The first article is titled “Global approaches to cardiogenetic evaluation after sudden cardiac death in the young: A survey among healthcare professionals”. A survey was administered among health care professionals recruited through professional associations, social media, and networks of researchers. Only 30% reported autopsy as mandatory, and overall practices were largely case by case and not standardized. North American respondents more often perceived practices as ineffective compared to those from Europe and Australia/New Zealand. Where a heritable cause is suspected, 69% considered postmortem genetic testing and 61% offered genetic counseling to surviving family members. In conclusion, postmortem genetic testing is not consistently available in the investigation of young sudden cardiac death despite being a recommendation in international guidelines. Access to postmortem genetic testing, which is critical in ascertaining a cause of death in many cases, must be guided by well-resourced, multidisciplinary teams.

Next up is “Sex differences in the origin of Purkinje ectopy initiating idiopathic ventricular fibrillation”. Purkinje ectopics are major triggers of idiopathic VF. The authors studied 73 patients of whom 32 had a history of syncope and 44 patients had VF at rest. Purkinje ectopics originated from the RV in 41 patients (49%), from the LV in 36 (44%), and from both ventricles in 6 (7%). RV Purkinje ectopics were more frequent in men than in women, whereas LV and biventricular Purkinje ectopics were more frequent in women. The authors conclude that Purkinje ectopics triggering idiopathic VF is a sex-related arrhythmia similar to Brugada syndrome or long QT syndrome. Sex-based factors influencing Purkinje arrhythmogenicity warrant investigation.

The next paper is “Nationwide Burden of Sudden Cardiac Death: A Study of 54,028 Deaths in Denmark”. There were 54,028 deaths in Denmark in 2010, of which 6867 (13%) were categorized as sudden cardiac death. The incidence rate of definite sudden cardiac death was 11 per 100,000 person-years. Including definite, probable, and possible SCD cases, the highest possible overall SCD incidence rate was 124 per 100,000 person-years. Almost half of all sudden cardiac death cases occurred in persons without a history of cardiovascular disease. Consequently, the optimization of risk stratification and prevention of sudden cardiac death in the general population should be given high priority.

Coming up is “Echocardiographic deformation imaging unmasks global and regional mechanical dysfunction in patients with idiopathic ventricular fibrillation.”Echocardiograms were analyzed with deformation imaging by 2-dimensional speckle tracking. In total, 47 idiopathic VF patients and 47 healthy controls were included. Idiopathic VF patients showed more global deformation abnormalities as indicated by lower LV global longitudinal strain and higher LV mechanical dispersion. In addition, idiopathic VF patients showed more regional LV postsystolic shortening compared to healthy controls. Abnormal RV deformation patterns were observed in 16% of idiopathic VF patients and in none of the control subjects. This study provides evidence that localized myocardial disease is present in a subset of idiopathic VF patients.

The next article is “Role of Endocardial Ablation in Eliminating an Epicardial Arrhythmogenic Substrate in Patients with Brugada Syndrome”. This study included 16 Brugada syndrome patients with previous VF, including 10 with an electrical storm. Epicardial abnormal potentials were present in the epicardial RV outflow tract in all patients and RV inferior wall in 12 (75%) of patients. Partial epicardial abnormal potentials elimination by endocardial RV ablation was feasible in all 10 patients. After the procedure, VF remained inducible in 37.5% of the patients. During the 25.1 months of follow-up, no patients experienced an electrical storm,and VF burden significantly decreased. The authors conclusion that endocardial ablation is feasible to eliminate some epicardial abnormal potentials and may be combined with epicardial ablation.

Up next is “Postinfarct ventricular tachycardia substrate: Characterization and ablation of conduction channels using ripple mapping”. Ripple maps of postinfarct scar were collected using the PentaRay during normal rhythm in 11 patients. Scar potential timing ranged from 98.1 ± 60.5 ms to 214.8 ± 89.8 ms post QRS peak. Earliest scar potentials were present at the border, occupying 16.4% of scar, whereas latest scar potentials occupied 4.8% at the opposing border or core. It was possible to eliminate latest scar potentials in all patients without direct ablation. No VT recurrence was recorded after a mean follow-up of 10.1 months. The authors conclude that conduction channels can be located using ripple mapping to analyze scar potentials. Ablation at channel entrances can eliminate the latest scar potentials and is associated with good medium-term results.

Up next is “Clinical characteristics and risk of arrhythmic events in patients younger than 12 years diagnosed with Brugada syndrome”. Forty-three patients younger than 12 years at the time of diagnosis were included. The median follow-up was 3.97 years. The authors found that a spontaneous type 1 Brugada ECG pattern is not associated with a higher incidence of syncope, first-degree atrioventricular block, premature beats, nonmalignant and malignant arrhythmia events than the drug/fever-induced type 1 Brugada ECG pattern. Syncope events are correlated with an increased incidence of malignant arrhythmia events. Moreover, SCN5A mutations are associated with a higher occurrence of malignant AEs.

Next paper is “Identification of a SCN5A Founder Mutation Causing Sudden Death, Brugada Syndrome and Conduction Blocks in Southern Italy”. The authors used a haplotype-based approach to investigate whether 2 SCN5A genetic variants could derive from founder events. One SCN5A variant (p.glutamine1118threonine) was identified in 3 probands with BrS originating from south Italy. The clinical presentation included multigenerational dominant transmission of Brugada electrocardiographic pattern, high incidence of sudden cardiac death, and cardiac conduction defects. Variant's age estimates suggested that origin of the variant dates back 76 generations. A second SCN5A variant identified in the region did not show similar founder signal. The authors conclude that they found a novel founder mutation. They illustrate how these findings provide insights on the inheritance patterns and phenotypes associated with SCN5A mutation.

In addition to the sudden death focused papers, we also have the following papers in this issue of the journal. The first one is titled “Impact of a Pre-defined Pacemapping Protocol Use for Ablation of Infrequent Premature Ventricular Complexes: A Prospective, Multicenter Study.” Of 185 patients, 60 (32%) underwent pacemapping-guided ablation. Mean number of pacemapping matching points acquired was 39 ± 21 (range 6-98). Significantly shorter procedural as well as RF times were needed in the pacemapping group using the proposed protocol than in activation mapping guided ablation. Global clinical success reached was 87% for the pacemapping group and 90% for local activation mapping group. The authors conclude that when local activation time mapping is precluded, application of a pacemapping-guided ablation protocol directed to >94% matching correlation target area is a more efficient alternative with comparable clinical results.

Up next is “Simple electrophysiological predictor of QRS change induced by cardiac resynchronization therapy: a novel marker of complete left bundle branch block”. The authors hypothesized that the absence of QRS duration prolongation by RV mid-septal pacing may indicate complete left bundle branch block. 133 consecutive patients were included in the study. They found that the absence of QRS duration prolongation by RV pacing may serve as an alternative and more specific marker of complete LBBB. Delta RV pacing correlates strongly with the CRT effect on QRS duration and outperforms the predictive value of ECG-based complete LBBB.

The next paper is titled “Long-term outcomes and periprocedural safety and efficacy of percutaneous left atrial appendage closure in a UK tertiary center: 11-year experience”. Device implantation was attempted in 229 patients, with an acute procedural success rate of 98.2% and low rate of major procedural complications of 2.6% at 30 days, including 1.3% procedure-related mortality. Over total follow-up of 889 patient-years, there were low rates of thromboembolic and significant bleeding events. The authors found that LAA occlusion with a same-day discharge strategy and early cessation of antiplatelet therapy seems to be safe and effective in reducing the risk of stroke and major bleeding over mean follow-up approaching 4 years.