Instability of depolarization appears to be related to the risk of fatal ventricular arrhythmias in patients with Brugada syndrome. Daily fluctuations in ECG and SAECG characteristics could be useful for distinguishing between high- and low-risk patients with Brugada syndrome.

No abstract

Multichannel Holter ECG recording in the third intercostal space is more sensitive and useful for the diagnosis of type 1 Brugada ECG than repeated 12-lead ECGs or multichannel Holter ECG in the standard position.

There are few reports about the incidence and predictors of silent cerebral thromboembolic lesions (SCLs) after atrial fibrillation (AF) ablation in patients treated with direct oral anticoagulants (DOACs). The purpose of this study is to evaluate the incidence and predictors of SCLs after AF ablation with cerebral magnetic resonance imaging (C-MRI) in patients treated with DOACs. We enrolled 117 consecutive patients who underwent first AF ablation and received DOACs, including apixaban, dabigatran, edoxaban, and rivaroxaban. DOACs were discontinued after administration 24 h before the procedure, and restarted 6 h after the procedure. During the procedure, activated clotting time (ACT) was measured every 15 min, and intravenous heparin infusion was performed to maintain ACT at 300-350 s. All patients underwent C-MRI the day after the procedure. SCLs were detected in 28 patients (24%) after AF ablation. Age, female sex, the presence of persistent AF, left atrial volume, procedure time, radiofrequency energy, electrical cardioversion, and mean ACT showed no correlations with the incidence of SCLs. Multivariate analysis revealed independent predictors of SCLs were CHADSVASc scores ≥3, left atrial appendage (LAA) emptying velocity ≤39 cm/s, and minimum ACT ≤260 s. Patients with both CHADSVASc scores ≥3 and LAA flow velocity ≤39 cm/s had the highest incidence of SCLs 15 of 26 patients (58%). In patients treated with DOACs, CHADSVASc score ≥3, minimum ACT ≤260 s, and LAA emptying velocity ≤39 cm/s were independent risk factors for the SCLs after AF ablation.

Coronary artery spasm is a rare complication associated with radiofrequency catheter ablation of the left atrium. Previous reports mentioned that various mechanisms including direct thermal injury, progressive inflammation, or stimulation of ganglionated plexuses (GP) might lead to coronary artery spasm. However, there are few reports about the relationship between ablation of GP sites and changes on the electrocardiogram (ECG). We present here, ECG changes associated with GP stimulation, and the risk of life-threatening coronary spasm. Case reportA 57-year-old man was admitted to our hospital for acute heart failure with atrial fibrillation (AF). However, he had no symptoms such as palpitations or chest pain. We suspected that the AF was associated with heart failure. Thus, he was admitted for pulmonary vein isolation (PVI) procedure for AF. The patient was placed under general anesthesia using propofol and dexmedetomidine. Two 8 Fr. Swartz sheaths (St Jude Medical Inc., Saint Paul, MN, USA) and AgilisNxT (St Jude Medical Inc.) were inserted into the left atrium, through a punctured trans-septal hole. The patient was administered 8000 units of heparin, and heparin was continued until a maintenance dose was reached, with minimal activated clotting time of 300 s. We flushed the sheaths carefully using saline with heparin to prevent air or thrombus. We used an irrigated tip radiofrequency (RF) ablation catheter (Navistar ThermoCoolS-martTouch; Biosense Webster, Irvine, CA, USA). Ablation was performed at a maximum temperature of 43 C and power limit of