Please join senior author Louise Olde Nordkamp, Editorialist Sana Al-Khatib, and Associate Editor Mark Link as they discuss the original research article Efficacy and Safety of Appropriate Shocks and Antitachycardia Pacing in "Transvenous and Subcutaneous Implantable Defibrillators: An Analysis of All Appropriate Therapy in the PRAETORIAN trial" and the editorial "Just When We Thought the Debate About the Value of Anti-Tachycardia Pacing Was Over Perplexing Results from the PRAETORIAN Trial Emerged." Dr. Carolyn Lam: Welcome to Circulation on the Run, your weekly podcast summary and backstage pass to the journal and its editors. I'm Dr. Carolyn Lam, your host and Associate Editor from the National Heart Center and Duke National University of Singapore. And as you can tell, I am sorely missing my co-host, Dr. Greg Hundley, who cannot make it today, but yet I am so excited to tell you about the wonderful papers in today's issue. Now, right after these summaries, we will be discussing appropriate shocks and anti-tachycardia pacing in transvenous and subcutaneous implantable defibrillators. A really interesting analysis from the PRAETORIAN trials. The results may surprise you as they did for me. I really highly recommend you listen to the discussion, important clinical take home messages there. Now, though, let me tell you about some original papers in today's issue. We know that symptomatic children with catecholaminergic polymorphic ventricular tachycardia and that's a mouthful. Dr. Carolyn Lam: So, I'll abbreviate it as CPVT. They are at risk for recurrent arrhythmic events, beta blockers decreases risk, but are some types of beta blockers better than others in this regard? That's what coauthors and corresponding authors, Dr. Peltonberg and van de Werf from University Medical Center, Amsterdam and colleagues looked at. Studying 329 patients with RYR2 variant carrying symptomatic children from two international registries of patients with CPVT, these authors found that beta-1 selective beta blockers were associated with a higher risk for arrhythmic events, defined as syncope, appropriate ICD shock, sudden cardiac arrest, or sudden cardiac death. And this was compared with non-selective beta blockers. The difference in non-selective versus beta-1 selective beta blockers was driven by a significantly lower risk for arrhythmic events in patients treated with nadolol compared with metoprolol, bisoprolol, and atenolol. So, what are the clinical implications? Well, symptomatic children with catecholaminergic polymorphic ventricular tachycardia should preferably be treated with nadolol or another non-selective beta blocker such as propranolol should nadolol be unavailable. Dr. Carolyn Lam: The next paper deals with the super hot topic of myocarditis-related COVID-19 vaccination in adolescents and young adults. Now, suspected myocarditis temporarily related to COVID-19 vaccination has been reported in adolescents above 12 years old and young adults since the emergency use authorization of the Pfizer COVID-19 vaccine. And this is particularly in male adolescents and young adults. Understanding the clinical course and short-term outcomes of suspected myocarditis following COVID-19 vaccine, of course, has important public health implications in the decision to vaccinate youth. So, these authors led by corresponding author, Dr. Truong from University of Utah and Primary Children's Hospital from Salt Lake City in Utah, retrospectively collected data on patients younger than 21 years old presenting before July 2021 with suspected myocarditis within 30 days of COVID-19 vaccination. And they found that in 139 adolescents and young adults with 140 episodes of suspected myocarditis, 49 of which were confirmed and 91 were probable. Dr. Carolyn Lam: And these were at 26 centers. Most patients were male and white with a median age of 15.8 years. Suspected myocarditis occurred in 98% following mRNA vaccine with 94% following the Pfizer vaccine, 91% o