The Effects of Pulmonary Valve Replacement for Severe Pulmonary Regurgitation on Exercise Capacity and Cardiac Function.

Patients may develop hemodynamic abnormalities after right ventricular outflow tract (RVOT) repair. Re-intervention timing remains a dilemma. This study evaluates exercise capacity and RV function before and after intervention using age-related comparisons. Twenty-six patients with severe pulmonary regurgitation (PR) after initial repair scheduled for pulmonary valve replacement (PVR) were enrolled. Metabolic treadmill testing (EST) and MRI were obtained before and after surgery. EST results were compared with matched controls. Preoperative exercise time and peak oxygen consumption (VO2 max) were significantly diminished compared with controls but were not significantly different postoperatively. The patients were then split into age-related cohorts. When comparing pre-PVR and post-PVR exercise time and VO2 max among themselves, neither cohort showed significant differences. However, patients younger than 25 years had better postoperative results, an age-related difference not seen in the controls. Preoperative MRI showed significantly dilated RV, PR, and low normal function. After PVR, the right to left ventricular end-diastolic volume ratio (RVEDV:LVEDV) and pulmonary artery regurgitant fraction (RF) significantly decreased. There was no change in ventricular ejection fractions (EF). Severe PR, decreased RVEF, and RV dilation can significantly diminish exercise capacity. PVR improves RVEDV:LVEDV and RF, but not EF. Younger patients had better exercise capacity that was maintained postoperatively. This age-related difference was not seen in the controls, indicating that earlier intervention may preserve exercise capacity. Serial ESTs in patients with severe PR following RVOT repair may identify deteriorating exercise capacity as an early indicator for the need for PVR.

Characterization of cardiac tumors in children by cardiovascular magnetic resonance imaging: a multicenter experience.

OBJECTIVES: The aim of this study was to report the results of an international multicenter experience of cardiac magnetic resonance imaging (MRI) evaluation of cardiac tumors in children, each with histology correlation or a diagnosis of tuberous sclerosis, and to determine which characteristics are predictive of tumor type. BACKGROUND: Individual centers have relatively little experience with diagnostic imaging of cardiac tumors in children, because of their low prevalence. The accuracy of cardiac MRI diagnosis on the basis of a pre-defined set of criteria has not been tested. METHODS: An international group of pediatric cardiac imaging centers was solicited for case contribution. Inclusion criteria comprised: 1) age at diagnosis ≤18 years; 2) cardiac MRI evaluation of cardiac tumor; and 3) histologic diagnosis or diagnosis of tuberous sclerosis. Data from the cardiac MRI images were analyzed for mass characteristics. On the basis of pre-defined cardiac MRI criteria derived from published data, 3 blinded investigators determined tumor type, and their consensus diagnoses were compared with histologic diagnoses. RESULTS: Cases (n = 78) submitted from 15 centers in 4 countries had the following diagnoses: fibroma (n = 30), rhabdomyoma (n = 14), malignant tumor (n = 12), hemangioma (n = 9), thrombus (n = 4), myxoma (n = 3), teratoma (n = 2), and paraganglioma, pericardial cyst, Purkinje cell tumor, and papillary fibroelastoma (n = 1, each). Reviewers who were blinded to the histologic diagnoses correctly diagnosed 97% of the cases but included a differential diagnosis in 42%. Better image quality grade and more complete examination were associated with higher diagnostic accuracy. CONCLUSIONS: Cardiac MRI can predict the likely tumor type in the majority of children with a cardiac mass. A comprehensive imaging protocol is essential for accurate diagnosis. However, histologic diagnosis remains the gold standard, and in some cases malignancy cannot be definitively excluded on the basis of cardiac MRI images alone.

Delayed-enhancement cardiovascular magnetic resonance identifies fibrous tissue in children after surgery for congenital heart disease.

OBJECTIVES: To determine whether delayed-enhancement magnetic resonance imaging can identify fibrous tissue associated with patch reconstructions in postoperative patients with congenital heart disease. Additionally, to determine whether fibrous structures not directly related to the surgical reconstruction exhibited delayed enhancement. METHODS: Seventy-three patients underwent magnetic resonance imaging. Studies were retrospectively reviewed for the presence of delayed enhancement along the ventricular outflow tracts, cardiac valves, and where available, the ascending aorta. Three groups were identified. Group A patients (n = 34) underwent right ventricular outflow tract reconstruction and ventricular septal defect patch closure. Group B patients (n = 33) had never undergone cardiac surgery. Group C patients (n = 6) had functional single ventricle and underwent Norwood reconstruction. RESULTS: In group A, 31 of 34 patients had delayed enhancement of the right ventricular outflow tract, and 14 of 34 had delayed enhancement of the ventricular septal defect patch (P < .001). In group B (n = 33), 1 patient with arrhythmogenic right ventricular dysplasia had delayed enhancement limited to the right ventricular outflow tract. The remainder had no delayed enhancement of either outflow tract. Delayed enhancement of the aortic valve and ascending aorta was observed in 13 of 34 (P = .002) and 10 of 26 (P = .05) group A patients, respectively, compared with 2 of 33 and 3 of 24 group B patients. In group C, delayed enhancement of the Norwood reconstruction was observed in 5 of 6 patients (P = .002). CONCLUSIONS: Delayed-enhancement imaging detects fibrous tissue along regions of reconstruction in patients who have had surgery for congenital heart disease. Furthermore, delayed-enhancement imaging detects fibrous tissue in regions not directly related to the reconstructive surgery, including cardiac valves and the wall of the ascending aorta.

After repair, atrioventricular valve regurgitation during cardiac extracorporeal membrane oxygenation predicts survival.

BACKGROUND: When echocardiography is used to follow up cardiac patients on extracorporeal membrane oxygenation (ECMO), ejection fraction as a measure of ventricular function has been used to determine likelihood of survival after decannulation. We hypothesized that systemic atrioventricular (AV) valve regurgitation while on ECMO may be a better predictor of survival. METHODS: From February 1995 to March 2001, 64 patients required ECMO postoperatively. Three were removed from ECMO owing to brain death, so 61 patients formed our study group. Retrospective chart review was performed with systemic AV valve regurgitation and ejection fraction while on ECMO recorded from echocardiography reports. Patients alive 1 month after decannulation were considered survivors. RESULTS: There were 29 survivors (47.5%). Ejection fraction in survivors (mean 41% +/- 0.13%) was not significantly different from that of nonsurvivors (41% +/- 0.18%; p < or = 0.839) but severity of systemic AV valve regurgitation was significantly different. Only 2 survivors (6.8%) had at least moderate AV valve regurgitation compared with 17 of the 32 nonsurvivors (53%). Patients with moderate to severe regurgitation while on ECMO were less likely to survive for 1 month after decannulation, with an odds ratio of 16.63 (95% confidence interval 3.08, 89.70; p = 0.001). Also female sex increased the odds of death by a factor of 5.43 (95% confidence interval 1.45, 20.36; p = 0.012). CONCLUSIONS: Severity of systemic AV valve regurgitation on ECMO is a more reliable predictor than ejection fraction for survival at 1 month after decannulation. Patients with less than moderate AV valve regurgitation have a significantly better chance of survival.