The impact of the dominant frequency of body surface electrocardiography in patients with persistent atrial fibrillation.

The dominant frequency (DF) of atrial fibrillation (AF) reflects atrial electrical activity. However, the relationship between DF measured using surface electrocardiography (ECG) and AF ablation success remains unclear. This study aimed to clarify whether the DF of surface ECG in patients with persistent AF could predict arrhythmia recurrence after catheter ablation. We investigated 125 patients with persistent AF who underwent catheter ablation between January 2009 and December 2016. Thirty-four patients (27%) had arrhythmia recurrence after catheter ablation. These patients showed a significantly high DF value in leads aVL (7.2 ± 0.7 Hz vs 6.6 ± 0.9 Hz, p < 0.001) and V1 (7.4 ± 0.8 Hz vs 6.7 ± 0.7 Hz, p < 0.001). We set the cutoff value of DF as 6.9 Hz in lead aVL (sensitivity, 80%; specificity, 63%) and as 7.1 Hz in lead V1 (sensitivity, 72%; specificity, 67%). Patients with DF < 6.9 Hz in lead aVL showed a significantly higher recurrence-free rate than those with DF ≥ 6.9 Hz (88% vs 45%; p < 0.001). Patients with DF of < 7.1 Hz in lead V1 showed a significantly higher recurrence-free rate than those with DF of ≥ 7.1 (87% vs 47%; p < 0.001). Patients with a high DF in leads aVL and V1 showed a lower success rate of persistent AF ablation. The DF measured from surface ECG can be a useful marker to predict ablation success.

Myocardial viability as shown by left ventricular lead pacing threshold and improved dyssynchrony by QRS narrowing predicts the response to cardiac resynchronization therapy.

INTRODUCTION: Patients with advanced heart failure and dyssynchrony can benefit from cardiac resynchronization therapy (CRT). To predict the response to CRT, myocardial viability and improved dyssynchrony are suggested to be important. METHODS: We retrospectively investigated 93 patients who underwent CRT implantation in Nagoya University Hospital. We assessed QRS narrowing the day after implantation to measure the improvement in dyssynchrony and measured the left ventricular pacing threshold (LVPT) to determine the local myocardial viability in all patients. Responders to CRT were defined as those having a greater than or equal to 15% decrease in left ventricular end-systolic volume by echocardiography at their 6-month follow-up. RESULTS: Sixty-two patients (67%) were classified as responders. The QRS width before CRT implantation, QRS narrowing after implantation, left atrial diameter, septal-to-posterior wall motion delay, left ventricular end-diastolic diameter, radial strain, and LVPT were significantly different between the responder and nonresponder groups. On multivariate analysis, QRS narrowing (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.01-1.05; P = 0.005) and LVPT (OR, 0.42; 95% CI, 0.22-0.82; P = 0.011) were independent predictors of a response to CRT. We calculated the cutoff values from the receiver operating characteristic curves as 22.5 milliseconds of QRS narrowing and 1.55 V of LVPT. The response rates in patients with both predictive factors (QRS narrowing ≥ 22.5 milliseconds and LVPT ≤ 1.55 V), one factor, and no factors were 91%, 61%, and 25%, respectively (P < 0.001). CONCLUSION: Both myocardial viability and improved electrical dyssynchrony may be essential to predict a good response to CRT.

Uninterrupted Direct Oral Anticoagulant and Warfarin Administration in Elderly Patients Undergoing Catheter Ablation for Atrial Fibrillation: A Comparison With Younger Patients.

OBJECTIVES: The goal of this study was to evaluate the efficacy and safety of uninterrupted direct oral anticoagulant (DOAC) use and uninterrupted warfarin administration in elderly patients undergoing catheter ablation for atrial fibrillation (AF). BACKGROUND: There is limited knowledge regarding the uninterrupted use of oral anticoagulant agents in elderly patients undergoing catheter ablation for AF. METHODS: This retrospective study included 2,164 patients (n = 325 ≥75 years of age and n = 1,839 <75 years of age) who underwent catheter ablation for AF. All the patients received uninterrupted oral anticoagulant agents during the procedure. We investigated the occurrences of periprocedural events and compared these between the DOAC and warfarin groups of the elderly and younger groups. RESULTS: Major bleeding events (3.1% vs. 1.3%; p = 0.023) and minor bleeding events (9.2% vs. 5.0%; p = 0.002), except for thromboembolic events (0% vs. 0.8%; p = 0.248), were significantly higher in the elderly group than in the younger group. No significant differences in thromboembolic and bleeding events were found between the DOAC and warfarin groups of both the elderly and younger groups. Adverse complications did not differ between the groups after adjustment using propensity score matching analysis. Multivariate analysis revealed that lower body weight (odds ratio: 0.96; p = 0.010) and antiplatelet drug use (odds ratio: 2.21; p = 0.039) were independent predictors of adverse events in the elderly group. CONCLUSIONS: The periprocedural bleeding risk during the use of uninterrupted oral anticoagulants was higher in the elderly group than in the younger group. This area needs more attention for these patients in whom caution is required.

Assessment of autonomic nervous system modulation after novel catheter ablation techniques for atrial fibrillation using multiple short-term electrocardiogram recordings.

PURPOSE: The effect of novel catheter ablation techniques for atrial fibrillation (AF) on the autonomic nervous system (ANS) is unclear. This study aimed to assess the ANS after three novel catheter ablation techniques for paroxysmal AF by evaluating heart rate variability (HRV) parameters using a 3-min electrocardiogram recording. METHODS: Two hundred and thirty-five patients who underwent catheter ablation for paroxysmal AF (119 in irrigated-tip, 51 in contact-force sensing-guided, and 65 patients in second-generation cryoballoon ablation) were included. HRV analysis was performed at baseline and 1, 3, 6, and 12 months after the ablation. RESULTS: The three ablation groups had similarly decreased HRV parameters after the ablation, and this change was maintained > 1 year. A reduction in parasympathetic nervous function was more apparent after the ablation, compared to changes in the sympathetic nervous function. Of the total population, 45 patients had recurrence. Ln high frequency (HF) 12 months after the ablation was significantly higher in the recurrence group than in the non-recurrence group (1.52 ± 0.47 vs. 1.26 ± 0.57 ms2, p = 0.007). Multivariate analysis demonstrated that AF duration (hazards ratio 1.09, 95% confidence interval 1.04-1.15, p = 0.001) and ln HF 12 months after ablation (hazards ratio 1.91, 95% confidence interval 1.12-3.25, p = 0.017) were independent predictors of AF recurrence after the ablation. CONCLUSIONS: ANS modulation after the three catheter ablation methods was similar and maintained > 1 year after the procedure. Higher parasympathetic nervous function at 1 year after ablation was associated with AF recurrence after the ablation.

Renal function and risk of stroke and bleeding in patients undergoing catheter ablation for atrial fibrillation: Comparison between uninterrupted direct oral anticoagulants and warfarin administration.

BACKGROUND: The effect of uninterrupted oral anticoagulant use in patients with chronic kidney disease (CKD) during catheter ablation for atrial fibrillation (AF) is not fully understood. OBJECTIVE: The present study aimed to evaluate the safety and efficacy of periprocedural uninterrupted direct oral anticoagulant (DOAC) use compared with those of uninterrupted warfarin use in patients undergoing catheter ablation for AF stratified by various renal function groups. METHODS: A total of 2091 patients were retrospectively included in this study. The study population was divided into 4 groups: creatinine clearance level ≥80 mL/min (n = 1086), 50-79 mL/min (n = 774), 15-49 mL/min (n = 209), and <15 mL/min (n = 22). We investigated periprocedural complications and compared them between uninterrupted DOAC and warfarin groups. RESULTS: There was no significant difference in thromboembolic events among the 4 groups (0.6%, 0.6%, 1.0%, and 0%, respectively; P = .792). However, major bleeding events (0.9%, 1.4%, 4.8%, and 4.5%; P < .001) and minor bleeding events (4.1%, 6.1%, 11.5%, and 13.6%; P < .001) primarily occurred in patients with CKD. The rate of periprocedural complications in the DOAC group was similar to that in the warfarin group for each renal function category. Adverse events did not differ after adjustment using propensity score-matched analysis. Multivariate analysis showed that lower body weight, antiplatelet drug use, initial ablation session, and CKD were independent predictors of adverse events. CONCLUSION: The periprocedural bleeding risk was increased in patients with CKD. Uninterrupted DOAC and warfarin administration during catheter ablation for AF in patients with CKD is feasible and effective.

Vagal response in cryoballoon ablation of atrial fibrillation and autonomic nervous system: Utility of epicardial adipose tissue location.

BACKGROUND: Mechanism and effects of vagal response (VR) during cryoballoon ablation procedure on the cardiac autonomic nervous system (ANS) are unclear. The present study aimed to evaluate the relationship between VR during cryoballoon catheter ablation for atrial fibrillation and ANS modulation by evaluating epicardial adipose tissue (EAT) locations and heart rate variability (HRV) analysis. METHODS: Forty-one patients with paroxysmal atrial fibrillation (11 with VR during the procedure and 30 without VR) who underwent second-generation cryoballoon ablation were included. EAT locations and changes in HRV parameters were compared between the VR and non-VR groups, using Holter monitoring before ablation, immediately after ablation and one month after ablation. RESULTS: The total EAT volume surrounding the left atrium (LA) in the VR and non-VR groups was 29.0±18.4 cm3 vs 27.7±19.7 cm3, respectively (p=0.847). The VR group exhibited greater EAT volume overlaying the LA-left superior pulmonary vein (PV) junction (6.1±3.6 cm3 vs 3.6±3.3 cm3, p=0.039) than the non-VR group. HRV parameters similarly changed following ablation in both the groups. EAT volume overlaying LA-right superior PV junction was significantly correlated with the relative changes in root-mean-square successive differences (r=-0.317, p=0.043) and high frequency (r=-0.331, p=0.034), immediately after the ablation. CONCLUSIONS: Changes in HRV parameters following ablation were similarly observed in both the groups. EAT volume on the LA-PV junction is helpful for interpretation of VR occurrence and ANS modulation.