). We compared XCD to septal-to-lateral delay in time-to-peak (SLD), maximum difference in the basal 2- or 4-chamber times to peak (MaxDiff), and SD of the 12 basal and midwall times-to-peak (Ts-SD). RESULTS: XCD and Ts-SD were significantly different between the positive and negative control groups (both P

Resynchronization and strain recovery following reimplantation of anomalous coronary artery: a tissue Doppler and three-dimensional echocardiographic study.

Resynchronization may play a significant role in recovery following surgical reimplantation of anomalous left coronary artery from the pulmonary artery (ALCAPA). Three-dimensional echocardiography and tissue Doppler may quantify this recovery. A 6-week-old infant presented with signs of congestive heart failure due to ALCAPA. Two-dimensional echocardiography showed a severely dilated left ventricular (LV) cardiomyopathy and the presence of ALCAPA was confirmed by catheterization. Three-dimensional echocardiography and tissue Doppler imaging showed severe abnormalities of systolic and diastolic synchrony and decreased contractility with a left ventricular ejection fraction (LVEF) of 13%. The infant underwent surgical coronary reimplantation and was discharged 5 weeks later with an LVEF of 54%. Serial quantitative assessment showed resynchronization and normalization of global LV function following reimplantation. However, segmental contractility improved significantly but remained depressed at discharge. The immediate recovery observed following reimplantation of anomalous coronary may be largely due to resynchronization.

Reduction in initial ventricular systolic and diastolic velocities after heart transplantation in children: improvement over time identified by tissue Doppler imaging.

BACKGROUND: Tissue Doppler imaging (TDI) is a non-invasive method for measuring ventricular function that can provide insight into the changes in hemodynamics that occur after pediatric heart transplantation. The purpose of this study was to quantify longitudinal changes in myocardial velocities within the first 6 months after transplantation in children. METHODS: Thirteen patients were serially studied (median age at transplant 5.9 years) and compared with controls. Tissue Doppler systolic (S), early (E) and late (A) diastolic velocities were recorded at the tricuspid annulus, mitral annulus and interventricular septum. RESULTS: TDI studies were serially performed during 6 months post-transplantation: <10 days (n = 48); 11 to 30 days (n = 26); 31 to 60 days (n = 13); 61 to 120 days (n = 12); and 121 to 180 days (n = 16). Mean systolic tissue velocities at the tricuspid annulus were 3.8 cm/s (95% confidence interval [CI]: 3.1 to 4.6) at baseline (<10 days) and 6.3 cm/s (95% CI: 4.1 to 8.6) at 6 months post-transplantation (mean increase from baseline: 2.5 cm/s; 95% CI: 0.1 to 4.9). Systolic tissue velocities at the mitral annulus also increased over time (mean change from baseline: 0.9 cm/s; p = 0.02). Early diastolic (E) velocities at the tricuspid annulus and mitral annulus significantly improved over time (p < 0.0001 and p = 0.002, respectively). Systolic and diastolic velocities measured at >121 days after transplantation, however, remained significantly lower than those of normal controls. CONCLUSIONS: TDI demonstrated systolic and diastolic velocities improved during the initial 180 days after heart transplantation. Systolic and diastolic velocities were reduced in children after heart transplantation when compared with controls.

Tissue Doppler imaging detects severely abnormal myocardial velocities that identify children with pre-terminal cardiac graft failure after heart transplantation.

BACKGROUND: Children with orthotopic heart transplants (OHT) may die or require retransplantation due to chronic graft failure usually due to severe coronary allograft vasculopathy (CAV). Non-invasive detection of chronic transplant failure has been problematic due to lack of specific echocardiographic findings. Tissue Doppler Imaging (TDI) is a non-invasive ultrasound methodology, which measures myocardial contraction and relaxation velocities. The purposes of this study were to: 1. Determine quantitative changes of longitudinal TDI velocities characteristic to "pre-terminal" patients who subsequently either died or were listed for re-transplantation due to graft failure; 2. to define the time course of these changes, and 3. to show whether RV and LV velocities were equally effected. METHODS: 53 heart transplantation recipients were evaluated. Of these, 45 were "well" patients. They ranged in age at enrollment from 0.5 to 20.1 (mean 10.21) years, age at transplantation from 0.2 to 18 (mean 5.7) years. The time from transplantation to enrollment was 1 day to 14.9 (mean 4.5) years. There were 8 "pre-terminal" (test group) patients who died or were listed for re-transplantation within 9 months after TDI echo. These ranged in age from 2.6 to 17 (mean 11.6) years, age at transplant from 1 month to 15.9 (mean 8.1) years, and time from transplant to enrollment was 0.7 to 9.8 (mean 3.6) years. TDI was performed in the apical four-chamber view. Systolic (S, cm/s) and diastolic early (E, cm/s) and late (A, cm/s) velocity. Mitral and tricuspid annular TDI velocities were measured. Tricuspid regurgitation and LV ejection fraction were also compared. RESULTS: Pre-terminal patient's Left Ventricular Ejection Fraction began diverging from controls at 3 to 6 months prior to endpoint (p < 0.001). Tricuspid TDI S velocities of pre-terminal patients diverged by 2.0 cm/sec from controls (p < 0.002) 6 months prior to, and reduced further by 2.9 cm/sec 3 months prior to endpoint (p < 0.001). Tricuspid TDI E velocities diverged 3 to 6 months before endpoint, by 1.9 cm/sec (p < 0.02) and by 3.7 cm/sec 0-3 months prior to endpoint, (p < 0.001). Mitral S velocities diverged from controls by 1.5 cm/sec at 0 to 3 months before terminal endpoints (p = 0.002). Mitral E velocities were statistically similar at all time intervals (p > or = 0.15). Septal S velocities equaled controls 6 months (p = 0.92) and between 3 to 6 months (p = 0.83) but diverged by 1.6 cm/sec 0 to 3 months before terminal endpoints (p = 0.01). Septal E velocities equaled controls. Mortality Prediction: LVEF, tricuspid annulus systolic and diastolic velocities, and tricuspid regurgitation severity were significant in predicting mortality. Coronary angiography was performed in 26 patients, 5 had severe coronary artery disease and all were pre-terminal. DISCUSSION: The TDI data reported here show 3 to 6 months before the terminal graft failure, tricuspid, but not mitral, S and E TDI velocities, deteriorated to uniquely low levels not seen in other clinically well pediatric transplant recipients. Further RV deterioration occurred during the final 3 months before death and severely reduced left ventricular velocities then occurred. Small decreases in LVEF and progressive increases in the severity of tricuspid regurgitation were also detectable and predicted an increased likelihood of mortality. Seven of the 8 preterminal patients had angiograms 5 of which showed severe CAV. These data suggest that there is a critical "pre-terminal" window of time in which children demonstrate uniquely reduced right and subsequently left sided myocardial velocities at approximately 6 months prior to graft failure. The practice of annual catheterization and coronary angiography may not allow caregivers an opportunity to intervene early in the process of graft dysfunction. Therefore, a strategy of tissue Doppler echocardiography 2 or 3 times each year might be an appropriate regimen to survey for graft impairment.

Left ventricular aneurysm in a five-week-old child.

Ventricular aneurysms in the pediatric population are rare and no standardized method of treatment exists. We present a case of left ventricular (LV) aneurysm in an infant, 5 weeks after a balloon aortic valvuloplasty for congenital aortic stenosis.

Elastic properties of the reconstructed aorta in hypoplastic left heart syndrome.

BACKGROUND: Patients with repaired coarctation of the aorta retain abnormal elastic properties of the aorta. It is not known whether patients with hypoplastic left heart syndrome also manifest abnormal elastic properties after palliative surgery. The presence of such abnormalities may have important clinical implications as reduced aortic compliance might adversely impact single right ventricular function. METHODS: We prospectively evaluated the elastic properties of the aorta in a cohort of patients with hypoplastic left heart syndrome who had undergone the Norwood procedure with aortic arch reconstruction and subsequent bidirectional Glenn or Fontan procedure. The hypoplastic left heart syndrome patients (n = 20) were compared with single-ventricle patients (n = 18) without history of arch reconstruction and patients with double-ventricular lesions (n = 22). Aortic elastic function was quantified by distensibility index and stiffness index. M-mode measurements of the transverse aortic arch were obtained with transesophageal echocardiography under general anesthesia. Patients were evaluated at a median age of 22.2 months with no age difference between patient subgroups. RESULTS: Distensibility index was significantly less (p = 0.007) and stiffness index greater (p = 0.005) in the reconstructed arch of hypoplastic left heart syndrome patients compared with single-ventricle and double-ventricle patients. CONCLUSIONS: Patients with hypoplastic left heart syndrome after Norwood palliation have increased aortic stiffness and decreased distensibility in the reconstructed transverse arch. As previous studies in adults have shown that decreased aortic compliance increases the energy cost of cardiac ejection, examination of modifications to the surgical technique that might improve elastic properties is warranted.

Velocity-encoded magnetic resonance image assessment of regional aortic flow in coarctation patients.

BACKGROUND: During primary coarctation repair, collateral blood vessels contribute significantly to distal perfusion. We sought to determine if velocity-encoded cine magnetic resonance imaging (VENC-MRI) could provide insight into anatomy and hemodynamics of collateral flow in patients with unrepaired coarctation. METHODS: Sixteen patients (median age, 6.2 years; range, 1 to 18) with discrete coarctation (65% severe, 29% mild-moderate) and 10 controls (median age, 12.0 years; range, 9 to 15) without left-sided heart lesions were referred for cardiac MRI. Flow volumes were calculated from VENC-MRI images at the coarctation (proximal), diaphragm (distal), and midway between the two points (midpoint). A means model, repeated-measure analysis, was performed for volumes. RESULTS: In coarctation patients, flow volumes increased by 59% (p = 0.0002) from coarctation to diaphragm, primarily between the proximal and midpoint sites (by 77%, p < 0.0001). In controls, flow volumes decreased by 11% along the entire aortic study length. Coarctation volumes were lower than controls by 54% (p = 0.0003) at the proximal site but showed no statistical difference at the midpoint or diaphragm. CONCLUSIONS: Coarctation flow volumes maximally increase in the upper thoracic aorta, but approach normal flow volumes in the lower thoracic region. Arteries arising from mid and lower thoracic level, such as those supplying the anterior spinal cord, may have nearly normal flow if collaterals are present. Velocity-encoded MRI can evaluate flow in patients who have poor collateral circulation to improve surgical planning and decrease neurologic complications of coarctation repair.

Mixed constrictive pericarditis and restrictive cardiomyopathy in a child: treatment guided by tissue Doppler imaging.

Mixed lesions of restrictive cardiomyopathy and constrictive pericarditis have been reported rarely and represent a diagnostic and therapeutic dilemma. Restrictive cardiomyopathy has a poor prognosis with an average 2-year survival rate of less than 50% from the time of diagnosis. Heart transplantation is usually the only treatment option available. On the other hand, constrictive pericarditis may be surgically treated by pericardiectomy with low mortality. When these two lesions coexist, the inappropriate selection of treatment may be disastrous. We report a case of this mixed lesion in a child in which tissue Doppler echocardiography provided important information indicating that pericardectomy might be successful.

Freedom from neoaortic insufficiency: a comparison of classic Norwood and Norwood-Sano procedures.

OBJECTIVES: To investigate the incidence of neoaortic insufficiency in patients with hypoplastic left heart syndrome treated with the Norwood-Sano palliation and to compare it with that occurring after the classic Norwood procedure. DESIGN, SETTING, PATIENTS, INTERVENTIONS: This was a retrospective review of all echocardiograms of patients diagnosed with hypoplastic left heart syndrome (concomitant presence of left ventricular and aortic and mitral severe hypoplasia or atresia) who underwent staged palliation of the Norwood or Norwood-Sano type at a single academic institution between September 1999 and February 2005 and who survived a minimum of 3 months. OUTCOME MEASURES: Neoaortic insufficiency was categorized as absent or mild <1 mm jet width, moderate 1-3 mm jet width, or severe >3 mm jet width. The patients were grouped according to initial palliation, that is, classic Norwood and Norwood-Sano operation. RESULTS: Fifty-nine consecutive patients (median age of 20 months with a range from 3 to 66 months) satisfied inclusion criteria. Neoaortic insufficiency was absent or mild in 55 of 59 (93.22%) of the patients. There were 4 cases of significant neoaortic insufficiency at late follow-up: 2 moderate following the classic Norwood and 1 moderate and 1 severe following the Norwood-Sano procedure, one of whom required valve replacement. CONCLUSIONS: In this series of patients with hypoplastic left heart syndrome, the Sano modification was not associated with an increased incidence of significant neoaortic insufficiency. When present, moderate/severe neoaortic insufficiency appeared late after initial palliation and was associated with recurrent ascending aortic or aortic arch pathology in every case.