Pulsed field ablation (PFA) is an innovative approach in the field of cardiac electrophysiology aimed at treating cardiac arrhythmias. Unlike traditional catheter ablation energies, which use radiofrequency or cryothermal energy to create lesions in the heart, PFA utilizes pulsed electric fields to induce irreversible electroporation, leading to targeted tissue destruction. This state-of-the-art review summarizes biophysical principles and clinical applications of PFA, highlighting its potential advantages over conventional ablation methods. Clinical data of contemporary PFA devices are discussed, which combine predictable procedural outcomes and a reduced risk of thermal collateral damage. Overall, these technological developments have propelled the rapid evolution of contemporary PFA catheters, with future advancements potentially impacting patient care.

Aims: Sudden cardiac death (SCD) annual incidence is 0.6–1% in post-myocardial infarction (MI) patients with left ventricular ejection fraction (LVEF)≥40%. No recommendations for implantable cardioverter-defibrillator (ICD) use exist in this population. Methods and results: We introduced a combined non-invasive/invasive risk stratification approach in post-MI ischaemia-free patients, with LVEF ≥ 40%, in a multicentre, prospective, observational cohort study. Patients with at least one positive electrocardiographic non-invasive risk factor (NIRF): premature ventricular complexes, non-sustained ventricular tachycardia, late potentials, prolonged QTc, increased T-wave alternans, reduced heart rate variability, abnormal deceleration capacity with abnormal turbulence, were referred for programmed ventricular stimulation (PVS), with ICDs offered to those inducible. The primary endpoint was the occurrence of a major arrhythmic event (MAE), namely sustained ventricular tachycardia/fibrillation, appropriate ICD activation or SCD. We screened and included 575 consecutive patients (mean age 57 years, LVEF 50.8%). Of them, 204 (35.5%) had at least one positive NIRF. Forty-one of 152 patients undergoing PVS (27–7.1% of total sample) were inducible. Thirty-seven (90.2%) of them received an ICD. Mean follow-up was 32 months and no SCDs were observed, while 9 ICDs (1.57% of total screened population) were appropriately activated. None patient without NIRFs or with NIRFs but negative PVS met the primary endpoint. The algorithm yielded the following: sensitivity 100%, specificity 93.8%, positive predictive value 22%, and negative predictive value 100%. Conclusion: The two-step approach of the PRESERVE EF study detects a subpopulation of post-MI patients with preserved LVEF at risk for MAEs that can be effectively addressed with an ICD. Clinicaltrials.gov identifier: NCT02124018

Pulsed field ablation (PFA), a non-thermal ablative modality, may show different effects on the myocardial tissue compared to thermal ablation. Thus, this study aimed to compare the left atrial (LA) structural and mechanical characteristics after PFA vs. thermal ablation. Cardiac magnetic resonance was performed pre-ablation, acutely (<3 h), and 3 months post-ablation in 41 patients with paroxysmal atrial fibrillation (AF) undergoing pulmonary vein (PV) isolation with PFA (n = 18) or thermal ablation (n = 23, 16 radiofrequency ablations, 7 cryoablations). Late gadolinium enhancement (LGE), T2-weighted, and cine images were analysed. In the acute stage, LGE volume was 60% larger after PFA vs. thermal ablation (P < 0.001), and oedema on T2 imaging was 20% smaller (P = 0.002). Tissue changes were more homogeneous after PFA than after thermal ablation, with no sign of microvascular damage or intramural haemorrhage. In the chronic stage, the majority of acute LGE had disappeared after PFA, whereas most LGE persisted after thermal ablation. The maximum strain on PV antra, the LA expansion index, and LA active emptying fraction declined acutely after both PFA and thermal ablation but recovered at the chronic stage only with PFA. Pulsed field ablation induces large acute LGE without microvascular damage or intramural haemorrhage. Most LGE lesions disappear in the chronic stage, suggesting a specific reparative process involving less chronic fibrosis. This process may contribute to a preserved tissue compliance and LA reservoir and booster pump functions.

Background: Achieving bidirectional mitral isthmus (MI) block using radiofrequency catheter ablation (RFCA) alone is challenging, and MI reconnection is common. Adjunctive vein of Marshall (VOM) ethanol infusion (VOM-Et) can facilitate acute MI block. However, little is known about its long-term success. This study sought to evaluate the impact of adjunctive VOM-Et on MI block achievement and durability compared with RFCA alone. Methods: Patients undergoing the first attempt of posterior MI ablation were grouped according to their MI block index strategy: adjunctive VOM-Et and RFCA alone. Rates of acute MI block and MI reconnection observed during repeat procedures were compared between the 2 groups. Results: The VOM-Et group consisted of 152 patients (63.8±9.4 years) undergoing adjunctive VOM-Et for MI block. The RFCA group consisted of 110 patients (60.9±9.2 years) undergoing MI ablation using RFCA alone. Acute MI block was more frequently achieved in the VOM-Et group (98.7% [150/152] versus 63.6% [70/110]; P <0.001) with shorter RFCA duration (5.00 [3.00–7.00] versus 19.0 [13.6–22.0] minutes; P <0.001). Of the 220 patients with MI block achieved during the index procedure, 81 underwent a repeat procedure during follow-up (VOM-Et group: 23.3% [35/150] versus RFCA group: 65.7% [46/70], respectively; P <0.001). A significantly greater number of patients exhibited durable MI block in the VOM-Et group (62.9% [22/35] versus 32.6% [15/46], respectively; P =0.008). Conclusions: Beyond facilitating acute MI block, VOM-Et is associated with greater lesion durability as evidenced by higher rates of MI block during repeat procedures.

Aims: Asymptomatic atrial fibrillation (AF) is frequent and associated with disease progression. This meta-analysis aimed to estimate the prevalence of asymptomatic AF and identify risk factors associated with asymptomatic status. Methods and results: MEDLINE (PubMed), Scopus, Cochrane, and ClinicalTrials.gov were searched until 8 January 2025. Double-independent study selection, data extraction, and quality assessments were performed. Random-effects meta-analysis was used. Estimates are presented with the asymptomatic individuals in the nominator and the symptomatic patients in the denominator. The assessment of the prevalence of asymptomatic AF and the identification of risk factors associated with the asymptomatic status comprised the main endpoints. Thirty-seven studies (224 273 participants) were included. The prevalence of asymptomatic AF was 27% [95% confidence interval (CI) = (22%, 33%); I2 = 100%]. Risk factors positively associated with the asymptomatic status were male sex [odds ratio (OR)=1.67, 95% CI = (1.48, 1.89), P < 0.001, I2 = 85%), diabetes mellitus [OR = 1.19, 95% CI = (1.07, 1.33), P = 0.002, I2 = 87%], chronic kidney disease [OR = 1.21, 95% CI = (1.08, 1.36), P < 0.001, I2 = 80%] and stroke/transient ischemic attack [OR = 1.43, 95% CI = (1.18, 1.73), P < 0.001, I2 = 95%], while heart failure was negatively associated with asymptomatic AF [OR = 0.71, 95% CI = (0.54, 0.94), P = 0.017, I2 = 97%]. Asymptomatic status was also positively associated with permanent AF [OR = 2.13, 95% CI = (1.28, 3.55); P = 0.004; I2 = 98%] and negatively associated with catheter ablation [OR = 0.63, 95% CI = (0.44, 0.91); P = 0.012; I2 = 95%], beta-blockers [OR = 0.90, 95% CI = (0.82, 0.98); P = 0.018; I2 = 68%] and antiarrhythmics [OR = 0.53, 95% CI = (0.35, 0.79); P = 0.002; I2 = 95%]. Conclusion: Asymptomatic AF was estimated at around 27%, with large variability depending on the prevalence of risk factors associated with asymptomatic status. Asymptomatic individuals had distinct characteristics compared with symptomatic patients, regardless of symptoms’ assessment methods and rhythm/rate control interventions. Our results could inform AF screening practices to target asymptomatic individuals. Registration: PROSPERO: CRD42024578738.