Background A computational model demonstrated that atrial fibrillation (AF) rotors could be distributed in patchy late‐gadolinium enhancement (LGE) areas and play an important role in AF drivers. However, this was not validated in humans. Objective The purpose of this study was to evaluate the LGE properties of AF rotors in patients with persistent AF. Methods A total of 287 segments in 15 patients with persistent AF (long‐standing persistent AF in 9 patients) that underwent AF ablation were assessed. Non‐passively activated areas (NPAs), where rotational activation (AF rotor) was frequently observed, were detected by the novel real‐time phase mapping (ExTRa Mapping). The properties of the LGE areas were assessed using the LGE heterogeneity and the density which was evaluated by the entropy (LGE‐entropy) and the volume ratio of the enhancement voxel (LGE‐volume ratio), respectively. Results NPAs were found in 61 (21%) of 287 segments and were mostly found around the pulmonary vein antrum. A receiver operating characteristic curve analysis yielded an optimal cutoff value of 5.7% and 10% for the LGE‐entropy and LGE‐volume ratio, respectively. The incidence of NPAs was significantly higher at segments with an LGE‐entropy of >5.7 and LGE‐volume ratio of >10% than at the other segments (38 [30%] of 126 vs. 23 [14%] of 161 segments; p = .001). No NPAs were found at segments with an LGE‐volume ratio of >50% regardless of the LGE‐entropy. Of five patients with AF recurrence, NPAs outside the PV antrum were not ablated in three patients and the remaining NPAs were ablated, but their LGE‐entropy and LGE‐volume ratio were low. Conclusion AF rotors are mostly distributed in relatively weak and much more heterogenous LGE areas.

Background Medium‐dose (25 gray) x‐ray radiation therapy has recently been performed on patients with refractory ventricular tachyarrhythmias. Unlike x‐ray, carbon ion and proton beam radiation can deliver most of their energy to the target tissues. This study investigated the electrophysiological and pathological changes caused by medium‐dose carbon ion and proton beam radiation in the left ventricle (LV). Methods and Results External beam radiation in the whole LV was performed in 32 rabbits. A total of 9 rabbits were not irradiated (control). At the 3‐month or 6‐month follow‐up, the animals underwent an open‐chest electrophysiological study and were euthanized for histological analyses. No acute death occurred. Significant LV dysfunction was not seen. The surface ECG revealed a significant reduction in the P and QRS wave voltages in the radiation groups. The electrophysiological study showed that the local conduction times in each LV site were significantly longer and that the local LV bipolar voltages were significantly lower in the radiation groups than in the control rabbits. Histologically, apoptosis, fibrotic changes, and a decrease in the expression of the connexin 43 protein were seen in the LV myocardium. These changes were obvious at 3 months, and the effects were sustained 6 months after radiation. No histological changes were seen in the coronary artery and esophagus, but partial radiation pneumonitis was observed. Conclusions Medium‐dose carbon ion and proton beam radiation in the whole LV resulted in a significant electrophysiological disturbance and pathological changes in the myocardium. Radiation of the arrhythmogenic substrate would modify the electrical status and potentially induce the antiarrhythmic effect.

A 41‐year‐old man with persistent atrial fibrillation (AF) underwent radiofrequency (RF) catheter ablation using an online real‐time phase mapping system: ExTRa Mapping. Box isolation could not terminate AF. Subsequently, RF applications on nonpassively activated areas (NPAs), where rotational activations were frequently observed, at the posterior bottom of left atrium outside of box lesion could convert AF to common atrial flutter. Of interest, the NPA near the posterior bottom were located on the patchy fibrotic tissue area assessed by the late‐gadolinium enhancement magnetic resonance imaging. This indicated the possibility of the critical AF rotor meandering through the fibrotic tissue area.

Background A computer simulation model has demonstrated that atrial fibrillation (AF) driver can be attached to heterogeneous fibrosis assessed by late gadolinium enhancement magnetic resonance imaging (LGE‐MRI). However, it has not been well elucidated in patients with persistent AF. The aim of this study was to investigate whether radiofrequency (RF) applications in the fragmented LGE area (FLA) could terminate AF or convert it to atrial tachycardia (AT) and improve the rhythm outcome. Methods A total of 31 consecutive persistent AF patients with FLAs were enrolled (FLA ablation group, mean age: 69 ± 8 years, mean left atrial diameter: 42 ± 6 mm). A favorable response was defined as direct AF termination or AT conversion during RF applications at the FLA. The rhythm outcome was compared between the FLA ablation group and FLA burden‐matched pulmonary vein isolation (PVI) group. Results Favorable responses were found in 15 (48%) of 31 patients in the FLA group (AF termination in seven, AT conversion in eight patients), but not in the PVI group. AF recurrence at 12 months follow‐up was significantly less in the FLA ablation group than in the PVI group (4 [13%] vs. 12 [39%] of 31 patients, log‐rank p = .023). In patients with a favorable response, AT recurred in 1 (7%) of 15 patients, but AF did not. Conclusions FLA ablation could terminate AF or convert it to AT in half of the patients. No AF recurrence was documented in patients with a favorable response.

Background: Demand is growing for remote electrocardiogram (ECG) monitoring systems in the COVID-19 era in Japan. This study describes initial experiences with a small wireless ECG monitoring device and the utility of delivery via the postal service for outpatient care in Japan. Methods and Results:Long-term ECG monitoring following postal delivery of the small ECG device was evaluated in 25 patients. The patients had no difficulties with either the postal delivery or self-fitting and wearing the devices. A median of 57 h monitoring per patient was performed. Arrhythmic events were detected in 8 patients. Most patients were satisfied with both the ECG devices and postal delivery. Conclusions:Postal delivery of ECG devices could be used in clinical practice to achieve less or no in-person contact during the COVID-19 era.

Hiccups (singultus) are one of the most challenging symptoms to diagnose a cause. Causes range from the gastrointestinal and cardiovascular systems to the neurological system. 1 It is essential to remember that area postrema syndrome (APS), particularly in cases caused by neuromyelitis optica spectrum disorders (NMOSD), is an important differential diagnosis. 2 Persistent and intractable hiccups are a representative symptom in patients with NMOSD and associated with damage to areas abundant with the aquaporin protein. [3][4][5] However, intractable hiccups caused by APS with NMOSD rarely are associated with sick sinus syndrome (SSS). 6,7 | C A S EA 77-year-old man presented with an acute onset of hiccups and reported vomiting 8 days prior to admission. Hiccups occurred about 10 times per minute and persisted over 48 hours. An electrocardiogram (ECG) did not show any abnormal findings. A gastrointestinal endoscope revealed an esophageal hiatal hernia and atrophic gastritis, but there was no clear cause of the hiccups. Intravenous administration of metoclopramide, haloperidol, diazepam, and chlorpromazine did not relieve the hiccups. At this point, he was transferred to our hospital, where he lost consciousness because of sinus arrests lasting 13 seconds. He was diagnosed with SSS (Figure 1A

Introduction:The skin overlying cardiovascular implantable electronic devices (CIEDs) sometimes becomes very thin after implantations, which could cause a device erosion. The factors related to the skin thickness of device pockets have not been elucidated. This study aimed to evaluate the skin thickness of CIED pockets and search for the factors associated with the thickness.Methods: Seventeen skin thickness points around the CIED pocket were measured through ultrasonography in each patient.Results: A total of 101 patients (76 ± 11 years, 26 female) were enrolled. The median duration from the implantation to the examination was 95 months (quartile: 52.5-147.5). The median skin thickness overlying the device was 4.1 mm (3.3-5.9).Patients with heart failure and malignancy had thinner skin overlying the CIED than those without. A significant correlation existed between skin thickness and body mass index (BMI), hemoglobin, serum creatinine, estimated glomerular filtration rate (eGFR), and left ventricular ejection fraction. In contrast, age, gender, and device size did not exhibit a significant correlation with skin thickness. A multivariate logistic regression analysis revealed that chronic heart failure and a decrease in the eGFR and BMI were independent predictive factors of "very thin (≦3.3 mm)" skin of the CIED pocket late after an implantation. Conclusion:Aside from a low BMI, the comorbidities (low hemoglobin, heart failure, and renal dysfunction) had a stronger impact on the skin thickness overlying the device than the device size. A careful observation of the device pocket should be performed in patients with those risk factors.

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