Background There are some controversial reports related to the pro‐arrhythmic or anti‐arrhythmic potential of cardiac resynchronization therapy (CRT) and little is known about the relationship between ventricular arrhythmia (VA) and left ventricular (LV)‐lead threshold. Hypothesis Upgrade CRT is anti‐arrhythmic effect of VA with implantable cardioverter‐defibrillator (ICD) patients and has a relationship with the incident of VA and LV‐lead threshold. Methods Among 384 patients with the implantation of CRT‐defibrillator (CRT‐D), 102 patients underwent an upgrade from ICD to CRT‐D. We divided patients into three groups; anti‐arrhythmic effect after upgrade (n = 22), pro‐arrhythmic effect (n = 14), and unchanging‐VA events (n = 66). The VA event was determined by device reports. We described the electrocardiography parameters, LV‐lead characteristics, and clinical outcomes. Results Before upgrade, the numbers of VA were 305 episodes and the numbers of ICD therapy were 157 episodes. While after upgrade, the numbers of VA were 193 episodes and the number of ICD therapy were 74 episodes. Ventricular tachycardia cycle length (VT‐CL) after upgrade was significantly slower as compared to those with before upgrade. Pro‐arrhythmic group was significantly higher with delta LV‐lead threshold (after 1 month—baseline) as compared to those with anti‐arrhythmic group (0.74 vs −0.21 V). Furthermore, pro‐arrhythmic group was significantly bigger with delta VT‐CL (after 3 months—before 3 months) as compared to those with anti‐arrhythmic group ( P = .03). Conclusions We described upgrade‐CRT was associated with reduction of VA, ICD therapies and VT‐CL. While 14 patients had a pro‐arrhythmic effect and LV lead threshold might be associated with VA‐incidents.

Background Insertable cardiac monitors (ICMs) improve diagnostic yield in patients with unexplained syncope. The most of cardiac syncope is arrhythmic causes include paroxysmal bradycardia and supraventricular tachycardia (SVT) in patients with unexplained syncope receiving ICM. Predictors for bradycardia and SVT that necessitate therapy in patients with unexplained syncope are not well known. Hypothesis This study aimed to investigate predictors of bradycardia and SVT necessitating therapy in patients with unexplained syncope receiving ICMs. Methods We retrospectively reviewed medical records of consecutive patients who received ICMs to monitor unexplained syncope. We performed Cox's stepwise logistic regression analysis to identify significant independent predictors for bradycardia and SVT. Results One hundred thirty‐two patients received ICMs to monitor unexplained syncope. During the 17‐month follow‐up period, 19 patients (14%) needed pacemaker therapy for bradycardia; 8 patients (6%) received catheter ablation for SVT. The total estimated diagnostic rates were 34% and 48% at 1 and 2 years, respectively. Stepwise logistic regression analysis indicated that syncope during effort (odds ratio [OR] = 3.41; 95% confidence interval [CI], 1.21 to 9.6; p = .02) was an independent predictor for bradycardia. Palpitation before syncope (OR = 9.46; 95% CI, 1.78 to 50.10; p = .008) and history of atrial fibrillation (OR = 10.1; 95% CI, 1.96 to 52.45; p = .006) were identified as significant independent predictors for SVT. Conclusion Syncope during effort, and palpitations or history of atrial fibrillation were independent predictors for bradycardia and for SVT. ICMs are useful devices for diagnosing unexplained syncope.

Background: Atrial fibrillation (AF) is a leading preventable cause of heart failure (HF) for which early detection and treatment is critical. Subclinical-AF is likely to go untreated in the routine care of patients with cardiac resynchronization therapy defibrillator (CRT-D). Hypothesis: The hypothesis of our study is that subclinical-AF is associated with HF hospitalization and increasing an inappropriate therapy. Methods: We investigated 153 patients with an ejection fraction less than 35%. We divided into three groups, subclinical-AF (n = 30), clinical-AF (n = 45) and no-AF (n = 78). We compared the baseline characteristics, HF hospitalization, and device therapy among three groups. The follow-up period was 50 months after classification of the groups. Results: The average age was 66 ± 15 years and the average ejection fraction was 26 ± 8%. Inappropriate therapy and biventricular pacing were significantly different between subclinical-AF and other groups (inappropriate therapy: subclinical-AF 13% vs clinical-AF 8.9% vs no-AF 7.7%: P = .04, biventricular pacing: subclinical-AF 81% vs clinical-AF 85% vs no-AF 94%, P = .001). Using Kaplan-Meier method, subclinical-AF group had a significantly higher HF hospitalization rate as compared with other groups. (subclinical-AF 70% vs clinical-AF 49% vs no-AF 38%, log-rank: P = .03). In multivariable analysis, subclinical-AF was a predictor of HF hospitalization. Conclusions: Subclinical-AF after CRT-D implantation was associated with a significantly increased risk of HF hospitalization. The loss of the biventricular pacing and increasing an inappropriate therapy might affect the risk of HF hospitalization.

Arakawa 2 & takumi takizawa 2* no imaging modality can be used to evaluate fontan-associated liver disease (fALD). We retrospectively reviewed hepatic gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) characteristics of patients within 1 year post-Fontan procedure, and we evaluated the association between hepatic imaging abnormalities and clinical parameters, including follow-up cardiac catheterization and laboratory test findings. The EOB-MR images were graded, based on the extent of the decreased enhancement, as "normal" (Grade 1), "segmental" (Grade 2), "regional" (Grade 3), and "diffuse" (Grade 4). We enrolled 37 patients (mean age, 3.5 ± 1.0 years): 9 patients had Grade 1 or 2; 14 patients, Grade 3; and 14 patients, Grade 4. EOB-MRI revealed characteristic reticular or mosaic patterns of diminished enhancement (i.e. "frog spawn" appearance). Ultrasonography did not detect diminished enhancement or "frog spawn" appearance. A trend existed toward increased grade severity in imaging with increased central venous pressure, pulmonary vascular resistance, and gammaglutamyltransferase levels. Noninvasive EOB-MRI revealed the characteristic pattern of diminished enhancement, which was correlated with certain clinical parameters indicative of Fontan physiology and liver dysfunction. early-stage fALD may occur soon after the fontan procedure and is associated with increased pressure in the inferior vena cava and hepatic veins.

Introduction Left bundle branch block (LBBB) with superior axis is common in patients with idiopathic‐ventricular arrhythmia (VA) originating from the tricuspid annulus (TA) and rarely from the cardiac basal crux and mitral annulus (MA). We described the electrocardiography and electrophysiological findings of idiopathic‐VA presenting with LBBB and superior axis. Methods and Results We described 42 idiopathic‐VA patients who had an LBBB and superior axis; 15 basal crux‐VA, 17 TA‐VA, and 10 MA‐VA. No patient had a structural heart disease. Among patients with idiopathic‐VA referred for ablation, we investigated the electrocardiogram and clinical characteristics of basal crux‐VA as compared with other LBBB and superior axis‐VA. The left ventricular ejection fraction with MA‐VA was significantly lower in comparison with basal crux‐VA (P = .01). All patients had a positive R wave in lead I and aVL. The maximum deflection index with basal crux‐VA was significantly higher in comparison with TA‐VA or MA‐VA (P = .01). Patients with basal crux‐VA presented with QS wave in lead II more frequently as compared with TA‐VA or MA‐VA (P = .001). All MA‐VA patients had Rs wave in V6, and basal crux‐VA, and TA‐VA patients had a monophasic R wave or Rs wave in V6. Basal crux‐VA patients underwent ablation in the middle cardiac vein (MCV) or coronary sinus (success rate: 94%, recurrence rate: 6%). Conclusions We could distinguish basal crux‐VA, TA‐VA, and MA‐VA, using a combination of clinical and electrocardiographic findings. These findings might be useful for counseling patients about an ablation strategy. Ablation via the MCV is effective for eliminating basal crux‐VA.