Ever since the first case was reported at the end of 2019, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the associated coronavirus disease 2019 (COVID-19) has become a serious threat to public health globally in short time. At this point in time, there is no proven effective therapy. The interactions with concomitant disease are largely unknown, and that may be particularly pertinent to inherited arrhythmia syndrome. An arrhythmogenic effect of COVID-19 can be expected, potentially contributing to disease outcome. This may be of importance for patients with an increased risk of cardiac arrhythmias, either secondary to acquired conditions or comorbidities or consequent to inherited syndromes. Management of patients with inherited arrhythmia syndromes such as long QT syndrome, Brugada syndrome, short QT syndrome, and catecholaminergic polymorphic ventricular tachycardia in the setting of the COVID-19 pandemic may prove particularly challenging. Depending on the inherited defect involved, these patients may be susceptible to proarrhythmic effects of COVID-19-related issues such as fever, stress, electrolyte disturbances, and use of antiviral drugs. Here, we describe the potential COVID-19-associated risks and therapeutic considerations for patients with distinct inherited arrhythmia syndromes and provide recommendations, pending local possibilities, for their monitoring and management during this pandemic.

Introduction: We aimed to clarify the effect of vein of Marshall (VOM) ethanol infusion for treating VOM triggers and/or mitral flutter after first-attempt endocardial ablation in patients with nonparoxysmal atrial fibrillation (AF). Methods and Results:Of the 254 consecutive patients (age, 56 ± 10 years; 221 male) undergoing catheter ablation for drug-refractory nonparoxysmal AF, 32 (12.6%) received VOM ethanol infusion. The patients were stratified into group 1 (pulmonary vein isolation [PVI], substrate modification, VOM ethanol infusion), group 2 (PVI, substrate modification), and group 3 (PVI alone). Propensity-matched analysis (N = 128) of long-term outcomes (3.9 ± 0.5 years) revealed a higher AF recurrence risk in group 2 (hazard ratio [HR], 4.17; 95% confidence interval [95% CI], 1.63-10.69; P = .003) and group 3 (HR, 1.82; 95% CI, 1.09-3.04; P = .021) than in group 1, as well as a higher atrial arrhythmia recurrence risk in group 2 than in group 1 (HR, 2.42; 95% CI, 1.16-5.03; P = .018). A higher procedural termination rate was observed in group 1 than groups 2 and 3 (41.7% vs 17.2% vs 18.8%; P = .042). On multivariate analysis, VOM ethanol injection was an independent predictor of freedom from recurrence of AF (HR, 0.20; 95% CI, 0.08-0.52; P = .001) and atrial arrhythmia (HR, 0.35; 95% CI, 0.17-0.74; P = .005), whereas a left atrial diameter >45 mm and hypertension were independent risk factors for recurrence. Periprocedural complications rates were comparable among the groups.Conclusion: Adjunctive VOM ethanol infusion is effective and safe for treating nonparoxysmal AF in patients with VOM triggers and/or refractory mitral flutter, providing good long-term freedom from AF and atrial arrhythmia. K E Y W O R D S ablation, atrial arrhythmia, atrial fibrillation, ethanol infusion, recurrence, vein of Marshall

No abstract

Background Acute failure of radiofrequency ablation (RFA) of ventricular arrhythmias (VAs) occur in 10%‐20% of patients and is partly attributed to inadequate lesion depth acquired with standard ablation protocols. Half‐normal saline (HNS)‐irrigation is a promising strategy to improve the success rate of VA ablation. Objective This study investigated the efficacy of HNS‐irrigated ablation after a failed standard plain normal saline solution (PNSS)‐irrigated ablation on idiopathic outflow tract ventricular arrhythmia (OT‐VA). Method This is a prospective observational study of consecutive patients undergoing RFA of idiopathic OT‐VA comparing the efficacy of additional HNS‐irrigated ablation for failed standard PNSS‐irrigated ablation. Acute failure was defined as persistence of spontaneous VA or persistent inducibility of the clinical VA. Results Out of 160 OT‐VA cases (51 ± 15‐year‐old, 62 males), 31 underwent HNS irrigation after a failed standard PNSS‐irrigated ablation. The HNS group had a significantly longer procedure time (60.06 ± 43.83 vs 37.51 ± 33.40 minutes; P = .013) and higher radiation exposure (31.45 ± 20.24 vs 17.22 ± 15.25 minutes; P = .001) than the PNSS group but provided an additional acute success in 21 of 31 (67.7%) patients. Over a follow‐up duration of 7.8 ± 4.6 months, 24 recurrences were identified, including 8 (25.8%) in the HNS and 16 (12.4%) in the PNSS group, with lower freedom from recurrence in the HNS group (log rank P = .009). No major complication was observed. Conclusion HNS‐irrigated ablation after failed standard PNSS‐irrigated ablation is safe and additionally improves acute ablation success by 67.7% for idiopathic OT‐VA but with a higher rate of recurrence on follow‐up. Whether the application of HNS as initial irrigant could result in better outcome requires further investigation.

Mixed squamous cell and glandular papilloma (mixed papilloma) is a very rare tumor, with fewer than 25 cases having been reported in the literature. Although a scattering of cases of p16Ink4a overexpression have been described to date, no human papillomavirus (HPV) DNA has been detected in these tumors, either by in situ hybridization (ISH) or polymerase chain reaction (PCR). This is the first case of mixed papilloma with PCR‐confirmed HPV genotype 16, 35, 51 infections in an 18‐year‐old non‐smoking male, coexisting with multiple atypical adenomatous hyperplasias (AAHs). Histologically, this tumor shows a predominant papillary architecture, covered by a mixture of stratified squamous cells, ciliated or non‐ciliated cuboidal to columnar cells, mucous cells, and scattered goblet cells. Immunohistochemically, the squamous component was positive for p40, and the glandular cells were focally positive for TTF‐1. Both components were diffusely immunoreactive to CK7. In addition, BRAF V600E mutation was also first demonstrated in mixed papilloma, but not in the AAHs. These findings suggest that HPV infection and the BRAF mutation may be important in the pathogenetic role in young non‐smoking patients.

BackgroundThis study investigated the feasibility of using the precordial surface ECG lead interlead QRS dispersion (IQRSD) in the identification of abnormal ventricular substrate in arrhythmogenic right ventricular cardiomyopathy (ARVC).MethodsSeventy-one consecutive patients were enrolled and reclassified into 4 groups: definite ARVC with epicardial ablation (Group 1), ARVC with ventricular tachycardia (VT, Group 2), idiopathic right ventricular outflow tract VT without ARVC (Group 3), and controls without VT (Group 4). IQRSD was quantified by the angular difference between the reconstruction vectors obtained from the QRS-loop decomposition, based on a principal component analysis (PCA). Electroanatomic mapping and simulated ECGs were used to investigate the relationship between QRS dispersion and abnormal substrate.ResultsThe percentage of the QRS loop area in the Group 1–2 was smaller than the controls (P = 0.01). The IQRSD between V1-V2 could differentiate all VTs from control (P<0.01). Group 1–2 had a greater IQRSD than the Group 3–4 (V4-V5,P = 0.001), and Group 1 had a greater IQRSD than Group 3–4 (V6-Lead I, P<0.001). Both real and simulated data had a positive correlation between the maximal IQRSD (γ = 0.62) and the extent of corresponding abnormal substrate (γ = 0.71, both P<0.001).ConclusionsThe IQRSD of the surface ECG precordial leads successfully differentiated ARVC from controls, and could be used as a noninvasive marker to identify the abnormal substrate and the status of ARVC patients who can benefit from epicardial ablation.

Introduction Identifying the critical isthmus (CI) in scar‐related macroreentrant atrial tachycardia (AT) is challenging, especially for patients with cardiac surgery. We aimed to investigate the electrophysiological characteristics of scar‐related macroreentrant ATs in patients with and without cardiac surgery. Methods A prospective study of 31 patients (mean age 59.4 ± 9.81 years old) with scar‐related macroreentrant ATs were enrolled for investigation of substrate properties. Patients were categorized into the nonsurgery (n = 18) and surgery group (n = 13). The CIs were defined by concealed entrainment, conduction velocity less than 0.3 m/s, and the presence of local fractionated electrograms. Results Among the 31 patients, a total of 65 reentrant circuits and 76 CIs were identified on the coherent map. The scar in the surgical group is larger than the nonsurgical group (18.81 ± 9.22 vs. 10.23 ± 5.34%, p = .016). The CIs in surgical group have longer CI length (15.27 ± 4.89 vs. 11.20 ± 2.96 mm, p = .004), slower conduction velocity (0.46 ± 0.19 vs. 0.69 ± 0.14 m/s, p < .001), and longer total activation time (45.34 ± 9.04 vs. 38.24 ± 8.41%, p = .016) than those in the nonsurgical group. After ablation, 93.54% of patients remained in sinus rhythm during a follow‐up of 182 ± 19 days. Conclusion The characteristics of the isthmus in macroreentrant AT are diverse, especially for surgical scar‐related AT. The identification of CIs can facilitate the successful ablation of scar‐related ATs.

Supplemental Digital Content is available in the text.