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In this paper, we propose a novel method of voltage-map reconstruction using the Advisor™ HD Grid (Abbott Laboratories, Abbott Park, IL) to elucidate the 3-dimensional anatomical and electrophysiological substrates. High-density mapping makes it possible to clarify the activation pattern during ventricular tachycardia and a substrate during sinus rhythm on the endocardial surface. To enhance the mapping resolution, the use of catheters with smaller electrodes and closer interelectrode spacing can be used.1 In contrast, the unipolar or bipolar with wider interelectrode can be a clue for estimating the substrate in 3 dimensions because of far-field potential sensing.2,3 In this case report, we describe the successful identification of a heterogeneous scar within a dense scar with the use of a reconstructed voltage map with wider interelectrode spacing and suggest the involvement of the heterogeneous scar in the mechanism of functional block.

Background Recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI) is associated with left atrial (LA) remodeling; however, its association with right atrial (RA) remodeling remains unclear. Objective This study aimed to identify whether RA structural remodeling could predict recurrence of AF after PVI. Methods This study prospectively analyzed 245 patients with AF who had undergone PVI. RA and LA volumes were determined by contrast‐enhanced computed tomography. Atrial structural remodeling was defined as an atrial volume of ≥110 mL according to previous reports and receiver operating characteristic curve analysis. Results After excluding 32 patients, 213 patients were analyzed. During a follow‐up period of 12 months, 41 patients (19%) demonstrated atrial arrhythmia recurrence after PVI. With the Cox proportional‐hazards model, RA structural remodeling was the only predictor of arrhythmia recurrence (hazard ratio, 1.012; 95% confidence interval 1.003‐1.021; P = .009). Kaplan–Meier analysis showed that arrhythmia recurrence was more frequent in the RA structural remodeling group compared with the group without RA remodeling (log‐rank, P, A greater incidence of recurrence was observed in the presence of RA structural remodeling regardless of the AF type. RA structural remodeling was a useful predictor of clinical outcomes after PVI.

Aim: Arterial stiffness results in elevated left ventricular filling pressure and can promote atrial remodeling due to chronic pressure overload. However, the impact of arterial stiffness on the process of atrial remodeling in association with atrial fibrillation (AF) has not been fully evaluated. Methods: We enrolled 237 consecutive patients diagnosed with AF who had undergone ablation; data from 213 patients were analyzed. Cardio-ankle vascular index (CAVI) was used as a marker of arterial stiffness. The left atrial (LA) and right atrial (RA) volumes were determined by computed tomography imaging; atrial conduction and voltage amplitude were evaluated using a three-dimensional electromapping system used to guide the ablation procedure. Result: In univariate analysis, CAVI significantly correlated with atrial structural and electrical remodeling (LA volume index, r =0.297, P =0.001; RA volume index, r =0.252, P =0.004; LA conduction velocity, r =0.254, P = 0.003; LA mean voltage, r =−0.343, P =0.001, RA mean voltage; r =−0.245, P =0.015). Multivariate regression analysis revealed that CAVI and plasma levels of N-terminal B-type natriuretic peptide were independent determinants of LA and RA remodeling, respectively. On the other hand, age and LA conduction velocity were independent variables with respect to CAVI. Age-adjusted CAVI was highest in long-standing persistent AF when compared with measures of persistent or paroxysmal AF. Conclusion: CAVI was closely associated with biatrial remodeling in patients diagnosed with AF. These results suggest that arterial stiffness may play a significant role with respect to disease progression.

Percutaneous mitral annuloplasty is widely used for the treatment of functional mitral regurgitation. There are limited imaging options to guide MitraClip procedure (Abbott Vascular, Santa Clara, CA, USA) in patients intolerant to transesophageal echocardiography. We describe a case using a 3-dimensional electro anatomical mapping system to facilitate the successful MitraClip procedure. LEARNING OBJECTIVES: There are situations in which percutaneous mitral valve repair (MitraClip) for mitral regurgitation is difficult to perform under transesophageal echocardiography due to esophageal disease. 3D mapping system may be useful when performing MitraClip under transthoracic echocardiography.

Atrial remodeling associated with atrial fibrillation (AF) and sleep apnea is well known. Although sleep apnea is known to be associated with left atrial (LA) remodeling, its association with right atrial (RA) remodeling remains unclear. The study aimed to investigate the effect of sleep apnea on RA remodeling.We enrolled 141 AF patients who had undergone ablation. Sleep study results were evaluated using a portable sleep apnea test device. RA and LA volumes were determined by computed tomography (CT), and atrial structural remodeling was defined as atrial volume on CT≥110mL according to previous reports. The atrial substrate was evaluated by three-dimensional electroanatomical mapping.After excluding 30 patients who received more than one catheter ablation or who could not receive enhanced CT, 111 patients were finally analyzed. The patients were classified into four groups according to the presence of RA and/or LA enlargement. Significant differences in AF type, N-terminal pro B-type natriuretic peptide (NT-proBNP) levels, and apnea-hypopnea index (AHI) were observed among the four groups. In univariate analysis, AHI values correlated with NT-proBNP levels (r=0.293, p=0.002), left ventricular ejection fraction (r=-0.198, p=0.044), LA volume (r=0.370, p0.001), and RA volume (r=0.465, p0.001). Multiple regression analysis showed that AHI was an independent predictor of increased RA volume, and LA was excluded as a multiple risk factor in AHI. AF type-adjusted AHI levels correlated with RA volume, and RA remodeling correlated with the percentage of LA low-voltage area.Sleep apnea was strongly associated with RA structural remodeling regardless of paroxysmal and non-paroxysmal AF, and this relationship was more prominent than the effect of LA. Our results suggest that the association between sleep apnea and RA dilatation should be given attention.

Background Radiofrequency catheter ablation (RFCA) is an effective therapy for atrial fibrillation (AF). However, it the problem of AF recurrence remains. This study investigates whether a deep convolutional neural network (CNN) can accurately predict AF recurrence in patients with AF who underwent RFCA, and compares CNN with conventional statistical analysis.Methods and Results:Three-hundred and ten patients with AF after RFCA treatment, including 94 patients with AF recurrence, were enrolled. Nine variables are identified as candidate predictors by univariate Cox proportional hazards regression (CPH). A CNNSurv model for AF recurrence prediction was proposed. The model's discrimination ability is validated by a 10-fold cross validation method and measured by C-index. After back elimination, 4 predictors are used for model development, they are N-terminal pro-BNP (NT-proBNP), paroxysmal AF (PAF), left atrial appendage volume (LAAV) and left atrial volume (LAV). The average testing C-index is 0.76 (0.72-0.79). The corresponding calibration plot appears to fit well to a diagonal, and the P value of the Hosmer-Lemeshow test also indicates the proposed model has good calibration ability. The proposed model has superior performance compared with the DeepSurv and multivariate CPH. The result of risk stratification indicates that patients with non-PAF, higher NT-proBNP, larger LAAV and LAV would have higher risks of AF recurrence. Conclusions The proposed CNNSurv model has better performance than conventional statistical analysis, which may provide valuable guidance for clinical practice.

COVID-19 vaccinations have been deployed to mitigate the effects of the COVID-19 pandemic. However, vaccine-associated myocarditis has been reported. Two typical cases in terms of young age and after the second vaccination were admitted to our hospital with symptoms of worsening chest pain, ST elevation on the electrocardiogram (ECG) and creatine kinase elevation. Emergency coronary angiography revealed no coronary arteries, and an endomyocardial biopsy showed no remarkable findings. Their symptoms were resolved within a few days of sufficient rest and non-steroidal anti-inflammatory drug. The ECG of Patient 1 showed typical change; therefore, the diagnosis of myocarditis was easy. However, the ECG of Patient 2 did not show typical change for myocarditis, and there was no abnormality in the wall motion on echocardiography. Cardiac magnetic resonance imaging (MRI), strain analysis by speckle-tracking echocardiography and serial ECG were useful for the diagnosis of myocarditis. This work shows that conducting early examinations with multimodality imaging and sufficient rest are needed to prevent the worsening of vaccine-associated myocarditis. Although the benefits of the vaccines outweigh the risks, we should be aware that myocarditis can occur after COVID-19 mRNA vaccination regardless of race, especially in young males.

Percutaneous left atrial appendage (LAA) closure with the Watchman device (Boston Scientific, Marlborough, Massachusetts) is effective in high-risk patients in whom warfarin is contraindicated; it is increasingly being used as an alternative to warfarin for long-term prevention of stroke [(1)][1].

A healthy 73-year-old woman unpredictably developed Takotsubo cardiomyopathy syndrome (TTS) during Holter-electrocardiogram (ECG) recording. Thus, the complete chronological ECG data on the actual onset day of TTS were obtained. Many heart rate variability (HRV) parameters, including the low-frequency components (LF) and the high-frequency components (HF), on the actual onset day and in the healing phase were calculated. The interesting facts on the actual onset day were that the suppression of both LF and HF appeared earlier than the changes of the ECG waveform; and the LF/HF ratio remained within the normal range, although both LF and HF were markedly suppressed. The abnormality on the actual onset day was clear compared with the healing phase. It is noteworthy to obtain the chronological ECG data on the actual onset day of TTS in a healthy patient. The present data are unique in terms of being analyzed on the actual onset day. Although the HRV parameters, including LF and HF, were obviously abnormal, there is some skepticism about using HRV parameters as indices of cardiac autonomic activity. In the present case, it was concluded that the abnormality of cardiac autonomic activity contributed to the onset of TTS. These data are unlikely to ever be replicated, and we hope that this report helps elucidate the TTS mechanism.

Background Atrial fibrillation (AF) induces functional mitral regurgitation (FMR) and tricuspid regurgitation (FTR) during atrial remodeling. FMR and FTR are associated with AF prognosis, but the effects for AF recurrence after ablation have not been determined conclusively. Methods Two hundred thirty nine patients who underwent AF ablation were enrolled. Forty five patients were excluded. In total, 194 patients were analyzed. FMR and FTR were assessed by echocardiography. The left atrial volume index (LAVI) was evaluated by contrast-enhanced computed tomography. Results Significant FMR and moderate FTR were observed in 15 (7.7%) and in 25 (12.9%) patients, respectively. The severity of tricuspid regurgitation (TR) significant correlated with age, NT-proBNP, and LAVI. During a 13.4 month follow-up period of, 39 patients (20.1%) demonstrated AF recurrence. In the Cox proportional-hazards model, E/e’, FTR, and LAVI, were termed as predictor factors of AF recurrence (E/e’. hazard ratio [HR] = 1.117; P = 0.019, significant FTR. HR = 4.679; P = 0.041, LAVI. HR = 1.057; P = 0.003). Kaplan–Meier analysis showed that AF recurrence was more frequent in FTR compared with the nonsignificant FTR cases (log-rank, P = 0.001). Although survival analysis showed no difference with or without FMR, the presence of FMR and FTR was strongly associated with high-AF recurrence (log-rank, P = 0.004). Conclusions AF recurrence was associated with E/e’, LAVI, and extensive FTR. Specifically, the combination of FTR and FMR markedly worsens the AF prognosis.

There is increased interest in creating high-power short duration (HPSD) ablation lesions in the field of atrial fibrillation (AF) radiofrequency ablation (RFA). We evaluated the lesion characteristics and collateral damage using two separate RFA protocols setting (HPSD: 50 W and 7 s vs control: 25 W and 30 s) in vitro model. Sixteen freshly killed porcine hearts were obtained, and the atrium and ventricle slabs were harvested for ablation. The each slabs were placed in a tissue bath with circulating 0.9% NaCl at maintained temperature 37 °C. RFA was performed with 4 mm tip irrigated force sensing catheter. All lesions were ablated under recording the electrical parameters using with Ensite Navx system (St. Jude Medical, St. Paul, Minnesota). After RFA, lesion characteristics were assessed for each lesion. Thirty-five lesions were made for each ablation protocol (total 70 lesions for analysis). Ablation parameters were similar between two groups (HPSD vs control; impedance drop (Ω): 34.2 ± 13.1 vs 36.1 ± 8.65 P = 0.49, contact force (g): 13.9 ± 4.37 vs 14.6 ± 5.09, P = 0.51, lesion size index: 4.8 ± 0.52 vs 4.73 ± 0.59, P = 0.62). Although the lesion volume was similar, the HPSD ablation creates wider but more shallower lesions compared to control group (HPSD vs control; lesion volume: 29.6 ± 18.1 mm3 vs 35.5 ± 17.1 mm3 P = 0.16, lesion diameter: 4.98 ± 0.91 mm vs 4.45 ± 0.74 mm P = 0.0095, lesion depth: 2.2 ± 0.76 mm vs 2.8 ± 1.56 mm P = 0.046). Of these, 38 lesions were assessed for adjacent tissue damage and adjacent tissue damages were more frequent seen in control group (HPSD vs control; 1/19 (5.26%) vs 6/19 (31.5%), P = 0.036). Effective lesions were made with HPSD, thereby reducing RFA procedure time. Although the lesion volume was similar between two groups, collateral damage was less seen in HPSD group attributed by lesion characteristics.

A 78-year-old male with a history of a cardiac embolic stroke due to persistent AF and cerebral bleeding (CHADS2 score 4, HAS-BLED score 4) was referred to our hospital to implant a left atrial appendage (LAA) closure (LAAC) device. A trans esophageal echocardiography was performed and a high echoic lesion that was difficult to differentiate the spontaneous echo contrast or thrombus was found in the LAA cavity. After isoproterenol infusion, a high echoic lesion disappeared and we confirmed that it was not an LAA thrombus. Successful LAAC device implantation was performed without any thromboembolic events.

Background Because device-related thrombus (DRT) portends a poor prognosis after left atrial appendage closure with the Watchman device, surveillance transesophageal echocardiography (TEE) is recommended at 45 days and 1 year. However, oral anticoagulants are just discontinued at 45 days, rendering this early TEE unlikely to detect DRT. Indeed, DRT is most likely to occur after instituting aspirin monotherapy. Objective The purpose of this study was to evaluate the alternative strategy of first TEE imaging (or computed tomography) at 4 months post–Watchman implantation. Methods After Food and Drug Administration approval, consecutive patients undergoing Watchman implantation at 2 centers received TEE or CT at 4 months and 1 year, along with a truncated drug regimen: 6 weeks of an oral anticoagulant (or clopidogrel in a subset) plus aspirin, then 6 weeks of dual antiplatelet therapy, and finally aspirin monotherapy. Results Of the 530-patient cohort (mean age 78.7±7.9 years; 65.5% (n = 347) male; CHA2DS2-VASc score 4.5±1.4), 465 patients (87.7%) received 4-month imaging: 83.0% (440 of 530) TEE and 4.7% (25 of 530) computed tomography. Over a median follow-up of 12 months, 16 ischemic strokes (ISs), 8 transient ischemic attacks, and 1 systemic embolization occurred. Importantly, no IS occurred between 45 days and 4 months; the sole transient ischemic attack in this period (at ∼2 months) occurred 1 week after transcatheter aortic valve replacement. DRT was detected in 2.4% (11 of 465) at 4 months and 0.9% (2 of 214) at 1 year. No IS, but 1 leg embolization, was observed after DRT detection. Conclusion Delaying the first imaging post-Watchman implantation to 4 months was associated with no IS between 45 days and 4 months, the “vulnerable” period of this follow-up strategy.

Objectives: This study sought to compare a novel lesion dimension estimation approach to actual measurements of lesion dimensions on necropsy in porcine atria and ventricles.Background: An ...

Background: Pulsed field ablation (PFA) is a uniquely tissue-selective, nonthermal cardiac ablation modality. Delivery parameters such as the electrical waveform composition and device design are critical to PFA’s efficacy and safety, particularly tissue specificity. In a series of preclinical studies, we sought to examine the electrophysiological and histological effects of PFA and compare the safety and feasibility of durable pulmonary vein and superior vena cava (SVC) isolation between radiofrequency ablation and PFA waveforms. Methods: A femoral venous approach was used to gain right and left atrial access under general anesthesia in healthy swine. Baseline potentials in right superior pulmonary and inferior common vein and in SVC were assessed. Bipolar PFA was performed with monophasic (PFA Mono ) and biphasic (PFA Bi ) waveforms in 7 and 7 swine sequentially and irrigated radiofrequency ablation in 3 swine. Vein potentials were then assessed acutely, and at ≈10 weeks; histology was obtained. Results: All targeted veins (n=46) were successfully isolated on the first attempt in all cohorts. The PFA Bi waveform induced significantly less skeletal muscle engagement. Pulmonary vein isolation durability was assessed in 28 veins: including the SVC, durability was significantly higher in the PFA Bi group (18/18 PFA Bi , 10/18 PFA Mono , 3/6 radiofrequency, P =0.002). Transmurality rates were similar across groups with evidence of nerve damage only with radiofrequency. Pulmonary vein narrowing was noted only in the radiofrequency cohort. The phrenic nerve was spared in all cohorts but at the expense of incomplete SVC encirclement with radiofrequency. Conclusions: In this chronic porcine study, PFA-based pulmonary vein and SVC isolation were safe and efficacious with demonstrable sparing of nerves and venous tissue. This preclinical study provided the scientific basis for the first-in-human endocardial PFA studies.

Objective To evaluate the outcomes of patients with concomitant Brugada syndrome and coronary artery vasospasm. Methods Patients diagnosed with Brugada syndrome with an implantable cardiac defibrillator were retrospectively investigated, and the coexistence of vasospasm was evaluated. The clinical features and outcomes were evaluated, especially in patients with coexistent vasospasm. A provocation test using acetylcholine was performed in patients confirmed to have no organic stenosis on percutaneous coronary angiography to confirm the presence of vasospasm. Implantable cardiac defibrillator shock status was checked every three months. Statistical comparisons of the groups with and without vasospasm were performed. A univariate analysis was also performed, and the odds ratio for the risk of implantable cardiac defibrillator shock was calculated. Patients Thirty-five patients with Brugada syndrome, of whom six had coexistent vasospasm. Results There were no significant differences in the laboratory data, echocardiogram findings, disease, or the history of taking any drugs between patients with and without vasospasm. There were significant differences in the clinical features of Brugada syndrome, i.e. cardiac events such as resuscitation from ventricular fibrillation or appropriate implantable cardiac defibrillator shock. Four patients with vasospasm had cardiac events such as resuscitation from ventricular fibrillation and/or appropriate defibrillator shock; three of them had no cardiac events with calcium channel blocker therapy to prevent vasospasm. The coexistence of vasospasm was a potential risk factor for an appropriate implantable cardiac defibrillator shock (odds ratio: 13.5, confidence interval: 1.572-115.940, p value: 0.035) on a univariate analysis. Conclusion Coronary artery vasospasm could be a risk factor for cardiac events in patients with Brugada syndrome.

A 70-years-old male with a history of hypertension and drug resistant paroxysmal atrial fibrillation (AF) presented to our hospital for catheter ablation to his symptomatic AF. He had no prior surgical or percutaneous procedure to close or exclude the left atrial appendage (LAA). A transesophageal echocardiography (TEE) was performed to rule out intra-cardiac thrombus prior to the ablation procedure. Although the TEE imaging at multiple acquisition angles was obtained, the LAA could not be visualized and an absence of the LAA was suspected. An absence of the LAA was confirmed using cardiac computed tomography (CT), which included 3D reconstruction. Additionally, the LAA was not visualized with left atrium (LA) angiography. During the ablation procedure, 3D voltage mapping in LA was created and no low voltage area or abnormal potential was recorded around the usual root location of the LAA. Successful electrical pulmonary vein isolation was achieved with no major complications. After six months of follow-up, the patient remained in sinus rhythm without any antiarrhythmic drugs and showed no related clinical symptoms. He stopped his anticoagulation therapy due to lack of evidence of AF recurrence and an absence of LAA. Multimodality imaging allowed us to identify the congenital absence of LAA.

Defibrillation threshold (DFT) testing during implantable cardioverter defibrillator (ICD) implantations is considered necessary for appropriate shock therapy and to measure the safety margin. However, the relationship between the DFT with modern era devices and the clinical outcome, including the total mortality is limited, which may lead to DFT testing itself being questioned. This study aimed to evaluate the relationship between the DFT and clinical outcome in ICD recipients.We enrolled 81 consecutive patients (66 males, aged 64.6 ± 13.8 years) who received an ICD implantation and underwent DFT testing. The DFT was measured with a step-by-step method in the patients upon implant. Further, we evaluated the relationship between the DFT and the clinical outcome, which included major cardiac adverse events and any cause of death.The mean DFT was 11.6 ± 9.24J in total. In 40 patients (49.4%), VF was terminated by a low output (5J), whereas 11 patients (13.6%) had a high DFT. The rates of atrial fibrillation were significantly higher in the high DFT group (63.6% versus 24.2%, P = 0.007). During the observational period (median 432 days; range from 151 days to 1146 days), the incidence of clinical events occurred in 22 patients (27.2%) in total. In a multivariate analysis, a high DFT was the only predictive factor for the incidence of the clinical outcome (OR 4.54, 95% CI 1.03-21.9, P = 0.045).

The recurrence of gastric cancer is rarely associated with cardiac tamponade induced by carcinomatous pericarditis. We encountered a patient in whom cancer recurred as carcinomatous pericarditis 9 years after surgery for advanced gastric cancer. Furthermore, pericardial effusion caused marked subcutaneous edema in her trunk and lower limbs after percutaneous pericardial drainage was applied to treat cardiac tamponade. A 49-year-old woman presented with lower limb edema and exertional dyspnea 9 years after distal gastrectomy for advanced gastric cancer. Chest computed tomography and ultrasonography showed bilateral pleural effusion and pericardial effusion. Pericardial drainage and thoracocentesis were performed, and her symptoms of respiratory distress remitted. Class V adenocarcinoma was detected on cytology from both effusions, and was diagnosed as the recurrence of gastric cancer. After systemic chemotherapy, she was admitted for the aggravation of dyspnea because of recurrent retention of pericardial effusion. Pericardiocentesis was repeated. The pericardial effusion became subcutaneously retained in the trunk below the puncture site over the lower limbs via the drainage route. Edema in the trunk below the abdomen and lower limbs gradually aggravated over time. The skin extended and became sclerotic because of severe edema, liquid leaked from abdominal skin injuries, and the condition became similar to skin lymphorrhea in lymphedema. Neoplastic cardiac tamponade due to gastric cancer has an extremely low incidence and a poor prognosis. We encountered a patient in whom pericardial effusion caused subcutaneous edema in the trunk and lower limbs after percutaneous pericardial drainage was applied to treat carcinomatous pericarditis associated with gastric cancer.

Background— Although percutaneous left ventricular assist devices (pLVADs) facilitate mapping and ablation of hemodynamically unstable ventricular tachycardia (VT), there is limited data whether clinical outcomes are improved. We sought to retrospectively compare the outcomes of patients undergoing scar-related VT ablation with and without pLVAD support. Methods and Results— The study population comprised 194 patients (109 pLVAD and 85 non-pLVAD). The pLVAD group more often had dilated cardiomyopathy (33% versus 13%; P =0.001), New York Heart Association heart failure class ≥III (51% versus 25%; P P P =0.04). Procedure times (422±112 versus 330±92 minutes; P P =0.02), and length of subsequent hospitalization (median 6 versus 4 days; P =0.001) were all higher in the pLVAD group. During median follow-up of 215 days, the primary end point (recurrent VT, heart transplantation, or death) occurred in 36% of the pLVAD versus 26% of the non-pLVAD groups ( P =0.14). After propensity matching for differences between groups, no differences were seen between groups for both acute procedural outcomes and the primary end point. Conclusions— In this large single-center scar-related VT ablation experience, despite the worse clinical status of the patients selected for pLVAD support, clinical outcomes were better than expected and were similar to healthier patients not receiving hemodynamic support. Patients with dilated cardiomyopathy presenting with electrical storm, advanced heart failure, and severe left ventricular dysfunction most frequently received hemodynamic support during VT ablation.

This study sought to compare a novel lesion dimension estimation approach to actual measurements of lesion dimensions on necropsy in porcine atria and ventricles.An irrigated-tip, force-sensing radiofrequency catheter with 6 temperature (tip-tissue interface) sensors allows for assessment of lesion dimensions based on estimated tissue temperature. Lesion dimension assessment has not been attempted previously in atrial tissue.Ablations were performed using this catheter in all chambers. Irrigated radiofrequency was delivered using 20 to 50 W for durations that ranged from 15 to 90 s with contact force ranging from 5 to 45 g to replicate a wide spectrum of clinical conditions. All swine were then sacrificed and lesions were identified and photographed. Three independent observers made offline measurements, which were then averaged to obtain lesion width and depth for comparison with estimated dimensions based on interface tissue temperature.In 9 swine, 54 atrial and 61 ventricular lesions were assessed. In the atria, the mean difference between the measured and estimated depth and width was 0.9 ± 0.74 mm and 1.2 ± 0.9 mm, respectively. Eighty percent of all lesions had a difference of ≤1.7 mm for depth and ≤1.74 mm for width. In the ventricle, the mean difference between the measured and estimated depth and width was 0.75 ± 0.6 mm and 1.66 ± 1.1 mm, respectively. Eighty percent of all lesions had a difference of ≤1.1 mm ventricular depth and ≤2.6 mm for width.Estimation of lesion dimensions can be achieved with clinically relevant accuracy using unique temperature signatures. These data have important implications for understanding the adequacy of lesion overlap and assessment of transmurality.

Point-by-point radiofrequency catheter ablation for scar-related ventricular tachycardia (VT) is frequently laborious and comes with long procedural times.1–3 This is driven, in part, by the time required to traverse the often large substrate with several point-by-point radiofrequency applications. The additional effort needed to optimize each radiofrequency application with regard to contact force, overlap, and duration can also be demanding. Although procedural success still requires operators to locate critical isthmuses and make deep lesions, a reduction in overall radiofrequency and procedure times would be widely welcomed both by operators and by our increasingly sick patients. The world of pulmonary vein isolation on the other hand, having been besieged by long radiofrequency times and reconnection related to gaps, has quickly embraced 1 shot approaches to ablation given their speed and efficacy.4,5 See Article by Nazer et al In this issue, Nazer et al6 make a case for bringing a similar approach to the world of scar VT ablation. This is particularly relevant given the increasing popularity of strategies, such as scar homogenization, core isolation, etc., where multiple radiofrequency lesions are …

Background Pacemaker generators are routinely implanted in the anterior chest. However, where to place the generator may need to be considered from the mental, functional, and cosmetic standpoints. Methods In this study, we performed the left axillary pacemaker generator implantation with a direct puncture of the left axillary vein in 40 consecutive patients, and evaluated the late safety and efficacy of this implantation. Complications, changes in the lead sensing, pacing threshold, and impedance were used as safety indexes for a mean follow-up of 3.4 years. In addition, the efficacy was also evaluated by comparing their questionnaire survey results to 119 patients in a control group of anterior chest implantation. Results Lead dislodgements were observed in two patients of the experiment group. There were no migrations of generators from the implantation site or abnormal variations in the pacing threshold, lead sensing, or impedance. In the left anterior chest and left axillary groups, 85% and 10% of the patients were worried about an external impact, 80% and 25% were worried about electromagnetic interference, and 68% and 0% answered that the pacemaker implantation site was noticeable, respectively. Apparently, more patients had a sense of security and cosmetic satisfaction with the left axillary implantation. Conclusion The left axillary generator implantations may reduce the mental burden and cause no safety concerns, and may be performed if functional or cosmetic outcomes are required.

Background In the stroke prevention trials of left atrial appendage closure with the Watchman device (Boston Scientific), a postimplantation antithrombotic regimen of 6 weeks of warfarin was used. Objective Given the clinical complexity of warfarin use, the purpose of this study was to study the relative feasibility and safety of using non-warfarin oral anticoagulants (NOACs) instead of warfarin during the peri- and initial postimplantation periods after Watchman implantation. Methods This was a retrospective multicenter study of consecutive patients undergoing Watchman implantation and receiving peri- and postprocedural NOACs or warfarin. Transesophageal echocardiography or chest computed tomography was performed between 6 weeks and 4 months postimplant to assess for device-related thrombosis. Bleeding and thromboembolic events also were evaluated at the time of follow-up. Results In 5 centers, 214 patients received NOACs (46% apixaban, 46% rivaroxaban, 7% dabigatran, and 1% edoxaban) in either an uninterrupted (82%) or a single-held-dose (16%) fashion. Compared to a control group receiving uninterrupted warfarin (n = 212), the rates of periprocedural complications, including bleeding events, were similar (2.8% vs 2.4%, P = 1). At follow-up, the rates of device-related thrombosis (0.9% vs 0.5%, P = 1), composite of thromboembolism or device-related thrombosis (1.4% vs 0.9%, P = 1), and postprocedure bleeding events (0.5% vs 0.9%, P = .6) also were comparable between the NOAC and warfarin groups. Conclusion NOACs proved to be a feasible peri- and postprocedural alternative regimen to warfarin for preventing device-related thrombosis and thromboembolic complications expected early after appendage closure with the Watchman device, without increasing the risk of bleeding.

Objective Electrical cardioversion (EC) is associated with an increased risk of thrombotic events in patients with non-valvular atrial fibrillation (NVAF). Patients who experience AF for a period of >48 hours therefore require adequate anticoagulation therapy for at least 3 weeks before and 4 weeks after EC. While the guidelines address the management of vitamin K antagonists (VKAs), there are limited data on the use of novel oral anticoagulants (NOAC). One NOAC, rivaroxaban, has a rapid onset of action and might therefore shorten the time for which anti-coagulant treatment is required before a patient undergoes EC. Methods This study included 91 patients with NVAF of >48 hours in duration or in whom the time of onset was unknown who were undergoing EC after pretreatment with rivaroxaban. All of the patients were pretreated with rivaroxaban for at least 2 hours before EC and the same dose of rivaroxaban was prescribed for 4 weeks after EC. The primary endpoint was a successful EC without any thrombotic events or bleeding complications within 30 days after EC. The secondary endpoint was the time to EC. Results The mean age was 63±12 years and 70 of the 91 patients were male. The CHADS2 and HAS-BLED scores were 1.0±1.0 and 1.7±1.3, respectively. Although there were no thrombotic events, minor bleeding (gingival hemorrhage) occurred 20 days after the initiation of rivaroxaban treatment in one patient. The average time to EC was 11.9±11.1 days. Conclusion Rivaroxaban is safe and effective drug for NVAF patients who are scheduled for an EC. Furthermore, since VKAs take a substantial amount of time to establish adequate anticoagulation, pretreatment with rivaroxaban could shorten the time to the EC.

BACKGROUND To reduce myocardial damage caused by implantable cardioverter defibrillator (ICD) shock, the left axilla was studied as an alternative pulse generator implantation site, and compared with the traditional implantation site, the left anterior chest. METHODS AND RESULTS Computer simulation was used to study the defibrillation conduction pattern and estimate the simulated defibrillation threshold (DFT) and myocardial damage when pulse generators were placed in the left axilla and left anterior chest, respectively; pulse generators were also newly implanted in the left axilla (n=30) and anterior chest (n=40) to compare the corresponding DFT. On simulation, when ICD generators were implanted in the left axilla, compared with the left anterior chest, the whole heart may be defibrillated with a lower defibrillation energy (left axilla 6.4 J vs. left anterior chest 12.0 J) and thus the proportion of cardiac myocardial damage may be reduced (2.1 vs. 4.2%). Clinically, ventricular fibrillation was successfully terminated with a defibrillation output ≤5 J in 86.7% (26/30) of the left axillary group, and in 27.5% (11/40) of the left anterior group (P

Background: Radiofrequency catheter ablation (RF) has recently become widely available for the treatment of atrial fibrillation (AF) and has broadened treatment options while confusing the selection of medication therapy or RF. Methods and Results: Two drugs for the maintenance of sinus rhythm (Ry) and 2 drugs for control of the pulse rate (Ra) were selected and the costs of medication therapy were calculated. RF procedures were grouped into 2 groups each for persistent or paroxysmal AF (RF) and for chronic AF (RFChr), according to the cost of the devices used. The calculated cost of medication therapy was 5,270-23,560 yen per month. The calculated cost of RF procedures was 1,063,200-2,029,640 yen. The costs of RF corresponded to those of Ry for 3.8-14.3 years. The costs of RFChr corresponded to those of Ra for 16.6-63.9 years. The treatment of complications ranged from 360,000 to 1,241,500 yen. Conclusions: From the aspect of medical costs and complications, RF should be considered for the treatment of patients with AF detected early or early-stage AF, whereas treatment for its complications should be given priority in patients with chronic AF associated with reduced cardiac function. (Circ J 2011; 75: 1860-1866)

Background Subcutaneous implantable cardiac defibrillator (S-ICD) systems have a lower invasiveness than traditional ICD systems, and expand the indications of ICD implantations. The S-ICD standard defibrillation shock output energy, however, is approximately 4 times that of the traditional ICD system. This raises concern about the efficacy of the defibrillation and myocardial injury. In this study, we investigated the defibrillation efficacy and myocardial injury with S-ICD systems based on computer simulations. Methods and results First, computer simulations were performed based on the S-ICD system configurations proposed in a previous study. Furthermore, simulations were performed by placing the lead at the left or right parasternal margin and the pulse generator in the superior and inferior positions (0-10 cm) of the recommended site. The simulated defibrillation threshold (DFT) for the 4 S-ICD system configurations were 30.1, 41.6, 40.6, and 32.8 J, which were generally similar to the corresponding clinical results of 33.5, 40.4, 40.1, and 34.3 J. Conclusions The simulated DFT were generally similar to their clinical counterparts. In the simulation, the S-ICD system had a higher DFT but relatively less severe myocardial injury compared with the traditional ICD system. Further, the lead at the right parasternal margin may correspond to a lower DFT and cause less myocardial injury.

A control system of variable geometry mixed compression axisymmetric intake is experimentally studied at ONERA S3 supersonic wind tunnel. The acceleration/deceleration of the space plane is simulated by changing the free stream velocity. The intake is successfully controlled with 90% of the maximum total pressure recovery and mass capture ratio. In this experiment, two subjects about control of axisymmetric intake are also cleared. First, the effect of the trapping of the terminal shock by bleed holes causes the disturbances in the terminal shock control system. Second, a special compression form change operation is necessary when the intake compression form change from all external compression to mixed compression.

11Abstract publication information: The abstracts of this study were presented at the conferences below:[1] Mahito N, Naoshi I, Yoshinari E, et al. Evaluation of defibrillation safety with the increased number of sensing to reduce shocks for ventricular fibrillation in Japanese ICD patients. 5th APHRS; 2012.[2] Mahito N, Xin Z, Naoshi I, et al. Evaluation of Defibrillation Safety with the increased Number of Sensing to Reduce Shocks for Ventricular Tachyarrhythmia in Japanese ICD Patients – SANKS STUDY. Venue of the 8th Tawara-Aschoff-Meeting; 2012.BackgroundThe need for ways to minimize the number of implantable cardioverter-defibrillator (ICD) shocks is increasing owing to the risk of its adverse effects on life expectancy. Studies have shown that a longer detection time for ventricular tachyarrhythmia reduces the safety of therapies, in terms of syncope and mortality, but not substantially in terms of the success rate. We aimed to evaluate the effects of increased number of intervals to detect (NID) VF on the safety of ICD shock therapy and on the reduction of inappropriate shocks.MethodsThe present study was a prospective, multicenter, randomized, crossover study. Randomized VF induction testing with NID 18/24 or 30/40 was performed to compare the success rate of defibrillation with a 25-J shock and the time to detection. Inappropriate shock episodes were simulated retrospectively to evaluate a possibility of episodes avoidable at NID 24/32 and 30/40.ResultsThirty-one consecutive patients implanted with an ICD or cardiac resynchronization therapy-defibrillator (CRT-D) were enrolled in this study. The success rate of defibrillation was 100% in both NID groups at the first shock. The time from VF induction to detection showed a significant increase in the NID 30/40 group (6.16±1.29s vs. 9.00±1.31s, p

Pacemaker generators are routinely implanted in the anterior chest. However, where to place the generator may need to be considered from the mental, functional, and cosmetic standpoints.In this study, we performed the left axillary pacemaker generator implantation with a direct puncture of the left axillary vein in 40 consecutive patients, and evaluated the late safety and efficacy of this implantation. Complications, changes in the lead sensing, pacing threshold, and impedance were used as safety indexes for a mean follow-up of 3.4 years. In addition, the efficacy was also evaluated by comparing their questionnaire survey results to 119 patients in a control group of anterior chest implantation.Lead dislodgements were observed in two patients of the experiment group. There were no migrations of generators from the implantation site or abnormal variations in the pacing threshold, lead sensing, or impedance. In the left anterior chest and left axillary groups, 85% and 10% of the patients were worried about an external impact, 80% and 25% were worried about electromagnetic interference, and 68% and 0% answered that the pacemaker implantation site was noticeable, respectively. Apparently, more patients had a sense of security and cosmetic satisfaction with the left axillary implantation.The left axillary generator implantations may reduce the mental burden and cause no safety concerns, and may be performed if functional or cosmetic outcomes are required.

Electrophysiological study should be done in patients who suppose to undergo the treatment including pulmonary vein isolation using catheter ablation for atrial fibrillation. The purpose of the electrophysiological study consist with confirmation of the induction and the origin of atrial fibrillation, and with recognition of electrical potential and arrhythmogenic substrate for maintenance of atrial fibrillation. The shortening and irregularity of the refractory periods and prolongation of conduction time are important factor in occurrence of atrial fibrillation. Moreover, the complex fractionated atrial electrograms(CFAE) and ganglionated plexus(GP) play an important role in maintenance of atrial fibrillation. As it is indispensable to record and distinguish the electrical potential of atrium and pulmonary vein for the ablation of atrial fibrillation, every physician who is concerned in the catheter ablation requires accustoming to these potentials.

This report describes an obese 39-year-old man who experienced ST-segment elevation myocardial infarction with total thrombotic occlusion of the right coronary artery. Culprit vessel flow was improved by aspiration. Data suggested that myocardial infarction had resulted from paradoxical embolus via a patent foramen ovale triggered by the Mueller maneuver, which had induced negative intrathoracic pressure following an acute increase of right-heart volume in the context of obesity and sleep-disordered breathing (SDB). Obesity is increasing among younger populations and it represents a risk for SDB and thrombosis. Thus, this mechanism should be included within the differential diagnosis for myocardial infarction in young patients.

Radiofrequency catheter ablation (RF) has recently become widely available for the treatment of atrial fibrillation (AF) and has broadened treatment options while confusing the selection of medication therapy or RF.Two drugs for the maintenance of sinus rhythm (Ry) and 2 drugs for control of the pulse rate (Ra) were selected and the costs of medication therapy were calculated. RF procedures were grouped into 2 groups each for persistent or paroxysmal AF (RF) and for chronic AF (RFChr), according to the cost of the devices used. The calculated cost of medication therapy was 5,270-23,560 yen per month. The calculated cost of RF procedures was 1,063,200-2,029,640 yen. The costs of RF corresponded to those of Ry for 3.8-14.3 years. The costs of RFChr corresponded to those of Ra for 16.6-63.9 years. The treatment of complications ranged from 360,000 to 1,241,500 yen.From the aspect of medical costs and complications, RF should be considered for the treatment of patients with AF detected early or early-stage AF, whereas treatment for its complications should be given priority in patients with chronic AF associated with reduced cardiac function.