Left ventricular synchrony, torsion, and recoil mechanics in Ebstein's anomaly: insights from cardiovascular magnetic resonance.

BACKGROUND: Disease progression and heart failure development in Ebstein's Anomaly (EA) of the tricuspid valve is characterized by both right and left ventricular (LV) deterioration. The mechanisms underlying LV dysfunction and their role in heart failure development are incompletely understood. We hypothesized that LV dyssynchrony and impaired torsion and recoil mechanics induced by paradoxical movement of the basal septum may play a role in heart failure development. METHODS: 31 EA patients and 31 matched controls underwent prospective cardiovascular magnetic resonance (CMR). CMR feature tracking (CMR-FT) was performed on apical, midventricular and basal short-axis and 4D-volume analysis was performed using three long-axis views and a short axis cine stack employing dedicated software. Circumferential uniformity ratio estimates (CURE) time-to-peak-based circumferential systolic dyssynchrony index (C-SDI), 4D volume analysis derived SDI (4D-SDI), torsion (Tor) and systolic (sysTR) and diastolic torsion rate (diasTR) were calculated for the LV. QRS duration, brain natriuretic peptide, NYHA and Total R/L-Volume Index (R/L Index) were obtained. RESULTS: EA patients (31.5 years; controls 31.4 years) had significantly longer QRS duration (123.35 ms ± 26.36 vs. 97.33 ms ± 11.89 p < 0.01) and showed more LV dyssynchrony (4D-SDI 7.60% ± 4.58 vs. 2.54% ± 0.62, p < 0.001; CURE 0.77 ± 0.05 vs. 0.86 ± 0.03, p < 0.001; C-SDI 7.70 ± 3.38 vs. 3.80 ± 0.91, p = 0.001). There were significant associations of LV dyssynchrony with heart failure parameters and QRS duration. Although torsion and recoil mechanics did not differ significantly (p > 0.05) there was an association of torsion and recoil mechanics with dyssynchrony parameters CURE (sysTR r = -0.426; p = 0.017, diasTR r = 0.419; p = 0.019), 4D-SDI (sysTR r = 0.383; p = 0.044) and C-SDI (diasTR r = -0.364; p = 0.044). CONCLUSIONS: EA is characterized by LV intra-ventricular dyssynchrony, which is associated with heart failure and disease severity parameters. Markers of dyssynchrony can easily be quantified from CMR-FT, and may have a role in the assessment of altered cardiac function, carrying potential management implications for EA patients.

Right Atrial Volume is Increased in Corrected Tetralogy of Fallot and Correlates with the Incidence of Supraventricular Arrhythmia: A CMR Study.

The aim of this study was to evaluate right atrial (RA) volume in corrected Tetralogy of Fallot (cTOF) and assess its correlation with the occurrence of supraventricular (SV) arrhythmia. Cardiac magnetic resonance imaging (CMR) and 24-h Holter were performed in n = 67 consecutive cTOF patients (age 30 ± 11.3 years). The CMR protocol included standard HASTE, SSFP cine, and blood flow measurements. Correlations between arrhythmia in ECG, heart volume, and functional parameters were investigated by negative binominal regression. Patients' characteristics (mean ± SD) included mean RA volume of 49 ± 19 ml/m(2) (HASTE sequence), mean right ventricular (RV) end-diastolic volume of 98 ± 27 ml/m(2), mean pulmonary valve regurgitation fraction (PR) of 21 ± 19 %, BMI of 25 kg/m(2), and heart rate of 75/min. Twenty-eight out of 67 patients experienced SV arrhythmia including SV couplets or bigeminus or longer non-sustained SV tachycardia (SVT) episodes. RA volume index was identified as an independent risk factor for different degrees of SV arrhythmia (SV couplets/bigeminus p < 0.001, SVT p < 0.001). Further risk factors for SV arrhythmia were male gender (p = 0.023) and decreased left ventricular (LV) ejection fraction (EF) (LV EF p < 0.001). RA volume is increased in adult patients with cTOF with larger RA volumes relating to higher incidence of SV arrhythmia. SV arrhythmia also appeared more often in male patients and those with decreased LV EF. Risk stratification according to these parameters could help to optimize early prevention and adjusted individual therapy to improve patient outcome and quality of life.

Atrio-ventricular deformation and heart failure in Ebstein's Anomaly - A cardiovascular magnetic resonance study.

PURPOSE: We aimed to quantify atrial and ventricular myocardial deformation in Ebstein's Anomaly (EA) in a case-control study with cardiovascular magnetic resonance (CMR) feature tracking and to correlate changes in cardiac performance with the severity of disease and clinical heart failure parameters. MATERIALS AND METHODS: Atrial and ventricular deformation was measured using CMR feature tracking in 30 EA and 20 healthy control subjects. Atrial performance was characterized using longitudinal strain and strain rate parameters for reservoir function, conduit function and booster pump function. Ventricular performance was characterized using RV and LV global longitudinal strain (εl) and LV circumferential and radial strain (εc and εr). Volumetric measurements for the ventricles including the Total Right/Left-Volume-Index (R/L-Volume-Index) and heart failure markers (BNP, NYHA class) were also quantified. RESULTS: EA patients showed significantly impaired right atrial performance, which correlated with heart failure markers (NYHA, BNP, R/L-Volume-Index). LA function in EA patients was also impaired with atrial contractile function correlating with NYHA class. EA patients exhibited impaired RV myocardial deformation, also with a significant correlation with heart failure markers. CONCLUSION: CMR feature tracking can be used to quantify ventricular and atrial function in a complex cardiac malformation such as EA. EA is characterized by impaired quantitative right heart atrio-ventricular deformation, which is associated with heart failure severity. While LV function remains preserved, there is also significant impairment of LA function. These quantitative performance parameters may represent early markers of cardiac deterioration of potential value in the clinical management of EA.

Non-invasive estimation of pulmonary outflow tract obstruction: A comparative study of cardiovascular phase contrast magnetic resonance and Doppler echocardiography versus cardiac catheterization.

AIM: To compare estimated pressure gradients from routine follow-up cardiovascular phase-contrast magnetic resonance (PC-MR) with those from Doppler echocardiography and invasive catheterization in patients with congenital heart disease (CHD) and pulmonary outflow tract obstruction. METHODS: In 75 patients with pulmonary outflow tract obstruction maximal and mean PC-MR gradients were compared to maximal and mean Doppler gradients. Additionally, in a subgroup of 31 patients maximal and mean PC-MR and Doppler pressure gradients were compared to catheter peak-to-peak pressure gradients (PPG). RESULTS: Maximal and mean PC-MR gradients underestimated pulmonary outflow tract obstruction as compared to Doppler (max gradient: bias = + 8.4 mm Hg (+ 47.6%), r = 0.89, p < 0.001; mean gradient: + 4.3 mm Hg (+ 49.0%), r = 0.88, p < 0.001). However, in comparison to catheter PPG, maximal PC-MR gradients (bias = + 1.8 mm Hg (+ 8.8%), r = 0.90, p = 0.14) and mean Doppler gradients (bias = - 2.3 mm Hg (- 11.2%), r = 0.87, p = 0.17) revealed best agreement. Mean PC-MR gradients underestimated (bias = - 7.7 mm Hg (- 55.6%), r = 0.90, p < 0.001) while maximal Doppler gradients systematically overestimated catheter PPG (bias = + 13.9 mm Hg (+ 56.5%), r = 0.88, p < 0.001). CONCLUSIONS: Estimated maximal PC-MR pressure gradients from routine CHD follow-up agree well with invasively assessed peak-to-peak pressure gradients. Estimated maximal Doppler pressure gradients tend to overestimate, while Doppler mean gradients agree better with catheter PPG. Therefore, our data provide reasonable arguments to either apply maximal PC-MR gradients or mean Doppler gradients to non-invasively evaluate the severity of pulmonary outflow tract obstruction in the follow-up of CHD.

BNP and haematological parameters are markers of severity of Ebstein's anomaly: correlation with CMR and cardiopulmonary exercise testing.

AIMS: Ebstein's anomaly (EA) involves a displaced and dysplastic tricuspid valve resulting in an atrialized portion of the right ventricle and an enlargement of the functional right ventricle and right atrium. Biomarkers targeting heart failure such as brain natriuretic peptide (BNP) or haematological parameters [haemoglobin (Hb) and haematocrit (Hct)] are upregulated in states of pulmonary hypoperfusion. We hypothesized that decreased pulmonary perfusion dependent on the stage of right heart failure is a possible mechanism in EA, and that it can be correlated with cardiac magnetic resonance (CMR) parameters. The aim of this study was to investigate the relationship between BNP and haematological parameters with functional parameters from CMR and exercise testing in patients with EA. METHODS AND RESULTS: Twenty-five patients with non-corrected EA were studied prospectively (mean age 26 ± 14 years). BNP level was increased (74 ± 127 ng/L), and in 16% markedly above the heart failure cut-off level of 100 ng/L. Hb and Hct were increased above normal levels in 20 and 24% of patients, respectively. BNP and Hct/Hb correlated with CMR [total right/left (R/L)-Volume-Index, right atrium-end-diastolic volume index (EDVi), functional right ventricle (fRV)-EDVi, fRV-ejection fraction (EF), tricuspid regurgitation, pulmonary artery flow, and left ventricular EF] and exercise testing [workload/kg, oxygen uptake (VO2), ventilatory response to carbon dioxide production (VE/VCO2), oxygen (O2) pulse, and heart rate reserve]. The higher BNP and haematological parameters, the higher was the disease severity and the more limited was the physical exercise capacity. CONCLUSION: In this EA cohort, BNP levels and haematological parameters correlated well with functional data from CMR and exercise testing. The total R/L-Volume-Index and BNP, and to some extent hematological parameters, may be useful as prognostic markers in patients with EA.

The total right/left-volume index: a new and simplified cardiac magnetic resonance measure to evaluate the severity of Ebstein anomaly of the tricuspid valve: a comparison with heart failure markers from various modalities.

BACKGROUND: The classification of clinical severity of Ebstein anomaly still remains a challenge. The aim of this study was to focus on the interaction of the pathologically altered right heart with the anatomically-supposedly-normal left heart and to derive from cardiac magnetic resonance (CMR) a simple imaging measure for the clinical severity of Ebstein anomaly. METHODS AND RESULTS: Twenty-five patients at a mean age of 26±14 years with unrepaired Ebstein anomaly were examined in a prospective study. Disease severity was classified using CMR volumes and functional measurements in comparison with heart failure markers from clinical data, ECG, laboratory and cardiopulmonary exercise testing, and echocardiography. All examinations were completed within 24 hours. A total right/left-volume index was defined from end-diastolic volume measurements in CMR: total right/left-volume index=(RA+aRV+fRV)/(LA+LV). Mean total right/left-volume index was 2.6±1.7 (normal values: 1.1±0.1). This new total right/left-volume index correlated with almost all clinically used biomarkers of heart failure: brain natriuretic peptide (r=0.691; P=0.0003), QRS (r=0.432; P=0.039), peak oxygen consumption/kg (r=-0.479; P=0.024), ventilatory response to carbon dioxide production at anaerobic threshold (r=0.426; P=0.048), the severity of tricuspid regurgitation (r=0.692; P=0.009), tricuspid valve offset (r=0.583; P=0.004), and tricuspid annular plane systolic excursion (r=0.554; P=0.006). Previously described severity indices ([RA+aRV]/[fRV+LA+LV]) and fRV/LV end-diastolic volume corresponded only to some parameters. CONCLUSIONS: In patients with Ebstein anomaly, the easily acquired index of right-sided to left-sided heart volumes from CMR correlated well with established heart failure markers. Our data suggest that the total right/left-volume index should be used as a new and simplified CMR measure, allowing more accurate assessment of disease severity than previously described scoring systems.