Electrophysiological findings during re-do procedures after single-shot pulmonary vein isolation for atrial fibrillation with pulsed field ablation.

BACKGROUND: Pulsed field ablation (PFA) is a novel ablation technology recently adopted in the treatment of atrial fibrillation (AF). Currently, little is known about the durability of PFA ablation lesions. METHODS: We investigated patients who underwent redo-ablation due to recurrent AF/atrial-flutter or tachycardia (AFL/AT) following PVI with PFA. We report electrophysiological findings and ablation strategy during redo-ablation. RESULTS: Of 447 patients undergoing index PVI with PFA, 14 patients (age: 61.9±10.8 years; 7 (50.0%) males; left atrial volume index (n=10): 39.4±14.6 mL/m2) were referred for redo-ablation. Initial indication was paroxysmal-AF in 7 patients, persistent-AF in 6 and long-standing-persistent-AF in one patient. Mean time-to-recurrence was 4.9±1.9 months. Three patients received additional posterior-wall-isolation during index PFA. Twelve (85.7%) patients suffered AF recurrence and 5/12 had concomitant AFL. In the remaining 2 patients, one had a (box-dependent) AFL, and one had an atypical AT. No patients had all PVs reconnected. Reconnection in zero, one, two or three PVs was found in 35.7%, 21.4%, 14.3%, and 28.6% of patients, respectively. All 7 patients with zero or one reconnection with AF recurrence received additional/repeat posterior-wall-isolation during re-ablation, while in the others, PVs were re-isolated. Patients with only AFL/AT had no reconnection of PVs, and the substrate was successfully ablated. CONCLUSIONS: Durable PVI (all PV's isolated) was observed in over one-third of patients at re-do. The predominant recurrent arrhythmia following PVI-only was AF. Concomitant (35.7%) or isolated (14.3%) AFL/AT recurrence was observed in 50% of patients.

Successful management of near-incessant bidirectional ventricular tachycardia in one-year-old child with COVID-19 infection: a case report.

Background: The COVID-19 is an infectious disease, caused by SARS-CoV-2 virus. Cardiovascular complications of COVID-19 are reported more often, from inflammatory cardiac diseases to acute coronary syndromes, thromboembolic events and arrhythmias. Sometimes, these arrhythmias may be life threatening and require urgent intervention. Case summary: This is a case of one-year-old boy, who was referred to our hospital because of premature ventricular complexes on ECG. The child had genetic chimerism with a karyotype of 46XY(12)/46XX(3) and small patent ductus arteriosus. We observed non-sustained episodes of bidirectional ventricular tachycardia (VT) on 24 h Holter monitor, which increased over time and caused multiple planned and urgent shocks, despite antiarrhythmic drugs and deep sedation and intubation. Patient was tested positive for COVID-19 using PCR. After thorough echocardiographic testing and a negative genetic analysis for arrhythmogenic disorders he was diagnosed with COVID-19 associated ventricular tachycardia, taking into account that he also developed multisystem inflammatory syndrome. Further, a significant decrease of ventricular activity was observed, which allowed us to implant a cardioverter-defibrillator (ICD). Soon after the implantation the storm of ventricular tachycardia restarted with multiple shocks of the device. This time left partial thoracic sympathectomy was performed and the patient didn't have ICD shocks any more. Discussion: COVID-19 infection can be associated with significant arrhythmias, including fatal ventricular arrhythmias also in children. Left partial thoracic sympathectomy can be a helpful option in patients with sustained ventricular tachycardia and multiple ICD shocks, in whom antiarrhythmic treatment or VT ablation is useless or not available.

Syncope in a pregnant woman with repaired Tetralogy of Fallot: a case report.

Background: Tetralogy of Fallot (TOF) is one of the most widespread cyanotic congenital heart disease (CHD), which can be successfully repaired in the neonatal period. However, residual problems and the surgical technique itself can create a favourable basis for arrhythmias and conduction abnormalities in these patients. Sometimes, these arrhythmias may worsen during pregnancy and require urgent intervention. Case summary: This is a case of a 25-year-old woman, who underwent a surgical repair of TOF at the age of 2 years. She suffered an ischaemic stroke postoperatively, which was complicated with secondary seizures and syncope. These episodes were evaluated as epilepsy. The patient was admitted to our hospital with the above-mentioned complaints in the 10th week of pregnancy. A comprehensive cardiac examination was performed. Her presyncopal event was captured during Holter monitoring, which documented a severe dysfunction of the sinus node. She was diagnosed with postoperative sick sinus syndrome and implanted with a permanent dual-chamber pacemaker (PM). After the operation, the patient did not have any episodes of syncope or seizures and the PM check-up showed almost 30% of atrial pacing. Conclusion: No matter how obvious the neurological or other nature of syncope may seem, it is advised to exclude the cardiac origin of syncope, especially in patients with repaired CHD. One of the most common complications after surgery of CHD is rhythm and conduction disturbances. In some of these cases, permanent PM implantation can be unavoidable, even during pregnancy. The implantation of the PM device during pregnancy can be performed safely.

An Uncommon Case of Incessant Tachycardia-induced Cardiomyopathy in a Child.

The case of a pediatric patient with a history of incessant narrow complex tachycardia is presented. The patient underwent successful catheter ablation for an uncommon concealed slow accessory pathway. The mechanism and ablation location are discussed.