Faculty Bibliography

African American (AA) adults are reported to have lower levels of cardiorespiratory fitness (CRF) as compared to Caucasian adults. CRF is linked to cardiovascular morbidity and mortality. We hypothesized that the disparities start early in childhood. This was a retrospective analysis of the cardiopulmonary exercise test (CPET). We included normal healthy children, ≤ 18 years of age, who had normal electrocardiograms and normal cardiac function. We excluded patients with congenital heart disease, obesity and suboptimal exercise test. The entire cohort was divided into two groups based on race (Caucasian vs. AA) and then further subcategorized by gender. The cohort of 248 patients had a mean ± SD age of 14.4 ± 2.1 years. 158 (60.8%) were males and 158 (60.8%) were Caucasians. Oxygen consumption was higher among Caucasian children when compared to the AA children (48.7 ± 7.9 vs. 45.4 ± 7 mL/kg/min, p = 0.01). This racial disparity continued to persist when comparisons were performed separately for girls and boys. Upon comparing the four groups, the AA females were found to have the lowest values of VO_2max, exercise time and METS (p = 0.001). Thus, in conclusion, the AA children have significantly lower level of CRF, as measured by VO_2max and exercise time. The racial disparity is independent of gender. African American females show the lowest level of aerobic capacity. The findings of our study suggest that the racial disparity in the CRF levels seen in the adult population may begin early in childhood.

AMPLATZER™ muscular ventricular septal defect occluder is used commonly for off-label purposes. We describe an unusual case of a patient with tetralogy of Fallot who underwent repair with a right ventricle to pulmonary artery homograft due to abnormal coronary artery pattern. During the initial surgery, the native right ventricular outflow tract was left open. At 30 years of age, he was symptomatic due to severe native right ventricular outflow tract insufficiency. Cardiac MRI confirmed a dilated right ventricle and pulmonary insufficiency through the native right ventricular outflow tract, despite no significant homograft insufficiency due to previous Melody^® valve placement. The right ventricular outflow tract was closed successfully using an 18 mm AMPLATZER™ muscular ventricular septal defect occluder. At 5-year follow-up, there is no native right ventricular outflow tract insufficiency and no additional arrhythmia. We suggest that percutaneous closure of the insufficient; native right ventricular outflow tract using a septal occluder is an alternative to surgical management.

PURPOSE OF REVIEW:We review the cardiotoxic chemotherapeutic agents, the clinical and subclinical presentations and progression of their cardiotoxicity, and the management of the subsequent cardiovascular disease in survivors of childhood cancer. We discuss various preventive measures, especially the cardioprotectant, dexrazoxane, whose use with anthracycline chemotherapy, including doxorubicin, is based on strong evidence. Most treatment recommendations for this unique population are based on expert opinion, not on empirical evidence. RECENT FINDINGS:As patients with childhood cancers live longer, morbidity from the cardiac side effects of chemotherapy is increasing. Treatment-related cardiac damage is irreversible and often progressive. It is imperative that such damage be prevented with strategies such as limiting the cumulative anthracycline dose, the use of anthracycline structural analogues and the use of cardioprotective agents. SUMMARY:A deeper understanding of the mechanisms of their cardiotoxicity reveals that there is no 'safe' dose of anthracyclines. However, certain risk factors, such as higher lifetime anthracycline cumulative doses, higher anthracycline dose rates, female sex, longer follow-up, younger age at anthracycline treatment and cardiac irradiation, are associated with more severe cardiotoxicity. We advocate the use of dexrazoxane to limit the cardiotoxic effects of anthracycline chemotherapy.

OBJECTIVES:The authors sought to assess the intermediate-term effects of percutaneous placed valves in the branch pulmonary artery (PA) position. BACKGROUND:Most patients with large right ventricular outflow tracts (RVOTs) are excluded from available percutaneous pulmonary valve options. In some of these patients, percutaneous branch PA valve implantation may be feasible. The longer-term effects of valves in the branch PA position is unknown. METHODS:Retrospective data were collected on patients with significant pulmonary regurgitation who had a percutaneous branch PA valve attempted. RESULTS:, p < 0.01 (n = 13). There were 5 late deaths. At a median follow-up of 2 years, all other patients were in NYHA functional class I or II. CONCLUSIONS:Percutaneous branch PA valve implantation results in a reduction in right ventricular volume with clinical benefit in the intermediate term. Until percutaneous valve technology for large RVOTs is refined and more widely available, branch PA valve implantation remains an option for select patients.

BACKGROUND:Transcatheter, bilateral branch pulmonary artery (PA) valve implantation is a novel treatment for patients with severe pulmonary insufficiency and oversized right ventricle (RV) outflow tract. There is scarce data on efficacy and safety of this approach. METHODS:This was a retrospective study of 8 patients with repaired tetralogy of fallot (TOF) who underwent bilateral branch PA valve implantation. Demographics, echocardiography, cardiac catheterization, and axial imaging data were reviewed. Variables were compared by a paired sample t-test. RESULTS:, P < .001). CONCLUSIONS:Transcatheter, bilateral branch PA valve implantation was technically feasible with satisfactory efficacy and safety in patients with repaired TOF, severe pulmonary insufficiency, and oversized RV outflow tracts. Elimination of pulmonary insufficiency with this method resulted in reduced RV end-diastolic volume. This approach can be offered as an alternative to surgery, particularly in patients considered high risk for standard surgical placement and who are not candidates for the newer self-expanding valve prosthesis for placement in RV outflow tracts larger than 30 mm diameter.

A 14-year-old female was referred for severe pulmonary valve insufficiency after undergoing radiofrequency ablation for a right ventricular outflow tract tachycardia that originated in the proximal pulmonary artery at 10 years of age. Clinical records indicated that ablation was guided solely by electrograms and electroanatomical mapping. Due to myocardial tissue extensions, mapping failed to identify the level of the pulmonary valve annulus, which resulted in delivery of energy on the valve proper and into the pulmonary artery. She developed severe pulmonary valve insufficiency and moderate proximal pulmonary artery stenosis necessitating intravascular stent placement 4 years later with an associated transcatheter valve. Although the nonfluoroscopic approach during ablation has gained wide acceptance for use in children, this report highlights the benefits of adjunctive imaging to identify the precise location of the pulmonary valve when ablation therapy is contemplated in the right ventricle outflow tract.

Arterial switch operation has become the standard of care for d-transposition of great arteries and has excellent short- and long-term outcomes. We report the case of a newborn with a diagnosis of d-transposition of great arteries with intact ventricular septum and a low-risk coronary artery anatomy who developed coronary artery vasospasm while coming off bypass following arterial switch operation in the operating room. The coronary artery spasm led to severe biventricular dysfunction and need for extracorporeal membranous oxygenation support. Despite extracorporeal membranous oxygenation and inotropic support, there was no improvement in the left ventricular function, and cardiac transplantation was performed after 8 days. The explanted heart showed extensive infarction of both ventricles. Both the coronary ostei were patent with no evidence of thrombus, suggesting coronary artery vasospasm rather than embolus or thrombus formation. This is the first case of coronary artery vasospasm in a neonate with d-transposition of great arteries leading to cardiac transplantation. We speculate that early identification of patients who are at a high risk for coronary vasospasm and prophylactic or timely infusion of papaverine directly into the coronary arteries may be beneficial in this condition.

OBJECTIVES:The purpose of this study was to use direct cardiac resynchronization therapy (CRT)-paced contractility (dP/dt-max) response as a pre-implantation evaluation among patients with congenital heart disease (CHD) and follow clinical parameters and contractility indexes after CRT implantation. BACKGROUND:Patients with CHD often develop early heart failure with few therapeutic options, leading to heart transplantation (HT). Unfortunately, guidelines for CRT do not apply, and function evaluations by cardiac ultrasound are often inaccurate among CHD anatomies. Therefore, which CHD patients would benefit from CRT remains an enigma. METHODS:From 1999 to 2015, 103 CHD patients with New York Heart Association (NYHA) functional class II to IV were listed for HT; 40 patients on optimal medical therapy were referred for paced contractility response cardiac catheterization before CRT consideration. If dP/dt-max improved ≥15% from baseline, these "responders" were given the option of CRT with continued follow-up after implantation. RESULTS:Of 40 patients studied, 26 (65%) (age 22 ± 8.2 years; 9 of 26 [35%] single or systemic right ventricle; 17 of 26 [65%] with pacemakers) met criteria for possible hemodynamic benefit and underwent CRT implantation. All 26 patients improved in NYHA functional classification: 5 of 26 patients (19%) were later relisted for HT (4 to 144 months, mean 55 months) after CRT implantation, whereas 21 of 26 (81%) continued with improved NYHA functional class (12 to 112 months, mean 44 months) later. A repeat dP/dt-max study following long-term CRT showed stable function or continued contractility improvement. CONCLUSIONS:Heart failure is common among CHD patients, and therapies are limited. CRT guidelines do not address clinical and anatomic issues of CHD. Short-term paced contractility response testing identifies those CHD patients who are likely to respond to CRT regardless of anatomy.

Cardiac lymphangioma is a rare primary benign tumor of the heart. We report a 3-year-old with cystic lymphangioma encasing the right coronary artery. Cardiac magnetic resonance imaging confirmed a intra-pericardial heterogeneous mass measuring 2.6 × 2.4 × 3.9 cm and situated right anterolateral to the ascending aorta and extending into the right atrioventricular groove. Furthermore, the right coronary artery traversed through the center of the mass. Surgical resection, on cardiopulmonary bypass, consisted of excision by skeletonizing the right coronary artery along the length of the mass. The pathology report was consistent with a lymphatic malformation. The postoperative course was uneventful without recurrence at follow-up.