Facility perception of nuclear cardiology accreditation: Results of an Intersocietal Accreditation Commission (IAC) survey.

BACKGROUND: The Medicare Improvements for Patients and Providers Act requires accreditation for all non-hospital suppliers of nuclear cardiology, nuclear medicine, and positron emission tomography (PET) studies as a condition of reimbursement. The perceptions of these facilities regarding the value and impact of the accreditation process are unknown. We conducted an electronic survey to assess the value of nuclear cardiology accreditation. METHODS: A request to participate in an electronic survey was sent to the medical and technical directors (n = 5,721) of all facilities who had received Intersocietal Accreditation Commission (IAC) Nuclear/PET accreditation. Demographic information, as well as, opinions on the value of accreditation as it relates to 16 quality metrics was obtained. RESULTS: There were 664 (11.6%) respondents familiar with the accreditation process of which 26% were hospital-based and 74% were nonhospital-based. Of the quality metrics examined, the process was perceived as leading to improvements by a majority of all respondents for 10 (59%) metrics including report standardization, report completeness, guideline adherence, deficiency identification, report timeliness, staff knowledge, facility distinction, deficiency correction, acquisition standardization, and image quality. Overall, the global perceived improvement was greater for hospital-based facilities (63% vs 57%; P < .001). Ninety-five percent of respondents felt that accreditation was important. Hospital-based facilities were more likely to feel that accreditation demonstrates a commitment to quality (43% vs 33%, P = .029), while nonhospital-based facilities were more likely to feel accreditation is important for reimbursement (50% vs 29%, P≤ .001). CONCLUSION: Although the accreditation process is demanding, the results of the IAC survey indicate that the accreditation process has a positive perceived impact for the majority of examined quality metrics, suggesting the facilities find the process to be valuable.

Characterization of left ventricular diastolic function by tissue Doppler imaging and clinical status in children with hypertrophic cardiomyopathy.

BACKGROUND: Conventional transmitral Doppler indices are unreliable in assessing clinical status in patients with hypertrophic cardiomyopathy (HCM) because they are affected by loading conditions. This study sought to determine whether tissue Doppler velocities are predictive of adverse clinical outcomes including death, cardiac arrest, ventricular tachycardia (VT), significant cardiac symptoms, and exercise capacity in children with HCM. METHODS AND RESULTS: We studied 80 consecutive children (median age 12 years, median follow-up 26 months) evaluated at 1 hospital from January 1999 to August 2003 compared with 80 age- and gender-matched controls. Patients underwent echocardiography, ambulatory Holter monitoring, and upright exercise testing. Children with HCM had significantly decreased early diastolic tissue Doppler velocities at the lateral mitral (13.2 versus 19.3 cm/s), tricuspid (13.3 versus 16.3 cm/s), and septal (9.4 versus 13.5 cm/s) annuli compared with controls (P<0.001 for each comparison). By forward stepwise regression analysis, early transmitral left ventricular filling velocity (E)/septal Ea ratio predicted death, cardiac arrest, or VT (r=0.610, R2=0.37, P<0.001). Peak oxygen consumption (VO2) was most predictive of children who developed symptoms (r=0.427, R2=0.182, P<0.001). Peak VO2 correlated inversely with E/Ea septal ratio (r=-0.740, P<0.01). CONCLUSIONS: Transmitral E/septal Ea ratio predicts children with HCM who are at risk of adverse clinical outcomes including death, cardiac arrest, VT, and significant cardiac symptoms. Peak VO2 correlated with peak exercise capacity in HCM patients.

Clinical characterization of left ventricular noncompaction in children: a relatively common form of cardiomyopathy.

BACKGROUND: Left ventricular noncompaction (LVNC) is a reportedly uncommon genetic disorder of endocardial morphogenesis with a reportedly high mortality rate. The purpose of this study was to identify the clinical characteristics of children with LVNC. METHODS AND RESULTS: We retrospectively reviewed 36 children with LVNC evaluated at Texas Children's Hospital (TCH) from January 1997 to December 2002. Five children had associated cardiac lesions. There were 16 girls and 20 boys. The median age at presentation was 90 days (range, 1 day to 17 years). The median duration of follow-up was 3.2 years (range, 0.5 to 12 years). Twenty-seven patients (75%) had ECG abnormalities, most commonly biventricular hypertrophy (10 patients, 28%). Both ventricles were involved in 8 patients (22%) and only the left ventricle in 28 patients (78%). Left ventricular systolic function was depressed in 30 patients (83%), with a median ejection fraction of 30% (range, 15% to 66%) at diagnosis. Nine patients presenting in the first year of life with depressed left ventricular contractility had a transient recovery of function; however, ejection fraction deteriorated later in life, at a median interval of 6.3years (range, 3 to 12 years). Two patients had an "undulating" phenotype from dilated to hypertrophic cardiomyopathy. Two patients (6%) were identified with an underlying G4.5 gene mutation. Five patients (14%) died during the study. CONCLUSIONS: LVNC does not have an invariably fatal course when diagnosed in the neonatal period. A significant number of patients have transient recovery of function followed by later deterioration, which may account for many patients presenting as adults, some manifesting an "undulating" phenotype.

Mitral valve morphology and morbidity/mortality in Shone's complex.

Early echocardiographic studies of 50 patients with Shone's complex were retrospectively examined to identify left-sided cardiac features associated with progressive mitral valve (MV) disease requiring intervention, as well as mortality. Thickened MV leaflets, shortened MV chordae coupled with either thickened MV leaflets or turbulence at or below the MV noted by color Doppler, left ventricular outflow tract obstruction without coarctation of the aorta, and mild or moderate aortic insufficiency were associated with a poor prognosis.

Characteristics and outcomes of fetuses with pericardial effusions.

Little is known about the characteristics and outcomes of fetuses with pericardial effusions (PEs); therefore, this study sought to identify factors associated with fetal PEs and the natural histories and outcomes of fetuses with PEs. Large PEs are associated with a greater likelihood of structural heart disease, impaired cardiac function, and chromosomal abnormalities, and PEs with hydrops or extracardiac malformations are associated with death. Most fetal PEs resolve, and fetuses with isolated PEs have a very good prognosis.

How Do Noninvasive Imaging Facilities Perceive the Accreditation Process? Results of an Intersocietal Accreditation Commission Survey.

The Intersocietal Accreditation Commission (IAC) accredits vascular, echocardiography, nuclear medicine, computed tomography, and magnetic resonance imaging laboratories. How facilities involved in the accreditation process view accreditation is unknown. The objective of this study was to examine the perception of laboratory accreditation from those who had undergone the process. An electronic survey request was sent to all facilities that had received IAC accreditation at least once. Demographic information, as well as opinions on the perceived value of accreditation as it relates to 15 quality metrics was acquired. Responses were obtained from 2782 facilities. Of the 15 quality metrics examined, the process was perceived as leading to improvements by a majority of respondents for 10 (67%) metrics including: report standardization, adherence to guidelines, test standardization, report completeness, identification of deficiencies, improved staff knowledge, report timeliness, distinguished facility, correction of deficiencies, and image quality. Overall, the perceived improvement was greater for hospital-based facilities (global 66% vs 59%; P < 0.001). Survey data demonstrate that the accreditation process has a positive perceived impact on the majority of examined metrics. These findings suggest that those undergoing the process find value in accreditation.

Improved early results with the Fontan operation in adults with functional single ventricle.

BACKGROUND: A growing number of adults with functional single ventricles are presenting as candidates for first-time and redo-Fontan operations. This study describes the clinical presentation and early operative results of adults who have undergone Fontan modifications. METHODS: Between July 1995 and April 2003, 23 patients (>18 years old) had Fontan operations. We retrospectively reviewed their perioperative courses. RESULTS: Twenty-three Fontan operations (first-time [n = 8] and redo [n = 15]) were performed with no early or late deaths. No patient has required reoperation. One patient has been listed for orthotopic heart transplantation. The overall mean age is 23 years (18 to 41 years); mean follow-up, 30 months; median postoperative hospital stay, 8 days (4 to 34 days); and median duration of chest tube drainage, 4 days (2 to 12 days). The postoperative New York Heart Association (NYHA) functional class was improved in 22 of 23 patients. Eight first-time Fontan operations (7 of 8 nonfenestrated) were performed; lateral tunnel (n = 7) and extracardiac conduit (n = 1). Two patients had preoperative arrhythmias. New onset arrhythmias (ventricular tachycardia and sinus node dysfunction), requiring treatment, occurred in two patients. Fifteen redo-Fontan operations (all nonfenestrated) were performed; lateral tunnel (n = 5) and extracardiac conduit (n = 10). Fifteen patients had preoperative arrhythmias, thirteen of which had intraatrial reentry tachycardia (IART) and required antiarrhythmic medications. Concomitant intraoperative radiofrequency ablation (RFA) (n = 11) and cryoablation (n = 1) procedures were performed. In the immediate postoperative period, there was IART recurrence in five patients (post-RFA [n = 4] and postcryoablation [n = 1]). At latest follow-up, no patient is being treated with antiarrhythmic medications. Two patients had new onset atrial arrhythmias that required treatment. CONCLUSIONS: The Fontan operation can be performed in adults with minimal morbidity and improved NYHA functional class. New onset arrhythmias requiring treatment are sources of perioperative morbidity. Complete arrhythmia resolution of the preoperative arrhythmia may not be achieved in the immediate postoperative period in redo-Fontan patients. However, modification (intraoperative radiofrequency ablation-right atrial debulking) of the atrial tachycardia circuits in the redo-Fontan patients can result in complete resolution of preoperative atrial tachyarrhythmias at early follow-up.

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.

Impact of cardiac growth on Doppler tissue imaging velocities: a study in healthy children.

BACKGROUND: Doppler tissue imaging (DTI) is a useful modality to quantitatively assess regional myocardial function. Studies attempting to establish reference values for DTI velocities in healthy children have been limited by small sample sizes and limited age distribution. In addition, the clinical effect of cardiac growth and other demographic and echocardiographic parameters on DTI velocities during childhood has not been adequately evaluated. METHODS: Pulsed wave DTI velocities were obtained in 325 healthy children at the lateral mitral annulus, interventricular septum, and lateral tricuspid annulus during early diastole, late diastole, and ventricular systole and were compared with demographic and echocardiographic study variables. RESULTS: In healthy children, parameters of cardiac growth, most notably left ventricular end-diastolic dimension, have the most significant correlation with the majority of DTI velocities. Age was also significantly correlated with most DTI velocities whereas sex, heart rate, and other echocardiographic parameters demonstrated minimal or no correlation. CONCLUSIONS: This study establishes reference values for DTI velocities and demonstrates the important clinical effects of cardiac growth and age on DTI velocities in neonates and children.

Meandering right pulmonary vein to the left atrium and inferior vena cava: the first case with associated anomalies.

We report a case of a healthy, asymptomatic 6-year-old boy in whom an anomalous right pulmonary vein was noted to drain into both the inferior vena cava and left atrium in association with findings consistent with scimitar syndrome. The anomalous pulmonary vein took a very circuitous route through the lungs before draining into the left atrium, a condition previously termed "meandering pulmonary vein." To aid in the diagnosis, cardiovascular magnetic resonance imaging and magnetic resonance angiography were used to delineate this complex course and the connection of the anomalous pulmonary vein. To our knowledge, this is the 1st reported case of a meandering pulmonary vein with dual drainage to the inferior vena cava and left atrium in association with other anomalies.

Cardiac effects of antiretroviral therapy in HIV-negative infants born to HIV-positive mothers: NHLBI CHAART-1 (National Heart, Lung, and Blood Institute Cardiovascular Status of HAART Therapy in HIV-Exposed Infants and Children cohort study).

OBJECTIVES: The aim of this study was to investigate the possible effects of antiretroviral therapy (ART) in utero on cardiac development and function in human immunodeficiency virus (HIV)-negative children. BACKGROUND: ART reduces vertical HIV transmission. Long-term cardiotoxicity after in utero exposure to ART is unknown in children but has occurred in young animals. METHODS: Using a prospective multisite cohort study design, echocardiograms taken between birth and 24 months were compared in 2 groups of HIV-negative infants of HIV-positive mothers: 136 infants exposed to ART (ART+) and 216 unexposed infants (ART-). RESULTS: Mean left ventricular (LV) mass z-scores were consistently lower in ART+ girls than in ART- girls: differences in mean z-scores were -0.46 at birth (p = 0.005), -1.02 at 6 months (p < 0.001), -0.74 at 12 months (p < 0.001), and -0.79 at 24 months (p < 0.001). Corresponding differences in z-scores for boys were smaller: 0.13 at 1 month (p = 0.42), -0.44 at 6 months (p = 0.01), -0.15 at 12 months (p = 0.37), and -0.21 at 24 months (p = 0.21). Septal wall thickness and LV dimension were smaller than expected in ART+ infants, but LV contractility was consistently about 1 SD higher at all ages (p < 0.001). In ART+ infants, LV fractional shortening was higher than in ART- infants; girls showed a greater difference. CONCLUSIONS: Fetal exposure to ART is associated with reduced LV mass, LV dimension, and septal wall thickness z-scores and increased LV fractional shortening and contractility up to age 2 years. These effects are more pronounced in girls than in boys. Fetal ART exposure may impair myocardial growth while improving depressed LV function.

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.

Prolonged QT interval in pediatric sickle cell disease.

We recently cared for a patient with sickle cell disease (SCD) who presented with cardiac arrest and was found to have a prolonged corrected QT interval (QTc). This prompted us to perform a retrospective review of all electrocardiograms performed in patients with SCD during the last two years. Among 142 patients with ECG results, we identified 12 patients (8 males and 4 females), who had one or more documented measurements of prolonged QTc intervals. The relatively high prevalence of borderline or moderately prolonged QTc intervals in our patient population warrants further investigation.

Increased pulmonary artery pressures among adolescents with sickle cell disease.

The prevalence of pulmonary hypertension (PHT) among adolescents with sickle cell disease (SCD) is unknown. A tricuspid regurgitant (TR) jet peak velocity of 2.5 m/s or more is a screening test for PHT. The authors retrospectively reviewed echocardiograms and clinical data of adolescents followed at the Texas Children's Sickle Cell Center. Of 80 evaluable adolescents with SCD and echocardiogram data, 21 (26%) had a TR jet velocity of 2.5 m/s or more. Of these 21 patients with PHT, 12 (57%) had an echocardiogram performed during an inpatient stay for vaso-occlusive crisis (n = 6), acute chest syndrome (n = 4), fever (n = 1), or seizures (n = 1), and 9 (43%) had an echocardiogram performed as an outpatient in a baseline state of health. Elevation of pulmonary artery pressures was common in this adolescent cohort, but clinical symptoms were rare. Prospective study is warranted to determine the prevalence and course of elevated pulmonary artery pressures in this age group.

Impact of chronic left ventricular preload and afterload on Doppler tissue imaging velocities: a study in congenital heart disease.

BACKGROUND: Doppler tissue imaging (DTI) velocities have been reported to be relatively independent of changes in ventricular loading conditions in adult studies. The clinical impact of altered left ventricular (LV) preload and afterload on DTI velocities in children with congenital heart disease has not been adequately evaluated. The purpose of this study was to evaluate the impact of chronic LV preload and afterload on DTI velocities in children with isolated ventricular septal defect and aortic valve stenosis compared with age-matched normal and abnormal (dilated cardiomyopathy) control groups. METHODS: From an apical 4-chamber view, DTI velocities were obtained at the cardiac base at the lateral mitral annulus, lateral tricuspid annulus, and interventricular septum in early diastole, late diastole, and ventricular systole. RESULTS: The majority of DTI velocities did not change significantly in patients with increased LV preload. Patients with increased LV afterload had significantly decreased systolic and early diastolic DTI velocities at both the lateral mitral annulus and ventricular septum compared with control subjects. Children with dilated cardiomyopathy had significantly decreased DTI velocities at all myocardial annular locations. CONCLUSIONS: We conclude that increases in chronic LV preload do not significantly affect the majority of DTI velocities in children with ventricular septal defects. In addition, significantly increased chronic LV afterload in children with aortic valve stenosis is associated with decreased DTI velocities in the absence of other identifiable abnormalities of LV function. Decreased DTI velocity may be secondary to increased afterload or may alternatively be an early marker of subclinical LV longitudinal dysfunction.

Myocardial performance index with sevoflurane-pancuronium versus fentanyl-midazolam-pancuronium in infants with a functional single ventricle.

BACKGROUND: Patients with congenital heart disease characterized by a functional single ventricle make up an increasing number of patients presenting for cardiac or noncardiac surgery. Conventional echocardiographic methods to measure left ventricular function, i.e., ejection fraction, are invalid in these patients because of altered ventricular geometry. Two recently described Doppler echocardiographic modalities, the myocardial performance index and Doppler tissue imaging, can be applied to single-ventricle patients because they are independent of ventricular geometry. This study assessed the changes in myocardial performance index and Doppler tissue imaging in response to two anesthetic regimens, fentanyl-midazolam-pancuronium and sevoflurane-pancuronium. METHODS: Thirty patients aged 4-12 months with a functional single ventricle were randomized to receive fentanyl-midazolam or sevoflurane. Myocardial performance index and Doppler tissue imaging were measured by transthoracic echocardiography at baseline and two clinically relevant dose levels. RESULTS: Sixteen patients receiving sevoflurane and 14 receiving fentanyl-midazolam were studied. Myocardial performance index was unchanged from baseline with either agent (fentanyl-midazolam: 0.50 +/- 15 baseline vs. 0.51 +/- 0.15 at dose 2; sevoflurane: 0.42 +/- 0.14 baseline vs. 0.46 +/- 0.09 at dose 2). Doppler tissue imaging S (systolic)- and E (early diastolic)-wave velocities in the lateral ventricular walls at the level of the atrioventricular valve annulus were unchanged in the sevoflurane group; however, both Doppler tissue imaging S- and E-wave velocities were decreased significantly from baseline at dose 1 and dose 2 with fentanyl-midazolam, consistent with decreased longitudinal systolic and diastolic ventricular function. CONCLUSIONS: Myocardial performance index, a global measurement of combined systolic and diastolic ventricular function, is not affected by commonly used doses of fentanyl-midazolam or sevoflurane in infants with a functional single ventricle.

Echocardiographic evaluation of asymptomatic parental and sibling cardiovascular anomalies associated with congenital left ventricular outflow tract lesions.

OBJECTIVE: Left ventricular outflow tract obstructive (LVOTO) malformations are a leading cause of infant mortality from birth defects. Genetic mechanisms are likely, and there may be a higher rate of asymptomatic LVOTO anomalies in relatives of affected children. This study sought to define the incidence of cardiac anomalies in first-degree relatives of children with congenital aortic valve stenosis (AVS), coarctation of the aorta (CoA), and hypoplastic left heart syndrome (HLHS). METHODS: A total of 113 probands with a nonsyndromic LVOTO malformation of AVS (n = 25), BAV (n = 3), CoA (n = 52), HLHS (n = 30), and aortic hypoplasia with mitral valve atresia (n = 2) were ascertained through chart review or enrolled at the time of diagnosis. Echocardiography was performed on 282 asymptomatic first-degree relatives. RESULTS: Four studies had poor acoustic windows, leaving 278 studies for analysis. BAV were found in 13 (4.68%) first-degree relatives. The relative risk of BAV in the relatives was 5.05 (95% confidence interval: 2.2-11.7), and the broad sense heritability was 0.49, based on a general population frequency of 0.9%. BAV was more common in multiplex families compared with sporadic cases. An additional 32 relatives had anomalies of the aorta, aortic valve, left ventricle, or mitral valve. CONCLUSIONS: The presence of an LVOTO lesion greatly increases the risk of identifying BAV in a parent or sibling, providing additional support for a complex genetic cause. The parents and siblings of affected patients should be screened by echocardiography as the presence of an asymptomatic BAV may carry a significant long-term health risk.