Characterization and identification of atrial fibrillation drivers in patients with nonparoxysmal atrial fibrillation using simultaneous amplitude frequency electrogram transform.

INSTRUCTION: We hypothesized that real-time simultaneous amplitude frequency electrogram transform (SAFE-T) during sinus rhythm (SR) is able to identify and characterize the drivers of atrial fibrillation (AF) in nonparoxysmal (NP) AF. METHODS: Twenty-one NPAF patients (85.71% males, mean age 52 years old) underwent substrate mapping during SR (SAFE-T and voltage) and during AF (complex fractionated atrial electrograms [CFAE] and similarity index [SI]). After pulmonary veins isolation, extensive substrate ablation was performed with the endpoint of procedural termination or elimination of all SI sites (>63% similarities). Sites with procedural termination and non-termination sites were tagged for postablation SR analysis using SAFE-T. RESULTS: In 74 CFAE sites identified (average of 3 ± 2 sites per person), 28 (37.84%) were identified as termination sites demonstrating a high SI compared with the non-termination sites (80.11 ± 9.57% vs. 45.96 ± 13.38%, p < .001) during AF. During SR, these termination sites have high SAFE-T values and harbor a highly resonant, localized, repetitive high frequency components superimposed in the low frequency components compared with non-termination sites (5.70 ± 3.04 vs. 1.49 ± 1.66 Hz·mV, p < .001). In the multivariate analysis, the termination sites have higher SAFE-T and SI value (p < .001). CONCLUSION: AF procedural termination sites harbored signal characteristics of repetitive, high frequency component of individualized electrogram during SR, which can be masked by the low frequency fractionated electrogram and are difficult to see from the bipolar electrogram. Thus, SAFE-T mapping is feasible in identifying and characterizing sites of AF drivers.

Clinical significance of J waves with respect to substrate characteristics and ablation outcomes in patients with arrhythmogenic right ventricular cardiomyopathy.

AIMS: J-wave syndrome in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) has been linked to an increased risk of ventricular arrhythmia. We investigated the significance of J waves with respect to substrate manifestations and ablation outcomes in patients with ARVC. METHODS AND RESULTS: Forty-five patients with ARVC undergoing endocardial/epicardial mapping/ablation were studied. Patients were classified into two groups: 13 (28.9%) and 32 (71.1%) patients with and without J waves, respectively. The baseline characteristics, electrophysiological features, ventricular substrate, and recurrent ventricular tachycardia/fibrillation (VT/VF) were compared. Among the 13 patients with J waves, only the inferior J wave was observed. More ARVC patients with J waves fulfilled the major criteria of ventricular arrhythmias (76.9% vs. 21.9%, P = 0.003). Similar endocardial and epicardial substrate characteristics were observed between the two groups. However, patients with J waves had longer epicardial total activation time than those without (224.7 ± 29.9 vs. 200.8 ± 21.9 ms, P = 0.005). Concordance of latest endo/epicardial activation sites was observed in 29 (90.6%) patients without J waves and in none among those with J waves (P < 0.001). Complete elimination of endocardial/epicardial abnormal potentials resulted in the disappearance of the J wave in 8 of 13 (61.5%) patients. The VT/VF recurrences were not different between ARVC patients with and without J waves. CONCLUSION: The presence of J waves was associated with the discordance of endocardial/epicardial activation pattern in terms of transmural depolarization discrepancy in patients with ARVC.

Deep Sedation with Intravenous Anesthesia Is Associated with Outcome in Patients Undergoing Cryoablation for Paroxysmal Atrial Fibrillation.

Whether deep sedation with intravenous anesthesia will affect the recurrence after cryoballoon ablation (CBA) of paroxysmal atrial fibrillation (AF) is yet to be examined. Thus, in this study, we hypothesize that there is difference in terms of the recurrence between local anesthesia and deep sedation with intravenous anesthesia after an index ablation procedure.In total, 109 patients were enrolled and received CBA, of which 68 (58.2 years) patients underwent pulmonary vein (PV) isolation with a local anesthesia (group 1) and 41 patients (63.2 years) underwent PV isolation with deep sedation using intravenous anesthesia (group 2).During the index procedure, isolation of all major PVs was achieved in 66 patients in group 1 and in 41 patients in group 2. There was no difference in non-PV triggers between the two groups. The periprocedural complication was found to be similar between the two groups (2.9% in group 1 and 4.9% in group 2). Further, 17 patients in group 1 and 4 patients in group 2 experienced recurrences after a follow-up of 19.3 months (P = 0.019). Repeat procedures revealed similar PV reconnection rates between the two groups. It has also been noted that the number of reconnected PV and incidence of atypical flutter seem to increase in group 1.Deep sedation with intravenous anesthesia during CBA for paroxysmal AF is safe and had a better long-term outcome than those with local anesthesia.

The importance of extrapulmonary vein triggers and atypical atrial flutter in atrial fibrillation recurrence after cryoablation: Insights from repeat ablation procedures.

INTRODUCTION: It has not been previously investigated whether the recurrence mechanism after cryoballoon ablation (CBA) of paroxysmal atrial fibrillation (AF) is similar to that of radiofrequency catheter ablation (RFCA). We aimed to evaluate the differences of recurrence characteristics between RFCA and CBA after the index procedure. METHODS: A total of 210 patients were enrolled in the study, and 69 patients underwent pulmonary vein (PV) isolation using a 28-mm second-generation CBA. The control group comprising 140 patients underwent PV isolation using an open-irrigated radiofrequency ablation catheter. A total of 69 patients in the CBA group and 69 patients in the RFCA group were investigated after propensity score matching. Recurrence patterns of AF were studied in the repeated procedure. RESULTS: During the index procedure, there was no difference in PV or non-PV triggers between the two groups. Nineteen (27.5%) patients in the CBA group and 19 (27.5%) patients in the RFCA group had recurrence after a follow-up of 11.3 ± 7 months. The Kaplan-Meier curve did not reveal significant difference in recurrence (log-rank, P = 0.364) between the two groups. In the second procedure, the CBA group had more non-PV triggers (63.6%, P = 0.009) and left atrial (LA) flutters (54.5%, P = 0.027) compared with the RFCA group (12.5% and 12.5%, respectively). The PV reconnection rates were similar between both groups. CONCLUSIONS: There was no difference in AF recurrence after catheter ablation between CBA and RFCA, but significant increases of non-PV triggers and LA flutter during the second procedure suggest the importance of the atrial substrate in maintaining AF during the second procedure after previous CBA.

Characteristics of recurrent ventricular tachyarrhythmia after catheter ablation in patients with arrhythmogenic right ventricular cardiomyopathy.

BACKGROUND: The reason for recurrence of ventricular arrhythmia (VA) after catheter ablation in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) is not clear. METHODS: In this study, 91 ARVC patients (age, 47 ± 13 years; 47 men) who underwent catheter ablation for drug-refractory ventricular arrhythmia (VA) were enrolled. The patients were categorized into single or multiple procedures (n = 28). The baseline characteristics and electrophysiological features of the patients were examined to elucidate the reason of the VA recurrences. RESULTS: A total of 186 VAs were induced during the index procedure and 176 (94.6%) were eliminated. Successful, partially successful, and failed ablations were achieved in 89.0%, 8.8%, and 2.2% of the patients, respectively. During a mean follow-up period of 32 ± 26 months, 35 patients had VA recurrences. Forty-two repeat procedures were performed for 81 induced VAs in 28 patients. Of the 42 repeat procedures, successful, partially successful, and failed ablations were achieved in 37, 4, and 1 of the procedures, respectively. Most of the recurrent VAs (70 [72.9%]) originated from the newly-developed circuits owing to the scar progression. The patients with repeat procedure had worsening right ventricular remodeling. The multivariate analysis revealed that history as endurance athlete significantly predicted the need of a repeat procedure in spite of the initially successful endocardial/epicardial ablation and negative inducibility (hazard ratio: 3.014, 95% confidence interval: 1.493-6.084, P = 0.002). CONCLUSIONS: In spite of the initial complete VA elimination, history as an athlete was associated with scar progression, RV remodeling, and VA recurrences from the newly developed arrhythmogenic substrates/circuit in ARVC.

Shorter Leukocyte Telomere Length Is Associated With Atrial Remodeling and Predicts Recurrence in Younger Patients With Paroxysmal Atrial Fibrillation After Radiofrequency Ablation.

BACKGROUND: Telomere length is a biologic aging marker. This study investigated leukocyte telomere length (LTL) as a new biomarker to predict recurrence after paroxysmal atrial fibrillation (PAF) ablation.Methods and Results:A total of 131 participants (26 healthy individuals and 105 symptomatic PAF patients) were enrolled. PAF patients (54.1±10.8 years) who received catheter ablation therapy were divided into 2 groups: recurrent AF (n=25) and no recurrent AF after catheter ablation (n=80). Peripheral blood mononuclear cells were collected from all subjects to measure LTL. Under 50 years old, LTL in healthy individuals (n=17) was longer than in PAF patients (n=31; 7.34±0.58 kbp vs. 6.44±0.91 kbp, P=0.01). In PAF patients, LTL was positively correlated with left atrial bipolar voltage (R=0.497, P<0.001), and negatively correlated with biatrial scar area (R=-0.570, P<0.001) and left atrial diameter (R=-0.214, P=0.028). LTL was shorter in the patients with recurrent AF than in those without recurrent AF after catheter ablation (5.68±0.82 kbp vs. 6.66±0.71 kbp; P<0.001). On receiver operating characteristic curve analysis, LTL cut-off <6.14 kbp had a specificity of 0.68 and sensitivity of 0.79 to predict recurrent AF after catheter ablation. CONCLUSIONS: Young PAF patients (≤50 years) had shorter LTL. Shorter LTL was associated with a degenerative atrial substrate and recurrence after catheter ablation in younger PAF patients.

Early detection of electromechanical dysfunction in patients with idiopathic premature ventricular contractions.

BACKGROUND: Premature ventricular contractions (PVCs) induced by subtle cardiac dysfunction are missed by echocardiography. We evaluated acoustic cardiography for detection of early electromechanical dysfunction in patients with idiopathic PVCs and normal left ventricular ejection fraction (LVEF), and investigated the impact of radiofrequency ablation (RFA) in reversing this adverse effect. METHODS: Eighty-six patients with PVCs and 33 normal controls having normal LVEF were studied. Fifty PVC patients were in the ablation group and 36 in the nonablation group. %Electromechanical activation time (%EMAT), %left ventricular systolic time (%LVST), third (S3) and fourth heart sound (S4), and systolic dysfunction index (SDI) during sinus rhythm (SR) were measured by acoustic cardiography (Audicor, Inovise Medical, Inc., Beaverton, OR, USA) pre- and postablation. In 28 patients, acoustic parameters were compared during SR without PVCs, and SR with single PVC, ≥ 2 PVCs, or ventricular tachycardia over 10-second Audicor recording in a single patient at different times. Twenty-four-hour acoustic cardiographic and acoustic cardiographic Holter recording were used to assess the impact of PVC burden on electromechanical function in 41 patients. RESULTS: %EMAT, S3, S4, and SDI showed significant worsening in the PVC versus control group. %EMAT and SDI were worsened with increasing PVC number in a 10-second strip. %EMAT showed significant linear increment with increasing PVC burden. There was a significant improvement in %EMAT, %LVST, S3, S4, and SDI postablation in patients with PVCs. CONCLUSION: Acoustic cardiography can detect PVC-induced minor electromechanical dysfunction in patients with normal LVEF. RFA can reverse this adverse effect.

Comparison of phase mapping and electrogram-based driver mapping for catheter ablation in atrial fibrillation.

INTRODUCTION: Adjunctive driver-guided ablation in addition to pulmonary vein isolation has been proposed as a strategy to improve procedural success and outcomes for various populations with atrial fibrillation (AF). First, this study aimed to evaluate the different mapping techniques for driver/rotor identification and second to evaluate the benefits of driver/rotor-guided ablation in patients with paroxysmal and persistent AF (PerAF). METHODS: We searched the electronic database in PubMed using the keywords "atrial fibrillation," "rotor," "rotational driver," "atrial fibrillation source," and "drivers" for both randomized controlled trials and observational controlled trials. Clinical studies reporting efficacy or safety outcomes of driver-guided ablation for paroxysmal AF or (PerAF) were identified. We performed subgroup analyses comparing different driver mapping methods in patients with PerAF. The odds ratios (ORs) with random effects were analyzed. RESULTS: Out of 175 published articles, seven met the inclusion criteria, of which two were randomized controlled trials, one was quasiexperimental study, and four observational studies (three case-controlled studies and one cross-sectional study). Overall, adjunctive driver-guided ablation was associated with higher rates of acute AF termination (OR: 4.62, 95% confidence interval [CI]: 2.12-10.08; P < 0.001), lower recurrence of any atrial arrhythmia (OR: 0.44, 95% CI: 0.30-0.065; P < 0.001), and comparable complication incidence. CONCLUSIONS: Adjunctive driver-guided catheter ablation suggested an increased freedom from AF/AT relative to conventional strategies, irrespective of the mapping techniques. Furthermore, phase mapping appears to be superior to electrogram-based driver mapping in PerAF ablation.

Electrocardiographic features of failed and recurrent right ventricular outflow tract catheter ablation of idiopathic ventricular arrhythmias.

INTRODUCTION: Various ECG algorithms have been proposed to identify the origin of idiopathic outflow tract (OT)-ventricular arrhythmia (VA). However, electrocardiographic features of failed and recurrent right ventricular outflow tract (RVOT) ablation of idiopathic OT-VAs have not been clearly elucidated. METHODS AND RESULTS: A total of 264 consecutive patients (mean age: 44.0 ± 13.0 years, 96 male) undergoing RVOT ablation for OT-VAs with a transition ≥V3 , including 241 patients (91.6%) with initially successful procedures and 23 patients (8.4%) with failed ablation. Detailed clinical characteristics and ECG features were analyzed and compared between the two groups. VAs with failed RVOT ablation had larger peak deflection index (PDI), longer V2 R wave duration (V2 Rd), smaller V2 S wave amplitude, higher R/S ratio in V2 , higher V3 R wave amplitude, and larger V2 transition ratio than those with successful ablation. Multivariate analysis demonstrated that PDI, V2 Rd, V2 transition ratio, and pacemapping score acquired during mapping independently predicted failed ablation (P  =  0.01, P  =  0.01, P  =  0.01, and P < 0.001, respectively). In 31 recurrent cases (12.8%) after initially successful ablation, multivariate Cox regression analysis showed that only the earliest activation time acquired during mapping predicted the recurrences after successful ablation (P  =  0.001). The recurrent cases displayed different ECG features comparing with those with failed ablation. CONCLUSION: The electrocardiographic features of failed RVOT ablation of idiopathic OT-VAs with a transition ≥V3 were characterized by PDI, V2 Rd, V2 transition ratio, and pacemapping score acquired during mapping, unlike the recurrent RVOT ablation.

Cigarette smoking causes a worse long-term outcome in persistent atrial fibrillation following catheter ablation.

INTRODUCTION: Cigarette smoking contributes to the development of atrial fibrosis via nicotine. The impact of smoking on ablation results in persistent atrial fibrillation (AF) is unknown. We aimed to investigate the triggers and long-term outcome between smokers and nonsmokers in the patients with persistent AF after catheter ablation. METHODS: This study included 201 (177 males, 53 ± 10 years old) patients who received index catheter ablation, including pulmonary vein isolation (PVI) and complex fractionated atrial electrograms (CFAEs) ablation for persistent AF, retrospectively. Electrophysiological characteristics at the index procedure and long-term outcome were investigated to determine the differences between smokers and nonsmokers. RESULTS: Baseline characteristics were similar between two groups. Pulmonary vein (PV) triggers were found in all patients in the two groups. There was a higher incidence of nonpulmonary vein (NPV) triggers in smokers than in nonsmokers (61% vs. 31%, P < 0.05). There were no differences of the long-term ablation outcomes between smokers and nonsmokers in Kaplan-Meier analysis. Smokers with PV plus right atrial NPV (RA-NPV) triggers had a higher incidence of recurrence (log-rank P < 0.05) than those without RA-NPV triggers, but not in nonsmokers, after a mean follow-up of 31 ± 25 months. CONCLUSIONS: Smoking increases the incidence of NPV triggers in patients with persistent AF. Smokers who have RA-NPV triggers during index procedure do have a worse outcome after catheter ablation, indicating the harmful effects of nicotine to right atrium.

Novel electrophysiological criteria for septal ventricular outflow tract tachycardias requiring a sequential bilateral ablation.

BACKGROUND: Septal ventricular outflow tract ventricular arrhythmias (OT-VAs) are defined as septal origin VAs from the right ventricular or left ventricular OT. Patients with septal OT-VAs may require a sequential bilateral OT ablation. This study aimed to evaluate the electrophysiological characteristics and ablation outcome in patients with septal OT-VAs. METHODS: We retrospectively analyzed the electrocardiography and electrophysiological parameters in 96 patients (mean age 49 ± 15 years, 49 male) undergoing bilateral activation mapping before catheter ablation of idiopathic septal OT-VAs. The patients were categorized into three groups based on the successful ablation sites, including the right ventricular outflow tract (RVOT), RVOT/left ventricular outflow tract (LVOT), and LVOT. RESULTS: Mapping in the three groups demonstrated a gradually decreasing and increasing trend in the earliest activation time obtained from the RVOT and LVOT, respectively. The absolute earliest activation time discrepancy (AEAD) of ≤18 milliseconds could predict the requirement for a sequential bilateral ablation with a sensitivity and specificity of 100.0% and 93.7%, respectively. The small AEAD (≤21 milliseconds) was associated with a higher recurrence rate in patients receiving a successful unilateral ablation, while patients with a longer distance between the bilateral OT earliest activation sites (DEA > 26 mm) increased future recurrences after an initially successful sequential bilateral ablation. CONCLUSIONS: The application of bilateral OT-VA activation mapping and the measurement of the AEAD and DEA provided not only pivotal information for the ablation strategy, but also prognostic implications for recurrences in patients with septal OT-VAs.

Circulating microRNAs in arrhythmogenic right ventricular cardiomyopathy with ventricular arrhythmia.

Aims: MicroRNAs (miRNAs) have been implicated in cardiac diseases. This study aimed to characterize the circulating miRNAs in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and correlate the miRNAs with the clinical outcomes of ARVC. Methods and results: This study included 62 patients with ventricular arrhythmia (VA): 28 patients (45%) had definite ARVC, 11 (18%) had borderline or possible ARVC, and 23 (37%) had idiopathic ventricular tachycardia (VT). In addition, 33 age- and sex-matched healthy subjects were enrolled as normal control subjects. The expression of selected miRNAs was analysed in all study subjects. The clinical outcomes of patients with definite ARVC after catheter ablation were further investigated. On the basis of the miRNA polymerase chain reaction array, we selected 11 miRNAs for analysis of their expression in the plasma of all subjects. Definite ARVC patients had significantly higher expression of circulating miR-144-3p, 145-5p, 185-5p, and 494 than the three other groups. Out of 25 definite ARVC patients who underwent radiofrequency catheter ablation, recurrent VA occurred in 8 patients (32%) during the follow-up period (45 ± 20 months). Definite ARVC patients with recurrent VA had a higher level of circulating miR-494 than did those without recurrence. Receiver operating characteristic analysis showed miR-494 to be a predictive factor of recurrent VA (area under the curve: 0.832). Conclusion: Plasma levels of miR-144-3p, 145-5p, 185-5p, and 494 were significantly elevated in definite ARVC patients with VA. An increased plasma level of miR-494 was associated with the recurrence of VA after ablation in definite ARVC patients.

Heterogeneous distribution of substrates between the endocardium and epicardium promotes ventricular fibrillation in arrhythmogenic right ventricular dysplasia/cardiomyopathy.

Aims: Whether the distribution of scar in arrhythmogenic right ventricular cardiomyopathy (ARVC) plays a role in predicting different types of ventricular arrhythmias is unknown. This study aimed to investigate the prognostic value of scar distribution in patients with ARVC. Methods and results: We studied 80 consecutive ARVC patients (46 men, mean age 47 ± 15 years) who underwent an electrophysiological study with ablation. Thirty-four patients receive both endocardial and epicardial mapping. Abnormal endocardial substrates and epicardial substrates were characterized. Three groups were defined according to the epicardial and endocardial scar gradient (<10%: transmural, 10-20%: intermediate, >20%: horizontal, as groups 1, 2, and 3, respectively). Sinus rhythm electrograms underwent a Hilbert-Huang spectral analysis and were displayed as 3D Simultaneous Amplitude Frequency Electrogram Transformation (SAFE-T) maps, which represented the arrhythmogenic potentials. The baseline characteristics were similar between the three groups. Group 3 patients had a higher incidence of fatal ventricular arrhythmias requiring defibrillation and cardiac arrest during the initial presentation despite having fewer premature ventricular complexes. A larger area of arrhythmogenic potentials in the epicardium was observed in patients with horizontal scar. The epicardial-endocardial scar gradient was independently associated with the occurrence of fatal ventricular arrhythmias after a multivariate adjustment. The total, ventricular tachycardia, and VF recurrent rates were higher in Group 3 during 38 ± 21 months of follow-up. Conclusion: For ARVC, the epicardial substrate that extended in the horizontal plane rather than transmurally provided the arrhythmogenic substrate for a fatal ventricular arrhythmia circuit.

Risk of Stroke in Patients With Short-Run Atrial Tachyarrhythmia.

BACKGROUND AND PURPOSE: The risk of stroke in patients with short-run atrial tachyarrhythmia (AT) remains unclear. This study aimed to investigate the relationship between short-run AT and the stroke and the use of the CHA2DS2-VASc score for the risk stratification. METHODS: From the registry of 24-hour Holter monitoring, 5342 subjects without known atrial fibrillation or stroke were enrolled. Short-run AT was defined as episodes of supraventricular ectopic beats <5 seconds. RESULTS: There were 1595 subjects (29.8%) with short-run AT. During the median follow-up period of 9.0 years, 494 subjects developed new-onset stroke. Patients with short-run AT had significantly higher stroke rates compared with patients without short-run AT (11.4% versus 8.3%; P<0.001). In patients with short-run AT, the number of strokes per 100 person-years for patients with CHA2DS2-VASc score of 0 and 1 were 0.23 and 0.67, respectively. However, the number of them for patients with CHA2DS2-VASc score of 2, 3, 4, and ≥5 were 1.62, 1.89, 1.30, and 2.91, respectively. In patients with CHA2DS2-VASc score of 0 or 1, age (>61 years old) and burden of premature atrial contractions (>25 beats/d) independently predicted the risk of stroke. In subgroup analyses, short-run AT patients were divided into 3 groups based on their CHA2DS2-VASc scores: low score (score of 0 [men] or 1 [women]; n=324), intermediate score (score of 1 [men] or 2 [women]; n=275), and high score (score of ≥2 [men] or ≥3 [women]; n=996). When compared with low score, intermediate and high scores were independent predictors for stroke (hazard ratio, 6.165; P<0.001 and hazard ratio, 8.577; P<0.001, respectively). CONCLUSIONS: Short-run AT increases the risk of stroke. Therefore, the CHA2DS2-VASc score could be used for the risk stratification. Age and burden of premature atrial contractions were independent predictors for stroke in patients with CHA2DS2-VASc score of 0 or 1.

Left Atrial Size and Left Ventricular End-Systolic Dimension Predict the Progression of Paroxysmal Atrial Fibrillation After Catheter Ablation.

INTRODUCTION: Although rare, some paroxysmal atrial fibrillations (AF) still progress despite radiofrequency (RF) ablation. In the study, we evaluated the long-term efficacy of RF ablation and the predictors of AF progression. METHODS: A total of 589 paroxysmal AF patients (404 men and 185 women; aged 54 ± 12 years) who received 3-dimensional mapping and ablation were enrolled. Their clinical parameters and electrophysiological characteristics were collected. They were divided into Group 1 (N = 13, with AF progression) and Group 2 (N = 576, no AF progression). AF progression was defined as recurrence of persistent AF. RESULTS: Group 1 patients had larger left atrial (LA) diameter, larger left ventricle (LV) end-systolic and end-diastolic diameters, poorer LV systolic function, and more amiodarone use at baseline. After 1.2 ± 0.5 procedures, 123 (21%) patients experienced recurrence during 56 ± 29 months' follow-up. In the multivariate analysis, LA diameter (P = 0.018, HR = 1.12, 95% CI = 1.02-1.24) and LV end-systolic diameter (P = 0.005, HR = 1.10, 95% CI = 1.03-1.17) independently predicted AF progression. LA diameter >43 mm and LV end-systolic diameter >31 mm were the best cut-off values for predicting AF progression by ROC analysis. AF progression rate achieved 19% if they had both larger LA diameter (>43 mm) and LV end-systolic diameter (>31 mm). CONCLUSION: RF ablation prevents the progression of paroxysmal AF effectively, except in patients with increased LA diameter and LV end-systolic diameter on echocardiogram, suggesting more aggressive rhythm control therapies should be considered in these patients.

The roles of alcohol dehydrogenase in patients with atrial fibrillation.

BACKGROUND: Alcohol consumption is known to increase the risk of atrial fibrillation (AF). Whether the genotypes of alcohol-metabolizing genes (alcohol dehydrogenase [ADH1B]) are associated with the risk of AF recurrence after catheter ablation remains unclear. METHODS AND RESULTS: The ADH1B genotypes of 281 patients who received catheter ablation for AF were examined. We followed this group of patients to monitor their AF recurrence. Alcohol consumption levels of this cohort were evaluated before and after catheter ablation. There was no difference in the underlying diseases presented by the patients with different ADH1B genotypes. Regardless of the ADH1B genotypes, the amount of alcohol consumption was the only factor associated with left atrial dilatation. The ADH1B*2 alleles (hazard ratio: ADH1B*1/*2 vs *1/*1: 2.64; ADH1B*2/*2 vs *1/*1: 1.80, P = 0.02) and the levels of alcohol consumption were independently associated with AF recurrence in the patients with paroxysmal AF after catheter ablation. ADH1B polymorphisms were not associated with AF recurrence in the patients with nonparoxysmal AF. We also found that the association of increased AF recurrence with alcohol consumption and the ADH1B genotypes cannot be explained by mechanisms of systemic inflammation. CONCLUSIONS: ADH1B*2/*2 genotype and amount of alcohol consumption increase the risk of AF recurrence after catheter ablation.

Left Ventricular Electromechanical Remodeling Detected by Acoustic Cardiography in Paroxysmal Atrial Fibrillation.

This study aimed to investigate the electromechanical function detected by acoustic cardiography before and after radiofrequency ablation therapy (RFA) in paroxysmal AF (PAF) patients with preserved left ventricular ejection fraction (LVEF). Seventy-five symptomatic PAF patients and 69 patients without arrhythmia were enrolled. Thirty-seven PAF patients received RFA therapy. Acoustic cardiographic exam was performed to check S3 and S4 heart sound, electromechanical activation time (EMAT), LV systolic time percentage (LVST), and systolic dysfunction index (SDI) in all participants. Furthermore, 37 PAF patients also received follow-up acoustic cardiography postRFA. PAF had impaired electromechanical systolic function compared with health participants (%EMAT 14.69 ± 3.62 vs. 10.84 ± 2.62; %LVST 40.83 ± 5.14 vs. 36.70 ± 3.87; SDI 4.75 ± 1.61 vs. 3.26 ± 0.96 all p < 0.001). RFA can improve electromechanical systolic function. Improvement below 13.1% could predict the recurrent AF postcatheter ablation. Higher degree of improved electromechanical systolic function postRFA contribute to lower recurrence of AF. Graphical Abstract Receiver operating characteristic (ROC) curve analysis for % change of systolic dysfunction index (SDI) postRFA in the detection of recurrent AF.

Dynamic unipolar voltage criteria of right ventricular septum for identifying left ventricular septal scar.

PURPOSE: The right ventricular (RV) septal unipolar voltage (UV) for predicting left ventricular (LV) septal scar wall thickness (WT) remains to be elucidated. METHODS: From 2013 to 2015, data obtained from RV and LV electroanatomic maps of 28 patients (mean age, 53 ± 16 years; 19 men [67.9%]) with/without identified LV septal scars were reviewed. Patients with an RV septal scar were excluded (n = 90). Direct measurement of septal WT was conducted (mean distance, 10.4 ± 3.3 mm). Patients in group 1 had a normal LV substrate, while those in group 2 had an LV septal scar. Fisher's linear discriminant formula was used to determine the dynamic UV criteria. RESULTS: A total of 552 points were collected: 323 in 12 patients from group 1 and 229 in 16 patients from group 2. The UV of the RV septum is capable of identifying the opposite LV endocardial bipolar scar and is proportional to the WT of the interventricular septum. In the absence of an RV endocardial scar, the formula of "RV septal cut-off value = 0.736 × WT - 0.117 mV" has better sensitivity and specificity for predicting the LV septal scar (0.96 vs. 0.68 and 0.91 vs. 0.80, respectively) than the predefined fixed criteria of 8.3 mV with a net reclassification improvement of 25.7% (P < 0.001). CONCLUSIONS: The combined measurement of UV and WT is more sensitive than the predefined fixed UV criteria for defining deep scars.

A link between bilirubin levels and atrial fibrillation recurrence after catheter ablation.

BACKGROUND: Bilirubin is associated with different cardiovascular diseases. The relationship between bilirubin and atrial fibrillation (AF) remains unclear. The aim of this study is to determine the association between bilirubin and AF recurrence after catheter ablation. METHODS: A total of 212 patients who received AF ablation were retrospectively studied. The total bilirubin level, clinical characteristics, and echocardiographic findings were analyzed to predict the outcome of AF ablations. RESULTS: During a mean follow-up period of 12.2 ± 5.8 months, 61 (28.8%) patients had AF recurrence after catheter ablation. The patients with AF recurrence had a larger left atrial (LA) diameter (39.8 ± 6.3 versus 36.7 ± 5.8 mm; p = 0.001) and higher total bilirubin levels (0.82 ± 0.37 versus 0.63 ± 0.29 mg/dL; p < 0.001) than those without recurrence. The patients with recurrence had higher direct and indirect bilirubin levels than patients without recurrence. The total bilirubin level remained an independent predictor of AF recurrence after multivariate analysis (odds ratio, 4.95; 95% CI, 1.65-14.83; p = 0.004). We identified a cut point of the total bilirubin level for predicting AF recurrence by receiver operator characteristic curve (cut point, 0.7 mg/dL; area under the curve, 0.65; p < 0.001). The total bilirubin levels were positively correlated with the neutrophil counts. However, there were no associations among the total bilirubin level, left atrial (LA) diameter, and voltage. CONCLUSION: Higher serum bilirubin levels were associated with AF recurrence in paroxysmal AF patients following catheter ablation.

Clinical significance of J wave in prediction of ventricular arrhythmia in patients with acute myocardial infarction.

BACKGROUND: J wave syndrome and myocardial ischemia are related with malignant ventricular arrhythmia (VA). The characteristics of dynamic J wave in patients with early phase of acute myocardial infarction (AMI) and subsequent VA or electrical storm (ES) have not been well evaluated. OBJECTIVE: We investigated the utility of J wave in the prediction of VA and ES in patients within the early phase of AMI. METHODS: This study retrospectively enrolled 208 patients (mean age 69±15 years, 171 males) with AMI. Of them, 50 patients had experienced VA during hospitalization and 24 had ES. The clinical and electrocardiographic characteristics of these patients with and without VA were compared. RESULTS: Patients with VA had a higher incidence of chronic kidney disease (CKD) and J wave compared with those without VA. The hazard ratio (HR) of J wave for VA was 4.31 (p<0.01) and CKD was 2.64 (p<0.01). In the VA group, ES patients had a higher incidence of diabetes mellitus (DM) (HR 2.73, p=0.02) and J wave (HR 4.21, p<0.01). If the AMI patients had J wave, the OR for mortality was 2.14 (p=0.03), VA events was 6.23 (p<0.01), and ES events was 12.15 (p<0.01). If VA patients had J wave, the mortality rate will significantly increase (OR 68.62, p=0.01). CONCLUSION: The AMI patients who develop VA in the early phase of AMI had a higher incidence of J wave and CKD, and those who develop ES had a higher incidence of J wave and DM. It seems that J wave in AMI patients is a poor prognostic factor, and we found that J wave will increase mortality, VA events, and ES events. The majority locations of J wave were inferior leads although there was no relationship between the locations and VA incidence. If the VA patients had inferior or lateral J wave, it would further increase the risk of mortality.