Echocardiography-Derived Left Ventricular Outflow Tract Gradient and Left Ventricular Posterior Wall Thickening Are Associated with Outcomes for Anatomic Repair in Congenitally Corrected Transposition of the Great Arteries

Results of the Double Switch Operation in Patients Who Previously Underwent Left Ventricular Retraining

BACKGROUND

Congenitally corrected transposition of the great arteries (CC-TGA) is a complex form of congenital heart disease that has numerous subtypes. While most patients with CC-TGA have a large ventricular septal defect (VSD) and pulmonary stenosis, there are some patients who have either no VSD or a highly restrictive VSD. These patients will require left ventricular (LV) retraining prior to double switch. The purpose of this study was to review our experience with the double switch procedure in patients who had previously undergone LV retraining.

METHODS

This was a retrospective review of a single institution experience with the double switch procedure in patients who had undergone LV retraining (2002-present).

RESULTS

Forty-five patients underwent double switch following LV retraining. Of these, 39 had an arterial switch with hemi-Mustard/bidirectional Glenn and six had a Senning. The median cross-clamp time was 135 min (range 71-272) and median bypass time was 202 min (range 140-430 min). Median hospital length of stay was eight days (range 4-108). There were no in-hospital deaths. Median duration of follow-up was 30 months (range 0-175). One patient subsequently underwent heart transplantation and died 65 months following double switch. At follow-up, 41 of the 44 survivors (93%) have normal or low normal LV function and 40 of the 44 survivors (91%) have no or trace mitral regurgitation.

CONCLUSIONS

The data demonstrate early and mid-term survival of 100% and 97%. Ninety-three percent had preserved LV function. These results suggest that patients with CC-TGA who undergo LV retraining and double switch can have excellent clinical outcomes.

ANALYSIS OF ECHOCARDIOGRAPHIC AND MRI ANATOMICAL CHARACTERISTICS AND HEMODYNAMIC CHARACTERISTICS OF LEFT VENTRICULAR OUTFLOW TRACT STENOSIS

Objective: To analyze the anatomical morphological and hemodynamic characteristics of left ventricular outflow tract stenosis (LVOTS) by echocardiography and MRI. Methods: The Echocardiography data of 112 patients with LVOTS were retrospectively analyzed by measuring the basal interventricular septal thickness (IVST-b), the left ventricle posterior wall thickness (LVPWT), and the peak pressure gradient of LVOTS, as well as by observing the characteristics of spectral pattern and the presence of systolic anterior motion of mitral valve leaflets. A Siemens 3.0T MRI scanner was used to scan the contrast-enhanced left ventricular (LV) volume of all cases. The obtained end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV) and ejection fraction (EF) of LV were compared with the Echocardiography results. Results: The 112 patients were divided into four groups: hypertrophic obstructive cardiomyopathy (Group I, 42 cases), hypertensive left ventricular hypertrophy (Group II, 40 cases), basal septal hypertrophy in the elderly (Group III, 21 cases), and the subaortic membrane (Group IV, 9 cases). The continuous wave (CW) Doppler characteristic of Groups I, II, and III was broadsword-shaped jet, and that of Group IV was equilateral triangle-like spectrum. The IVST-b, IVST-b/LVPWT ratio and peak pressure gradient of LVOTS of Group I was significantly higher than those in Groups II and III ([Formula: see text]). The LVPWT of the first three groups was slightly correlated with the LVOTS peak pressure gradient ([Formula: see text], respectively, [Formula: see text]). There were no statistically significant differences between Echocardiography and MRI results regarding the LV EDV, ESV, SV, and EF ([Formula: see text]), and no statistically significant differences were found between Echocardiography and MRI results regarding the myocardial thicknesses of septal, anterior, lateral, and inferior walls ([Formula: see text]). The Pearson’s correlation analysis demonstrated correlations between MRI and Echocardiography results for LV EDV, ESV, SV, and EF ([Formula: see text], 0.002, 0.009, and [Formula: see text], respectively). The MRI enhancement was shown as delayed enhancement in 52 cases, localized enhancement in 8 cases, diffuse enhancement in 6 cases, and transmural enhancement in 3 cases, with abnormal enhancement lesions distributed in the area of ventricular septum free wall junctions and ventricular septum. Conclusion: Using MRI to evaluate LV function of hypertrophic cardiomyopathy is reliable and accurate. MRI enhancement can be used for the quantitative measurement of myocardial fibrosis. Echocardiography can distinguish the stenosis types of LVOTS. The IVST-b and existence of SAM may be important anatomical characteristics determining the degree of dynamic stenosis, and MRI combined with Echocardiography can provide important detailed information.

Pattern Analysis of Left Ventricular Remodeling Using Cardiac Computed Tomography in Children with Congenital Heart Disease: Preliminary Results

OBJECTIVE

To assess left ventricular remodeling patterns using cardiac computed tomography (CT) in children with congenital heart disease and correlate these patterns with their clinical course.

MATERIALS AND METHODS

Left ventricular volume and myocardial mass were quantified in 17 children with congenital heart disease who underwent initial and follow-up end-systolic cardiac CT studies with a mean follow-up duration of 8.4 ± 9.7 months. Based on changes in the indexed left ventricular myocardial mass (LVMi) and left ventricular mass-volume ratio (LVMVR), left ventricular remodeling between the two serial cardiac CT examinations was categorized into one of four patterns: pattern 1, increased LVMi and increased LVMVR; pattern 2, decreased LVMi and decreased LVMVR; pattern 3, increased LVMi and decreased LVMVR; and pattern 4, decreased LVMi and increased LVMVR. Left ventricular remodeling patterns were correlated with unfavorable clinical courses.

RESULTS

Baseline LVMi and LVMVR were 65.1 ± 37.9 g/m² and 4.0 ± 3.2 g/mL, respectively. LVMi increased in 10 patients and decreased in seven patients. LVMVR increased in seven patients and decreased in 10 patients. Pattern 1 was observed in seven patients, pattern 2 in seven, and pattern 3 in three patients. Unfavorable events were observed in 29% (2/7) of patients with pattern 1 and 67% (2/3) of patients with pattern 3, but no such events occurred in pattern 2 during the follow-up period (4.4 ± 2.7 years).

CONCLUSION

Left ventricular remodeling patterns can be characterized using cardiac CT in children with congenital heart disease and may be used to predict their clinical course.

Global diastolic strain rate for the assessment of left ventricular diastolic dysfunction in young peritoneal dialysis patients: a case control study

Background

Left ventricular (LV) myocardial longitudinal diastolic strain rate measured by two-dimensional speckle tracking imaging (2D-STI) was proved to have a better correlation with the LV diastolic function. We aimed to use this sensitive tool to predict LV myocardial diastolic dysfunction in young peritoneal dialysis (PD) patients with preserved LV ejection fraction (LVEF).

Methods

We enrolled 30 PD patients aged ≤60 with LVEF ≥54% and classified as normal LV diastolic function by conventional echocardiography, and 30 age- and sex-matched healthy people as the control group. The left atrial maximum volume index (LAVI), LV mass index (LVMI), LVEF, LV posterior wall thickness (LVPWT), interventricular septal thickness (IVST), peak velocity of tricuspid regurgitation (TR), peak early diastolic velocity/late diastolic velocity (by Pulsed Doppler) (E/A) and E/peak velocity of the early diastolic wave (by Pulsed-wave tissue Doppler) (E/e’) were recorded by conventional echocardiographic. Next, the average LV global longitudinal systolic strain (GLS avg) and the average LV global longitudinal diastolic strain rate (DSr avg) during early diastole (DSrE avg), late diastole (DSrA avg) and isovolumic relaxation period (DSrIVR avg) were obtained from 2D-STI. Combined them with E, the new noninvasive indexes (E/DSrE avg., E/DSrA avg. and E/DSrIVR avg) were derived.

Results

The PD group ‘s LVEF, E/e′, TR and LAVI were in the normal range compared with the controls, and only e′ (p < 0.001) was decreased. The LVMI (p < 0.001), LVPWT (p < 0.001), IVST (p < 0.001) increased while E/A (p < 0.001) decreased. The GLS avg. (p = 0.008) was significantly decreased in PD patients compared with the controls. DSrA avg. (p = 0.006) and E/DSrE avg. (p = 0.006) were increased, while DSrE avg. (p < 0.001), DSrIVR avg. (p = 0.017) and E/DSrA avg. (p < 0.001) decreased. After the multivariable regression analysis, the correlation between DSrE and the conventional parameters including LVPWT (p < 0.001), E/A (p < 0.001) still remained significant.

Conclusions

Young PD patients with preserved LVEF already exhibited myocardial diastolic dysfunction. Global diastolic strain rate indexes were valuable parameters to evaluate diastolic dysfunction. Additionally, LVPWT was highly correlated with DSrE, such parameter should be taken into account for predicting the early LV diastolic dysfunction in clinical practice.

Left Ventricular Re-training: Feasibility and Effectiveness-What Are the Limits?

The concept of 're-training' the morphologic left ventricle (mLV) is based on the crude principle of applying a fixed afterload by means of pulmonary artery banding. The complex physiological, molecular and structural responses to banding are poorly understood, and complicated by the fact that re-training is undertaken in a variety of different morphological settings and age-groups. This article reviews the evidence for re-training in different situations with particular focus on the age at banding and on the best ways to assess suitability for subsequent repair. Particular importance is placed on the role of re-training in congenitally corrected transposition as this is the commonest current indication - looking at better ways to train the mLV, the role of combined pressure and volume loading, and more sophisticated ways of assessing the adequacy of training. Current evidence suggests that age at banding has a fundamental impact on ability to re-train and long-term mLV function with the best results being achieved in infancy and concerns at any attempt beyond 2 years of age.