A Comparison of the Electrophysiological and Anatomic Characteristics of Pacing Different Branches of the Left Bundle Conduction System

Introduction: Left bundle branch pacing (LBBP) is a rapidly growing conduction system pacing technique. However, little is known regarding the electrophysiological characteristics of different types of LBBP. We aimed to evaluate the electrophysiological characteristics and anatomic lead location with pacing different branches of the left bundle branch.Methods: Consecutive bradycardia patients with successful LBBP were enrolled and classified into groups according to the paced electrocardiogram and the lead location. Electrocardiogram, pacing properties, vectorcardiogram, and lead tip location were analyzed.Results: Ninety-one patients were enrolled, including 48 with the left bundle trunk pacing (LBTP) and 43 with the left bundle fascicular pacing (LBFP). The paced QRS duration in the LBTP group was significantly shorter than that in the LBFP group (108.1 ± 9.9 vs. 112.9 ± 11.2 ms, p = 0.03), with a more rightward QRS transition zone (p = 0.01). The paced QRS area in the LBTP group was similar to that during intrinsic rhythm (35.1 ± 15.8 vs. 34.7 ± 16.6 μVs, p = 0.98), whereas in the LBFP group, the paced QRS area was significantly larger compared to intrinsic rhythm (43.4 ± 15.8 vs. 35.7 ± 18.0 μVs, p = 0.01). The lead tip site for LBTP was located in a small fan-shaped area with the tricuspid valve annulus summit as the origin, whereas fascicular pacing sites were more likely in a larger and more distal area.Conclusions: Pacing the proximal left bundle main trunk produced better electrical synchrony compared with pacing the distal left bundle fascicles. A visualization technique can facilitate achieving LBTP.

Clinical Application of Individualized Pulmonary Bi-Orifice for the Reconstruction of Right Ventricular Outflow Tract in Tetralogy of Fallot

Objective: The study aims to establish a new method in the Tetralogy of Fallot (ToF) called the pulmonary valve bi-orifice method (pulmonary annular sparing with an individualized autologous pericardial patch; thus, two orifices are formed at the level of the pulmonary valve annulus) to reconstruct the right ventricular outflow tract (RVOT).Methods: A retrospective analysis of 128 TOF patients from October 2009 to June 2018 with severe pulmonary valve dysplasia who underwent transvalvular annular patch (TAP) procedure (control group) or an individualized pulmonary valve bi-orifice procedure (observation group) were studied. The RVOT for each patient in the observation group was individually reconstructed per the patient's weight and the size of the autologous pulmonary valve using the bi-orifice method; however, increasing the cross-sectional area of the pulmonary valve annulus without destroying its integrity. The result was then compared to the control group, where TAP procedures were applied to evaluate the short to mid-term outcome(s). An in vitro simulation test was used to verify the anti-regurgitation mechanism of the new method.Results: The in vitro simulation test indicated that the anti-regurgitation mechanism was completed by the pericardial patch and the autologous pulmonary valve movement toward each other. Thus, for clinical applications, patients in both groups were compared. The results showed no significant differences in cardiopulmonary bypass and aortic cross-clamp time, mechanical ventilation, and ICU and post-operative residence between the two groups.During the follow-up period (3- to 12-years), 14 patients in the observation group had mild regurgitation after surgery (22.2%), while 10 patients had moderate pulmonary regurgitation (15.8%) with no right ventricular (RV) dilation. On the other hand, 22 patients (39.6%) had moderate to severe regurgitation in the control group, while left pulmonary artery stenosis occurred in one patient. In the control group, six patients (9.2%) with severe RV dilation were reoperated.Conclusion: Individualized pulmonary valve bi-orifice procedure is a safe and excellent method for reconstructing RVOT in ToF.

The circle method for preoperative TAVI sizing in a Sievers type 0 stenotic bicuspid aortic valve

The most common congenital cardiac anomaly, affecting an estimated 0.4–2.25% of the general population, is the bicuspid aortic valve. The “pure” bicuspid aortic valve (non-raphe-type or bicuspid aortic valve type 0) is composed of 2 cusps, morphologically and functionally. The shape of the bicuspid aortic valve annulus is often elliptical, is relatively larger than the tricuspid aortic valves, and probably shows severe eccentric calcification. This situation contributes to the difficulties in selecting the correct type and size of transcatheter heart valve when treating bicuspid aortic valve stenosis. Furthermore, it is often associated with a dilated, horizontal ascending aorta and effaced sinuses. The goal of our video tutorial is to present the contemporary circle method used in preoperative sizing during TAVI procedures in patients with a bicuspid aortic valve as well as certain technical considerations and useful advice. Although annular sizing is the main focus for most patients with a bicuspid aortic valve, some patients may need the supra-annular level of sizing. For a dedicated sizing and positioning approach for the SAPIEN 3 Ultra valve, experts in the field propose the circle method.

Open-sleeve technique: A new approach for aortic valve leaflet reconstruction in small children

A boy was diagnosed with a unicuspid aortic valve with severe stenosis at birth. Percutaneous balloon aortic valvuloplasty was performed four times; however, he had severe heart and growth failure. Thus, aortic valve repair was performed at age 2 years and 6 months. He weighed 6.6 kg. The aortic valve annulus diameter was 9.8 mm (z value = 0.43). We report on a small toddler with congenital aortic stenosis who was successfully treated with autologous pericardial aortic valve leaflet reconstruction using the open-sleeve technique.

Assessment of the intramural segment of interarterial anomalous coronary arteries originating from the opposite sinus of Valsalva on CT angiography

Background Of the coronary anomaly variants, an anomalous coronary artery originating from the opposite sinus (AAOCA) with an interarterial course poses the highest the risk of sudden cardiac death. Assessment of high risk anatomical characteristics can be done with Computed Tomography Angiography (CTA). High risk features are a slit-like ostium, acute angle take-off, proximal narrowing and an intramural course. For an intramural course no clear-cut CT parameters exist. Purpose To deduct new CTA criteria to identify an intramural course as well as the length of the intramural segment based on peroperative findings. Material and methods Twenty patients were included that received unroofing surgery of the right or left AAOCA between 2010 and 2019. All patients had a pre-operative CTA (0.5–1mm slice-thickness) performed. The presence of the intramural segment was measured peroperatively by the surgeon and used as indicator for CTA evaluation. Using multiplanar reconstructions, CTA images were rotated perpendicular to the horizontal plane of the aortic valve annulus and AAOCA to assess the distance between the aortic and AAOCA lumen and the shape of the AAOCA. This was done at every 2mm for the length of the intramural course as described by the surgeon (Figure 1). Results Analysis of 20 patients (40% male, AAORCA n=17, age at diagnosis AAOCA 45.6±10.5 years), showed a mean intramural length of 11.5±2.4mm at surgery. The median distance between the aortic and AAOCA lumen was 0.76mm (IQR 0.72–0.97mm) for the intramural segment. At the distal end of the intramural part (indicated by no. 5 in Figure 1), the mean distance was 1.20mm±0.27mm. The median ratio between the antero-posterior and transverse diameter of the AAOCA lumen at the distal end of the intramural part was 0.94 (IQR 0.88–0.99). Along the intramural part (Figure 1, no. 1–4) this ratio was 0.56mm±0.11mm, indicating a more flattened ostial shape along the course of the vessel. Conclusions Results indicate that an aortic to AAOCA lumen distance of ≤0.76mm on CTA is suggestive of an intramural course. A distance between the aorta and AAOCA of ≥1.2mm combined with an antero-posterior to transverse diameter ratio of 0.94 of the AAOCA indicates that the intramural trajectory has ended. FUNDunding Acknowledgement Type of funding sources: None.

Developmental changes in bicuspid aortic valve and associated aortopathy in small children

Background The prevalence of bicuspid aortic valve (BAV) in newborns is 0.8%. BAV is associated with an increased risk of aortic valve dysfunction and aortopathy. Aortopathy with increased aortic diameters has recently been reported in newborns with BAV. As most patients with BAV are diagnosed in adulthood the development of BAV and associated aortopathy during early years of life is not well described. Purpose The purpose of the study was to assess changes in aortic valve function and aortic dimensions at two to four years of age in children diagnosed with BAV neonatally. Methods Children with BAV were included from a population-based cohort study, in which newborns (n≈25,000) underwent standardized transthoracic echocardiography (TTE). Follow-up TTE was performed and analyzed according to established guidelines. Neonatal (baseline) and follow-up data were compared. Diameters were indexed to body surface area (BSA). Z-scores were calculated using formulas from the Pediatric Heart Network Echocardiogram Database. Results At follow-up 101 newborns with BAV (mean age 2 years 5 months, SD 11 months), 75% male) were examined from May 2019 to April 2021. From baseline to follow-up there was an increase in the BSA-adjusted diameter of the aortic valve annulus (z-score −0.19 at baseline vs 0.95 at follow up, p<0.001), and of the sino-tubular junction (z-score 0.16 at baseline vs 0.43 at follow up, p<0.05). Conversely, there was a decrease in the Z-score for the diameter measured 1 cm from the valve annulus (z-score 1.31 at baseline vs 0.68 at follow up, p<0.001) and at the widest point of the visualized ascending aorta (z-score 2.44 at baseline vs 1.45 at follow up, p<0.001). There was no significant change in the diameter of the sinus of Valsalva (z-score 0.83 at baseline vs 0.80 at follow up, p=0.92). The number of children with at least one aortic z-score >3 was 31 (30.6%) at baseline and 17 (17.8%) at follow up. At baseline mild aortic valve regurgitation was observed in 18 children (17.8%) and in 23 children at follow up (23%). Mean maximum systolic velocities across the aortic valve were 1.03 m/s at baseline (SD 0.24) and 1.11 m/s at follow up (SD 0.27), p<0.05. Aortic stenosis, defined as flow velocity >2.5 m/s was seen in one child both at baseline and at follow-up. Conclusion In children diagnosed with BAV neonatally, re-examination at the age of 2.5 years showed significant increases in the diameter of the aortic valve annulus and the sino-tubular junction, but a significant decrease in the diameter of the ascending aorta. The maximum blood flow velocity across the aortic valve increased and more children had developed mild aortic valve regurgitation. Thus, the bicuspid aortic valve and the associated aortopathy seem to undergo remodeling during early childhood. FUNDunding Acknowledgement Type of funding sources: Foundation. Main funding source(s): The Danish Children's Heart Foundation, Boernehjertefonden.

Linear increase in the number of non-pulmonary vein triggers from paroxysmal to persistent and long-standing persistent AF in patients undergoing repeat procedure after successful isolation of pulmona

Introduction This study evaluated the prevalent triggers responsible for recurrence following successful PVI in different types of atrial fibrillation (AF). Methods Consecutive AF patients undergoing repeat catheter ablation with permanently isolated PV were included in the analysis. High-dose isoproterenol challenge (20- 30μg/min for 15–20min) was used to confirm PV reconnection and identify non-PV triggers. Circular mapping catheter (CMC) was used to map the site of origin of significant ectopic activity by comparing the activation sequence of the sinus beat with that of the ectopic beat. For the coronary sinus (CS), ablation catheter was positioned at the level of the mitral valve annulus, parallel to the one positioned in the CS. Left atrial appendage (LAA) firing was detected by placing the CMC in the left superior PV and thus recording far-field potentials from the LAA. Results This prospective study included 1850 AF patients undergoing repeat AF ablation (Table 1), of which 573 (31%) had received one and the remaining 1277 patients had received 2 earlier ablations. Permanent PVI was confirmed with isoproterenol challenge. Table 1 shows the distribution of non-PV triggers. A linear increase in the number of non-PV triggers was observed from PAF to PerAF to LSPAF. Significantly higher number of LSPAF patients had detectable non-PV triggers compared to PerAF and PAF cases. Conclusion We observed a linear increase in the number of non-PV triggers in PAF to PerAF and LSPAF patients experiencing recurrence with successful isolation of PVs. As non-PV triggers are often not targeted by operators, this could be the underlying mechanism for more frequent recurrences in non-paroxysmal AF. FUNDunding Acknowledgement Type of funding sources: None. Table 1

Dynamic changes of mitral valve annulus geometry at preprocedural CT: relationship with functional classes of regurgitation

Background We investigated mitral valve annular geometry changes during the cardiac cycle in patients with severe mitral regurgitation (MR) who underwent cardiac computed tomography angiography (CCTA) prior to percutaneous mitral valve replacement or annuloplasty. Methods Fifty-one patients with severe MR and high surgical risk (Carpentier classification: 3 type I, 16 type II, 16 type IIIa, 16 type IIIb) underwent multiphase electrocardiographically gated (0–90%) CCTA, using a second generation dual-source CT scanner, as pre-procedural planning. Twenty-one patients without MR served as controls. The mitral valve annulus was segmented every 10% step of the R-R interval, according to the D-shaped segmentation model, and differences among groups were analysed by t-test or ANOVA. Results Mitral annular area and diameters were larger in MR patients compared to controls, particularly in type II. Mitral annular area varied in MR patients throughout the cardiac cycle (mean ± standard deviation of maximum and minimum area 15.6 ± 3.9 cm2versus 13.0 ± 3.5 cm2, respectively; p = 0.001), with greater difference between annular areas versus controls (2.59 ± 1.61 cm2 and 1.98 ± 0.6 cm2, p < 0.001). The largest dimension was found in systolic phases (20–40%) in most of MR patients (n = 27, 53%), independent of Carpentier type (I: n = 1, 33%; II: n = 10, 63%; IIIa: n = 8, 50%; IIIb: n = 8, 50%), and in protodiastolic phases (n = 14, 67%) for the control group. Conclusions In severe MR, mitral annular area varied significantly throughout the cardiac cycle, with a tendency towards larger dimensions in systole.

Percutaneous Coronary Sinus-Based Mitral Valve Repair Differentially Modulates Coronary Sinus to Mitral Valve Annulus Geometry and Topography

Objectives: Coronary sinus (CS) based mitral annuloplasty using the Carillon device is a therapeutic option for the treatment of functional mitral valve regurgitation (FMR).Background: Little is known about the change of CS and mitral valve annulus (MVA) planes following Carillon implantation and how they are modulated by the tension applied on the device.Methods: In a retrospective single-center analysis, 10 patients underwent Carillon device implantation and received CT-angiography (CTA) prior and post CS based percutaneous mitral valve repair. Patients were assigned to responders or non-responders according to the 3-month transthoracic echocardiographic follow-up. A prototype software was used to assess distance and angulation of both CS (pre) or Carillon-device (post) and mitral annulus planes.Results: Comparison of the distance and angulation of the CS plane or Carillon device plane and the MVA plane prior and post intervention showed significant reduction of distance and unchanged angulation in responders while angulation was increased and distance reduced in non-responders without statistical significance. Furthermore, in FMR responders MVA perimeter, anterior-posterior diameter, intercommisural diameter and MVA area were decreased following successful indirect mitral valve annuloplasty, while in FMR non-responders Carillon device implantation had no effect on MVA geometry.Conclusions: Insufficient reduction of FMR following indirect mitral valve annuloplasty is associated with device malposition in relation to the mitral valve annulus. Patient selection using CTA-derived distance and angulation of CS to MVA planes is one option to increase effectiveness of indirect mitral valve annuloplasty.