Four-dimensional endocardial surface imaging with dynamic virtual reality rendering: a technical note.

Open heart surgery requires a proper understanding of the endocardial surface of the heart and vascular structures. While modern four-dimensional (4D) imaging enables excellent dynamic visualization of the blood pool, endocardial surface anatomy has not routinely been assessed. 4D image data were post-processed using commercially available virtual reality (VR) software. Using thresholding, the blood pool was segmented dynamically across the imaging volume. The segmented blood pool was further edited for correction of errors due to artifacts or inhomogeneous signal intensity. Then, a surface shell of an even thickness was added to the edited blood pool. When the cardiac valve leaflets and chordae were visualized, they were segmented separately using a different range of signal intensity for thresholding. Using an interactive cutting plane, the endocardial surface anatomy was reviewed from multiple perspectives by interactively applying a cutting plane, rotating and moving the model. In conclusions, dynamic three-dimensional (3D) endocardial surface imaging is feasible and provides realistic simulated views of the intraoperative scenes at open heart surgery. As VR is based on the use of all fingers of both hands, the efficiency and speed of postprocessing are markedly enhanced. Although it is limited, visualization of the cardiac valve leaflets and chordae is also possible.

Multidetector Computed Tomography Assessment of Anatomical Ventricular Tachycardia Isthmuses in Repaired Tetralogy of Fallot.

BACKGROUND: Tetralogy of Fallot (TOF) is associated with risk for sustained monomorphic ventricular tachycardia (VT). Preemptive electrophysiology study before transcatheter pulmonary valve placement is increasing, but the value of MDCT for anatomical VT isthmus assessment is unknown. OBJECTIVES: The purpose of this study was to determine the impact of multidetector computed tomography (MDCT) in the evaluation of sustained monomorphic VT for repaired TOF. METHODS: Consecutive pre-transcatheter pulmonary valve MDCT studies were identified, and anatomical isthmus dimensions were measured. For a subset of patients with preemptive electrophysiology study, MDCT features were compared with electroanatomical maps. RESULTS: A total of 61 repaired TOFs with MDCT were identified (mean 35 ± 14 years, 58% men) with MDCT electroanatomical map pairs in 35 (57%). Calcification corresponding to patch material was present in 46 (75%) and was used to measure anatomical VT isthmuses. MDCT wall thickness correlated positively with number of ablation lesions and varied with functional isthmus properties (blocked isthmus 2.6 mm [Q1, Q3: 2.1, 4.0 mm], slow conduction 4.8 mm [Q1, Q3: 3.3, 6.0 mm], and normal conduction 5.6 mm [Q1, Q3: 3.9, 8.3 mm]; P < 0.001). A large conal branch was present in 6 (10%) and a major coronary anomaly was discovered in 3 (5%). Median ablation lesion distance was closer to the right vs the left coronary artery (10 mm vs 15 mm; P = 0.01) with lesion-to-coronary distance <5 mm in 3 patients. CONCLUSIONS: MDCT identifies anatomical structures relevant to catheter ablation for repaired TOF. Wall thickness at commonly targeted anatomical VT isthmuses is associated with functional isthmus properties and increased thermal energy delivery.

Apical muscular ventricular septal defect closure via hybrid approach using a right ventricular stay suture.

Transcatheter closure of large apical muscular ventricular septal defects (VSDs) can be performed via transfemoral or hybrid approach. A very large apical muscular VSD was closed via a hybrid approach. A strategy for deployment of a right ventricular stay suture was utilized to minimize the risk of device embolization without the use of bypass and without externalization of a portion of the device.

Ten-year outcomes of transcaval cardiac puncture for catheter ablation after extracardiac Fontan surgery.

BACKGROUND: Although they are at lower risk, patients with previous extracardiac conduit (EC) Fontan still may require catheter ablation for supraventricular arrhythmia. OBJECTIVE: The purpose of this study was to determine the optimal approach to pulmonary venous atrium (PVA) access after EC Fontan operation. METHODS: All electrophysiological procedures requiring PVA over a 10-year period at the UCLA Medical Center were reviewed. PVA was grouped by transcaval cardiac puncture (TCP) or direct conduit puncture. Procedural characteristics and outcomes were compared. RESULTS: Between June 2009 and November 2019, 23 electrophysiological procedures requiring PVA access were performed in 17 EC Fontan patients (53% male; median age 25 years; interquartile range 11-34). Cavoatrial overlap was identified in 14 patients by preprocedural imaging (10 cardiac computed tomography, 4 cardiac magnetic resonance). PVA access was obtained via TCP in 11, direct conduit puncture in 6, pre-existing fenestration in 5, and pulmonary artery puncture in 1. Time to PVA was significantly shorter for TCP vs direct conduit puncture (0.2 vs 1.1 hours, respectively; P = .03). The only predictor of successful TCP was the length of cavoatrial overlap by preprocedural imaging (14 vs 3 mm; P = .02). No procedural complications occurred. No change in oxygen saturation was noted, and no evidence of residual shunting was detected by follow-up echocardiography. CONCLUSION: TCP is feasible in most patients after EC Fontan surgery and can be predicted by preprocedural advanced imaging. TCP is associated with shorter time to PVA and was uncomplicated in this single-center study. Preoperative assessment of cavoatrial overlap should be considered before catheter ablation for EC Fontan.

Growth and weight gain of prepubertal children after cardiac transplantation.

This study evaluated changes in growth parameters after pediatric heart transplantation and identified factors associated with the changes after pediatric heart transplantation (OHT). We retrospectively evaluated the somatic growth of 46 children <11 yr of age who underwent OHT for changes in weight, height, and BMI. The patient age range was 3.5 months to 10.7 yr. Gain in Z score for weight and BMI was significant at six months post-OHT (mean weight Z score changed from -1.1 to -0.1 and mean BMI Z score changed from -0.1 to 1.3; p < 0.001). After six months post-OHT, there was no further significant change in weight or BMI Z score. Height Z score did not show significant change from pre-OHT at six months, one yr, or two yr post-OHT. Eight patients (17%) became overweight during the two-yr follow-up period as evidenced by a BMI Z score > 2. Multivariate analysis showed length of steroid treatment as a predictor for negative height Z score change, and age at transplant as a predictor for positive height Z score change. Post-OHT, weight significantly increases without proportional increases in height, resulting in a significant proportion of these children becoming obese. Length of steroid therapy is negatively related to the "catch-up" linear growth following OHT.