Tricuspid Annulus Research Articles

Right heart echocardiographic parameters and outcomes of patients with aortic stenosis after transcatheter aortic valve implantation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction The impact of right ventricular (RV) function and RV to pulmonary artery (RV-PA) coupling on outcomes of patients with aortic stenosis undergoing transcatheter aortic valve implantation (TAVI), and the early effect of the intervention, remain partly unclear. Aim To evaluate the impact of right heart echocardiographic (echo) parameters on the outcome of patients undergoing TAVI. Methods Retrospective analysis including consecutive patients submitted to TAVI at our center between 2007–2021. Pre and postprocedural (≤96h) echo parameters were analyzed: tricuspid annular plane systolic excursion (TAPSE), S-wave tissue Doppler velocity of the tricuspid annulus (S'), pulmonary arterial systolic pressure (PASP). TAPSE/PASP ratio was used as a surrogate of RV-PA coupling; TAPSE/PASP ratio<0.31 defined RV uncoupling. Primary endpoint (PE) was defined as all-cause death within 1-year after TAVI. Echo parameters were compared between patients according to the PE. Pairwise comparison of pre- and post-TAVI indexes was also performed, for the overall cohort and according to the primary endpoint. Statistical significance was considered if p<0.05. Results Of 1040 TAVI patients, 615 patients with complete echo data were included: median age 81 years, 53% female, left ventricular ejection fraction 55(45–60)%. Before TAVI, 60 patients (11%) presented RV dysfunction (TAPSE<17mm), and 30 (15%) RV-PA uncoupling. A significant reduction in PASP was observed after TAVI (40 vs 36 mmHg, p<0.01).[image] TAPSE decreased post-TAVI (20.0 vs 19.5 mm, p = 0.04); S’ values did not differ between evaluations (11.20 vs 11.50, p = 0.08). 1-year follow up data was available for 467 patients; the primary endpoint occurred in 37 (7.9%) patients. Patients meeting the PE had higher preprocedural PASP (42 vs 39 mmHg, p = 0.036). PASP decreased after TAVI (39 vs 36 mmHg, p<0.001) in patients who survived the 1st year, but not in patients meeting the PE (p = 0.82). Postprocedural TAPSE/PASP ratio was lower in the deceased group (0.43 vs 0.57, p = .031); persistence of RV-PA uncoupling post-TAVI was more frequent in patients who met the PE (25% vs 8.1%, p = .047). Conclusions In this cohort, RV longitudinal function parameters did not improve after TAVI. Contrastingly, RV-PA coupling improved after the procedure. Persistence of RV-PA uncoupling after TAVI was more frequent in patients who died during the 1st year of follow-up.

Functional tricuspid regurgitation after transcatheter closure of atrial septal defect

Abstract Funding Acknowledgements Type of funding sources: None. Main funding source(s): none Background Significant functional tricuspid regurgitation (FTR) often improves during the long-term follow-up after transcatheter atrial septal defect (ASD) closure. However, the timing of TR improvement and its relationship with right ventricle (RV) reverse remodeling are unknown. Methods A total of 50 patients (age: mean age 58 +/- 16 years old, range:18–88; male: 66%) who underwent transcatheter ASD closure were enrolled. Echocardiography was performed at baseline, 1month and 1year after transcatheter ASD closure. Results TR improved significantly 1month after treatment compared to baseline, but no further significant improvement in TR severity was observed up to 1 year after treatment. Tricuspid annulus diameter decreased gradually over 1 year, while RV diameter decreased significantly at 1 month and throughout 1 year after treatment. (Figure). Conclusion Reverse remodeling of the RV was achieved immediately after ASD closure and continued thereafter, whereas significant improvement in TR severity was demonstrated only immediately after ASD closure. Meticulous follow-up with more intensive therapies should be considered for patients with residual significant TR after ASD closure.

Left atrial remodeling and right ventricular-pulmonary arterial coupling after MitraClip implantation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Transcatheter edge-to-edge mitral valve repair (TEER) with the MitraClip system has emerged as a therapeutic alternative to surgical solutions in high risk patients with severe mitral regurgitation (MR). MR is characterized by left ventricular volume overload, which leads to left ventricular dilatation. Furthermore, MR is a common cause of pulmonary hypertension. Right ventricular (RV) intrinsic contractility and its response to afterload is referred to as RV-pulmonary arterial (PA) coupling. Effect of TEER in patients with MR on left atrial (LA) function and RV-PA coupling is less investigated. Purpose The aim of our study was to assess clinical characteristics of patients undergoing MitraClip implantation including LA function and RV-PA coupling. Methods Eighty-eight consecutive patients with chronic severe MR were enrolled in the single-center observational study (mean age 71.5±7.9 years, male 54.5%, ischemic cardiomyopathy 54.5%). Primary MR (PMR) was present in 22.7%, secondary MR (SMR) in 73.9 % and mixed (MxMR) etiology in 3.4%. Conventional and advanced echocardiography examination was performed using speckle tracking echocardiography before TEER and at 6 month post-TEER follow-up. Left atrial maximal (LAV max) and minimal (LAV min) volumes were measured indexed for body surface area. Furthermore, we analysed left atrial functional parameters, such as reservoir strain, conduit strain and contraction strain. Results The technical success of MitraClip implantation was 95,5%. Mortality rate at 6 month follow-up time was 10.8% (1/88 PMR, 7/88 SMR, 1/88 MxMR). Severe residual MR developed during follow-up in 4.2% and New York Heart Association class III-IV functional status was concluded in 6.8% at 6 month post-TEER. Significant decrease in left ventricular end-diastolic median diameter (mm) was observed at follow-up compared to pre-TEER: 57.5 (IQR: 51.25 – 63.75) vs 60.5 (IQR: 52.5 – 66.75), respectively, p = 0.01. Similarly, the median value of pulmonary artery systolic pressure (PASP) substantially decreased (mmHg) after TEER: 42 (IQR: 32 – 52) vs 49.5 (IQR: 41 – 57), respectively, p = 0.003. Tricuspid annulus systolic excursion/PASP median value, representing RV-PA coupling, improved remarkably: 0.45 (IQR: 0.31 – 0.69) vs 0.38 (IQR: 0.29 – 0.52), respectively, p = 0.02. Compared to pre-TEER, median LA volumes and strain parameters did not change significantly at 6 month post-TEER: reservoir strain (%) 12.88 (IQR: 8.18–18.78) vs 11.74 (IQR: 7.48–20.36), p = 0.41; LAV max (ml) 48.70 (IQR: 39.81–62.29) vs 48.17 (IQR: 42.08–58.7), p = 0.31; LAV min (ml) 34.33 (IQR: 24.5–46.32) vs 33.89 (IQR: 26.02–44.53), p = 0.69. Conclusions The function of the enlarged LA was severely reduced, which did not change after MitraClip implantation in our population. However, positive left ventricular remodeling and improvement in RV-PA coupling was observed 6 month after MitraClip procedure.

Semiautomated Quantification of the Tricuspid Annulus Using Three-Dimensional Echocardiography

Semiautomated Quantification of the Tricuspid Annulus Using Three-Dimensional Echocardiography

The Early Effects on Tricuspid Annulus and Right Chambers Dimensions in Successful Tricuspid Valve Bicuspidization.

It is unclear to what degree of tricuspid annulus (TA) reduction is necessary to achieve good postoperative results in surgical bicuspidization. The study aimed to evaluate TA and right heart chamber's dimensions before and after heart surgery; and to compare TA parameters assessed by different modalities. Forty patients underwent mitral valve surgery with or without concomitant tricuspid valve (TV) bicuspidization. Preoperative and postoperative measurements of TA dimensions were performed prospectively using two-dimensional (2D) and three-dimensional (3D) transthoracic echocardiography (TTE). Additionally, preoperative transesophageal echocardiography (TOE) was performed in the operating room prior to surgery. All patients had no or mild TR immediately after surgery. There was a significant reduction in 2D and 3D parameters of the TV and right chambers in the TV bicuspidization group. However, TV leaflets' tethering parameters did not change significantly. Preoperative 3D TTE measurements were smaller than those obtained through 3D TOE in the operation room, before surgery under general anesthesia. The 2D systolic apical 4Ch diameter and the parasternal short axis diameter mainly represent the 3D minor axis of the TA and are smaller than its 3D major axis. Although bicuspidization results in a one-third reduction of the TV area, tethering of the TV leaflets remains unchanged. Moreover, 3D TOE parameters of the TV under general anesthesia are larger than preoperative 3D TTE measurements. Conventional 2D measurements are insufficient for evaluating the maximum diameter of the TA.

Papillary muscle approximation in chronic ovine functional tricuspid regurgitation

ObjectiveIsolated tricuspid ring annuloplasty remains the surgical standard for functional tricuspid regurgitation repair but offers suboptimal results when right ventricular dilation and remodeling along with papillary muscle displacement is present. Addressing subvalvular remodeling with papillary muscle approximation may improve clinical outcomes. MethodsFunctional tricuspid regurgitation and biventricular dysfunction were induced in 8 healthy sheep by rapid ventricular pacing (200-240 bpm) for 27 ± 6 days. Subsequently, animals underwent cardiopulmonary bypass for implantation of sonomicrometry crystals on the tricuspid annulus, right ventricle, and papillary muscle tips. Papillary approximation sutures were anchored between anterior-posterior and anterior-septal papillary muscles and externalized through right ventricular free wall to epicardial tourniquets. After weaning from cardiopulmonary bypass, sequential papillary muscle approximations were performed. Simultaneous hemodynamic, sonomicrometry, and echocardiographic data were collected at baseline and after each papillary muscle approximation. ResultsWith rapid pacing, right ventricular fractional area change decreased from 59 ± 6% to 38 ± 8% (P < .001), whereas tricuspid annulus diameter increased from 2.4 ± 0.3 cm to 3.3 ± 0.6 cm (P = .003). Tricuspid regurgitation (0-4+) increased from +0 ± 0 to +3.3 ± 0.7 (P < .001). Both anterior–posterior and anterior–septal papillary muscle approximation significantly reduced functional tricuspid regurgitation from +3.3 ± 0.7 to +2 ± 0.5 and +1.9 ± 0.6, respectively (P < .001). Reduction of tricuspid insufficiency with both subvalvular interventions was associated with decreased distance of the anterior papillary muscle to the annular centroid. ConclusionsPapillary muscle approximations were effective in reducing severe ovine functional tricuspid regurgitation associated with right ventricular dilation and papillary muscle displacement. Further studies are needed to evaluate efficacy of this adjunct to ring annuloplasty in repair of severe functional tricuspid regurgitation.

Two Rare Cases of Septal, Annular, Valvular, and Ventricular Disorders

Ventricular noncompaction is thought to occur due to the arrest of maturation of the myocardium during fetal development. It may be confined to one or both ventricles. The spectrum of noncompaction varies from an incidental finding to severe systolic and diastolic dysfunction or may manifest as ventricular arrhythmia and thromboembolism. It is known to be associated with congenital heart diseases (CHDs). Annular disjunction is an established morphological entity involving the mitral annulus commonly; although uncommon, it may also involve the tricuspid annulus. Annular disjunction is also commonly associated with atrioventricular (AV) valve regurgitation of various degrees. Association of annular disjunction and AV valve prolapse is known to be associated with ventricular tachyarrhythmia and even sudden cardiac death. The combination of CHD, bi-ventricular non-compaction, annular disjunction, and AV valve prolapse with regurgitation is extremely rare; each of these conditions will be additive to worsen prognosis. Here is a report of two such cases of rare combinations of widely varying morphological features. Whether these morphological alterations are coincidental or a link exists is speculative.

#5221 PULMONARY HYPERTENSION: AN IMPORTANT RISK FACTOR IN CARDIOVASCULAR MORTALITY IN DIALYSIS PATIENTS

Abstract Background and Aims It is widely known that chronic dialysis patients experience significantly higher cardiovascular (CV) death rates than the overall population. Among other CV risk factors, recent research has shown pulmonary hypertension (PH) as a consequence of chronic kidney disease and end-stage renal failure. The present study aimed to determine the risk factors that impact survival in chronic haemodialysis and peritoneal dialysis patients and to analyse the correlation of these factors with pulmonary hypertension. Method We studied 125 stable haemodialysis and peritoneal patients (females 40%, mean age 52.42 ±11.88 years) on RRT for more than three months with a two-year follow-up. Demographic information, clinical characteristics, blood tests, and a thorough echocardiographic evaluation were collected at the optimal dry weight. After conventional echocardiographic examination, a tissue Doppler echocardiographic (TDE) examination was performed to evaluate the global and regional myocardial systolic and diastolic functions and pulmonary hypertension. Systolic pulmonary artery pressure (sPAP) of 35 mmHg was used to define PH. Results The cardiovascular mortality rate was 15.5%. In ROC analysis for CV mortality, the area under the curve (AUC) for PH and CRP was found 0.8; for LVM-I, E/E', and PP, the AUC was 0.76, 0.75, 0.72, respectively, while the inverse relationship was found with MASa and TASa with AUC = 0.66 and 0.95 respectively. According to the echocardiographic findings, PH was found in 28% (35 patients) of all patients. The mean PH was 33.46±5.38 mmHg. The higher level of higher parathormone (PTH), C-reactive protein (CRP), and E/E’ average, the lower left ventricular ejection fraction (EF), the peak systolic velocity at the lateral mitral annulus (MASa), and the peak systolic velocity at the lateral tricuspid annulus (TASa) were found to be predictors of PH. Patients evaluated with PH have a significantly lower cardiovascular survival rate [Long Rank (Mantel-Cox) p = 0.0001. Conclusion Our research demonstrates that cardiovascular morbidity and death in dialysis patients are mainly attributed to pulmonary hypertension, inflammation, vascular stiffness, and left ventricular hypertrophy. PH is common among dialysis patients. Inflammation, CKD-MBD biomarkers linked to systolic and diastolic left and right ventricular dysfunction, and inflammation all influence it. These conditions are all connected. Cardiovascular imaging is simple to use, offers a favourable viewpoint in the early identification of cardiac abnormalities and quick treatment of this disease, and is thus strongly advised in the dialysis population.

Activation pattern within Koch's triangle during sinus rhythm in patients with and without atrioventricular nodal reentrant tachycardia.

Several studies have visualized the slow pathway during sinus rhythm using high-density mapping of Koch's triangle (KT) in patients with atrioventricular nodal reentrant tachycardia (AVNRT). However, it is unclear whether the slow pathway can be visualized in all people. Therefore, we evaluated the activation pattern within KT during sinus rhythm in patients with and without AVNRT. High-density mapping using the Advisor HD Grid mapping catheter (Abbott) within KT during sinus rhythm was created in 10 patients with slow-fast AVNRT and 30 patients without AVNRT. In 8 (80%) patients with AVNRT, the activation pattern pivoting around a block line (BL) within KT was observed. In 12 (40%) patients without AVNRT, similar activation pattern pivoting around BL was observed, but jump was observed in 11 (92%) of these patients. In all patients, the activation pattern pivoting around BL was observed in 17 (85%) of 20 patients with jump, but only 3 (15%) of 20 patients without jump (p < 0.0001). During jump, there was a long period of no potential from the last atrial potential within KT to the His bundle potential, suggesting the slow pathway conduction through the rightward inferior extension that cannot be visualized. A linear ablation between the pivot point and the septal tricuspid annulus was successful for slow-fast AVNRT. Although the slow pathway could not be visualized using high-density mapping during sinus rhythm, the activation pattern pivoting around BL within KT was observed in most patients with the dual pathway physiology, with or without AVNRT.

Multimodality imaging in caseous necrosis of tricuspid annulus

Multimodality imaging in caseous necrosis of tricuspid annulus

Tricuspid valve repair concomitant with mitral valve surgery: a systematic review and meta-analysis.

Uncertainties persist about whether to aggressively and effectively treat tricuspid regurgitation (TR) during mitral valve (MV) surgery. Systematic literature searches were performed in five databases to collect all relevant studies published before May 2022 on whether the tricuspid valve was treated during MV surgery. Separate meta-analyses were performed on data from unmatched studies and randomized controlled trials (RCT)/adjusted studies. A total of 44 publications were included, of which eight were RCT studies and the rest were retrospective studies. There was no difference in 30-day mortality [odds ratio (OR): 1.00, 95% CI: 0.71-1.42, OR: 0.66, 95% CI: 0.30-1.41)] or overall survival [hazard ratio (HR): 1.01, 95% CI: 0.85-1.19, HR: 0.77, 95% CI: 0.52-1.14] in unmatched studies and RCT/adjusted studies. Late mortality (OR: 0.37, 95% CI: 0.21-0.64) and cardiac-related mortality (OR: 0.36, 95% CI: 0.21-0.62) were lower in the tricuspid valve repair (TVR) group in the RCT/adjusted studies. In the unmatched studies, overall cardiac mortality (OR: 0.48, 95% CI: 0.26-0.88) was lower in the TVR group. In the late TR progression analysis, the late TR progression was lower among patients in the concomitantly intervened tricuspid group, and patients in the untreated tricuspid group were prone to TR progression in both studies (HR: 0.30, 95% CI: 0.22-0.41, HR: 0.37, 95% CI: 0.23-0.58). TVR concomitant with MV surgery is most effective in patients with significant TR and dilated tricuspid annulus, especially those with a significantly reduced risk of distant TR progression.

Effect of papillary muscle approximation on acute ovine functional tricuspid regurgitation.

Ring annuloplasty represents the standard surgical treatment, but offers suboptimal results in patients with severe functional tricuspid regurgitation. Addition of papillary muscles (PMs) approximation may improve clinical outcomes. Eight healthy adult male sheep (56 ± 4 kg) underwent cardiopulmonary bypass and implantation of sonomicrometry crystals on the tricuspid annulus, PM tips and right ventricular (RV) free wall. Papillary muscles approximation sutures were anchored between anterior-posterior and anterior-septal PMs and their loose ends externalized through RV free wall to epicardial tourniquets. After weaning from cardiopulmonary bypass, acute right heart failure and tricuspid regurgitation were induced, and subsequent sequential anterior-posterior and anterior-septal PM approximations were performed. Echocardiographic, haemodynamic and sonomicrometry data were collected. Tricuspid regurgitation at baseline in eight sheep was none or trace in 3 and mild in 5, and after induction of acute right heart failure increased significantly to moderate in 5, moderately severe in 1 and severe in 2 (P = 0.011). RV pressure increased from 31 [28; 43] to 51 [47; 55] mmHg (P = 0.012). Anterior-posterior PM approximation decreased regurgitation grade to none or trace in 1, mild in 4 and moderate in 3 (P = 0.016) and reduced PM area from 208 [160; 241] to 108 [48; 181] mm2 (P = 0.008), and anterior-posterior PM distance from 18 [16; 20] to 10 [7; 13] mm (P = 0.037). Anterior-septal approximation also significantly reduced PM area but had no effect on regurgitation grade. Anterior-posterior but not anterior-septal PM approximation alleviated acute ovine tricuspid regurgitation. Selective PM approximation may offer better control of tricuspid regurgitation.

True relationship between tricuspid annular motion and velocity displacement components: Potential role in assessing right ventricular decoupling.

Although measures of longitudinal displacement of the tricuspid annulus measured by M-mode as tricuspid annular systolic plane excursion (TAPSE) and systolic velocity by tissue Doppler imaging (TA TDI s) are routinely used for assessment of right ventricular (RV) systolic function; these measures describe different phenomena and should not be used interchangeably. Previously published data was used to determine the individual relationship between TAPSE and TA TDI s with increasing pulmonary artery systolic pressures (PASP). In this retrospective analysis, 488 patients were divided into 2 groups based on TAPSE (Group 1:<1.8cm and Group 2: ≥1.8cm). A robust correlation (R=.79) between TAPSE and TA TDI s noted for the entire population. However, a statistically lower correlation (R=.43) was seen between Group 1 and Group 2 (R=.65; p<.0047). With increasing pulmonary pressures, only PASP (p<.0001) and TA TDI s (p<.0001) discriminated between low and normal TAPSE/PASP values. Suggesting that a TA TDI s/PASP ratio would be most useful than TAPSE/PASP with a specificity of 80%. Significant differences exist between TAPSE and TA TDI s, particularly at low TAPSE values with increased PASP, were uncoupling occurs. Our data seems to suggest that TA TDI s/PASP would be most useful than TAPSE/PASP ratio. Future studies should address, if abnormalities in the material properties along the RV free wall account for these differences seen between TAPSE and TA TDI s.

Normal range of intraoperative three-dimensionally derived right ventricular free-wall strain in coronary artery bypass surgery patients.

Data on intraoperative three-dimensionally derived right ventricular free-wall strain (3D-RV FWS) is sparse. We sought to evaluate the normal range of intraoperative 3D-RV FWS in patients scheduled for coronary artery bypass graft (CABG) surgery and compared to conventional echocardiographic parameters. Prospective observational study. A total of 150 patients with preserved left and right ventricular (RV) function and sinus rhythm, without significant heart valve disease or pulmonary hypertension undergoing isolated on-pump CABG surgery, with an uneventful, complication-free intraoperative course. 3D-RV FWS analysis and conventional echocardiographic assessment of RV function were performed intraoperatively in anesthetized and ventilated patients using transesophageal echocardiography (TEE). TomTec 4D RV-Function 2.0 software for assessment of 3D-RV FWS and three-dimensional right ventricular ejection fraction (3D-RV EF). Philips QLAB 10.8 was used to evaluate tissue velocity of the tricuspid annulus (RV S´), tricuspid annular systolic excursion (TAPSE), and RV fractional area change (FAC). All echocardiographic measurements were performed under stable hemodynamic conditions and predefined fluid management without any vasoactive support or pacing. The prospective observational study was performed in a single university hospital setting. Assessment of 3D-RV FWS was feasible in 95% of patients. No included patient experienced any serious perioperative complication. In our group of patients, median values with interquartile range (IQR) for 3D-RV FWS and 3D-RV EF were -25.2 (IQR -29.9 to -21.8) and 46.3% (IQR 41.0%-50.1%), respectively. RV FAC, RV S´, and TAPSE accounted for 39.7% (IQR 34.5%-44.4%), 14.8cm/s (IQR 11.8-19.0cm/s), and 22mm (IQR 20-25mm). The normal range (2.5% to 97.5% percentile) for 3D-RV FWS was -37.1 to -12.8. There was no relevant correlation of 3D-RV FWS to postoperative outcome in this group of CABG patients. We present distribution values for intraoperative 3D-RV FWS and conventional parameters of RV function assessment in a healthy on-pump CABG patient population without serious perioperative complications. We observed no correlations of these parameters with any of the outcome parameters considered. Therefore, we consider these values to be intraoperative TEE-assessed normal values, which can be expected in on-pump CABG patients.

Surpassing the complex substrate of accessory pathways ablation in ebstein anomaly

Abstract Funding Acknowledgements Type of funding sources: None. Background and Aims Data regarding long-term follow-up of radiofrequency catheter ablation (RFCA) of accessory pathways (APs) in patients (P) with Ebstein's anomaly are limited. This type of procedure is considered challenging due to multiple and broad APs. The present study aimed to describe the electrophysiological features of APs in P with Ebstein's anomaly, and report our RFCA experience with an open-window electroanatomic 3D mapping using high-density mapping catheters in these patients. Methods and results A retrospective study of 15 consecutive Ebstein anomaly P with APs who underwent an electrophysiologic study and RFCA from 2013 to 2022. There were a total of 21 manifested non-decremental APs. APs were mainly located on the posterior, posteroseptal, and posterolateral tricuspid annulus. The index procedure was unsuccessful in six P, with the need for a redo procedure. This redo procedure was performed with a high-density catheter (Pentaray, Biosense or HD-Grid, Abbott), using the open-window annotation algorithm (Abbott's NavX Precision or BiosenseWebster Carto3), guided by CT integration and intracardiac echo. Broad APs were documented in all these six patients (width range 2-15cm) and successfully ablated. In one P, the AP encompassed ¾ of the TA, resulting in a complete AV block after the procedure, having fitted a pacemaker. All P remained free from tachycardias during 15±8 months of follow-up, with the majority (n=12) having sinus rhythm with morphology of right bundle branch block, while three patients showed a narrow QRS. Conclusions RFCA in P with Ebstein anomaly is challenging, but safe, and has a high long-term success rate. APs are predominantly right-sided, manifest and localized to the lower half of the anatomic tricuspid annulus. Some APs have broad widths. In this population, the new high-resolution mapping catheters, using the open-window annotation, produce an improved anatomical resolution of the APs, increasing the odds of success.

His bundle pacing and AV nodal ablation for non-controlled atrial arrhythmia: a technical challenge with major clinical benefits

Abstract Funding Acknowledgements Type of funding sources: None. Background His bundle pacing (HBP) is an appealing alternative to right ventricular pacing in patients referred for permanent ventricular pacing and AV nodal ablation (AVNA) as it preserves physiological ventricular activation. Only limited amount of data is available in the literature regarding HBP combined with AVNA. Purpose To provide further evidence on the feasibility and efficacy of this therapeutic approach in patients with uncontrolled atrial arrhythmia. Methods We prospectively included all patients who underwent AVNA after HBP in three different hospitals between 2017 and 2022. Results AVNA following HBP lead implantation was performed in 75 patients. A complete AV block was obtained in 58 patients (77%) whereas significant modulation of the AV node conduction (heart rate &amp;lt; 60bpm) was obtained in 12 (16%). AVNA failure was observed in 5 (7%). The recording of an atrial signal by the HBP lead was more frequently observed in patients with AVNA modulation/failure compared to patients with complete AV block (11/17 vs 5/58; p &amp;lt; 0.001). There was no lead dislodgment during the AVNA procedures. Acute HB capture threshold increase &amp;gt; 1V occurred in 11 patients (15%) with return to baseline value at day one in 9. NYHA class and LVEF significantly improved from baseline to last follow-up (3.0 ± 0.7 vs 1.6 ± 0.5, p &amp;lt; 0.001; 47 ± 14% vs 60 ± 9%; p &amp;lt; 0.0001, respectively), Conclusion AVNA combined with HBP for non-controlled atrial arrhythmia was feasible and clinically efficient. Implanting the HB lead on the ventricular aspect of the tricuspid annulus avoiding atrial signal recording can facilitate AVNA.

P101 HIGH–DENSITY MAPPING OF KOCH‘S TRIANGLE DURING SINUS RHYTHM AND TYPICAL AV NODAL REENTRANT TACHYCARDIA INTEGRATED WITH THE DIRECT RECORDING OF ATRIOVENTRICULAR NODE STRUCTURES POTENTIAL: A MULTICENTER NON–RANDOMIZED STUDY

Abstract Background Atrioventricular nodal re–entrant tachycardia (AVNRT) is humans‘ most frequent regular tachycardia. Nevertheless, understanding the exact mechanism and pathways involved in the circuit that sustains the arrhythmia is still incomplete. Also, the recording of nodal potential was performed previously in animals with relative success, but not in humans. The aim of our study is to identify the potential of the compact atrioventricular node (AVN) and inferior extensions by using an electroanatomic mapping of the right atrium and the Koch‘s triangle in sinus rhythm and during AVNRT. Methods From March 2021 to July 2022, 79 patients with AVNRT underwent high–resolution mapping and complete ablation in 12 Italian Hospitals. No patients with atrial fibrillation or sustained ventricular tachycardia were included. The diagnosis of AVNRT was established according to standard criteria and diagnostic pacing manoeuvres. The presence and location of SP potentials, i.e., Jackman potential (JP) and Haïssaguerre potential (HP) were evaluated in each patient. The electroanatomic mapping obtained were merged with cardiac computerized tomography (CT) scan. Results Forty–five cases of successful AVNRT ablation were included in the analysis. The AVN potential has been demonstrated to be a very low frequency signal distinct from atrial, His bundle or ventricular activations, that can be recorded from electrodes overlying the region of the compact AVN by using a non–conventional bipolar electrogram filtering both during sinus rhythm and slow fast AVNRT. AVN potential was identified in all cases in the mid–septal region (#5) in both sinus rhythm and tachycardia. The mid–septal region and the postero–septal regions (#7) bounded anteriorly by the tricuspid annulus and posteriorly by the lateral wall toward the crista terminalis showed a higher prevalence of HP than other regions (46.7% in region #5 and 51.1% in region #7, p&amp;lt;0.0001 vs other regions, respectively). JPs seemed to have a converse distribution across the KT and they were mainly observed in the mid–postero–septal region (73.3%). After 359±121 days of follow–up, no patients had a recurrence of AVNRT. Conclusion The exact anatomical site and pathways involved in AVNRT are still unclear as well as the analysis and characterisation of the AVN potential. Our results represent the first evidence of the recording of AVN potential. Further studies and technological improvements are needed to confirm our results.

C46 ELECTROPHYSIOLOGICAL ASSESSMENT OF ATRIAL TACHYCARDIA SUBSTRATES IN PATIENTS WITH REPAIRED TETRALOGY OF FALLOT

Abstract Introduction Adults with repaired tetralogy of Fallot (rToF) experience episodes of atrial tachycardia (AT) and radiofrequency catheter ablation (RFCA) is often required but systematic evaluation of the mechanisms and recurrences is lacking. Methods Between January 2013 and October 2021, 20 rToF patients with AT referred for catheter ablation were enrolled. Electrophysiologic study with 3D electroanatomic mapping with multi–electrode mapping catheters was done, with right atrial bipolar voltage and activation mapping of the AT. Three mechanisms were searched: intra–atrial re–entrant tachycardias (IART), focal (FAT), other. Critical isthmus (CI) for IART was identified with activation mapping. FATs were localized according to the earliest uni/bipolar signal. All induced AT were treated. RFCA was aimed at the earliest activation point for FAT and at the critical isthmus for IART, anchoring lesion to fixed obstacles (valve annuli or scar). Written informed consent was provided. Results Among 20 adult (age 46±14 years) and mainly females (n=11, 55%) enrolled pts, 36 AT were documented: 25 (70%) IART, 10 (27%) FAT and only 1 (3%) had a typical atrioventricular nodal reentrant tachycardia. Mean tachycardia cycle length was 307±95 ms. Two ATs were induced in 11 pts, 3 in 4 pts and 4 in 2 during index EPS. Among IART, cavo–tricuspid isthmus (CTI) was the prevalent CI (n=14, 60%), while incisional IART (IARTinc, atriotomy and superior and inferior vena cava orifices, SVC and IVC, respectively) was the second mechanism (n=9, 39%). In two pts, due to non–inducibility, a pre–emptive lesion set comprising in one case CTI and in the second case CTI+SVC–atriotomy–IVC line was performed. Among FAT, in 3 cases the AT was mapped in the coronary sinus, in two at the tricuspid annulus, other at the crista terminalis, right appendage base, posterolateral scar or between atriotomy and SVC. During a median follow–up of 23 months (interquartile range, 6–37) recurrence occurred in 8 pts (25% of pts, 22% of tachycardias). Pts with recurrences were younger (43±7 vs. 48±17 y, p=0.04); no differences were found according to critical isthmus location (4 CTI and 4 IARTinc, 50%, p=ns). Conclusions Among rToF pts with AT, IART is the prevalent mechanism and CTI is the prevalent CI; atriotomy scar, however, is involved in a substantial portion of the critical isthmuses of the IART; FAT location is much more variable. Long–term freedom from AT in this clinical setting is encouraging.

P13 THE PHANTOM OF TRICUSPID PROSTHESIS: CASE REPORT OF A PECULIAR TRANSCATHETER TRICUSPID VALVE–IN–VALVE IMPLANTATION

Abstract Background Transcatheter tricuspid valve–in–valve replacement for patients with degenerative tricuspid surgical bioprosthesis disease has emerged in recent years as a new treatment possibility in patients that required tricuspid valve replacement at young age and in circumstances where redo tricuspid valve replacement is not feasible because of the remarkable morbidity and mortality. Case presentation. A 76 year–old Caucasian male was referred to our center for worsening dyspnoea and fatigue. He had a pacemaker implanted for third degree atrio–ventricular block in 1996. After massive endocarditis affecting the tricuspid valve and the pacemaker right ventricular lead, the patient underwent surgical tricuspid valve replacement with a 32 mm Liotta BioImplant L.P.B., right ventricular lead extraction and concomitant epicardial pacemaker reimplantation. Transthoracic echocardiogram at hospital admission denoted a degenerative stenosis of the tricuspid prosthesis with a trans–valvular mean gradient of 8 mmHg associated with right atrial and inferior vena cava dilatation. Given the high surgical risk due to comorbidities (systemic arterial hypertension, paroxysmal atrial fibrillation in DOAC, grade II obesity, smoking history and chronic lymphoproliferative leukemia) the patient was deemed not suitable for a re–do surgical tricuspid valve replacement and was offered a percutaneous replacement. Preprocedural planning with computed tomography allowed accurate reconstruction of the tricuspidal prosthetic annulus and correct sizing of Edwards SAPIEN valve, the most used in valve–in–valve procedures. The degenerated prosthesis was not visible at fluoroscopy meaning no fluoroscopic landmarks available to provide an anatomic view for valve deployment. Therefore, a combination of balloon valvuloplasty and right atrium angiographies before the valve–in–valve deployment were critical to provide the correct valve position and yield the procedure effective and safe. Hemodynamic gradient post–TVIV was absent and no paravalvular leaks were observed. Clinical and echocardiographic improvement were confirmed after the procedure and at 1 year–follow up. Conclusion Tricuspid valve–in–valve replacement can be technically feasible and a safer alternative to re–do surgical valve replacement, also in radiolucent bioprosthesis. In our case the successful procedural outcome not only relied on meticulous planning before the procedure, but also on specific intra–procedural adjustments.

C63 PREVALENCE AND CLINICAL SIGNIFICANCE OF RIGHT VENTRICULAR PULMONARY ARTERIAL UNCOUPLING IN CARDIAC AMYLOIDOSIS

Abstract Background This study aims to evaluate the prevalence and clinical significance of the right ventricular pulmonary arterial (RV–PA) uncoupling in patients with cardiac amyloidosis (CA). Methods The study population consisted in 92 consecutive patients with CA (age 71.1±12.2 years, 71% males; 47% with immunoglobulin light chain (AL), 53% with transthyretin [ATTR]). All patients underwent a comprehensive evaluation. A pre–specified tricuspid annulus plane systolic excursion on pulmonary arterial systolic pressure (TAPSE/PASP) value &amp;lt;0.31 mm/mmHg was used to define RV–PA uncoupling and to dichotomize the study population. Results Thirty–two patients (35%) showed RV–PA uncoupling at baseline evaluation (15/44 [34%] AL and 17/48 [35%] ATTR). Patients with RV–PA uncoupling in both AL and ATTR showed worse NYHA functional class, lower systemic blood pressure, and more pronounced left and right ventricular systolic dysfunction than those with RV–PA coupling. During a median follow–up of 8 months (IQR 4–13), 26 patients (28%) experienced cardiovascular death. Patients with RV–PA uncoupling showed lower survival at 12 months follow–up than those with RV–PA coupling (42.7% [95%CI 21.7–63.7%] vs. 87.3% [95%CI 78.3–96.3%], p–value&amp;lt;0.001). Multivariate analysis identified high–sensitivity troponin I values (HR 1.01 [95%CI 1.00–1.02] per 1 pg/mL increase; p–value 0.013) and TAPSE/PASP (HR 1.07 [95%CI 1.03–1.11] per 0.01 mm/mmHg decrease; p–value 0.002) as independent predictors of cardiovascular death. Conclusions RV–PA uncoupling is common among patients with CA, and it is a marker of advanced disease and worse outcomes. This study suggest that TAPSE/PASP ratio has the potential to improve risk stratification and guide management strategies in patients with CA.