Left ventricular rotational mechanics in Tanzanian children with sickle cell disease.

BACKGROUND: Sickle cell disease (SCD) is a common inherited hemoglobinopathy. Adults with SCD manifest both systolic and diastolic cardiac dysfunction, though the age of onset of dysfunction has not been defined. Left ventricular (LV) rotational mechanics have not been studied in children with SCD. The aim of this study was to investigate whether cardiac rotational mechanics differed between children with SCD and age-matched controls. METHODS: Basal and apical LV short-axis images were acquired prospectively in 213 patients with SCD (mean age, 14.1 ± 2.6 years) and 49 controls (mean age, 13.3 ± 2.8 years) from the Muhimbili Sickle Cohort in Dar es Salaam, Tanzania. The magnitude of basal and apical rotation, net twist angle, torsion, and untwist rate were obtained by two-dimensional speckle-tracking. The timing of events was normalized to aortic valve closure. RESULTS: Mean basal rotation was significantly lower in patients with SCD compared with controls (P = .012), although no difference was observed in apical rotation (P = .37). No statistically significant differences in torsion or net twist angle were detected. Rotation rate at the apex (P = .001) and base (P = .0004) were significantly slower in subjects with SCD compared with controls. Mean peak untwisting rate was also significantly slower in patients with SCD (P = .006). No associations were found between hemoglobin concentration and apical rotation, basal rotation, net twist, and torsion. CONCLUSION: This study demonstrates alterations in LV rotational mechanics in children with SCD, including lower basal rotation, peak differential twist, and untwist rate. These abnormalities denote subclinical changes in LV systolic and diastolic performance in children with SCD. Future work may reveal an association between rotational metrics and long-term patient outcomes.

Cardiac mechanics in patients with human immunodeficiency virus: a study of systolic myocardial deformation in children and young adults.

Human immunodeficiency virus (HIV) infection causes dysfunction of different organ systems. Myocardial diastolic dysfunction has been reported previously in an adult HIV population. Our aim was to study myocardial strain in children and young adults infected by HIV who have apparently normal ejection fraction. Forty HIV-infected patients (mean age 20.6 ± 1.5 years) with normal ejection fraction and 55 matched normal controls (mean age 17 ± 1.5 years) were studied by two-dimensional echocardiogram. The images were stored then exported to velocity vector imaging software for analysis. Measures considered were left-ventricular peak global systolic strain (LV S) and strain rate (LV SR) as well as right-ventricular peak global systolic strain (RV S) and strain rate (RV SR). Circumferential measures of the left ventricle included the following: LV circumferential peak global systolic strain (LV circ S), strain rate (LV circ SR), radial velocity (LV rad vel), and rotational velocity (LV rot vel) at the level of the mitral valve. Statistical significance was set at p < 0.05. The means of all longitudinal deformation parameters were significantly lower in HIV patients compared with normal controls: LV S (-14.15 vs. -19.31), LV SR (-0.88 vs. -1.30), RV S (-19.58 vs. -25.09), and RV SR (-1.34 vs. -2.13), respectively (p < 0.05). LV rot vel was lower in patients compared with controls (43.23 vs. 51.71, p = 0.025). LV circ S, LV circ SR, and LV rad vel showed no significant difference between the two groups (p ≥ 0.05). HIV infection affects longitudinal systolic cardiac strain and strain rate in children and young adults. Normal ejection fraction might be attributed to preserved circumferential myocardial deformation. Strain and strain rate may help identify HIV patients at high risk for cardiac dysfunction and allow early detection of silent myocardial depression.

Quantitative real-time three-dimensional echocardiography provides new insight into the mechanisms of mitral valve regurgitation post-repair of atrioventricular septal defect.

BACKGROUND: Mechanisms of mitral valve regurgitation after atrioventricular septal defect repair are unclear. METHODS: To gain further insight into mitral valve regurgitation, real-time three-dimensional echocardiography was performed in 53 patients after atrioventricular septal defect repair (30 partial and 23 complete) and 40 controls. Mitral valve {x, y, z} coordinates from the annulus, leaflet surface, papillary muscle, and chordal attachments were recorded. Vena contracta area of the regurgitant jet(s) and volume of leaflet prolapse and tethering were measured. RESULTS: Twenty-three patients had mild (group 1) and 30 moderate (group 2) mitral valve regurgitation. Patients in both groups 1 and 2 had more circular annuli than controls. Annular area was greater in group 2 than in group 1 and controls (P < .01). Group 2 had more frequent segmental prolapse in the superior-mural leaflet segment. The anterolateral papillary muscle was more laterally displaced in group 2 than in controls and group 1 at end-diastole (P = .01 and P = .05) and formed a more acute angle with the mitral valve annulus than in controls or group 1 (P = .01). CONCLUSIONS: In patients with atrioventricular septal defects, significant mitral valve regurgitation is associated with leaflet prolapse, larger annular area, and lateral papillary muscle displacement.

Foetal atrial flutter management-the role of electrical cardioversion.

We report a successful electrical cardioversion of a foetal atrial flutter (AFL) immediately post delivery. We describe the diagnostic tools, assessment and the management antenatally. Then, we review the literature and discuss the debate about management. We stress the point that if the flutter wave is not progressing, the foetal heart will tolerate till term and we can try electrical cardioversion with confidence after delivery.

Torsion of young hearts: a speckle tracking study of normal infants, children, and adolescents.

AIM: Our aim was to study the rotational mechanics of the heart in a special population including neonates, young children, and adolescents. We showed the effect of age on torsion and the different rotational variables. This study is the first that focuses on neonatal heart mechanics. METHODS AND RESULTS: We recruited 70 normal children between few hours and 18 years old. We excluded abnormal rhythm and function. Short-axis parasternal views were taken at the base of the heart and the apex. Using the speckle tracking technique, we analysed the rotation curves at apex and base and calculated the net twist and torsion of the left ventricle (LV). We also calculated the twist and untwist rates to get the correlation with age and body surface area (BSA). Rotational patterns during diastole also were studied. Deformational time delay between the base and the apex was looked up. Apical rotation and net twist increased with age significantly (r = 0.41 and 0.38, respectively, P = 0.001) but when normalized by LV length there was fixed torsion among age groups. Rotation velocity declined with ageing during systole and diastole for both base and apex (r = -0.58 and -0.62 for twist rate, -0.69 and -0.6 for untwist rate, respectively, P < 0.001). Concordant results were reported for BSA. Deformational delay was decreasing with age (r = -0.74 for systolic and -0.53 for diastolic, P < 0.001). CONCLUSION: Infants hearts tend to deform more and faster than other groups. While apical twist and net twist increase with age, torsion is fixed among age groups. In young hearts, torsion is the result of differential twist.

Normal rotational, torsion and untwisting data in children, adolescents and young adults.

BACKGROUND: Left ventricular (LV) torsion and untwisting are important components of LV performance, but there is little information on the effect of age, particularly in younger populations. METHODS: LV rotation and LV rotation rate, torsion, recoiling, and untwisting were measured in normal subjects (n=111) aged 3 to 40 years (mean age, 19.3 years) using speckle-tracking imaging. RESULTS: LV torsion increased with age because of the augmentation of apical LV rotation, but this disappeared when normalized by LV length. Although peak LV torsion and apical LV rotation increased with age, the normalized peak torsion rate decreased. As well, the peak untwisting rate decreased with age and was enhanced when normalized by LV length. Younger hearts demonstrated greater untwisting and recoiling of the apex during isovolumic relaxation and early diastole. The time difference between apical and basal events decreased with advancing age. CONCLUSION: The heart maintains a constant LV torsion and LV rotation profile when normalized by length and cardiac cycle. Younger hearts tend to twist, untwist, and deform faster.

Total anomalous pulmonary venous drainage to coronary sinus combined with left-sided obstructive lesions: a previously unreported association.

We present a very rare cardiac lesion where we found a combination of abnormal pulmonary venous drainage and left-sided obstructive lesions. This case gives new insight into the complex malformation of the heart, raising questions about cardiac embryology and timing of interfering events. Here we describe the lesion for the first time and review the related literature. To the best of our knowledge, this combination has never been reported.

Transposition of great arteries with constrictive ductus arteriosus revisited.

A case is presented of neonatal death despite prompt management of a baby diagnosed at 30 h of age with d-transposition of great arteries and intact ventricular septum, restrictive foramen ovale, and constrictive ductus arteriosus. The literature in this matter is reviewed and the poor prognosis of such cases despite rapid intervention is again emphasized.

A familial variant of the Scimitar syndrome with a meandering pulmonary vein.

We report a rare variant of the Scimitar syndrome, in which the right lower pulmonary vein takes a meandering course before finally connecting in normal fashion to the left atrium. The pulmonary parenchymal segment drained by the tortuous vein is supplied by a systemic collateral artery, which was coiled via a catheter. We also closed the intracardiac defects by surgery. The elder brother of the patient had classical Scimitar syndrome.