Background: Pulsed field ablation (PFA) is a uniquely tissue-selective, nonthermal cardiac ablation modality. Delivery parameters such as the electrical waveform composition and device design are critical to PFA’s efficacy and safety, particularly tissue specificity. In a series of preclinical studies, we sought to examine the electrophysiological and histological effects of PFA and compare the safety and feasibility of durable pulmonary vein and superior vena cava (SVC) isolation between radiofrequency ablation and PFA waveforms. Methods: A femoral venous approach was used to gain right and left atrial access under general anesthesia in healthy swine. Baseline potentials in right superior pulmonary and inferior common vein and in SVC were assessed. Bipolar PFA was performed with monophasic (PFA Mono ) and biphasic (PFA Bi ) waveforms in 7 and 7 swine sequentially and irrigated radiofrequency ablation in 3 swine. Vein potentials were then assessed acutely, and at ≈10 weeks; histology was obtained. Results: All targeted veins (n=46) were successfully isolated on the first attempt in all cohorts. The PFA Bi waveform induced significantly less skeletal muscle engagement. Pulmonary vein isolation durability was assessed in 28 veins: including the SVC, durability was significantly higher in the PFA Bi group (18/18 PFA Bi , 10/18 PFA Mono , 3/6 radiofrequency, P =0.002). Transmurality rates were similar across groups with evidence of nerve damage only with radiofrequency. Pulmonary vein narrowing was noted only in the radiofrequency cohort. The phrenic nerve was spared in all cohorts but at the expense of incomplete SVC encirclement with radiofrequency. Conclusions: In this chronic porcine study, PFA-based pulmonary vein and SVC isolation were safe and efficacious with demonstrable sparing of nerves and venous tissue. This preclinical study provided the scientific basis for the first-in-human endocardial PFA studies.

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COVID-19 vaccinations have been deployed to mitigate the effects of the COVID-19 pandemic. However, vaccine-associated myocarditis has been reported. Two typical cases in terms of young age and after the second vaccination were admitted to our hospital with symptoms of worsening chest pain, ST elevation on the electrocardiogram (ECG) and creatine kinase elevation. Emergency coronary angiography revealed no coronary arteries, and an endomyocardial biopsy showed no remarkable findings. Their symptoms were resolved within a few days of sufficient rest and non-steroidal anti-inflammatory drug. The ECG of Patient 1 showed typical change; therefore, the diagnosis of myocarditis was easy. However, the ECG of Patient 2 did not show typical change for myocarditis, and there was no abnormality in the wall motion on echocardiography. Cardiac magnetic resonance imaging (MRI), strain analysis by speckle-tracking echocardiography and serial ECG were useful for the diagnosis of myocarditis. This work shows that conducting early examinations with multimodality imaging and sufficient rest are needed to prevent the worsening of vaccine-associated myocarditis. Although the benefits of the vaccines outweigh the risks, we should be aware that myocarditis can occur after COVID-19 mRNA vaccination regardless of race, especially in young males.

All procedures were performed under general anesthesia with endotracheal intubation. Hemodynamic monitoring was performed using radial or femoral arterial blood pressure monitoring, and bilateral © 2017 American Heart Association, Inc. were all higher in the pLVAD group. During median follow-up of 215 days, the primary end point (recurrent VT, heart transplantation, or death) occurred in 36% of the pLVAD versus 26% of the non-pLVAD groups (P=0.14). After propensity matching for differences between groups, no differences were seen between groups for both acute procedural outcomes and the primary end point. Conclusions-In this large single-center scar-related VT ablation experience, despite the worse clinical status of the patients selected for pLVAD support, clinical outcomes were better than expected and were similar to healthier patients not receiving hemodynamic support. Patients with dilated cardiomyopathy presenting with electrical storm, advanced heart failure, and severe left ventricular dysfunction most frequently received hemodynamic support during VT ablation. (Circ Arrhythm Electrophysiol. 2017;10:e004717.

COVID-19 vaccines have been used to counteract the global COVID-19 pandemic. While these are effective, adverse reactions have been reported, such as injection-site pain, muscle ache, fever, palpitation, and chest discomfort. The release of inflammatory cytokines, such as interleukin (IL)-6 and IL-1β, is a potential mechanism for post-vaccine side-effects. Chest discomfort after the vaccination, including myocarditis and acute coronary syndrome, is a particularly serious adverse reaction. It is important to be familiar with the differential diagnoses of chest discomfort and organ-specific diseases associated with COVID-19 vaccines as the preparation for booster shots and vaccinations among children aged 5–11 years begins. High-intensity exercise, alcohol, tobacco smoking, and baths promote inflammatory cytokines, such as IL-6, which may exacerbate the adverse reactions after vaccination. Japanese data show that deaths during baths are the most common for several days after mRNA vaccination. Additionally, alcohol and tobacco smoking were identified as predictive factors of lower antibody titers after vaccination. In this review, we aimed to provide a few recommendations to prevent vaccine-associated disease.