Subtle Myocardial Dysfunction and Fibrosis in Children with Rheumatic Heart Disease: Insight from 3D Echocardiography, 3D Speckle Tracking and Cardiac Magnetic Resonance Imaging.

Rheumatic heart disease (RHD) is a major cause of morbidity and mortality in developing countries, so early diagnosis and treatment can reduce morbidity and mortality resulting from subsequent valvular damage. The aim of this study was to detect subtle myocardial dysfunction among children with RHD with preserved left ventricular systolic function. This is a cross-sectional case-control study that was conducted on 30 children with RHD (who had valvular affection of any degree and were not in activity) compared to 23 healthy children. After history taking and cardiac examination, 2D echocardiography, tissue Doppler imaging, 3D-echocardiography and 3D speckle tracking echocardiography were done to both groups, whereas cardiac magnetic resonance imaging was done only to the patient group. The 3D-derived left ventricular end-diastolic volume and sphericity index among patients were significantly increased when compared to controls [131.5 (101.5 to 173.7) vs. 69 (58 to 92), P = 0.001, and 0.46 (0.36 to 0.59) vs. 0.33 (0.29 to 0.38), P = 0.001, respectively]. The 3D-derived ejection fraction and longitudinal strain did not differ significantly among both groups. The 3D-derived global circumferential strain was higher in patients when compared to controls [- 14 (- 16 to - 10) vs. - 11(- 13 to - 10), P = 0.04]. None of the examined patients demonstrated late enhancement myocardial fibrosis. In children with RHD and preserved systolic function, subtle systolic dysfunction could not be detected using conventional and novel non-conventional methods. This may indicate that the myocardial affection during the acute stage of rheumatic carditis is minimal with almost complete resolution.

Unusual cause of neonatal cyanosis.

We present a case of a full-term female neonate who presented at 6 h of age with severe cyanosis and was partially responsive to oxygen supplementation. An echocardiogram showed an isolated congenital severe tricuspid valve insufficiency due to rupture of the papillary muscle of the anterior tricuspid valve leaflet. Magnesium sulfate was infused to lower the pulmonary resistance and thus enhancing the antegrade pulmonary blood flow. Ductal patency was secured by prostaglandin infusion thus providing an additional pulmonary blood flow through the ductus arteriosus. The above measures were adequate to stabilize the patient with no further deterioration or the need for other supportive measures such as Nitric Oxide therapy or extracorporeal membrane oxygenation (ECMO). Therefore, early diagnosis and adequate measures to improve the pulmonary blood flow are mandatory, important pre-operative measures in the management of these patients.

Advantages of C2 monitoring to avoid acute rejection in pediatric heart transplant recipients.

BACKGROUND: Inadequate cyclosporine (CsA) blood levels are a major risk factor for acute rejection in transplant recipients. The CsA trough level (C0 level) measured just before the next dose is commonly used to adjust the oral dosage. However, the 2-hour post-CsA dose concentration (C2 level) is favored as the best single-point correlate of CsA area-under-the-curve concentration and may better reflect the immunosuppressive effect of CsA. Because an adequate C2 level has not yet been defined, this study was performed to assess the value of C2 monitoring for the prevention of acute rejection and to define target levels in pediatric heart transplant recipients. METHODS: C2 levels were assessed in 50 pediatric heart transplant patients with oral CsA therapy and compared with trough C0 levels using full blood sampling, mass spectrometry and a blinded analysis. Acute graft rejection was detected using intramyocardial electrocardiogram (IMEG) and serial conventional and tissue Doppler echocardiography (TDE). Rejection was confirmed or excluded by endomyocardial biopsy. RESULTS: C2 and not C0 levels were significantly reduced in patients with acute graft rejection (ISHLT Grade > or =2). Patients with a C2 level <600 ng/ml had a significantly higher risk of developing acute rejection (100% sensitivity and 82% specificity). Patients with impaired CsA absorption were identified with C2 monitoring and switched to another calcineurin inhibitor. CONCLUSIONS: Monitoring of the C2 rather than the C0 level better reflects immunosuppressive efficiency and identifies patients at increased risk of acute rejection. A C2 level of >600 ng/ml should be the target to prevent acute rejection.

Comparison of the tissue Doppler-derived left ventricular Tei index to that obtained by pulse Doppler in patients with congenital and acquired heart disease.

We compared the left ventricular Tei index measured by tissue Doppler imaging (TDI) to that obtained by pulsed Doppler (PW) in patients with congenital heart disease. In 40 consecutive patients with a variety of congenital and acquired heart diseases, the left ventricular (LV) PW Doppler-derived Tei index was assessed on-line as previously described. TDI-derived anatomic curved M-mode and the unprocessed velocity trace from the basal septum were used to time the opening and closure of the mitral and aortic valves in one cardiac cycle, respectively. The TDI Tei index was calculated off-line according to the equation (isovolumetric relaxation time + isovolumetric contraction time)/ ejection time. The Tei index calculated from TDI correlated significantly with that measured by pulsed Doppler (r = 0.92, p = 0.001). The mean difference (range) between pulsed Doppler-derived Tei index and TDI-derived Tei index was 0.005 (-0.07-0.06), which was within the limits of agreements. Interobserver variability for the TDI-derived Tei index was 5 +/- 3%. The TDI Tei index can be used to assess the global LV function in patients with congenital heart disease. In contrast to the PW Doppler-derived Tei index, the TDI-derived Tei index obtained from the same cardiac cycle may help to differentiate systolic from diastolic dysfunction by providing specific information on the isovolumetric intervals.

Quantitative analysis of paradoxical interventricular septal motion following corrective surgery of tetralogy of fallot.

This study aimed to quantify paradoxical interventricular septal motion (PSM) among 20 patients following tetralogy of Fallot (TOF) repair without severe pulmonary regurgitation and 20 age-matched normal subjects. PSM was quantified using the echocardiography-derived paradox index. Tissue Doppler-derived strain rate was used to assess the longitudinal and radial systolic function of the interventricular septum (IVS). The tissue Doppler-derived Tei index was used to assess the global left ventricular function. Compared to the control group, the paradox index in patients after repair of TOF was significantly higher (p = 0.001), whereas the regional IVS longitudinal (p = 0.02) and radial (p = 0.001) systolic strain rate peaks were significantly reduced. The paradox index in the patient group correlated inversely with the IVS radial peak systolic strain rate (r = -0.64, p = 0.004) and positively with QRS duration (r = 0.50, p = 0.02). The left ventricular (LV) Tei-index correlated significantly with the paradox index (r = 0.71, p = 0.001) and with the septal radial systolic strain rate peak (r = 0.59, p = 0.004). We conclude that electrical delay and reduced regional septal systolic function were the main causes for paradoxical septal motion among patients following TOF repair without significant pulmonary regurgitation. The reduced LV systolic function among this group of patients is mainly secondary to diminished septal systolic function and the paradoxical septal motion.

Comparison of modified short axis view and apical four chamber view in evaluating right ventricular function after repair of tetralogy of Fallot.

BACKGROUND: In clinical settings an easy and reliable method for following up right ventricular (RV) function in patients after repair of tetralogy of Fallot (TOF) is needed. It is, however, unclear whether the novel modified short axis view from echocardiography is superior to the apical four chamber view in this aspect. MATERIALS AND METHODS: Thirty postoperative TOF patients with median age 17 years (range 6-45 years) and follow up period of 10 years (range 0.5-40 years) were examined echocardiographically using the apical four chamber view and the novel modified short axis view. RV areas in end-systole (Amin) and end-diastole (Amax) were measured and an area fraction [(Amax - Amin)/Amax * 100%] was calculated from the respective view. RV ejection fraction was assessed through magnetic resonance imaging (MRI). The RV area fractions from echocardiography were compared to the RV ejection fraction. RESULTS: The right ventricular area fraction derived from the modified short axis view was significantly lower than that from the apical four chamber view (34.3+/-9.1% vs. 42.5+/-10.2%, p=0.007). Both the RV area fractions obtained from the modified short axis view (r=0.674, p<0.001) and from the apical four chamber view (r=0.512, p=0.025) correlated significantly with the MRI derived RV ejection fraction. CONCLUSION: The novel modified short axis view from echocardiography may be superior to the apical four chamber view for routine follow up of patients after TOF repair, in whom the right ventricular outflow tract plays an important role in the right ventricular systolic function.

Analysis of atrial and ventricular performance by tissue Doppler imaging in patients with atrial septal defects before and after surgical and catheter closure.

OBJECTIVE: To compare the effects of surgical and device closure of atrial septal defects on atrial and ventricular performance assessed by the novel tissue Doppler derived strain rate. BACKGROUND: Despite the increasing number of transcatheter closures, there is no information comparing the effect of the transcatheter closure technique on atrial performance with that of conventional surgery. Tissue Doppler derived strain rate can effectively quantify local myocardial function independent of the overall heart motion. DESIGN AND PATIENTS: Twenty-four patients [aged 21.5 (6-70) years] with isolated atrial septal defect of the secondum type before and 1 week after surgical (n = 12) or Amplatzer Septal Occluder closure (n = 12) and 30 healthy controls [aged 26.0 (2-58) years] were studied. Atrial and ventricular strain rate curves were assessed in the middle of their corresponding lateral walls in an apical four-chamber view. The systolic, early diastolic, and late diastolic strain rates peaks were measured. RESULTS: Compared to preclosure condition, the right atrial late diastolic (P < 0.01), right ventricular systolic (P < 0.01), right ventricular early diastolic (P < 0.01), and left atrial late diastolic peak (P < 0.01) strain rates were reduced after surgery but not after Amplatzer Septal Occluder closure. The LV parameters did not significantly differ before and after atrial septal defect closure by either technique. CONCLUSIONS: In contrast to surgery, transcatheter closure of atrial septal defect preserves atrial and right ventricular function. Tissue Doppler derived strain rate can be applied to provide quantitative analysis of regional atrial and ventricular performance.

Assessment of myocardial function of the systemic right ventricle in patients with D-transposition of the great arteries after atrial switch operation by tissue Doppler echocardiography.

INTRODUCTION: The long-term follow-up of patients with D-transposition of the great arteries after atrial switch operation shows specific problems such as tricuspid valve insufficiency, rhythm disturbances and failure of the morphologic right ventricle in systemic position. Assessment of the myocardial contractility of the subaortic right ventricle by conventional echocardiography is limited. The usage of tissue Doppler echocardiography with strain combined with strain rate imaging provides a new approach for quantitative analysis of longitudinal myocardial function. The aim of this study was to assess patterns of wall motion and regional contractile function of the systemic right ventricle in patients after atrial switch operation for D-transposition of the great arteries and to compare them to those of normal subjects. PATIENTS AND METHODS: Twenty-four patients with Dtransposition of the great arteries after atrial switch operation with a mean age of 21.3 (range, 13 to 31) years and a postoperative period of 16.9 years were examined and compared to 22 control individuals with a mean age of 21.5 (range, 3 to 43) years. Tissue Doppler studies were obtained from apical 4- chamber view to determine regional systolic (Syst(T)) and diastolic (E(T), A(T)) velocities as well as E(T)/A(T) ratio at the basal free wall. The presystolic isovolumic contraction peak was assessed and the ratio of the presystolic peak velocity to the isovolumic acceleration time as the IVA index was calculated. Strain and peak systolic and diastolic strain rates were assessed on basal, middle and apical segments of the right ventricular free wall. Data obtained from the morphologic right systemic ventricle in patients were compared to those derived from the left and the right ventricle in controls. RESULTS: The right ventricular free wall systolic velocities were significantly reduced in patients compared to velocities obtained from the normal right and left ventricle. On the other hand, the IVA index was only reduced in patients compared to the IVA index in the normal subpulmonary right ventricle. Compared to data obtained from the normal systemic left ventricle, the IVA index in patients was not significantly different. In contrast, strain and strain rate parameters in all analyzed segments mostly showed a highly significant reduction compared to normal right and left ventricular data. CONCLUSION: Tissue Doppler echocardiography is a promising tool for the evaluation of regional myocardial contractile function of the morphologic right systemic ventricle in patients following atrial switch operation for D-transposition of the great arteries. Presystolic, systolic and diastolic regional ventricular function was reduced in the systemic right ventricle. However, further comparative studies using other quantitative parameters of global and regional myocardial function derived from cardiac catheterization or MRI should be performed in order to evaluate the reliability of tissue Doppler echocardiography for the assessment of global right ventricular function in these patients.

Value of the new Doppler-derived myocardial performance index for the evaluation of right and left ventricular function following repair of tetralogy of fallot.

The systolic and diastolic function in both ventricles may be altered even after successful corrective surgery of tetralogy of Fallot. The aim of this study was to assess the combined diastolic and systolic function of both ventricles using the Doppler-derived myocardial performance index (MPI) in patients with operated tetralogy of Fallot (TOF). We performed a prospective analysis of 51 patients following corrective surgery of TOF: 21 had a subannular patch, 20 had a homograft implantation at initial operation, and 10 were reoperated with secondary homograft implantation. Patients were examined with Doppler echocardiography, and the MPI, which incorporates ejection and isovolumetric relaxation and contraction times and is an index of global ventricular function, was calculated 10.2 +/- 8.0 (0.89-36) years after surgery. In 86.4% of the examined patients the right ventricular isovolumetric relaxation time was shortened compared to the normal published range or even did not exist (negative value) (p <0.01). The right ventricular MPI was paradoxically below the normal published range in 76.5% of the examined patients. The left ventricle global function was impaired in 23.5% of the examined patients, mainly due to altered systolic function with a prolonged left ventricular isovolumetric contraction time. The z score of the comparison between patients' left ventricular isovolumetric contraction time and the normal published values was 3.03. Patients with severe pulmonary regurgitation also had a prolongation of the isovolumetric relaxation time compared to patients with mild to moderate pulmonary regurgitation. The noncompliant right ventricle may shorten the right ventricular isovolumetric relaxation time, resulting in a paradoxically low right MPI. This may reduce the sensitivity of the index in recognizing patients with right ventricular dysfunction following corrective surgery of TOF. Additional diastolic impairment occurs in patients with right ventricular volume overload.

Relation between right ventricular enlargement, QRS duration, and right ventricular function in patients with tetralogy of Fallot and pulmonary regurgitation after surgical repair.

OBJECTIVE: In patients with repaired tetralogy of Fallot, to examine (1) a possible relation between right ventricular enlargement and QRS prolongation, and (2) the effect of right ventricular enlargement caused by pulmonary regurgitation on the right ventricular ejection fraction, evaluated by three dimensional echocardiography, and global function, evaluated by the myocardial performance index. DESIGN AND PATIENTS: 40 patients with repaired tetralogy were studied. Right ventricular volumes were derived from three dimensional echocardiographic data after this method had been validated by comparison with magnetic resonance imaging in 21 patients. Ejection fraction was calculated from end diastolic and end systolic volumes. The Doppler derived myocardial performance index was measured in all patients. Measured data were correlated with QRS duration. SETTING: Tertiary cardiac centre for congenital heart disease. RESULTS: There was good agreement between three dimensional echocardiographic and magnetic resonance assessment of right ventricular volumes and ejection fraction. The z score of the right ventricular end diastolic volume and ejection fraction of all patients was 1.35 and -4.15, respectively. Patients with severe pulmonary regurgitation had a lower right ventricular ejection fraction (p < 0.01) and an increased myocardial performance index (p < 0.01) compared with patients with mild to moderate pulmonary regurgitation. The correlation between ejection fraction and right ventricular end diastolic volume was r = -0.35 (p < 0.05). The mean (SD) QRS duration was 131.89 (25.69) ms, range 80-180 ms. The correlation between QRS duration and right ventricular end diastolic volume was r = 0.6 (p < 0.01). CONCLUSIONS: There is a correlation between the right ventricular size obtained by three dimensional echocardiography and QRS duration on the surface ECG, indicating mechanoelectrical interaction. The severity of pulmonary regurgitation has a negative influence on right ventricular ejection fraction and combined systolic and diastolic global function, as assessed by myocardial performance.