Accuracy of Imaging Modalities in Detection of Baffle Leaks in Patients Following Atrial Switch Operation.

AIMS: Patients with dextro-transposition of the great arteries (d-TGA) status post atrial switch operation are vulnerable to complications such as baffle leaks. The best noninvasive imaging modality to detect baffle leaks is unknown. The purpose of this study was to determine the sensitivity and specificity of different noninvasive imaging modalities in the detection of baffle leaks in this population. METHODS AND RESULTS: A single center retrospective chart review of atrial switch patients was performed. Sensitivity, specificity, negative predictive value, and positive predictive value for detecting leaks were calculated for transthoracic echocardiogram (TTE) with and without agitated saline, transesophageal echocardiogram (TEE) with and without agitated saline, and cardiac magnetic resonance imaging (cMRI). Studies were included if performed within 1 year of catheterization. Angiography via catheterization was used as the gold standard for the detection of baffle leaks. Fifty-eight atrial switch patients (54 Mustards: four Sennings) from a single pediatric center, undergoing 76 catheterizations, were analyzed. Thirty-nine catheterizations documented a baffle leak. Overall combination of sensitivity and specificity was better in agitated saline studies (TTE: sensitivity 71.4%, specificity 100%; TEE: sensitivity 100%, specificity 92.3%) versus nonagitated studies (TTE: sensitivity 50.0%, specificity 100%; TEE: sensitivity 83.3%, specificity 77.8%; or cMRI: sensitivity 66.7%, specificity 100%). CONCLUSION: TTE or TEE with agitated saline is superior to cardiac magnetic resonance imaging or nonagitated saline TTE and TEE in detecting baffle leaks in atrial switch patients. Agitated saline studies should be performed in this population when looking for baffle leaks.

Diastolic Dyssynchrony Differences in Patients with Single Right Ventricles vs. Control Patients.

AIMS: Diastolic dyssynchrony is increasingly being recognized as another marker for possible adverse cardiac events. Minimal data exist in hypoplastic left heart syndrome (HLHS) patients. The goal of this study was to determine if there were differences in diastolic dyssynchrony in patients with HLHS vs. control patients. METHODS/RESULTS: Tissue Doppler imaging (TDI) and strain rate (SR) analysis of the right ventricle in HLHS and control patients were performed. Time interval from onset of QRS complex on electrocardiography to peak TDI e' wave was obtained. Differences in intervals were calculated: QRSe'(RV) - QRSe'(IVS) and QRSe'(RV) - QRSe'LV). Time interval from onset of QRS to peak strain rate early diastolic wave (SRe) was obtained for the six-segment model RV. Standard deviation of the six SRe time intervals was calculated. t-tests were performed to determine if differences were present between groups. Sixty patients were studied (35 HLHS, 25 control). There were no significant differences between HLHS and control patients in age (6.5 ± 3.2 years vs. 6.1 ± 2.6 years) or heart rate (91 ± 22 bpm vs. 91 ± 13 bpm), respectively. There were no significant differences between HLHS and control patients in QRSe'(RV) - QRSe'(IVS) (19.9 ± 15.4 ms vs. 23.3 ± 13.6 ms) and QRSe'(RV) - QRSe'(LV) (20.7 ± 13.8 vs. 22.8 ± 14.6 ms), respectively. There was a significant difference in SRe standard deviation between the HLHS and control patients (25.3 ± 12.4 ms vs. 15.5 ± 6.9 ms, P = .0007), respectively. CONCLUSION: Patients with HLHS had increased diastolic dyssynchrony compared with control patients as measured via deformation analysis. Future studies are needed to determine the significance of these findings.

Strain echocardiographic assessment of ventricular function after percutaneous pulmonary valve implantation.

INTRODUCTION: Percutaneous pulmonary valve implantation (PPVI) is an emerging therapy for pulmonary valve dysfunction. Minimal data on the midterm effects of PPVI on ventricular function exist. We describe the effects of PPVI on right and left ventricular (RV, LV) function with speckle tracking echocardiography. METHODS: Patients who met the inclusion criteria of the Food and Drug Administration Phase 1 Feasibility Clinical Trial PPVI were identified. Patients were studied with echocardiograms at baseline, post-PPVI (day of discharge), 3 months, and at 6 months. Patients were studied by cardiac magnetic resonance at baseline and at 6 months. Longitudinal strain was measured at the basal, mid, and apical portions of the RV, interventricular septum (IVS), and LV. Global RV and LV strain and strain rates were recorded. Paired t-tests were used for analysis. RESULTS: Ten patients were analyzed: nine patients were a variant of tetralogy of Fallot and one patient had complex LV outflow obstruction requiring a Ross and RV-pulmonary atresia conduit. Mean age was 24.4 ± 7.6 years. Indication for PPVI was pulmonary regurgitation in six patients, stenosis in two patients, and stenosis/regurgitation in two patients. After PPVI, both RV systolic pressure and RV to pulmonary artery pressure gradient significantly decreased. Cardiac magnetic resonance RV end-diastolic volume significantly decreased. IVS-mid, IVS-apical, and LV-global strain significantly increased and RV-basal decreased immediately after PPVI. Global RV a' strain rate significantly increased immediately after PPVI. However, RV, IVS, and LV strain/strain rate values between baseline and the 6 month echocardiographic study were either similar or significantly decreased. CONCLUSION: Despite improvement in RV hemodynamics, there was a decrease or no improvement in RV and LV function as measured by strain echocardiographic values at midterm follow-up. Larger studies with longer follow-up are needed to determine if these results remain consistent.