Adding interactive face-to-face lectures to passive lectures effectively reduces radiation exposure during atrial fibrillation ablation.

BACKGROUND: Radiation exposure remains a major concern for electrophysiologists and patients. This study aimed to investigate the effect of altering awareness of radiation exposure during atrial fibrillation ablation using interactive face-to-face (FTF) lectures compared to passive lectures. METHODS: Patients who underwent their first catheter ablation with radiofrequency energy for atrial fibrillation between January 2014 and December 2020 were included in this study. All operators attended an e-learning lecture on radiation exposure before catheter ablation. The addition of FTF lectures to this lecture was introduced in 2018. The effect on radiation exposure was compared between the pre-FTF and FTF periods by comparing fluoroscopy time and radiation dose. RESULTS: A total of 896 patients [mean age, 66 ±â€¯11 years; 603 men (67 %)] were included in this study. For pre-FTF (n = 345), only pulmonary vein isolation (PVI) was performed in 112 patients and PVI with additional ablation in 233 patients. For FTF lectures (n = 551), PVI-only was performed in 302 patients and PVI with additional ablation in 249 patients. Fluoroscopy time, cumulative air kerma, and cumulative air kerma per time significantly reduced after FTF introduction in both PVI-only group [pre-FTF and FTF; 37 ±â€¯15 min and 16 ±â€¯10 min (p < 0.0001), 477 ±â€¯582 mGy and 108 ±â€¯156 mGy (p < 0.0001), 11 ±â€¯12 mGy/min, and 5 ±â€¯6 mGy/min (p < 0.0001), respectively] and PVI with additional ablation group [pre-FTF and FTF; 48 ±â€¯17 min and 15 ±â€¯13 min (p < 0.0001), 613 ±â€¯483 mGy and 68 ±â€¯96 mGy (p < 0.0001), 12 ±â€¯10 mGy/min, and 4 ±â€¯4 mGy/min (p < 0.0001), respectively]. There were no significant differences in intraoperative complications between the two periods. CONCLUSIONS: FTF lectures can reduce radiation exposure.

Efficacy of intrinsic antitachycardia pacing for ventricular tachycardia refractory to conventional burst pacing: A case series.

Intrinsic antitachycardia pacing (iATP) is a novel automated ventricular ATP algorithm that designs ATP sequences based on the analysis of prior failed ATP. Real-world data on the efficacy and safety of iATP are lacking. Among 124 ventricular tachycardia (VT) episodes in 130 consecutive patients (mean age at implantation: 63.8 ± 14.9 years; sex, 95 male and 35 female) for whom implantable cardioverter defibrillator or cardiac resynchronization therapy defibrillator equipped with iATP algorithm was implanted, we investigated the efficacy and safety of iATP for VT refractory to conventional burst pacing. Eight patients had a total of 17 episodes of iATP therapy after failed conventional burst pacing within 11.2 ± 6.6 months of follow-up. Eleven VT episodes (64.7%) in seven patients (87.5%) were successfully terminated by iATP, and only one patient (12.5%) experienced VT acceleration. iATP might be useful for VTs refractory to conventional burst pacing with a low risk of VT acceleration.

A multicenter prospective randomized study comparing the incidence of periprocedural cerebral embolisms caused by catheter ablation of atrial fibrillation between cryoballoon and radiofrequency ablation (Embo-Abl study): Study design.

BACKGROUND: Although catheter ablation (CA) has become a standard therapeutic approach to atrial fibrillation (AF), it imposes a low but relevant risk of thromboembolic complications of around 0.5%-1%, including ischemic strokes, and has an additional risk of clinically silent cerebral embolisms (SCEs) of 10%-40%. Both cryoballoon (CB) and radiofrequency (RF) ablation are routinely used clinically worldwide, yet there are few prospective data comparing the incidence of cerebral embolism after CA of AF between CB and RF ablation. METHODS: The aim of the Embo-Abl study will be to compare the incidence of cerebral embolisms on 3 T diffusion-weighted image magnetic resonance imaging (MRI) after CA of AF between CB and RF ablation in patients with AF in a prospective, multicenter, open-label, controlled, randomized fashion. The primary endpoint of the Embo-Abl study will be the occurrence of MRI-detected SCE 1-3 days after CA. The patients will be registered and randomly assigned to either the CB or RF ablation group in a 1:1 ratio. The study cohort will include 230 patients with AF from a multicenter in Japan. RESULTS: The results of this study are currently under investigation. CONCLUSION: The Embo-Abl study will be the first to compare the incidence of periprocedural cerebral embolisms caused by CA of AF between CB and RF ablation in a prospective, multicenter, randomized, controlled fashion.

Impact of nocturnal hypoxemia on the recurrence of atrial tachyarrhythmia after catheter ablation of atrial fibrillation.

Factors causing atrial tachyarrhythmia recurrence after catheter ablation (CA) of atrial fibrillation (AF) remain undetermined. This study aimed to investigate the effect of nocturnal hypoxemia on the recurrence of atrial tachyarrhythmia after CA of AF. Among 594 patients with AF who underwent an ambulatory sleep study at the National Cerebral and Cardiovascular Center, Suita, Osaka, Japan (2014-2019), 365 underwent CA of AF; 290 patients who underwent CA were followed up for > 3 months. Multivariate Cox regression analysis was used to calculate hazard ratios (HRs) using clinical variables, to identify the independent predictors of atrial tachyarrhythmia recurrence after the final CA. Atrial tachyarrhythmia recurred in 45 of 290 (15.5%) patients during the median follow-up period of 479 days (interquartile range 225-1002). On the performing multivariate analysis of the data of patients who did not receive continuous positive airway pressure (CPAP), severe nocturnal hypoxemia [defined as the percentage of sleep time spent with SaO2 of < 90% (T90) over 20%] [HR 8.53, 95% confidence interval (CI) 1.872-38.814; P < 0.01] and an 1 mL/m2 increase in the left atrial volume index (HR 1.02, 95% CI 1.004-1.044; P = 0.02) were found to be independently associated with the recurrence of atrial tachyarrhythmia. In addition, the rates of freedom from atrial tachyarrhythmia after the final AF ablation with CPAP were significantly lower in the group with more severe nocturnal hypoxemia (Log-rank P = 0.03). In conclusion, it is necessary to consider both, AHI and nocturnal hypoxia while performing an ambulatory sleep apnea study. CA may be less effective in patients with more severe nocturnal hypoxia, despite the administration of CPAP.

Relationship between electrical gaps after Maze procedure and atrial tachyarrhythmias and ablation outcomes after cardiac surgery and concomitant Maze procedure.

Atrial tachycardia (AT) and atrial fibrillation (AF) commonly occur after cardiac surgeries (CSs). This study investigated the mechanisms and long-term outcomes of AT and AF ablation after various Maze procedures, particularly whether atrial tachyarrhythmias after the Maze procedure occur due to gaps in the Maze lines. We analyzed 37 consecutive cases with atrial tachyarrhythmias after the Maze procedures and concomitant CSs between 2007 and 2019. Fifty-nine atrial tachyarrhythmias were induced in 37 consecutive cases, and 49 of those atrial tachyarrhythmias were mappable ATs. Forty ATs were related to the Maze procedures in the 49 mappable ATs (81.6%). All 37 consecutive cases had residual electrical conductions (gaps) in the Maze lines (88 gaps; 2.4 ± 1.2 gaps/patient). Forty of 88 gaps (45.5%) were associated with gap-related ATs. The common ATs in this study were 1. peri-mitral atrial flutter due to gaps at pulmonary vein isolation (PVI) line to mitral valve annulus (MVA) (20 cases), and 2. peri-tricuspid atrial flutter due to gaps at right atrial incision to the tricuspid valve annulus (TVA) (10 cases). Forty-seven of 49 ATs (95.9%) were successfully ablated at the first session, and there were no complications. The mean follow-up period after ablation was 3.6 ± 3.2 (median, 2.1; interquartile range, 0.89-6.84) years. The Kaplan-Meier analysis of freedom from recurrent atrial tachyarrhythmias after Maze procedure was 82.7% at 1-year follow-up and 75.5% at 4-year follow-up after a single procedure. Reentry was the main mechanism of ATs after Maze procedures and concomitant CSs, and ATs were largely related to the gaps on the Maze lines between the PVI line and the MVA or those on the lines between right atrial incision to the TVA. Long-term follow-up data suggest that catheter ablation of atrial tachyarrhythmias after various Maze procedures is effective and safe.

Electrocardiographic features of arrhythmogenic right ventricular cardiomyopathy in school-aged children.

It can be difficult to distinguish children with early-stage arrhythmogenic right ventricular cardiomyopathy (ARVC) from those with benign premature ventricular contraction (PVC). We retrospectively evaluated six school-aged children with ARVC and compared with those of 20 with benign PVC. The median age at initial presentation was 11.4 and 10.2 years in ARVC and benign PVC, respectively. None of the ARVC patients fulfilled the diagnostic criteria of ARVC at initial presentation. At ARVC diagnosis, the treadmill exercise test and Holter monitoring showed provoked PVC during exercise and pleomorphic PVC in all ARVC cases, respectively. During the observation period, terminal activation duration (TAD) was prolonged in all ARVC patients. In addition, ΔTAD (5.5 [3-10] ms) were significantly longer than those with benign PVC (p < 0.001). A new notched S-wave in V1 appeared in four (67%) ARVC patients, who had myocardial abnormalities in the right ventricle, and in zero benign PVC. Our electrocardiographic findings, such as provoked PVC during exercise, pleomorphic PVC, prolonged TAD, and a new notched S-wave in V1 could contribute to the early detection of ARVC in school-aged children.

Subcutaneous and transvenous implantable cardioverter defibrillator in high-risk long-QT syndrome type 3 associated with Val411Met mutation in SCN5A.

Congenital long-QT syndrome type 3 (LQT3) with SCN5A-V411M mutation has been reported as a malignant case of LQT3 with highest risk for sudden cardiac death (SCD). Here, we present two cases of LQT3 with SCN5A-V411M who had been implanted with subcutaneous (S-) or transvenous (TV-) implantable cardioverter defibrillators (ICD). Case 1, a 2-year-old boy, although he had no symptoms, was diagnosed as having LQT3 (V411M-SCN5A) due to family history. The QTc interval was still longer than 500 ms during follow-up even under oral mexiletine. Case 2 (his aunt) diagnosed as LQT3 suffered from syncope caused by ventricular fibrillation at 35-years-old despite taking mexiletine. Furthermore, case 1's father and half-brother, both had the V411M mutation with LQT3, had suddenly died. Thus, case 1 was recommended S-ICD when he was 15-years-old for primary prevention of SCD but not necessary for pacing therapy, while, case 2 had been implanted TV-ICD for secondary prevention of SCD. They had no event after ICD implantation, however, case 2 had to have added an extra ICD-lead due to lead failure when she was 44-years-old. The S-ICD may be a potent therapeutic option for high-risk LQTS when patients are younger and do not need pacing therapy. .

Clinical Differences in Japanese Patients Between Brugada Syndrome and Arrhythmogenic Right Ventricular Cardiomyopathy With Long-Term Follow-Up.

Some Brugada syndrome (BrS) patients have been suspected of being in the initial state of arrhythmogenic right ventricular cardiomyopathy (ARVC). This study aimed to clarify the electrocardiographic (ECG) and clinical differences between BrS and ARVC in long-term follow-up (mean 11.9 ± 6.3 years). A total of 50 BrS and 65 ARVC patients with fatal ventricular tachyarrhythmia (VTA) were evaluated according to the revised Task Force Criteria for ARVC. Based on the current diagnostic criteria concerning electrocardiographic, repolarization abnormality was positive in 2.0% and 2.6% of BrS patients at baseline and follow-up, and depolarization abnormality was positive in 6.0% and 12.8% of BrS patients at baseline and follow-up, respectively. At baseline, none of the BrS patients were definitively diagnosed with ARVC. Considering patients' lives since birth, Kaplan-Meier analysis revealed that age at first VTA attack showed the same tendency between the groups (BrS: mean 42.2 ± 12.5 years old vs ARVC: mean 44.8 ± 13.7 years old, log-rank p = 0.123). Moreover, the incidence of VTA recurrence was similar between the groups during follow-up (log-rank p = 0.906). Incidence of sustained monomorphic ventricular tachycardia was significantly higher in ARVC than in BrS whereas the opposite was true for ventricular fibrillation (log-rank p <0.001 and p <0.001, respectively). None of the diagnoses of BrS patients were changed to ARVC during follow-up. During long-term follow-up, although age at first VTA attack and VTA recurrence were similar, BrS consistently exhibited features that differed from those of ARVC.

Multicenter Study of the Validity of Additional Freeze Cycles for Cryoballoon Ablation in Patients With Paroxysmal Atrial Fibrillation: The AD-Balloon Study.

BACKGROUND: Pulmonary vein isolation (PVI) is a cornerstone of catheter ablation in patients with paroxysmal atrial fibrillation, and balloon-based ablation has been recently performed worldwide. The second-generation cryoballoon (CB2) ablation has proven to be highly effective in achieving freedom from paroxysmal atrial fibrillation. However, there are some debatable questions, including the ideal number of freeze cycles. METHODS: The AD-Balloon study (Multicenter Study of the Validity of Additional Freeze Cycles for Cryoballoon Ablation) was designed as a prospective, multicenter, and randomized clinical trial for investigation of the optimal strategy of freeze cycles for the CB2 ablation. One hundred and ten consecutive patients (aged 64±11 years) were randomly assigned to 2 groups after achieving a PVI by the CB2 ablation: 3-minute freeze cycles were added to each pulmonary vein (AD group: n=55) or not (non-AD group: n=55). Delayed-enhancement magnetic resonance imaging was also performed 1 to 2 months after the PVI to assess the ablation lesions. RESULTS: The patient characteristics did not differ between the 2 groups. A complete PVI was achieved in all patients. The total number of freeze cycles and durations for all pulmonary veins were significantly shorter in the non-AD group than in the AD group (5.7±1.6 versus 9.1±1.6 cycles, P<0.0001, and 932±244 versus 1483±252 seconds, P<0.0001). The cumulative freedom from any atrial tachyarrhythmia at 1 year was 87.3% in the AD group and 89.1% in the non-AD group (log-rank test P=0.78). There was no significant difference in the frequency of gaps on the PVI lines in the delayed-enhancement magnetic resonance imaging (46% in the AD group versus 36% in the non-AD group; P=0.38). CONCLUSIONS: No benefit was found in the patients receiving additional 3-minute freeze cycles after the complete PVI with the CB2 ablation, suggesting that an insurance freeze after achieving a PVI with the CB2 may be unnecessary and time consuming.

Heart failure in patients with arrhythmogenic right ventricular cardiomyopathy: What are the risk factors?

BACKGROUND: We previously demonstrated that heart failure (HF) was one of the major causes of death in arrhythmogenic right ventricular cardiomyopathy (ARVC). The purpose of this study was to elucidate the clinical impact and risk factors of HF in patients with ARVC. METHODS AND RESULTS: We evaluated cardiac adverse outcomes including HF in 113 consecutive patients with ARVC (85 men, mean age: 44±15years). During a median follow-up of 10.0years (interquartile range: 5.2 to 15.7years), 29 patients (26%) were hospitalized for progressive HF. The patients with one or more episodes of HF hospitalization had about a 10-fold increased incidence of cardiac death (14/29 [48%] vs. 4/84 [4.7%], p<0.0001). Left ventricular ejection fraction (LVEF) and right ventricular ejection fraction (RVEF) were significantly lower in the patients with HF hospitalization compared to the patients without HF hospitalization (LVEF, 45±15 vs. 54±13%, p=0.001; RVEF, 26±10 vs. 33±11%, p=0.003, respectively). Regarding the ECG findings, the prevalence of first-degree atrioventricular block (AVB, PR interval >200ms) and epsilon waves were significantly higher in patients with HF hospitalization than those without HF hospitalization (first-degree AVB, 14/29 [48%] vs. 11/84 [13%], p<0.0001; epsilon waves, 10/29 [34%] vs. 12/84 [14%], p=0.02). In multivariate analysis, first-degree AVB at baseline was the strongest independent risk factor for HF hospitalization in patients with ARVC (hazard ratio 4.24, 95% confidence interval 1.79-10.47, p=0.0011). CONCLUSION: HF hospitalization has a significant relation with malignant clinical course in ARVC patients. First-degree AVB was an independent determinant for increased risk of HF hospitalization.

Risk factors associated with bleeding after multi antithrombotic therapy during implantation of cardiac implantable electronic devices.

Previous studies showed that continuous anticoagulation or single antiplatelet therapy during implantations of cardiac implantable electronic devices (CIED) was relatively safe. However, the safety of continuous multi antithrombotic therapy (AT) in patients undergoing CIED interventions has not been clearly defined. We sought to evaluate the safety of this therapy during CIED implantations. A total of 300 consecutive patients (mean 69 years old, 171 males) with CIED implantations were enrolled in this study. The patients were divided into 6 groups [No-AT, oral anticoagulant therapy (OAT), single antiplatelet therapy (SAPT), OAT and SAPT, dual antiplatelet therapy (DAPT), triple AT (TAT)], and the perioperative complications were evaluated. Clinically significant pocket hematomas (PH) were defined as PH needing surgical intervention, prolonged hospitalizations, interruption of AT, or blood product transfusions. There were 129, 89, 49, 20, 10, and 3 patients in No-AT, OAT, SAPT, OAT + SAPT, DAPT, and TAT groups, respectively. The occurrence of clinically significant PH and thromboembolism did not differ among 6 groups (p = 0.145 and p = 0.795, respectively). However, high HAS-BLED score and valvular heart disease (VHD) were associated with clinically significant PH (p = 0.014 and p = 0.015, respectively). Continuous multi AT may be tolerated, but patients with high HAS-BLED score or VHD would require a careful attention during CIED implantations.

Impact of renal function deterioration on adverse events during anticoagulation therapy using non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation.

Renal function is crucial for patients with non-valvular atrial fibrillation (NVAF) using non-vitamin K antagonist oral anticoagulants (NOAC). The incidence of renal function deterioration during anticoagulation therapy and its impact of adverse events are unknown. In 807 consecutive NVAF patients treated with NOAC and with estimated creatinine clearance (eCCr) ≥ 50 ml/min (mean age 68 ± 11 years, mean CHADS2 score = 1.8 ± 1.4, CHA2DS2-VASc score = 2.8 ± 1.8, HAS-BLED score = 1.7 ± 1.1), we analyzed the time course of renal function and clinical outcomes, and compared these with the data of general Japanese inhabitants from the Suita Study (n = 2140). Of the 807 patients, 751 (93 %) maintained eCCr ≥ 50 ml/min (group A) whereas the remaining 56 (7 %) fell into the eCCr < 50 ml/min (group B) during the 382 ± 288 days of follow-up. Multivariate logistic regression analysis revealed that advanced age, lower body weight, and congestive heart failure were independent predictors for renal function deterioration in patients with eCCr ≥ 50 ml/min at baseline. Major and/or minor bleedings were more commonly observed in group B than in group A (21 vs. 8 %; P = 0.0004). The CHADS2, CHA2DS2-VASc, and HAS-BLED scores were also significant predictors of renal function deterioration (P < 0.0001). The incidences of renal function deterioration were 1.4, 3.4, 10.5 and 11.7 % in patients with CHADS2 score of 0, 1, 2 and ≥3, respectively. As to CHA2DS2-VASc score, renal function deterioration occurred in 0, 1.7, 9.8 and 15.0 % with a score of 0, 1-2, 3-4 and ≥5, respectively. In the Suita Study of the general population, on the other hand, 122 of 2140 participants with eCCr ≥ 50 ml/min at baseline (5.7 %) fell into the eCCr < 50 ml/min during about 2 years. The incidence of renal function deterioration increased with the CHADS2 score in the general population as well as in our patients. Renal function deterioration was not uncommon and was associated with more frequent adverse events including major bleeding in NVAF patients with anticoagulation therapy. CHADS2, CHA2DS2-VASc, and HAS-BLED scores may be useful as an index of predicting renal function deterioration.

Frequency and location of yellow and disrupted coronary plaques in patients as detected by angioscopy.

BACKGROUND: Clarification of frequency and distribution of yellow plaques and disrupted plaques will increase understanding of acute coronary syndrome (ACS) onset. METHODS AND RESULTS: Consecutive patients with ACS (n=75) or without ACS (n=90) who received coronary angioscopic examination were studied. Distance from ostium to yellow plaques, diameter stenosis and vessel wall irregularity at the site of yellow plaques, their yellow color grade (grade 13) and if they had thrombus were analyzed. Yellow plaques with thrombus were regarded as disrupted. Average number of yellow plaques, grade-3 yellow plaques and disrupted yellow plaques per vessel was 4.0, 0.87 and 1.0, respectively. The number of grade-3 yellow plaques and disrupted yellow plaques per vessel were larger in ACS than in non-ACS patients. Yellow plaques were distributed diffusely in the right coronary artery but more in mid-segments in the left anterior descending coronary artery and left circumflex coronary artery. Diameter stenosis in the non-culprit segments was severer at disrupted than at non-disrupted yellow plaques. Vessel wall irregularity was detected more frequently at disrupted than at non-disrupted yellow plaques. CONCLUSIONS: Approximately 4 yellow plaques, 1 grade-3 yellow plaque and 1 disrupted yellow plaque were detected per vessel. About 25% of detected yellow plaques were disrupted. More grade-3 yellow plaques and disrupted yellow plaques were detected in ACS than in non-ACS patients. These findings strengthen the association between yellow plaques detected by angioscopy and ACS events.

Acute coronary syndrome: insight from angioscopy.

Although the concept of vulnerable plaque has become common, it is still impossible to predict effectively the onset of acute coronary syndrome (ACS). Thin-cap fibroatheroma (TCFA) is regarded as vulnerable from pathological studies and various diagnostic tools have tried to detect TCFA clinically but failed to predict ACS. Because there are so many silent plaque ruptures detected, it is supposed that many vulnerable plaques might have ruptured but not caused ACS. Some factor(s) other than the rupture of vulnerable plaque is required for the onset of ACS. "Vulnerable blood" may be one of them. The thrombogenic potential of blood (ie, vulnerable blood) may play an important and determinant role in the onset of ACS, the process of which will be discussed from the angioscopic point of view.