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.

Preliminary evidence on the measurement properties of the Chinese version of the Child Health Questionnaire, parent form (CHQ-pF50) and child form (CHQ-CF87).

UNLABELLED: The objective of this study was to evaluate the reliability and construct validity of the Chinese parent form (PF50) and child form (CF87) of the Child Health Questionnaire (CHQ). METHODS: To assess the construct validity and reliability of the Chinese versions, we invited 1099 parents of healthy children and 816 school children to complete the Chinese CHQ-PF50 and CHQ-CF87, respectively. RESULTS: Psychometric analysis on item convergent validity and discriminant validity showed > or = 99% rates of success for all 10 scales in the CF87 and > or = 94% for all but one scale in the PF50, the exception being general health scale (86%). We observed minimal floor effects for both questionnaires, but substantial ceiling effects for five scales in both the PF50 and CF87 (physical functioning, role-emotional/behavioral, role-physical, bodily pain and family activities). A substantially lower ceiling effect was observed for the physical scale and bodily pain in the CF87 (19% and 25%, respectively) relative to the PF50 (46% and 42%, respectively). The median alpha coefficient for CF87 and PF50 was 0.90 (range, 0.80-0.94) and 0.78 (range, 0.44-0.88), respectively. CONCLUSIONS: Our findings suggest that the Chinese CHQ-PF50 and CHQ-CF87 are robust and sufficiently reliable for group comparisons and perhaps also for use in other Chinese populations.

Assessment of left ventricular function long term after arterial switch operation for transposition of the great arteries by dobutamine stress echocardiography.

OBJECTIVES: To use dobutamine stress echocardiography to determine left ventricular (LV) function and wall motion of children long term after arterial switch operation (ASO) for transposition of the great arteries. DESIGN AND PATIENTS: 31 patients (24 boys) with ASO performed at a mean (SD) of 15.5 (4.3) days of life were studied at an age of 9.4 (2.0) years. All had normal coronary angiographic findings. LV echocardiographic indexes, including fractional shortening, ejection fraction, rate corrected velocity of circumferential fibre shortening (VCFc), and wall stress, as well as LV wall motion abnormalities were determined at rest and under dobutamine stress. The results were compared with those of 20 healthy age matched control participants. SETTING: Tertiary paediatric cardiac centre. RESULTS: Fractional shortening, ejection fraction, and VCFc were significantly lower in patients than in controls at rest (all with p < 0.001). Stress-velocity index detected impaired LV contractility in 19 (61%) patients at rest. An older age at operation (p = 0.01), longer bypass (p = 0.01) and circulatory arrest times (p = 0.045), and an unusual coronary artery pattern (p = 0.059) were associated with impaired resting LV contractility. Dobutamine stress echocardiography unmasked wall motion abnormalities in 23 (74%) patients. Exercise myocardial perfusion scan, performed in 22 patients, showed reversible myocardial perfusion defects in 17. These defects corresponded to segments of hypokinesia as detected by dobutamine stress echocardiography. CONCLUSION: A significant proportion of children, albeit asymptomatic, had impaired baseline LV contractility and reversible myocardial perfusion defects and mild wall motion abnormalities on stress after ASO.

Airway obstruction in children with congenital heart disease: assessment by flexible bronchoscopy.

We assessed the spectrum of airway disorders in children with congenital cardiac anomalies, and reviewed our experience in using flexible bronchoscopy for assessment of airway problems in this patient group. The clinical records, flexible bronchoscopic findings, and cardiac imaging results of pediatric cardiac patients who presented with either clinical or radiological signs of airway obstruction between 1992-1999 were reviewed. Flexible bronchoscopic assessment was performed with the patients under sedation and topical anesthesia, using one of two bronchoscopes, i.e., an Olympus BFN20 or Olympus BF3C20. Of a total of 52 patients, 33 had acyanotic cardiovascular lesions, the commonest being left-to-right shunts (61%), while 19 had cyanotic heart lesions, with right ventricular outflow obstruction being the commonest (63%). Twenty-seven patients had undergone either surgical or transcatheter interventions. The median age at bronchoscopic assessment was 6 months (range, 4 days to 6 years). None of the patients developed significant procedural complications. A definitive diagnosis was made in 48 (92%) patients, 8 of whom had abnormalities involving only the upper airways, 35 only the lower airways, and 5 both. Abnormalities of the upper airway included laryngomalacia (n = 6), subglottic stenosis (n = 3), pharyngeal collapse (n = 2), and 1 each of choanal stenosis and supraglottitis. Extrinsic compression was the commonest lower airway abnormality that was found in 27/40 patients (67%), with a predilection for the left main bronchus (18/27, 67%). The structures that caused extrinsic compression included dilated pulmonary arteries with or without left atrial dilation (n = 20), an anomalous aortic or pulmonary arterial course (n = 3), a dilated aorta (n = 1), and a shunt (n = 1), but were not obvious in 2 patients. Intrinsic lower airway abnormalities included bronchomalacia (n = 4), tracheal stenosis (n = 4), and one each of variant bronchial bifurcation and a pouch arising from the tracheal wall. Intraluminal mucus plugging of the lower airways occurred in the remaining 3 patients. Children with congenital heart disease are at risk of airway obstruction both before and after surgery. Flexible bronchoscopy, being safe and effective in diagnosing airway disorders in this patient group, should be considered as the first line of investigation.

Serial assessment of left ventricular diastolic function after Fontan procedure.

OBJECTIVE: To assess longitudinal changes in systemic ventricular diastolic function late after the Fontan procedure. DESIGN AND PATIENTS: Prospective study of 13 patients at 2.8 (2.0) years (early) and again at 11.4 (2.0) years (late) after the Fontan procedure by Doppler echocardiography with simultaneous ECG, phonocardiogram, and respirometer. SETTING: Tertiary paediatric cardiac centre. RESULTS: The isovolumic relaxation time (IVRT) was significantly longer, and E wave deceleration time, E and A wave velocities, and E:A velocity ratio were reduced compared to normal both early and late after the procedure. The mean (SD) z score of IVRT decreased significantly from +2.50 (1.00) to +1.24 (0.80) (p = 0.002), and the z score of the E wave deceleration time decreased from -1.69 (1.31) to -2.40 (1.47) (p = 0.03) during follow up. The A wave deceleration time also tended to decrease (early 80 (12) ms v late 73 (11) ms, p = 0.13) with increased follow up. There were no changes of the E and A wave velocities and E:A velocity ratio. The E wave velocity was inversely related to IVRT both early (r = -0.82, p = 0.001) and late (r = -0.59, p = 0.034) after the operation. The prevalence of diastolic flow during isovolumic relaxation decreased from 85% (11/13) to 38% (5/13) (p = 0.04), while that of mid diastolic flow increased from 23% (3/13) to 77% (10/13) (p = 0.02) between the two assessments. CONCLUSIONS: Left ventricular diastolic function remains highly abnormal late after the Fontan procedure. The longitudinal changes demonstrated on follow up are compatible with reduction of left ventricular compliance in addition to persisting abnormalities of relaxation.