Associations of the fibrosis-4 index with left atrial low-voltage areas and arrhythmia recurrence after catheter ablation: cardio-hepatic interaction in patients with atrial fibrillation.

Background: The relationship between liver fibrosis and left atrial (LA) remodeling in atrial fibrillation (AF) remains uncertain. We examined the associations between the fibrosis-4 (FIB4) index, an indicator of liver fibrosis, and both LA low-voltage areas (LVAs) on electroanatomic mapping and AF recurrence postablation. Methods: We recruited 343 patients who underwent radiofrequency catheter ablation (RFCA) or cryoballoon ablation (CBA) for AF. First, the association between the FIB4 index and LA LVAs (<0.5 mV) was evaluated in RFCA using electroanatomic mapping (n = 214). Next, the utility of a FIB4 index ≥1.3, recommended cut-off value of liver fibrosis, was verified to assess the risk for AF recurrence in CBA without additional LVA ablation (n = 129). Results: Patients with a FIB4 index ≥1.3 had a higher prevalence of LA LVAs (>5 cm2) compared to those without. Additionally, the quantitative size of LVAs showed a positive correlation with the FIB4 index (R = .642, p < .001). In multivariate logistic models, a FIB4 index ≥1.3 was related to the presence of LVAs after adjusting for LA diameter, right atrial end-systolic area, and nonparoxysmal AF (odds ratio 2.508; p = 0.039). In CBA, AF recurrence rate was 13.1% during 3-12 months postablation. In multivariate Cox models, a FIB4 index ≥1.3 was an important predictor of AF recurrence (hazard ratio 3.796; p = .037), suggesting that LVAs might be associated with AF recurrence after CBA. Conclusion: The FIB4 index was a novel predictor of the existence of LA LVAs on electroanatomic mapping and AF recurrence after CBA.

Characteristics of right pulmonary vein with an epicardial connection needing additional carina ablation for isolation.

Background: This study thought to elucidate the anatomical features that can predict an epicardial connection (EC) between the right pulmonary vein (RPV) and right atrium. Methods: We retrospectively analyzed 251 consecutive patients undergoing initial radiofrequency pulmonary vein isolation. We defined EC as present when RPV could not be isolated with circumferential ablation and additional ablation for the conduction gap if needed, and RPV isolation could be achieved by ablation for the earliest activation site >10 mm inside the initial ablation line. Using computed tomography data, we evaluated the RPV bifurcation angle, and the area occupation ratio of the carina region to the RPV antrum (ARC) for predicting EC. In subjects with EC undergoing RPV activation mapping after circumferential ablation, the correlation between conduction delay and bipolar/unipolar potential voltage in the carina region was investigated. Results: There were ECs in 45 out of 251 patients (17.9%). The RPV bifurcation angle (47.7° vs. 38.8°, p < .001) and ARC (37.2% vs. 29.7%, p < .001) were significantly greater in the EC (+) group. Multivariate logistic regression analysis revealed that RPV bifurcation angle (odds ratio [OR]: 1.994, p = .002) and ARC (OR: 3.490, p = .013) were independent predictors of EC. In nine patients with EC undergoing carina region mapping, the unipolar potential voltage was correlated with conduction delay in RPV with EC (R = -0.401, p < .001). Conclusion: Anatomical features suggesting a wider RPV carina region could predict the presence of EC, and potential with high voltage could be helpful for detecting EC connection sites.

Utility of short-time electrocardiogram to assess risk for atrial arrhythmia recurrence: Impact of atrial premature beat occurrence 1 day after pulmonary vein isolation for atrial fibrillation.

INTRODUCTION: Atrial premature beats (APBs) are the trigger for atrial fibrillation (AF). We sought to investigate the clinical significance of APB occurrence 1 day after pulmonary vein isolation (PVI) for AF using a short-time electrocardiogram. METHODS: A total of 206 patients undergoing PVI for paroxysmal AF were included. Electrocardiogram recording for 100 consecutive beats was performed 1 day after PVI. The patients were divided into two groups: those with reproducible APBs (≥1 beat) during reassessment (APB group, n = 49) or those without (non-APB group, n = 157). Late recurrence was defined as atrial tachyarrhythmia recurrence 3-12 months after PVI. The impact of APB occurrence on outcomes was investigated. RESULTS: Late recurrence occurred in 19 patients (9.2%). The presence of low-voltage areas, left atrial volume, and recurrence rate were higher in the APB group than in the non-APB group. In the APB group, the patients with recurrence had lower prematurity index (PI, coupling interval of APB/previous cycle length) compared to those without. Receiver-operating characteristic analysis revealed PI (<59.3) to be a predictive factor of recurrence (area under the curve: 0.733). The study subjects were then reclassified into three groups according to the absence of APB occurrence (n = 157), presence thereof with PI ≥ 59.3 (n = 33), and presence with PI < 59.3 (n = 16). The multivariate Cox models revealed that APB with PI < 59.3 was an independent predictor for recurrence (hazard ratio, 8.735; p < 0.001). CONCLUSION: A short-time electrocardiogram enables risk assessment for arrhythmia recurrence, and APB with low PI 1 day after PVI is a powerful predictor.

Left atrial epicardial adipose tissue exacerbates electrical conduction disturbance in normal-weight patients undergoing pulmonary vein isolation for atrial fibrillation.

INTRODUCTION: Epicardial adipose tissue (EAT) exacerbates both electrical and structural remodeling in obese atrial fibrillation (AF) patients, but the impacts of EAT on atrial arrhythmogenicity remain unclear in normal-weight AF patients. Therefore, we sought to investigate this issue using electroanatomic mapping. METHODS AND RESULTS: We enrolled drug-refractory 105 paroxysmal AF patients in the normal body mass index range (18.5-24.9 kg/m2 ), who had undergone electroanatomic mapping after pulmonary vein isolation (PVI). One day before PVI, we assessed P-wave duration in a 12-lead electrocardiogram and left atrial (LA)-EAT volumes using contrast-enhanced computed tomography. The patients were divided into two groups based on the median LA-EAT volume (16.0 ml); the high LA-EAT group (≥16.0 ml, n = 53) and low LA-EAT group (<16.0 ml, n = 52). We compared P-wave duration, LA conduction velocity and bipolar voltage, the presence of low-voltage zone (<0.5 mV), and LA volume index on echocardiography between the two groups. The LA bipolar voltage, low-voltage zone, and LA volume index were not different between the high and low LA-EAT groups. However, P-wave duration was significantly longer in the high group than in the low group (p < .001). Additionally, the LA conduction velocity was significantly more depressed in the high group than in the low group (p < .001). Multivariate linear regression analysis revealed that LA-EAT volume was correlated with P-wave duration (ß = .367, p < .001) and conduction velocity (ß = -.566, p < .001), respectively. CONCLUSIONS: Increased LA-EAT volumes were associated with electrical conduction disturbance after PVI in normal-weight patients with AF. P-wave duration may be a clinically useful predictor of LA-EAT.

Utility of a novel wearable electrode embedded in an undershirt for electrocardiogram monitoring and detection of arrhythmias.

BACKGROUND: A 12-lead electrocardiogram (ECG) and Holter ECG have been established as gold standards for detection of arrhythmias. Recently, wearable ECG monitoring devices have been available. Our purpose of the present study was to investigate whether a novel wearable electrode embedded in an undershirt is useful for ECG monitoring and detection of arrhythmias. METHODS: We studied 31 consecutive hospitalized patients who underwent catheter ablation of tachyarrhythmias. Patients equipped a wearable electrode and a lead CM5 of Holter ECG simultaneously, and total heart beats, maximum heart rate (HR), mean HR, minimum HR, detections of arrhythmias, such as atrial fibrillation, non-sustained ventricular tachycardia, and premature ventricular contractions (Lown's grade >II), were compared between the two methods using a Holter ECG analysis software. RESULTS: Median recording time of ECG by wearable electrodes was 12.6 hours. Strong correlations between the two methods were observed in total heart beats (R = 0.999, P <0.001), maximum HR (R = 0.997, P <0.001), mean HR (R = 0.999, P <0.001), minimum HR (R = 0.989, P <0.001) and QRS duration (R = 0.900, P <0.001). Bland-Altman analysis showed excellent concordance between each parameter measured by two methods. In addition, the detection of atrial fibrillation (nine events), non-sustained ventricular tachycardia (two events), and premature ventricular contractions of Lown's grade >II (five events) were concordant in two methods. In addition, there were no significant difference in parameters of time-domain and frequency-domain analyses of heart rate variability between the two methods. CONCLUSIONS: The usefulness of a novel electrode embedded in an undershirt is equivalent to that of a Holter ECG in monitoring the ECG and detection of arrythmias.

Procedural characteristics of pulmonary vein isolation with high-power short-duration setting compared to conventional setting.

PURPOSE: The purpose of this study was to investigate the safety and efficacy of high-power short-duration (HP-SD) ablation compared to conventional ablation in patients with atrial fibrillation (AF). METHODS: We enrolled consecutive 158 drug-refractory symptomatic AF patients (119 males, mean age 63 ± 10 years) who had undergone first radiofrequency pulmonary vein isolation (PVI). PVI was performed using the conventional setting (20-35 W) in 73 patients (Conventional group) and using the HP-SD setting (45-50 W) in 85 patients (HP-SD group). The rate of first pass isolation, remaining gaps after circumferential ablation, dormant conduction, and the radiofrequency application time in each pulmonary vein (PV) were compared between the groups. RESULTS: The first pass isolation ratio was significantly higher in the HP-SD group than in the Conventional group (81% vs. 65%, P = 0.027) in the right PV, but did not differ in the left PV. The remaining gaps were fewer in the right superior PV (4% vs. 21%, P = 0.001) and left inferior PV (1% vs. 8%, P = 0.032) areas, and the radiofrequency application time in each PV was shorter (right PV, 12.0 ± 8.9 min vs. 34.0 ± 31.7 min, P < 0.001; left PV, 10.6 ± 3.6 min vs. 25.7 ± 22.3 min, P < 0.001) in the HP-SD group than in the Conventional group. CONCLUSION: The use of the HP-SD setting might contribute to improve the first pass isolation rate and to shorten the radiofrequency application time in each PV.

Predictive impacts of chronic kidney disease and cardiac sympathetic nervous activity on lethal arrhythmic events in chronic heart failure.

BACKGROUND: The clinical implications of chronic kidney disease (CKD) and cardiac sympathetic nervous activity (CSNA) regarding lethal arrhythmic events have not yet been fully elucidated in patients with chronic heart failure (CHF). We hypothesized that the combination of CKD and abnormal CSNA, assessed by 123 I-metaiodobenzylguanidine (123 I-MIBG) scintigraphy, may provide useful prognostic information for lethal arrhythmic events. METHODS: We studied 165 consecutive hospitalized CHF patients without dialysis. Cardiac 123 I-MIBG scintigraphy was performed in a clinically stable condition, and abnormal CSNA was defined as a late heart-to-mediastinum ratio of <1.6. CKD was defined as an estimated glomerular filtration rate of <60 ml/min/1.73 m2 . We then investigated the incidence of lethal arrhythmic events (sustained ventricular tachyarrhythmia, appropriate implantable cardioverter-defibrillator therapy, or sudden cardiac death). RESULTS: During a median follow-up of 5.3 years, lethal arrhythmic events were observed in 40 patients (24.2%). The patients were divided into four groups according to the presence of CKD and CSNA abnormality: non-CKD/normal CSNA (n = 52), CKD/normal CSNA (n = 39), non-CKD/abnormal CSNA (n = 33), and CKD/abnormal CSNA (n = 41). Kaplan-Meier analysis showed that CKD/abnormal CSNA had the highest event rate (log-rank p = .004). Additionally, the Cox proportional hazard analysis revealed that CKD/abnormal CSNA was a predictor for lethal arrhythmic events compared with non-CKD/normal CSNA (hazard ratio, 5.368, p = .001). However, the other two groups did not show significant differences compared with the non-CKD/normal CSNA group. CONCLUSIONS: The combination of CKD and abnormal CSNA, assessed by 123 I-MIBG scintigraphy, had a high predictive value for lethal arrhythmic events in patients with CHF.

Influence of power setting on superior vena cava potential during right pulmonary vein isolation.

PURPOSE: High-power short-duration (HP-SD) ablation could reduce collateral tissue damage by shortening the conductive heating phase. However, it is difficult to evaluate the transmural effect of ablation lesions during pulmonary vein isolation (PVI) procedures. The present study aimed to evaluate the change in superior vena cava (SVC) potential delay as a surrogate marker of collateral tissue damage during right PVI, which is adjacent to SVC. METHODS: Out of 250 consecutive patients who underwent PVI, 86 patients in whom SVC potential during sinus rhythm was recorded both before and after right PVI were analyzed. In 46 of the patients, an HP-SD setting of 45-50 W was used (HP-SD group). In the remaining 40 patients, a conventional power setting of 20-30 W was used (conventional group). We compared the change in SVC potential delay after right PVI, radiofrequency energy, and mean contact force in the anterior-superior right PVI line, which was close to the posterior aspect of SVC, between the two groups. RESULTS: Although the total delivered radiofrequency energy (2,924 J vs. 2,604 J) and the mean contact force (18.5 g vs. 16.0 g) in the SVC overlapping area did not differ, the change in SVC potential delay after right PVI was significantly longer in the conventional group compared to the HP-SD group (5.0 ms vs. 0.0 ms, p < 0.001). CONCLUSIONS: The changes in SVC potential delay after right PVI might be a surrogate marker of collateral tissue damage according to the used energy settings.

Albumin-Bilirubin Score for Prediction of Outcomes in Heart Failure Patients Treated with Cardiac Resynchronization Therapy.

BACKGROUND: Liver function may be a useful indicator of response to cardiac resynchronization therapy (CRT). We aimed to investigate the clinical significance of albumin-bilirubin (ALBI) score, an assessment tool of liver function, on outcomes in heart failure (HF) patients treated with CRT. METHODS: We studied 180 patients undergoing CRT. The ALBI score, derived from albumin and total bilirubin, and left ventricular ejection fraction (LVEF) were assessed before and 6 months after CRT. The patients were classified according to the ALBI score before CRT; High (>-2.60) or Low (≤-2.60) ALBI groups. The patients were then reclassified based on the ALBI score before and 6 months after CRT; High/High, High/Low, Low/High, and Low/Low ALBI groups. We evaluated the prognostic value of the ALBI score for HF deaths after CRT. RESULTS: During a median follow-up period of 50 months, there were 41 (22.7%) HF deaths. A Cox proportional hazard analysis revealed that high ALBI scores at baseline were not related to HF deaths (hazard ratio, 1.907, p = 0.068). However, High/High ALBI scores, but not High/Low or Low/High ALBI scores, were an independent predictor of HF deaths compared with Low/Low ALBI scores (hazard ratio, 3.449, p = 0.008), implying that consistently high ALBI scores were associated with poor prognosis. The percentage change in LVEF from baseline to 6 months after CRT did not differ among the four groups, suggesting that left ventricular systolic function was not linked with the ALBI score. CONCLUSIONS: ALBI scores before and after CRT are a new indicator of CRT response, and have a predictive value for HF deaths in HF patients.

Sporadic Cardiac Amyloidosis by Amyloidogenic Transthyretin V122I Variant.

Hereditary ATTR amyloid cardiomyopathy is defined as the intramyocardial deposition of amyloid fibrils derived from the mutation of transthyretin (TTR). A 51-year-old man was referred to our hospital for congestive heart failure. He and his family had no past history of heart diseases. Echocardiography showed remarkable left ventricular hypertrophy and reduced ejection fraction. Endomyocardial biopsy specimens presented positive staining of Congo-Red and transthyretin. A genetic test showed heterozygous V122I TTR gene mutation, which is very rare in Japan. We diagnosed him as with sporadic ATTR amyloidosis with mutation, and tafamidis was administered to stabilize TTR tetramer. Since the phenotype of ATTR amyloidosis varies depending on its penetration rate, it is crucial to always keep in mind the possibility of hereditary ATTR amyloidosis even in the case of amyloidosis with no clear family history.