Restrictive right ventricular physiology and right ventricular fibrosis as assessed by cardiac magnetic resonance and exercise capacity after biventricular repair of pulmonary atresia and intact ventricular septum.

BACKGROUND: The hypertrophic myocardium, myocardial fiber disarray, and endocardial fibroelastosis in pulmonary atresia and intact ventricular septum (PAIVS) may provide anatomic substrates for restrictive filling of the right ventricle. HYPOTHESIS: Restrictive right ventricle (RV) physiology is related to RV fibrosis and exercise capacity in patients after biventricular repair of PAIVS. METHODS: A total of 27 patients, age 16.5 +/- 5.6 years, were recruited after biventricular repair of PAIVS. Restrictive RV physiology was defined by the presence of antegrade diastolic pulmonary flow and RV fibrosis assessed by late gadolinium enhancement (LGE) cardiac magnetic resonance. Their RV function was compared with that of 27 healthy controls and related to RV LGE score and exercise capacity. RESULTS: Compared with controls, PAIVS patients had lower tricuspid annular systolic and early diastolic velocities, RV global longitudinal systolic strain, systolic strain rate, and early and late diastolic strain rates (all P < 0.05). A total of 22 (81%, 95% confidence interval: 62%-94%) PAIVS patients demonstrated restrictive RV physiology. Compared to those without restrictive RV physiology (n = 5), these 22 patients had lower RV global systolic strain, lower RV systolic and early diastolic strain rates, higher RV LGE score, and a greater percent of predicted maximum oxygen consumption (all P < 0.05). CONCLUSION: Restrictive RV physiology reflects RV diastolic dysfunction and is associated with more severe RV fibrosis but better exercise capacity in patients after biventricular repair of PAIVS.

New two-dimensional global longitudinal strain and strain rate imaging for assessment of systemic right ventricular function.

OBJECTIVES: To determine the usefulness of new two-dimensional strain indices, based on speckle tracking imaging, for assessment of systemic right ventricular (RV) function after an atrial switch operation for transposition of the great arteries. DESIGN: Cross-sectional study. SETTING: Tertiary paediatric cardiac centre. METHODS: 26 patients, mean (SD) age 21.0 (3.6) years at 19.9 (3.2) years after an atrial switch operation, and 27 age-matched controls were studied. Two-dimensional imaging at the four-chamber view was obtained with tracing of the entire RV endocardial border. The RV global longitudinal strain (GLS) and GLS rate were derived using automated software (EchoPAC, GE Medical) and correlated with tissue Doppler-derived RV isovolumic acceleration (IVA), and, in the patient cohort, with cardiac magnetic resonance-derived RV ejection fraction. RESULTS: Intra- and interobserver variability for measurement of GLS, as determined from the mean (SD) of differences in two consecutive results from 20 studies, were 0.06 (1.39)% and 0.24 (1.77)%, respectively. Compared with controls, patients had lower RV GLS (17.1 (1.9)% vs 26.3 (2.9)%, p<0.001), a reduced GLS rate (0.78 (0.11)/s vs 1.33 (0.23)/s, p<0.001), lower RV IVA (1.10 (0.36) m/s(2) vs 1.56 (0.53) m/s(2), p<0.001) and increased RV myocardial performance index (0.52 (0.09) vs 0.38 (0.09), p<0.001). Both RV GLS and GLS rate correlated positively with RV IVA (r = 0.43, p = 0.001 and r = 0.46, p<0.001, respectively), and negatively with RV myocardial performance index (r = -0.65, p<0.001 and r = -0.57, p<0.001, respectively). In patients, the GLS rate correlated positively with RV ejection fraction (r = 0.62, p = 0.001). CONCLUSIONS: Two-dimensional RV GLS and GLS rate are new, potentially useful indices for assessment of systemic RV function.

Pericardial effusion after open heart surgery for congenital heart disease.

OBJECTIVES: To determine the prevalence and time course of pericardial effusion after open heart surgery for congenital heart diseases and to identify predisposing risk factors. DESIGN AND PATIENTS: Prospective assessment of development of pericardial effusion in 336 patients (163 males) undergoing open heart surgery for congenital heart disease by serial echocardiography on days 5, 7, 14, 21, and 28 postoperatively. SETTING: Tertiary paediatric cardiac centre. RESULTS: The prevalence of pericardial effusion was 23% (77 of 336). Of the 77 patients who developed effusion, 43 (56%) had moderate to large effusions and 18 (23%) were symptomatic. Patients who had a large amount of effusion were more likely to be symptomatic than those with only a small to moderate amount (47.4% v 15.5%, p = 0.01). The mean (SD) onset of pericardial effusion was 11 (7) days after surgery, with 97% (75 of 77) of cases being diagnosed on or before day 28 after surgery. The prevalence of effusion after Fontan-type procedures (60%, 6 of 10) was significantly higher than that after other types of cardiac surgery: repair of left to right shunts (22.1%, 43 of 195), repair of lesions with right ventricular outflow tract obstruction (22.6%, 19 of 84), arterial switch operation (6.7%, 1 of 15), and miscellaneous procedures (25%, 8 of 32) (p = 0.037). Univariate analyses showed that female patients (p = 0.009) and those receiving warfarin (p = 0.002) had increased risk of postoperative pericardial effusion. A greater pericardial drain output in the first four hours after surgery also tended to be significant (p = 0.056). Multivariate logistic regression similarly identified warfarin treatment (beta = 1.73, p = 0.009) and female sex (beta for male = -0.63, p = 0.037) as significant determinants. CONCLUSIONS: Pericardial effusion occurs commonly after open heart surgery for congenital heart disease. Serial echocardiographic monitoring up to 28 days postoperatively is indicated in selected high risk patients such as those with symptoms of postpericardiotomy syndrome and those given warfarin.