Distributions and number of drivers on real-time phase mapping associated with successful atrial fibrillation termination during catheter ablation for non-paroxysmal atrial fibrillation.

BACKGROUND: Real-time phase mapping (ExTRa™) is useful in determining the strategy of catheter ablation for non-paroxysmal atrial fibrillation (AF). This study aimed to investigate the features of drivers of AF associated with its termination during ablation. METHODS: Thirty-six patients who underwent catheter ablation for non-paroxysmal AF using online real-time phase mapping (ExTRa™) were enrolled. A significant AF driver was defined as an area with a non-passively activated ratio of ≥ 50% on mapping analysis in the left atrium (LA). All drivers were simultaneously evaluated using a low-voltage area, complex fractionated atrial electrogram (CFAE), and rotational activity by unipolar electrogram analysis. The electrical characteristics of drivers were compared between patients with and without AF termination during the procedure. RESULTS: Twelve patients achieved AF termination during the procedure. The total number of drivers detected on the mapping was significantly lower (4.4 ± 1.6 vs. 7.4 ± 3.8, p = 0.007), and the drivers were more concentrated in limited LA regions (2.8 ± 0.9 vs. 3.9 ± 1.4, p = 0.009) in the termination group than in the non-termination group. The presence of drivers 2-6 with limited (≤ 3) LA regions showed a tenfold increase in the likelihood of AF termination, with 83% specificity and 67% sensitivity. Among 231 AF drivers, the drivers related to termination exhibited a greater overlap of CFAE (56.8 ± 34.1% vs. 39.5 ± 30.4%, p = 0.004) than the non-related drivers. The termination group showed a trend toward a lower recurrence rate after ablation (p = 0.163). CONCLUSIONS: Rotors responsible for AF maintenance may be characterized in cases with concentrated regions and fewer drivers on mapping.

Effect of mastication evaluation and intervention on body composition and biochemical indices in female patients with obesity: a randomized controlled trial.

BACKGROUND: A limited number of studies have evaluated the masticatory indices of individuals with obesity who only chew their food a few times and for shorter duration or who were provided with an instructional intervention. This study aimed to examine the effects of a 6-month instructional mastication intervention on the body composition and biochemical indices in female patients with obesity. METHODS: Female patients with obesity were randomly classified into a conventional treatment group (CTG; 12 individuals), which only received normal nutritional and exercise guidance, and a mastication intervention group (MIG; 16 individuals), which received an additional mastication guidance. The MIG received guidance on foods requiring increased number of chews and chewing duration, eating techniques, and the proper method of cutting foods. RESULTS: Changes in the masticatory, body composition, and biochemical indices were compared before and after the 6-month intervention. The values of body composition indices decreased significantly in both groups; however, the rate of change in body mass index significantly decreased in the MIG. In addition, the values of biochemical indices were significantly decreased in the MIG compared with that in the CTG, which is attributed to the addition of mastication instruction to female patients with obesity. CONCLUSION: Increasing the number of chews and duration of chewing times for carbohydrates, which are staple foods, possibly contributed to weight loss and improvement of glucose metabolism. TRIAL REGISTRATION: UMIN, UMIN000025875. Registered on 27 Jan 2017.

Personality traits and preoperative lifestyle improvement are predictors of early weight loss after sleeve gastrectomy.

PURPOSE: This study investigated the associations of personality traits and preoperative lifestyle improvements with early weight loss after sleeve gastrectomy. METHODS: This was a single-center, retrospective study of 57 patients who underwent preoperative lifestyle intervention with a multidisciplinary team approach based on cognitive behavioral therapy before sleeve gastrectomy. All patients underwent preoperative psychological testing with the Neuroticism-Extraversion-Openness Five-Factor Inventory (NEO-FFI) and the Tokyo University Egogram New Version II (TEG II). We investigated the associations of psychological testing results and lifestyle improvements with percent total weight loss (%TWL) one year after surgery. RESULTS: The median %TWL at 1 year was 38.2% for patients with an improved lifestyle and 26.9% for those without improvement (P = 0.0008). Although TEG II factors were not associated with %TWL at 1 year, higher NEO-FFI extraversion (E) scores were significantly associated with a better %TWL at 1 year. The median %TWL at 1 year was 35.2% for patients with higher E scores and 25.4% for those with lower E scores (P = 0.0247). Lifestyle improvement and the NEO-FFI E score significantly influenced %TWL at 1 year based on a logistic regression analysis. CONCLUSION: The NEO-FFI E score and preoperative lifestyle improvement may be predictors of early weight loss after sleeve gastrectomy.

Masticatory Behaviors and Gender Differences in People with Obesity as Measured via an Earphone-Style Light-Sensor-Based Mastication Meter.

While people with obesity have been found to chew fewer times and for shorter durations, few studies have quantitatively evaluated mastication among this group. This study examined the relationship between the mastication characteristics of people with obesity and the factors correlated with obesity. To this end, 46 people with obesity and 41 healthy participants placed an earphone-style light sensor in the aperture of their outer ear. We also examined the partial correlation between this, their body composition, and various biochemical markers by gender. A two-way analysis of variance (ANOVA) regarding the masticatory index, gender, and the presence/absence of obesity for all three food items revealed the main effects in the gender difference and the presence/absence of obesity. Additionally, the number of times the salad was chewed showed an interaction between the gender and the presence/absence of obesity. In the BMI-corrected partial correlation analysis of the chewing index and the glucose/lipid metabolism index, the chewing time and the number of chews of all the food items negatively correlated with hemoglobin A1c(HbA1c), fasting plasma glucose (FPG), immunoreactive insulin (IRI), and homeostasis model assessment of insulin resistance (HOMA-R) in the female obese group. These findings might be used in weight-loss interventions for men with obesity and treatments that target the metabolic function among women with obesity.

The relationship between changes in serum myostatin and adiponectin levels in patients with obesity undergoing a weight loss program.

BACKGROUND: An effective strategy for weight loss in patients who are overweight or obese is to reduce body fat mass while maintaining skeletal muscle mass. Adiponectin and myostatin are affected through changes in body composition due to weight loss, and examining their dynamics may contribute to strategies for maintaining skeletal muscle mass through weight loss. We aimed to examine the relationships among myostatin, adiponectin, and body composition, depending on the extent of weight loss, in patients with obesity undergoing a weight loss program. METHODS: We examined 66 patients with obesity (age: 46.8 ± 14.0 years, body mass index: 34.3 [31.0-38.4] kg/m2) attending a hospital weight loss program. We categorized the patients into two groups, namely an L group (those with a weight reduction of < 5% from baseline) and an M group (those with a weight reduction of > 5% from baseline). All patients underwent blood tests and were assessed for body composition, insulin resistance, adipocytokine and myokine levels, exercise tolerance, and muscle strength at baseline and post-intervention. RESULTS: Serum myostatin and adiponectin levels increased post-intervention in both groups. Body weight and %fat decreased, and the rate of lean body mass (%LBM) increased in both groups. Exercise capacity and muscle strength improved in the M group only. Change in (⊿) myostatin correlated with ⊿%fat, ⊿%LBM, and ⊿adiponectin. ⊿adiponectin (ß = - 0.262, p = 0.035) was an independent predictor of ⊿myostatin. CONCLUSIONS: Myostatin and adiponectin might cross-talk and regulate changes in skeletal muscle and fat mass with or without successful weight loss. These findings indicate that evaluating serum myostatin and adiponectin levels in clinical practice could be used to predict the effects of weight loss and help prevent skeletal muscle mass loss.

Dynamic Changes in Electrocardiogram Parameters After Epicardial Substrate Catheter Ablation of Brugada Syndrome.

BACKGROUND: Catheter ablation (CA) is effective for recurrent episodes of ventricular fibrillation (VF) in Brugada syndrome (BrS). VF development in BrS is associated with several electrocardiogram (ECG) abnormalities. This study investigated changes in ECG parameters in high-risk BrS patients who underwent epicardial CA.Methods and Results:In all, 27 BrS patients were implanted with an implantable cardioverter-defibrillator (ICD). Patients were divided into 2 groups: (1) an ablation group (n=11) that underwent epicardial CA because of VF recurrence; and (2) a primary prevention (PP) group (n=16) with ICD implantation only. ECG parameters were evaluated before and 12 months after CA and compared with ECG parameters in the PP group. The T wave peak-to-end interval was significantly longer and the number of abnormal spikes in leads V1-V3 at the second, third, and fourth intercostal spaces was greater in the ablation than PP group. After ablation, ST levels and the sum of abnormal spikes in leads V1-V3 were significantly decreased. The mean (±SD) number of ICD shocks decreased markedly during a mean follow-up period of 42.0 months (from 3.8±3.7 to 0.2±0.4/year). Four patients had an ICD shock following the ablation procedure. Greater reductions in ST-segment elevation and abnormal spikes were observed in the group without than with VF recurrence. CONCLUSIONS: Improvements in surface ECG parameters appear to be associated with successful ablation in high-risk BrS patients.

Evaluation of oxygen uptake adjusted by skeletal muscle mass in cardiovascular disease patients with type 2 diabetes.

[Purpose] We aimed to evaluate oxygen uptake adjusted by total skeletal muscle mass in patients with cardiovascular disease with or without type 2 diabetes mellitus. [Participants and Methods] The participants included 54 males ≥50 years of age without heart failure who underwent cardiopulmonary exercise testing during cardiac rehabilitation. We divided the participants into two groups: patients with type 2 diabetes mellitus (DM group) and patients without type 2 diabetes mellitus (NDM group). [Results] We found no significant differences in age, weight, fat mass, or skeletal muscle mass between the groups. There were also no differences in cardiac function, body composition, and heart rate response. The DM group showed significantly lower peak oxygen uptake values adjusted by skeletal muscle mass, despite the absence of significant differences in skeletal muscle mass. A significant positive correlation was found between peak oxygen uptake and age, weight, and skeletal muscle mass. Stepwise regression analysis revealed that age, skeletal muscle mass, and medical history of diabetes were independent predictors of absolute peak oxygen uptake. [Conclusion] Peak oxygen uptake adjusted by skeletal muscle mass in patients with cardiovascular disease and type 2 diabetes mellitus is lower than that in those without type 2 diabetes mellitus.

The mechanism and prognosis of acute and late improvement in mitral regurgitation after cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) improves functional mitral regurgitation (MR); however, the mechanism and differences in acute and late improvement in MR are unclear. We aimed to evaluate the factors associated with the acute and late MR improvements and the prognosis of MR improvement after CRT. This retrospective study included 121 patients who underwent CRT implantation with full echocardiography assessment at baseline, 1 week, and 6 months after implantation. MR severity was classified into five grades (0: none to 4: severe). Two-dimensional speckle-tracking echocardiography with radial strain was used to assess dyssynchrony, and the time difference between the lateral and inferior segments at papillary muscle levels (TDlate-inf) was calculated. The MR improved 1 week and 6 months after CRT in 40 (33%) and 45 (37%) patients, respectively. On multivariate analyses, TDlate-inf (baseline-1 week) and SPWMD were independently associated with acute MR improvement. The %reduction in left ventricular end-systolic volume (LVESV) (baseline-6 months) and TDlate-inf (baseline-1 week) were independently correlated with late MR improvement. The patients with pre-MR grades 2-4 and improved MR after CRT showed significantly better prognosis in heart failure hospitalization. Cutoff values of ≥ 19.5 ms of the reduction of TDlate-inf and ≥ 30.8% of the %reduction of LVESV were significantly associated with the decrease in heart failure hospitalization. The improved interpapillary muscle activation time delay and volume reduction after CRT were associated with acute and late MR improvements. There may be different time course of recovery and distinct causes for late MR improvement.

Early improvement of daily physical activity after catheter ablation for atrial fibrillation in an accelerometer assessment: A prospective pilot study.

BACKGROUND: Catheter ablation improves physical activity in patients with atrial fibrillation (AF). However, continuous daily evaluation and time course of improvement in physical activity after ablation have not been fully assessed. This prospective study was conducted to evaluate the daily physical activities and changes in the physical performance in patients undergoing catheter ablation for AF by continuous monitoring of a portable accelerometer. METHODS: Ten patients scheduled for catheter ablation for AF were fitted with a uniaxial accelerometer prior to and 6 months after the procedure. This study evaluated changes in daily steps, activity intensity, and activity duration. We also evaluated changes in activity intensity using a short version of the International Physical Activity Questionnaire (IPAQ). RESULTS: The maximum daily steps significantly increased from baseline to postablation (baseline, 9,232 [6,716-11,485]; after 1-3 months, 11,605 [8,285-14,802]; and after 4-6 months, 11,412 [8,939-13,808], p = .020). Similarly, Δ maximum-mean daily steps increased significantly (baseline, 2,431 [1,199-6,181]; after 1-3 months, 4,674 [4,164-6,474]; and after 4-6 months, 4,871 [3,657-6,117], p = .014). These improvements were more pronounced in patients with paroxysmal and symptomatic AF. The total IPAQ score significantly improved from baseline to after 6 months ablation (from 1,170 [693-3,930] to 4,312 [1,865-6,569], p = .037). All patients were recurrence-free from AF after ablation. CONCLUSIONS: The physical activity improved significantly even in the early phase following catheter ablation. The effect of suppressing AF on activity levels was apparent soon after the procedure.

Periprocedural Management of Cardiac Tamponade During Catheter Ablation for AF Under Uninterrupted DOAC and Warfarin.

OBJECTIVES: This was a retrospective analysis of a registry of patients who underwent catheter ablation for atrial fibrillation (AF) under uninterrupted direct oral anticoagulant (DOAC) and warfarin administration. BACKGROUND: Uninterrupted DOAC used during catheter ablation for AF causes a life-threatening bleeding risk of cardiac tamponade. METHODS: Of 3,149 catheter ablation procedures for AF with uninterrupted oral anticoagulants used in 2,406 patients in 3 institutions, DOAC and warfarin were administered in 1,896 and 1,253 procedures, respectively. Among them, cardiac tamponade requiring pericardiocentesis and surgical intervention occurred in 13 (0.7%) and 11 (0.9%) procedures in the DOAC and warfarin groups, respectively. In this study, the outcomes between these 2 groups were compared. RESULTS: The total blood volumes drained after pericardiocentesis was 300 (190 to 715) ml and 300 (200 to 380) ml in the DOAC and warfarin groups, respectively (p = 0.697). Approximately two-thirds of patients (9 in the DOAC group and 7 in the warfarin group) recovered with only pericardiocentesis and protamine infusion (including vitamin K in the warfarin group) in both groups. Two patients in the DOAC group underwent surgical intervention but recovered uneventfully, whereas none of the patients taking warfarin required surgical intervention. DOAC and warfarin were successfully resumed 2.0 (2.0 to 5.0) days and 4.0 (2.0 to 5.5) days after tamponade in all patients without an increase in effusion (p = 0.102). CONCLUSIONS: Managing cardiac tamponade under uninterrupted DOAC administration was feasible. Early intensive treatment resulted in hemostasis in most patients. However, surgical intervention was required in some cases refractory to the initial treatment.

Changes in Body Composition and FTO Whole Blood DNA Methylation Among Japanese Women: A Randomized Clinical Trial of Weight-Loss Program.

OBJECTIVE: DNA methylation is an epigenetic mechanism that regulates gene expression. The obesity-related (FTO) gene is the first gene found to be associated with fat mass and obesity. However, no studies have examined the relationship between weight-loss intervention effect and FTO methylation in obese individuals with whole blood DNA. The purpose of this study was to quantify FTO whole blood DNA methylation and investigate the relationship between body composition, exercise capacity, and blood parameters with a 6-month weight-loss program intervention. PARTICIPANTS AND METHODS: Eighteen female participants (mean age, 50.6 ±12.1 years, body mass index (BMI), 33.5 ± 6.2 kg/m2) who completed a 6-month weight-loss program at the obesity outpatient department at the Health Science Center of Kansai Medical University Hospital from March 2017 to October 2018 were included in the analysis. Participants were randomized into a normal treatment group (NTG) and a group with additional resistance training (RTG). Body composition, exercise tolerance and metabolic index were measured in each participant. DNA methylation status in whole blood samples was determined using pyrosequencing. All measurements were taken during the first visit and at the 6-month post-intervention visit. RESULTS: The methylation rate was significantly decreased in the NTG in CpG1 (p=0.011) and total value of CpG (p=0.011), whereas in the treatment group containing resistance training (RTG), CpG3 (p=0.038) was increased significantly. Furthermore, the independent factors that determine %CpG3 of RTG were visceral fat area change rate (%VFA) (ß = -0.568, P = 0.007, R2 = 0.527) and resistance training (ß = 0.517, P = 0.012, R2 = 0.527), which have been extracted. CONCLUSION: A 6-month weight-loss program, including resistance training, may be associated with decreased visceral fat area changes and increased RTG CpG3 methylation changes. However, further replication studies with larger sample sizes are warranted to verify the findings of this study.

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.

Electrocardiogram characteristics of P wave associated with successful pulmonary vein isolation in patients with paroxysmal atrial fibrillation: Significance of changes in P-wave duration and notched P wave.

BACKGROUND: The mechanisms involved in changes in P wave following catheter ablation for atrial fibrillation (AF) are uncertain. This study aimed to assess the relationship between changes in P-wave morphology and pulmonary vein (PV) reconnection following ablation by the assessment of 12-lead surface electrocardiogram and signal-averaged electrocardiogram. METHODS: This retrospective study included 115 consecutive patients with paroxysmal AF that underwent repeat ablation for recurrence following initial ablation. We investigated changes in P-wave morphology between baseline and repeat procedure in patients with and without PV reconnection. The study also included as validation group without recurrence (n = 67) following initial ablation. RESULTS: The maximum P-wave duration (PWD) was significantly decreased from baseline to just after the procedure in all groups. However, for the PV reconnection group (n = 100), the maximum PWD was significantly increased again at the repeat procedure. In contrast, the maximum PWD was significantly reduced between baseline and repeat procedure in the non-PV reconnection group (n = 15). The signal-averaged PWD was significantly decreased from baseline to repeat procedure in the non-PV reconnection group, but, conversely, was increased in the PV reconnection group. In the non-PV reconnection group, the disappearance of notched P wave was detected in 8 of 15 patients (53%), which was significantly higher than in other groups (p = .001). A new or delayed notched P wave was identified in the PV reconnection group only. These results were confirmed in the validation group. CONCLUSIONS: The reverse dynamics of PWD after initial shortening directly following ablation were significantly associated with PV reconnection.

Prothrombotic Responses After Catheter Ablation for Atrial Fibrillation During Uninterrupted Oral Anticoagulant Agent Administration.

OBJECTIVES: The aim of this study was to evaluate the extent of changes in prothrombotic responses after catheter ablation for atrial fibrillation (AF) under uninterrupted oral anticoagulant agent (OAC) administration. BACKGROUND: Catheter ablation for AF has a potential risk for prothrombotic activation and silent thromboembolic events. METHODS: A total of 814 patients (n = 172 [warfarin], n = 153 [dabigatran], n = 134 [rivaroxaban], and n = 301 [apixaban] patients undergoing AF ablation and a control group of 54 patients undergoing non-AF ablation) were included. Uninterrupted OACs were administered during the procedure in patients with AF. Blood samples were collected the day before and 3 days after the procedure. RESULTS: At baseline, D-dimer levels were within normal limits (≤1.0 µg/ml) in more than 90% of the patients in all groups. However, after 3 days, this proportion decreased to 67%, 73%, 59%, 68%, and 65% in the warfarin, dabigatran, rivaroxaban, apixaban, and control groups, respectively (p = 0.180). Changes in prothrombin fragment 1+2 levels differed (p < 0.001), whereas fibrin monomer complex levels 3 days after ablation at a trough were equivalent within normal ranges among the groups (p = 0.146). Multivariate analysis revealed that age, CHA2DS2-VASc score, first session, and radiofrequency ablation were independent predictors of increased D-dimer levels after the procedure. Various changes in prothrombotic markers were observed between the warfarin and direct OAC groups after propensity score matching analyses. CONCLUSIONS: The coagulation cascade was activated after catheter ablation for AF under uninterrupted OAC administration. The changes in various prothrombotic markers differed among the OAC groups.

The effects of toe grip training on physical performance and cognitive function of nursing home residents.

BACKGROUND: Toe grip-related training requires individuals to actively exercise muscles that are not frequently used; therefore, it may improve not only toe grip strength but also cognitive function. The purpose of this study was to examine the effects of toe grip-related training on predictors of physical performance and cognitive function in nursing home residents. METHODS: A total of 35 nursing home residents (35 left and 35 right feet; mean age, 82.1 ± 7.9 years) were included in this study. The participants were divided into two groups: a training group and a control group. The Mini-Mental State Examination (MMSE) was used to assess the cognitive function of the participants, and the Fall Risk Index (FRI) was used to evaluate the risk of falls. Toe grip-related physical function was also assessed. Baseline endpoints were evaluated and the effects of toe grip-related training were examined following a 12-week training intervention. RESULTS: The training group showed significant improvements in MMSE score, FRI score, toe grip strength, and the toe skill (TS) test; however, the control group did not show these changes. The training group showed significant increases in Δ MMSE, Δ toe grip strength, and Δ TS (right foot) than the control group. Stepwise regression analysis revealed that Δ toe grip strength is an independent factor of Δ MMSE. CONCLUSIONS: Toe grip training improves not only toe grip strength itself, but also cognitive function. Furthermore, change in toe grip strength was an independent factor of change in MMSE in those populations. TRIAL REGISTRATION: UMIN, UMIN000027437 . Registered on 26 May 2017.

Discontinuous contraction in the left ventricle assessed by 2-D speckle tracking echocardiography benefits from CRT.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves the morbidity and mortality rate in patients with left bundle-branch block (LBBB); however, some LBBB patients are non-responders for CRT. Previous studies have shown that a transmural functional line block alters the left ventricular (LV) activation sequence, and that the presence of a line block is predictive for responders. We investigated whether responders could be predicted in patients with LBBB by 2-dimensional (2-D) speckle tracking strain imaging. METHODS: We enrolled 54 patients with LBBB, who underwent echocardiography before and 6 months after CRT implantation. A responder was defined by a decrease in the LV end-systolic volume >15% at the 6-month follow-up. We calculated a difference in the time from QRS onset to maximum strain between adjacent segments and defined the Tmax-diff as the maximum difference among six intersegments. We compared the Tmax-diff between responders and non-responders. RESULTS: Among 54 patients, 37 patients were identified as responders. The Tmax-diff of the responders was significantly longer than that of the non-responders (309.6 ± 168.6 ms vs 181.5 ± 138.4 ms, P = .009). Furthermore, Tmax-diff ≥ 195 ms was higher in the septal and the anterior area. And patients with a Tmax-diff ≥ 195 ms tended to be responders (P = .02). CONCLUSION: The present study showed that discontinuous contraction of the LV could be detected in CRT responders by 2-D speckle tracking strain imaging, which may be a useful tool to identify the contraction pattern of patients with LBBB and predict CRT responders.

T-wave changes of cardiac memory caused by frequent premature ventricular contractions originating from the right ventricular outflow tract.

INTRODUCTION: Cardiac memory is recognized as altered T-waves when the sinus rhythm resumes after an abnormal myocardial activation period that recovers slowly over several weeks. The T-wave changes after ablation of frequent premature ventricular contractions (PVCs) as cardiac memory was not known. OBJECTIVE: This study identified whether cardiac memory exists after successful ablation of PVCs from the right ventricular outflow tract (RVOT). METHODS: We investigated 45 patients who underwent successful ablation of PVCs from RVOT and 10 patients who underwent unsuccessful ablation. We analyzed the amplitude of the T-wave, QT intervals, and QRST time-integral values of a 12-lead electrocardiogram before ablation and 1 day, 3 days, and 1 month after ablation. RESULTS: In the successful ablation group, the amplitude of the T-wave and QRST time-integral values of lead II, III, aVR, aVL, and aVF significantly changed after ablation and gradually normalized within 1 month. In addition, if the number of pre-ablation PVCs was small, then the corresponding impact was also small. However, the greater the number of pre-ablation PVCs, the more prominent the changes. Significant changes were not observed in the unsuccessful ablation group. CONCLUSION: When ablation of PVCs from RVOT was successful, primary T-wave changes because of cardiac memory and the gradual normalization of the amplitude of the T-wave were observed. No significant T-wave changes were detected after unsuccessful ablation.

Clinical significance of the timing of early recurrence of atrial arrhythmia after pulmonary vein isolation: a two-institution clinical study.

Early recurrence of atrial arrhythmia (ERAA) after ablation frequently occurs, but there is limited evidence about ERAA-timing. This study aimed to investigate the association between ERAA-timing and late recurrence. We retrospectively investigated 332 patients who underwent PVI for paroxysmal atrial fibrillation at Nagoya University Hospital and Komaki City Hospital. Seventy-six patients (23%) had ERAA. The cutoff value of the first ERAA for late recurrence was set as 3 days, with a specificity of 77% and sensitivity of 43%. On multivariate analysis, first ERAA beyond 3 days (hazard ratio, 2.477; 95% confidence interval, 1.168-5.25; p = 0.018) and large left atrial diameter (LAD) (hazard ratio, 1.101; 95% confidence interval, 1.024-1.184; p = 0.009) were independent predictors for late recurrence. Patients who had first ERAA within 3 days and no ERAA beyond 3 days showed a significantly higher recurrence-free rate than those who had first ERAA beyond 3 days and those who had ERAA both within 3 days and beyond 3 days (89% versus 39%, 44%; p < 0.001). Moreover, the patients with ERAA within 3 days and LAD ≤ 37.7 mm showed a significantly higher recurrence-free rate than those with ERAA beyond 3 days and LAD > 37.7 mm, and as compared with the other patients (100% versus 26% and 60%, respectively; p < 0.001). ERAA beyond 3 days after ablation was a predictor for late recurrence. Among patients with ERAA, those with ERAA within 3 days and smaller LAD showed favorable prognosis after ablation.