Kenichi Kaseno

Idiopathic ventricular arrhythmias arising from the pulmonary artery: prevalence, characteristics, and topography of the arrhythmia origin.

BACKGROUND The characteristics of idiopathic ventricular tachycardias (VTs) or idiopathic premature ventricular contractions (PVCs) arising from the pulmonary artery (PA) have not been sufficiently clarified. OBJECTIVE The purpose of this study was to clarify the prevalence, characteristics, and preferential sites of idiopathic VT/PVCs arising from the PA (PA-VT/PVCs). METHODS Data obtained from 276 patients with idiopathic VT/PVCs who underwent radiofrequency (RF) catheter ablation were analyzed. RESULTS Twelve VT/PVCs (4%) were PA-VT/PVCs, and their onset (34 +/- 14 years) was the youngest among all subgroups. Because those QRS morphologies were similar to VT/PVCs arising from the right ventricular outflow tract (RVOT-VT/PVC) and the earliest ventricular activation was from the RVOT, an initial ablation was performed in the RVOT in all patients. However, RF catheter ablation at the RVOT resulted in a QRS morphology change in all patients, so thereafter PA mapping and ablation was performed. A characteristic potential during sinus rhythm and/or the arrhythmia was recorded at the successful PA ablation site in all patients. A perfect or good pace map was obtained in 7 (70%) of 10 patients. The successful ablation site was the septal side of the PA close to the posterolateral attachment in 9 patients (75%) and the septal side close to the anterior attachment in the remaining 3 (25%). No PA-VT/PVCs recurred during follow-up of 27 +/- 13 months. CONCLUSION PA-VT/PVCs should always be considered when the ECG suggests RVOT-VT/PVCs and RF catheter ablation in the RVOT results in both a failed ablation and a change in QRS morphology. PA-VT/PVCs often originate from the septal side of the PA.

Silent Cerebral Ischemic Lesions After Catheter Ablation of Atrial Fibrillation in Patients on 5 Types of Periprocedural Oral Anticoagulation - Predictors of Diffusion-Weighted Imaging-Positive Lesions and Follow-up Magnetic Resonance Imaging.

BACKGROUND The aim of this study was to identify the predictors of silent cerebral ischemic lesions (SCIL) after catheter ablation of atrial fibrillation (AF) and to determine whether SCIL develop into cerebral infarcts in patients with 5 types of oral anticoagulants (OAC). METHODSANDRESULTS We retrospectively studied 286 consecutive patients (median, 67 years; 208 male; paroxysmal/persistent/long-standing persistent AF [LSP-AF], 147/90/49) who received periprocedural OAC and underwent MRI after the procedure. Warfarin (n=46) was continued, while dabigatran (n=47), rivaroxaban (n=89), apixaban (n=87), and edoxaban (n=17) were discontinued on the day of the procedure. I.v. heparin was infused to maintain an activated clotting time of 300-350 s during the procedure. Fifty-eight SCIL in 40 patients (14.0%) were identified on diffusion-weighted MRI. On multivariate logistic analysis, LSP-AF and dabigatran use were significant positive predictors of SCIL (OR, 2.912 and 2.287; P=0.006 and 0.042, respectively). Among 34 patients with 49 SCIL undergoing follow-up MRI, 45 (91.8%) of the lesions disappeared and 4 lesions developed into chronic cerebral infarcts. The SCIL with development into infarcts had a larger lesion diameter than those without (median, 6.55 mm vs. 4.2 mm; P=0.002). CONCLUSIONS LSP-AF and dabigatran use were independent risk factors for post-ablation SCIL in patients with uninterrupted warfarin and interrupted non-vitamin K antagonist OAC, but the majority of SCIL disappeared.

Left atrial catheter ablation promotes vasoconstriction of the right coronary artery.

Background: Multiple cardiac ganglia are present in the left atrial (LA) region, and marked changes in autonomic nervous activity can occur after left atrial catheter ablation (CA) for atrial fibrillation (AF). Vasospastic angina involving the inferior wall of the left ventricle has been reported as a complication shortly after LACA.

Non-Contact Three-Dimensional Mapping and Ablation of Swallowing-Induced Atrial Tachyarrhythmias: Two Case Reports

We describe two cases of swallowing‐induced tachyarrhythmias that were cured by radiofrequency ablation (RFCA) using a non‐contact mapping system (NCMS). In both patients, tachyarrhythmias occurred during swallowing solids and liquids, and mapping and ablation of the arrhythmia using the NCMS was attempted during swallowing a rice ball. During a premature atrial contraction shortly after the swallow, the earliest endocardial breakthrough occurred at the right superior pulmonary vein (PV) ostium in Case 1 and at the left superior PV ostium and postero‐inferior right atrium in Case 2. Guided by the NCMS catheter navigation system, the ablation catheter was easily and precisely positioned at a site where the earliest endocardial breakthrough occurred. RFCA at that site resulted in success and no recurrence or complications occurred during the follow‐up in either patient.

Optimal observation time after completion of circumferential pulmonary vein isolation for atrial fibrillation to prevent chronic pulmonary vein reconnections

PURPOSE To identify predictors of chronic pulmonary vein (PV) reconnection (CPVR) after successful circumferential PV isolation (CPVI) for atrial fibrillation (AF). MATERIALS AND METHODS A total of 718 PVs from 181 consecutive AF patients (141 males, median age 61 years, 92 paroxysmal AF) who underwent a second ablation procedure for recurrent AF were retrospectively analyzed. RESULTS During the second procedure, a CPVR was observed in 477 PVs (66.4%) among 169 patients. In a multiple logistic regression analysis, the observation time after the final completion of the PVI (OT-final) was a significant negative predictor (odds ratio 0.980; P<0.001). A receiver operating characteristic analysis demonstrated that the greatest area under the curve was for the OT-final (0.670). At an optimal cutoff of 35 min, the sensitivity and specificity for predicting a CPVR were 66.9% and 60.6%, respectively. By Kaplan Meier analysis, CPVR was more frequent in PVs with an OT-final of <35 min than ≥35 min (log-rank test, P=0.018). In a vessel-by-vessel analysis, the OT-final at all PV sites was a significant negative predictor, while male gender in the right PVs and left-inferior PV, number of RF applications for the ipsilateral CPVI in the right PVs and left-superior PV, and major PV diameter in the left-superior PV were significant positive predictors of a CPVR (all P<0.05). CONCLUSIONS An optimal observation time (≥35 min in this study) to determine whether PVI is successfully completed during the initial CPVI for AF may be needed to prevent a CPVR and subsequent AF recurrence thereafter.

Predictors of asymptomatic cerebral infarction associated with radiofrequency catheter ablation for atrial fibrillation using an irrigated-tip catheter.

AIMS Catheter ablation is a potentially curative treatment for atrial fibrillation (AF). However, complications such as ischaemic stroke are more frequent and more severe compared with ablation procedures for other arrhythmias. Irrigated-tip catheters have been reported to reduce the risk of stroke. The present study aimed to evaluate predictors of asymptomatic cerebral infarction (CI) after AF ablation using an irrigated-tip catheter. METHODS AND RESULTS A total of 70 consecutive AF patients who underwent catheter ablation were subjected to brain magnetic resonance imaging (MRI) 1 day after the procedure. In 10 (14.3%) of 70 patients, MRI revealed acute CI, but neither symptoms nor abnormal neurological findings were present in these patients. In univariate analysis, a history of persistent AF, left atrial dimension, presence of spontaneous echo contrast (SEC), procedure duration prior to heparin injection, and electrical cardioversion during the procedure differed significantly between the two groups, those with and without CI (P = 0.02, 0.05, 0.01, 0.01, and 0.05, respectively). Multivariate logistic regression analysis identified SEC [odds ratio (OR), 9.39; 1.60-55.2; P = 0.01] and procedure duration prior to heparin injection (OR, 1.19; 1.04-1.36; P = 0.01) as predictive of acute asymptomatic CI after AF ablation. CONCLUSION The presence of SEC and procedure duration prior to heparin injection are determinants of asymptomatic CI during AF ablation despite the use of an irrigated-tip catheter.

Predictive Utility of the Changes in Matrix Metalloproteinase‐2 in the Early Phase for Left Ventricular Reverse Remodeling After an Acute Myocardial Infarction

Background The relationship between the serum levels of matrix metalloproteinase (MMP) and tissue inhibitors of MMP (TIMP) and left ventricular (LV) reverse remodeling (LV‐RR) after an acute myocardial infarction (AMI) has not been sufficiently examined. Methods and Results In 25 patients with successful reperfusion after an AMI and 15 normal control subjects, the serum MMP‐2 and TIMP‐2 levels were measured on days 1, 2, 3, and 7 and at 1 and 6 months after the AMI onset. LV‐RR was defined as a >15% decrease in the LV end‐systolic volume index at 6 months after the AMI. The MMP‐2 level on day 1 and TIMP‐2 levels throughout the study period were comparable between the patients with and without LV‐RR. The MMP‐2 on day 7 (P<0.05) and the changes in the MMP‐2 from day 1 to day 7 (∆MMP‐2; P<0.01) were lower in patients with than in those without LV‐RR. The ∆MMP‐2 was strongly correlated with the changes in the LV volume and ejection fraction from 1 month to 6 months after the AMI. The ∆MMP‐2 value of <−158.5 ng/mL predicted LV‐RR with a high accuracy (91.7% sensitivity and 76.9% specificity; area under the curve=0.82). Conclusions Changes in MMP‐2 are associated with LV‐RR after an AMI. The ΔMMP‐2 might be a useful predictor of subsequent LV‐RR.

Maximum Ventricular Dyssynchrony Predicts Clinical Improvement and Reverse Remodeling during Cardiac Resynchronization Therapy

Background: Tissue synchronization imaging (TSI) and tissue tracking imaging (TTI) might facilitate the evaluation of ventricular dyssynchrony.

Association between matrix metalloproteinase-9 and worsening heart failure events in patients with chronic heart failure: MMP-9 predicts HF events

Matrix metalloproteinase (MMP) is up‐regulated during heart failure (HF) and influences ventricular remodeling. We hypothesized that disparity between MMP‐9 and tissue inhibitors of MMP‐1 (TIMP‐1) results in clinical manifestations and is related to prognostic risk in patients with chronic HF.

Integration of intracardiac echocardiography and computed tomography during atrial fibrillation ablation: Combining ultrasound contours obtained from the right atrium and ventricular outflow tract

BACKGROUND We aimed to optimize the acquisition of the left atrial (LA) and pulmonary vein (PV) ultrasound contours for more accurate integration of intracardiac echocardiography (ICE) and computed tomography (CT) using the CARTO® 3 system during atrial fibrillation (AF) ablation. METHODS Eighty-five AF patients underwent integration of ICE and CT using (1) the LA roof and posterior wall contours acquired from the right atrium (RA), (2) all LA/PV contours from the RA (Whole-RA-integration), (3) the LA roof/posterior wall contours from the RA and right ventricular outflow tract (RVOT) (Posterior-RA/RV-integration), and (4) all LA/PV contours from the RA and RVOT (Whole-RA/RV-integration). The integration accuracy was compared using the (1) surface registration error, (2) distances between the three-dimensional CT and eight specific sites on the anterior, posterior, superior, and inferior aspects of the right and left circumferential PV isolation lines, and (3) registration score: a score of 0 or 1 was assigned for whether or not each specific site was visually aligned with the CT, and summed for each method (0 best, 8 worst). RESULTS Posterior-RA/RV-integration revealed a significantly lower surface registration error (1.30±0.15mm) than Whole-RA- and Whole-RA/RV-integration (p<0.001). The mean distances of the eight specific sites and the registration score for Posterior-RA/RV-integration (median 1.26mm and 2, respectively) were significantly smaller than those for the other integration approaches (p<0.001). CONCLUSIONS Image integration with the LA roof and posterior wall contours acquired from the RA and RVOT may provide greater accuracy for catheter navigation with three-dimensional CT during AF ablation.