Long-term outcomes after catheter ablation for idiopathic atypical atrial flutter.

BACKGROUND: Idiopathic atypical (non-cavotricuspid isthmus-dependent) atrial flutter (IAAFL) may be seen in patients without structural heart disease and without previous cardiac surgery or ablation. OBJECTIVE: This study sought to determine the patient characteristics, electrophysiologic and electroanatomic properties, and clinical outcomes after ablation in patients with IAAFL. METHODS: We retrospectively compared IAAFL patients with cavotricuspid isthmus-dependent AFL (C-AFL) patients undergoing catheter ablation. The primary outcome was a composite of death from cardiovascular causes, ischemic stroke, and hospitalization for worsening of heart failure. RESULTS: Of 180 patients who underwent catheter ablation for AFL, 89 were included in this study (22 IAAFL and 67 C-AFL). Electrophysiologic study showed significantly longer intra-atrial conduction time and lower atrial voltage during sinus rhythm in the IAAFL group compared with the C-AFL group. The atrial scar was observed in all 22 IAAFL patients, with the most common sites being the posterior or lateral wall of the right atrium in 10 (45.5%) and the anterior wall of the left atrium in 8 (36.4%). During 3.5 ± 2.8 years of follow-up, the composite primary end point occurred significantly more frequently in the IAAFL group (hazard ratio [HR], 3.45; 95% confidence interval [CI], 1.20-9.89; P = .015). In multivariable analysis, brain natriuretic peptide levels (HR, 1.01; 95% CI, 1.00-1.01, per 1 pg/mL; P = .01) and IAAFL (HR, 4.14; 95% CI, 1.21-14.07; P = .02) were independently associated with the primary outcome. CONCLUSION: IAAFL in patients had distinct electrophysiologic features suggestive of atrial cardiomyopathy. These patients are at risk for development of cardiovascular adverse events after ablation.

Paced QRS morphology mimicking complete left bundle branch block induced by right ventricular pacing is associated with pacing-induced cardiomyopathy.

INTRODUCTION: Right ventricular (RV) pacing sometimes causes left ventricular (LV) systolic dysfunction, also known as pacing-induced cardiomyopathy (PICM). However, the association between specifically paced QRS morphology and PICM development has not been elucidated. This study aimed to investigate the association between paced QRS mimicking a complete left bundle branch block (CLBBB) and PICM development. METHODS: We retrospectively screened 2009 patients who underwent pacemaker implantation from 2010 to 2020 in seven institutions. Patients who received pacemakers for an advanced atrioventricular block or bradycardia with atrial fibrillation, baseline LV ejection fraction (LVEF) ≥ 50%, and echocardiogram recorded at least 6 months postimplantation were included. The paced QRS recorded immediately after implantation was analyzed. A CLBBB-like paced QRS was defined as meeting the CLBBB criteria of the American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society in 2009. PICM was defined as a ≥10% LVEF decrease, resulting in an LVEF of <50%. RESULTS: Among the 270 patients analyzed, PICM was observed in 38. Baseline LVEF was lower in patients with PICM, and CLBBB-like paced QRS was frequently observed in PICM. Multivariate analysis revealed that low baseline LVEF (odds ratio [OR]: 0.93 per 1% increase, 95% confidence interval [CI]: 0.89-0.98, p = 0.006) and CLBBB-like paced QRS (OR: 2.69, 95% CI: 1.25-5.76, p = 0.011) were significantly associated with PICM development. CONCLUSION: CLBBB-like paced QRS may be a novel risk factor for PICM. RV pacing, which causes CLBBB-like QRS morphology, may need to be avoided, and patients with CLBBB-like paced QRS should be followed-up carefully.

Precordial ST-Segment Elevation: Anterior Myocardial Infarction or Something Else?

The differential diagnosis of ST-segment elevation on electrocardiogram is multifaceted. Particularly, in cases of precordial ST-segment elevation, considering anterior myocardial infarction is crucial. Herein, we present a case of precordial ST-segment elevation with normal left coronary arteries.

Acute pulmonary vein stenosis during radiofrequency catheter ablation for atrial fibrillation.

We encountered acute pulmonary vein (PV) stenosis during radiofrequency catheter ablation. PV stenosis was not apparent before redo ablation (A). However, acute PV stenosis was observed after repeat ablation, including carina ablation (B, C). Computed tomography performed 6 months post-ablation revealed chronic PV stenosis (D).

Narrow QRS Complex Tachycardia With Variable R-R Intervals and Discrete P Waves.

Irregular narrow QRS complex tachycardia is associated with a wide range of differential diagnoses, including atrial fibrillation and atrial tachyarrhythmia with altered atrioventricular conduction. Here, we present a case of narrow QRS complex tachycardia with variable R-R intervals and discrete P waves. (Level of Difficulty: Intermediate.).

Prognostic Value of Left Atrial Calcification After Catheter Ablation for Atrial Fibrillation.

BACKGROUND: Left atrial calcification (LAC) has occasionally been observed in patients who underwent catheter ablation for atrial fibrillation (AF) by chest computed tomography (CT). However, the evidence regarding the clinical impact of LAC in patients with AF is lacking. OBJECTIVES: This study aims to investigate the prevalence of LAC in AF patients and evaluate its clinical significance after AF ablation. METHODS: This observational registry included AF patients who received computed tomography and serial transthoracic echocardiography between January 2010 and November 2017. The primary composite outcome included cardiovascular death, hospitalization for worsening heart failure, and ischemic stroke. RESULTS: Among 534 patients (age 72 ± 13 years, 62.5% men) who met the inclusion criteria, 31 (5.8%) had LAC. In multivariable analysis, AF ablation was associated with an 11.8-fold (OR: 11.8; 95% CI: 2.03-227.65) increased risk of the development of LAC in AF patients. Among 218 patients with AF ablation, LAC was detected in 30 (13.8%) patients. Prior stroke (HR: 2.73; 95% CI: 1.08-6.93) and multiple ablation procedures (HR: 4.21; 95% CI: 1.63-10.87) were independently associated with the development of LAC in AF-ablation patients. During a median follow-up of 5.8 years, the primary composite outcome occurred in 11 patients in the LAC group (39.8 per 1,000 person-years) and 10 patients in the non-LAC group (8.9 per 1,000 person-years). The adjusted HR for the primary composite outcome in the LAC group, as compared with the non-LAC group, was 2.81 (95% CI: 1.16-6.84; P = 0.02). CONCLUSIONS: The presence of LAC was a significant and independent prognostic factor for identifying major adverse cardiovascular events after AF ablation.

Intra-atrial activation pattern is useful to localize the areas of non-pulmonary vein triggers of atrial fibrillation.

BACKGROUND: Pulmonary vein isolation (PVI) is an established ablation procedure for atrial fibrillation (AF), however, PVI alone is insufficient to suppress AF recurrence. Non-pulmonary vein (non-PV) trigger ablation is one of the promising strategies beyond PVI and has been shown to be effective in refractory/persistent AF cases. To make non-PV trigger ablation more standardized, it is essential to develop a simple method to localize the origin of non-PV triggers. METHODS: We retrospectively analyzed 37 non-PV triggers in 751 ablation sessions for symptomatic AF from January 2017 to December 2020. Regarding non-PV triggers, intra-atrial activation interval from the earliest in right atrium (RA) to proximal coronary sinus (CS) (RA-CSp) and that from the earliest in RA to distal CS (RA-CSd) obtained by a basically-positioned duodecapolar RA-CS catheter were compared among 3 originating non-PV areas [RA, atrial septum (SEP) and left atrium (LA)]. RESULTS: RA-CSp of RA non-PV trigger (56.4 ± 23.4 ms) was significantly longer than that of SEP non-PV (14.8 ± 25.6 ms, p = 0.019) and LA non-PV (-24.9 ± 27.9 ms, p = 0.0004). RA-CSd of RA non-PV (75.9 ± 32.1 ms) was significantly longer than that of SEP non-PV (34.2 ± 32.6 ms, p = 0.040) and LA non-PV (-13.3 ± 41.2 ms, p = 0.0008). RA-CSp and RA-CSd of SEP non-PV were significantly longer than those of LA non-PV (p = 0.022 and p = 0.016, respectively). Sensitivity and specificity of an algorithm to differentiate the area of non-PV trigger using RA-CSp (cut-off value: 50 ms) and RA-CSd (cut-off value: 0 ms) were 88% and 97% for RA non-PV, 81% and 73% for SEP non-PV, 65% and 95% for LA non-PV, respectively. CONCLUSIONS: The analysis of intra-atrial activation sequences was useful to differentiate non-PV trigger areas. A simple algorithm to localize the area of non-PV trigger would be helpful to identify non-PV trigger sites in AF ablation.

Location and coupling interval of an ectopic excitation determine the initiation of atrial fibrillation from the pulmonary veins.

INTRODUCTION: Ectopic beats originating from the pulmonary vein (PV) trigger atrial fibrillation (AF). The purpose of this study was to clarify the electrophysiological determinant of AF initiation from the PVs. METHODS: Pacing studies were performed with a single extra stimulus mimicking an ectopic beat in the left superior PVs (LSPVs) in 62 patients undergoing AF ablation. Inducibility of AF, effective refractory period (ERP), and conduction properties within the PVs were analyzed. RESULTS: A single extra stimulus in LSPV induced AF in 20 patients (32% of all patients) at the mean coupling interval (CI) of 172 ms. A CI-dependent anisotropic conduction at the AF onset was visualized in a three-dimensional mapping. Onset of AF was site-specific with reproducibility in each individual. Mean ERP in LSPV in the AF-inducible group was shorter than that in the AF-noninducible group (182 ± 55 vs. 254 ± 51 ms, p < .0001). LSPV ERP dispersion was greater in the AF-inducible group than in the AF-noninducible group (45 ± 28 vs. 27 ± 19 ms, p < .01). Circumferential intra-PV conduction time (IPVCT) exhibited decremental properties in response to shortening of CI and the prolongation of IPVCT in the AF-inducible site was greater than that in the AF-noninducible site (p < .05) in each individual. CONCLUSIONS: Location and CI of an ectopic excitation ultimately determine the initiation of AF from the PVs. ERP dispersion and circumferential conduction delay may lead to anisotropic conduction and reentry within the PVs that initiate AF.

Anatomical evaluation of the esophagus using computed tomography to predict acute gastroparesis following atrial fibrillation ablation.

BACKGROUND: Catheter ablation for atrial fibrillation is an effective treatment; however, periesophageal vagal nerve injury is not rare and sometimes results in acute gastroparesis (AGP) after atrial fibrillation ablation (AFA). We sought to investigate the incidence and risk factors of AGP via preprocedural computed tomography (CT) analysis. METHODS: We retrospectively reviewed 422 patients who underwent index AFA at our center. Using contrast-enhanced CT performed before ablation, the anatomical characteristics of the esophagus were compared between patients with and without post-ablation AGP. AGP was diagnosed by the presence of symptoms, fasting abdominal X-ray radiography as a screening test, and additional abdominal imaging. RESULTS: Of the 422 patients (age, 67 ± 11 years; male, 68.5%; cryoballoon, 63.7%), AGP developed in 14 (3.3%) patients, and six of 14 patients were asymptomatic. AGP resolved in all patients within 4 weeks without invasive treatment. In the AGP group, the esophagus was frequently located on the vertebra (middle-positioned esophagus) (AGP vs non-AGP, 42.9% vs 11.5%; P = .01), and additional posterior wall ablation was frequently performed (50.0% vs 14.5%; P = .02). In the multivariate analysis, middle-positioned esophagus (P = .02; odds ratio, 9.0; 95% confidence interval [CI], 1.5-53.3) and additional posterior wall ablation (P = .01; odds ratio, 7.6; 95% CI, 1.5-42.1) were independent predictors of AGP. CONCLUSIONS: Anatomical evaluation of the esophagus using CT may be simple and useful for predicting AGP after AFA. High-risk patients who have middle-positioned esophagus or who underwent excessive posterior wall ablation should be followed up closely.

Responsiveness to bepridil predicts atrial substrate in patients with persistent atrial fibrillation.

BACKGROUND: The low voltage zone (LVZ) detected with three-dimensional electroanatomical mapping is a surrogate marker of atrial scar in patients with persistent atrial fibrillation (PeAF) and is associated with poor clinical outcomes after catheter ablation. However, fewer studies have reported the relationship between responsiveness to antiarrhythmic drugs and the LVZ. METHODS: We retrospectively analyzed 76 patients who underwent catheter ablation for PeAF at our center. Rhythm control with bepridil was initiated before ablation in all patients, and electrical cardioversion was performed in cases of failure to restore sinus rhythm with bepridil alone. Patients with successful sinus restoration with bepridil alone (≤200 mg/d) were defined as "responders", while those who required electrical cardioversion as well were defined as "non-responders". We compared the LVZ ratio (ratio of the LVZ surface area to the left atrium surface area on three-dimensional electroanatomical mapping) and the recurrence-free rate after ablation between the two groups. RESULTS: Of the 76 patients, 48 (63.2%) were responders to bepridil. The median LVZ ratio was significantly lower in the responder group than in the nonresponder group (7.5% vs 14.0%, P = .009). Multivariate analysis revealed that response to bepridil was an independent predictor of normal voltage (P = .02, odds ratio = 0.20, 95% confidence interval = 0.04-0.76). The recurrence-free rate at 1 year after catheter ablation was significantly higher in the responder group than in the nonresponder group (87.1% vs 62.3%, P = .03). CONCLUSIONS: Response to bepridil is a marker of normal voltage in electroanatomical mapping and is significantly associated with better clinical outcomes after catheter ablation.

Bidirectional atrioventricular reentrant tachycardia using bilateral accessory pathways.

Patients with Wolff-Parkinson-White (WPW) syndrome rarely have multiple accessory pathways (APs). Here, we present a case of a 21-year-old man with the manifest type B WPW syndrome who was experiencing multiple attacks of palpitations. The electrophysiological study revealed two APs located bilaterally: the anterolateral tricuspid annulus and lateral mitral annulus. Atrial/ventricular extrastimulations induced two types of wide QRS tachycardia conducting via two APs in the clockwise and counterclockwise direction. These two APs were eliminated with careful mapping and catheter ablation. .

Mahaim fiber connecting the right atrium to the left ventricle: a case report.

In the majority of cases presenting with the Mahaim fiber (MF), the MF connects the lateral right atrium (RA) to the right bundle branch or the right ventricle. We present the case of a 33-year-old man with antidromic atrioventricular reentrant tachycardia using MF connected to the septal RA and left ventricle (LV). Although the Mahaim potential was recorded at the septal RA, ablation at this site could not eliminate the MF and had a potential risk of injury to the atrioventricular node. Additional application at the posterior septal LV achieved successful MF ablation.

Atrial pacing and administration of nifekalant hydrochloride for unstable atrial fibrillation: a case report.

BACKGROUND: Atrial fibrillation (AF) is a common arrhythmia in patients with hypertrophic cardiomyopathy (HCM) and can deteriorate haemodynamic status. CASE SUMMARY: We report a case of a 77-year-old woman with cardiogenic shock due to paroxysmal AF, complicated with HCM and aortic stenosis. Atrial fibrillation was successfully managed with temporary atrial pacing and administration of nifekalant hydrochloride without invasive mechanical circulatory support until surgery. Septal myectomy, aortic valve replacement, and pulmonary vein isolation were performed. DISCUSSION: This case suggests that atrial pacing and nifekalant may be safe and effective for rhythm control.

Efficacy of hybrid therapy using prior administration of bepridil hydrochloride and cryoballoon ablation in patients with persistent atrial fibrillation.

BACKGROUND: Rhythm control before catheter ablation for persistent atrial fibrillation (PeAF) can improve clinical outcomes. We sought to investigate the efficacy of pretreatment with bepridil prior to cryoballoon ablation (CBA) with respect to clinical outcomes in patients with PeAF. METHODS: We retrospectively analyzed 65 consecutive patients with PeAF who underwent CBA following pretreatment with bepridil hydrochloride (bepridil). Electrical cardioversion was additionally performed in cases involving failure of pharmacological sinus restoration before CBA. The primary endpoint was survival free from atrial tachyarrhythmia at the one-year follow-up, and the secondary endpoints were changes in P-wave morphology and left atrium diameter (LAD) before CBA. RESULTS: At the one-year follow-up, 51 patients (78.5%) achieved the primary endpoint (non-recurrence group). Compared to the P-wave duration (Pdur) and dispersion at the time of sinus restoration, they significantly shortened at the time of CBA in the non-recurrence group, while they did not change in the recurrence group. There were no changes in LAD in both groups. Multivariate analysis revealed that refractoriness of bepridil (p = 0.03, odds ratio = 4.72, 95% confidence interval = 1.18-18.92), and longer Pdur at admission for CBA (p = 0.003, odds ratio = 1.08, 95% confidence interval = 1.01-1.14) were independent predictors of recurrence. CONCLUSIONS: Rhythm control with bepridil induced electrical reverse remodeling; bepridil may improve clinical outcomes after CBA.

Left Ventricular Noncompaction with Multiple Thrombi in Apical Aneurysm.

A 44-year-old man was admitted to our hospital due to heart failure. Transthoracic echocardiography demonstrated global hypokinesis with an ejection fraction of 25%, prominent trabeculation and deep intertrabecular recesses, and apical aneurysm with multiple thrombi (10×13 mm in the inferior wall, 15×8 mm in the anterior wall). Cardiac magnetic resonance imaging showed an increased ratio of noncompacted (NC) to compacted (C) myocardium (NC/C ratio >2.3) and apical aneurysm. Coronary angiography revealed no significant stenosis. He was therefore diagnosed with left ventricular noncompaction complicated by apical aneurysm. Four weeks after starting anticoagulation, the multiple apical thrombi disappeared without clinical signs of embolism.

Non-Pulmonary Vein Triggers of Atrial Fibrillation Are Likely to Arise from Low-Voltage Areas in the Left Atrium.

The pathophysiology of non-pulmonary vein (PV) triggers of atrial fibrillation (AF) is unclear. We hypothesized that left atrial non-PV (LANPV) triggers are associated with atrial tissue degeneration. This study analyzed 431 patients that underwent catheter ablation (mean age 62 yrs, 303 men, 255 paroxysmal AF [pAF] patients). Clinical and electrophysiological characteristics of non-PV trigger were analyzed. Fifty non-PV triggers in 40 patients (9.3%) were documented; LANPV triggers were the most prevalent (n = 19, 38%). LANPV triggers were correlated with non-paroxysmal AF (non-pAF) (OR 3.31, p = 0.04) whereas right atrial non-PV (RANPV) triggers (n = 14) and SVC triggers (n = 17) were not. The voltage at the LANPV sites during SR was 0.3 ± 0.16 mV (p < 0.001 vs. control site). Low-voltage areas (LVAs) in the LA were significantly greater in non-pAF compared to pAF (14.2% vs. 5.8%, p < 0.01). RANPV trigger sites had preserved voltage (0.74 ± 0.48 mV). Long-term outcomes of patients with non-PV triggers treated with tailored targeting strategies were not significantly inferior to those without non-PV triggers. In conclusion, non-PV triggers arise from the LA with degeneration, which may have an important role in AF persistence. A trigger-oriented, patient-tailored ablation strategy considering LA voltage map may be feasible and effective in persistent/recurrent AF.

Predictive value of the induction test with atrial burst pacing with regard to long-term recurrence after ablation in persistent atrial fibrillation.

BACKGROUND: Induction test of atrial fibrillation (AF) is one of endpoint measures in catheter ablation (CA). However, its predictive value in long-term outcome remains controversial. METHODS: Ninety-eight patients (61 years, 77 males) with persistent AF who underwent pulmonary vein antrum isolation-based CA were retrospectively analyzed. We determined whether inducibility of AF/atrial tachyarrhythmias (AT) by atrial burst pacing at the end of CA and other characteristics were associated with the recurrence of AF/AT. Atrial burst pacing was performed with 30-beat from the coronary sinus; increasing from 240 to 320 ppm. Inducibility was defined as AF/AT lasting ≥5 minutes following atrial burst pacing. RESULTS: AF/AT was induced in 50 patients (51%). During 1 year of follow-up, 71 patients (72.4%) had no recurrence of AF/AT. A logistic regression analysis showed that female gender (OR 3.8; P = 0.02), multiple sessions (OR 3.5; P = 0.02), and early recurrence of AF/AT (OR 5.3; P = 0.004) were associated with clinical recurrence. AF/AT Inducibility was not associated with clinical recurrence (P = 0.65). A subanalysis in patients with enlarged LA (LA diameter ≥45 mm, n = 40) showed that AF/AT inducibility was associated with recurrence (OR 8.1; P = 0.04). The positive and negative predictive values of AF/AT inducibility for AF/AT recurrence were 41 and 89%, respectively. Negative predictive value was increased to 92.3% when the inducibility was defined as AF/AT of ≥30 seconds following atrial burst pacing. CONCLUSIONS: AF/AT inducibility cannot predict long-term clinical recurrence in patients with persistent AF. However, it may have a prognostic value especially in patients with enlarged LA.