Septal Tricuspid Annulus Research Articles

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.

P-Wave Morphology in Focal Atrial Tachycardia: An Updated Algorithm to Predict Site of Origin.

This study sought to report P-wave morphology (PWM) from a series of paraseptal (PS) atrial tachycardia (AT), revise then prospectively evaluate a simplified PWM algorithm against a contemporary consecutive cohort with focal AT. The 2006 PWM algorithm was useful in predicting the origin of focal AT. An updated algorithm was developed given advances in multipolar 3-dimensional mapping, potential limitations of PWM in separating PS sites, and a renewed interest in the P-wave in mapping non-pulmonary vein triggers. The PWM from a consecutive series of 67 patients with PS AT were analyzed. PS sites included were coronary sinus ostium, perinodal, left and right septum, septal tricuspid annulus, superior mitral annulus, and noncoronary cusp. Next the P-wave algorithm was revised and prospectively evaluated by 3 blinded assessors. The P-wave for PS sites was neg/pos (n= 50), iso/pos (n= 10), or isoelectric (n= 4) in lead V1 (96%). The P-wave algorithm was modified and prospectively applied to 30 consecutive patients with focal AT who underwent successful ablation. Foci (n=30) originated from the right atrium (33.3%), left atrium (30%), and PS (36.7%). Using the PW algorithm, the correct anatomic location was identified in 93%. Incorrect interpretation of the terminal positive P-wave component (n=3) and initial negative P-wave deflection (n=1) in lead V1 misidentified 4 paraseptal cases. The revised PWM algorithm offers a simplified and accurate method of localizing the responsible site for focal AT. The P-wave remains an important first step in mapping atrial arrhythmias.

Physiology of slow pathway conduction during sinus rhythm: evidence from high density mapping within the triangle of Koch.

To evaluate nature of AV nodal activation in patients with AVNRT using high density electro-anatomic mapping (HD-EAM). HD-EAM was created in 30 patients with AVNRT from the triangle of Koch (ToK) in sinus rhythm (SR). Isochronal late activation maps (ILAM) were created. EAMs were analyzed for slow pathway (SPW) and fast pathway (FPW) activation. A pivot point (PP) was defined where FPW and SPW collided and pivoted back to the AV node (AVN). Conduction was assessed with programmed extrastimulus (PES) in 9 patients until FPW refractory period (ERP). The change in PP distance from the HIS (ΔPP) was measured in SR and PES. The ΔPP was compared to ΔAH. The PP was ablated and SR re-mapped. The FPW activates the His and moves inferiorly toward the coronary sinus (CS). Activation also enters the ToK near the CS and collides with the FPW which then pivots around a functional line of block (LOB) within the ToK and moves superiorly along the septal tricuspid annulus. PP electrograms are fractionated, low amplitude, and consistent with SPW potentials (Haissaguerre et al. in Circulation 85:2162-2175, 1992). During PES the PP moved superiorly until FPW ERP when only SPW activation occurs. Normalized ΔAH and ΔPR vs ΔPP was highly correlated p < 0.0001. Ablation at the PP was successful and associated with loss of SPW fusion and pivot. We conclude HD-EAM/ILAM provide a novel method for localizing the SPW in SR. This study provides further understanding of dual AV nodal physiology and may aid in targeting the SPW for ablation of AVNRT.

B-AB16-02 P WAVE MORPHOLOGY IN FOCAL ATRIAL TACHYCARDIA: AN UPDATED 2021 ALGORITHM TO PREDICT SITE OF ORIGIN

The 2006 P wave morphology (PWM) algorithm was useful in predicting the origin of focal atrial tachycardia (AT). An updated algorithm was developed given advances in three dimensional(3D) mapping, potential limitations of PWM in separating paraseptal (PS) sites, and a renewed interest in the P wave in mapping non- pulmonary vein triggers in atrial fibrillation ablation. To report PWM from a series of PS AT, revise then prospectively evaluate a simplified PWM algorithm against a contemporary cohort with focal AT. The P wave morphology from a consecutive series of 67 patients with PS AT were analysed. PS sites included: CS ostium, perinodal, left and right septum, septal tricuspid annulus, superior mitral annulus and non-coronary cusp. Next the P wave algorithm was revised and prospectively evaluated by 3 blinded assessors. The PWM was not useful in separating PS sites. Generally the PS P wave was negative/positive, isoelectric/positive or isoelectric in lead V1 in 93% of cases. The P wave algorithm was prospectively applied to 30 consecutive patients with focal AT who underwent successful ablation. Foci (30) originated from right atrium (33.3%), left atrium (30%) and PS (36.7%). Using the P wave algorithm, the correct anatomic location was identified in 93%. Incorrect interpretation of the terminal positive P wave component(3) and initial negative P wave deflection(1) in lead V1 misidentified 4 paraseptal cases. The revised 2021 P wave morphology algorithm offers a simplified and accurate method of localising the responsible site for focal atrial tachycardia. The P wave remains an important first step in mapping atrial arrhythmias.

OP-274 Right Ventricular Dysfunction in Patients with End-Stage Renal Disease on Regular Hemodialysis

Although there are considerable data on the changes in left ventricular function in hemodialysis (HD) patients, only a few studies on right ventricular (RV) function can be found in the literature. We investigated the changes in RV function in HD patients. We examined 74 individuals grouped as follows: healthy controls (n = 24) and HD patients (n = 50). Echocardiography including tissue Doppler imaging (TDI) of the RV was performed in all patients. HD patients had significantly lower RV systolic indices than control participants in right ventricle fractional area change (37.54 ± 9.86 vs. 43.5± 4.8%,P<0.001), tricuspid plane systolic excursion (2.09 ± 0.49 vs. 2.61± 0.36 cm, P<0.001),Septal TDIS'(peak systolic velocity at septal tricuspid annulus) (7.99± 1.37 vs. 9.66± 1.86 cm/s,P<0.001), and Lateral TDIS' wave (peak systolic velocity at lateral tricuspid annulus) (11.86 ± 2.86 vs.16.04 ±3.60 cm/s, P<0.001). HD patients had statistically significantly higher systolic pulmonary pressure compared with those in the control group (32.75 ± 10.11 vs. 25.23± 3.99 mmHg, P<0.001). There were no statistically significant correlations between systolic pulmonary pressure and RV dimensions or RV function indices. Subclinical RV dysfunction – as estimated by RV function indices; tricuspid plane systolic excursion, right ventricle fractional area change, and Lateral TDIS' – is increased among HD patients. A high prevalence of pulmonary hypertension was found among HD patients and this was not associated significantly with RV or left ventricular dysfunction in these patients.

Idiopathic premature ventricular contractions and ventricular tachycardias originating from the vicinity of tricuspid annulus: Results of radiofrequency catheter ablation in thirty-five patients

BackgroundIn recent years, catheter ablation has increasingly been used for ablation of idiopathic premature ventricular complexes (PVCs) or ventricular tachycardias (IVTs). However, the mapping and catheter ablation of the arrhythmias originating from the vicinity of tricuspid annulus (TA) may not be fully understood. This study aimed to investigate electrophysiologic characteristics and effects of radiofrequency catheter ablation (RFCA) for patients with symptomatic PVCs and IVTs originating from the vicinity of TA.MethodsCharacteristics of body surface electrocardiogram (ECG) and electrophysiologic recordings were analyzed in 35 patients with symptomatic PVCs/ IVTs originating from the vicinity of TA. RFCA was performed using pace mapping and activation mapping.ResultsAmong the 35 patients with PVCs/IVTs arising from the vicinity of TA, complete elimination of PVCs/IVTs could be achieved by RFCA in 32 patients (success rate 91.43%) during a median follow-up period of 21 months. PVCs/IVTs originating from the vicinity of TA had distinctive ECG characteristics that were useful for identifying the precise origin. An rS pattern was recorded in lead V1 in 93.1% of patients with PVCs/IVTs from the free wall of TA, vs 16.7% of patients with PVCs/IVTs from the septal TA, whereas a QS pattern in lead V1 occurred in 83.3% of patients with PVCs/IVTs from the septal TA vs 6.9% of patients with PVCs from the free wall of the TA. The precordial R wave transition occurred by lead V3 or earlier in all patients with PVCs/IVTs originating from the septal portion of the TA, as compared to transition beyond V3 in all patients with PVCs/IVTs from the free wall of the TA.ConclusionsRFCA is an effective curative therapy for symptomatic PVCs/IVTs originating from the vicinity of TA. There are specific characteristics in ECG and the ablation site could be located by ECG analysis.

Left Atrionodal Connections in Typical and Atypical Atrioventricular Nodal Reentrant Tachycardias: Activation Sequence in the Coronary Sinus and Results of Radiofrequency Catheter Ablation

The presence of atrionodal connections and coronary sinus (CS) breakthrough in atrioventricular nodal reentrant tachycardia (AVNRT) has been suggested. However, the incidence, anatomic relationship with reentrant circuit, and results of catheter ablation are unknown. Fifty-two patients with typical slow/fast AVNRT and 10 patients with atypical slow/intermediate or fast/slow AVNRT were included. Eccentric activation of the CS (EACS) was observed in 3 of 52 patients with typical and 8 of 10 patients with atypical AVNRT. The earliest CS activation in patients with an EACS was recorded at a site 10-20 mm inside the CS ostium. The postpacing interval after transient entrainment at the proximal CS in patients with EACS was 23 +/- 21 msec longer than the pacing cycle length. Modification or ablation of the slow pathway was successful in all patients with typical slow/fast AVNRT and in 7 of 9 patients with atypical AVNRT by RF energy delivered at the right septal tricuspid annulus (TA). In 2 patients with atypical AVNRT and an EACS, RF delivery inside the CS targeting the earliest CS activation eliminated the sustained AVNRT. Eccentric coronary sinus activation is observed in some rare cases of typical AVNRT, and in a majority of atypical AVNRT. Entrainment results suggest that the proximal coronary sinus may be part of the reentrant circuit. RF ablation of atypical AVNRT, if it fails from the standard right-side approach, can be targeted at the site of earliest retrograde atrial activation inside the CS.