Pulsed-field ablation (PFA) had potential advantages in atrial fibrillation ablation, and we aim to confirm the optimal parameter and target of PFA for atrial fibrillation. Two ablation modes in vitro of single-cell system (ablation in electrode cup) and monolayer cell system (ablation in inserts with electrode tips) were established to perform PFA for myocardial cell H9C2 and smooth muscle cell A7r5. Ablation effect, calcium ion influx, the expression of Cx45, and surface morphological change were observed. Three Bama minipigs were used to verify the in vivo ablation effect of PFA. In monolayer cell system, H9C2 was significantly sensitive to PFA compared with A7r5, with shrinking of the whole monolayer. The ablation effect of bidirectional pulse was weaker than that of the two mono-polar pulses. Expressed Cx45 proteins were increased in H9C2 but decreased in A7r5 cells. Bidirectional PFA performed on Bama minipigs was able to effectively block electrical activity from the pulmonary vein to the atrium with week muscle contraction, not generating pulmonary vein stenosis. Bidirectional PFA was able to significantly ablate myocardial cells, maintain cell–cell connection, and reduce muscle contraction, which was a kind of optimized PFA strategy for atrial fibrillation.

Background: The aim of this study was to perform a retrospective analysis of patients with acute anterior wall ST-segment elevation myocardial infarction (AAW-STEMI) whose left anterior descending (LAD) artery was completely occluded and reperfused by primary percutaneous coronary intervention (PPCI) and to determine the influencing factors and prognostic value of left ventricular systolic dysfunction (LVSD) in the acute phase of acute myocardial infarction (AMI). Methods: A total of 304 patients with AAW-STEMI were selected. The selected patients were divided into two groups: the preserved left ventricular ejection fraction (pLVEF) group (LVEF≥50%, n=185) and the reduced left ventricular ejection fraction (rLVEF) group (LVEF<50%, n=119). The influencing factors of LVSD and their predictive value for LVSD were analyzed. Patients were followed up (median follow-up: 47 months [interquartile range: 27 to 64 months]) by examining outpatient records and via telephone. The predictive value of LVSD for the survival of patients with AAW-STEMI was analyzed. Results: Age, heart rate (HR) at admission, number of ST-segment elevation leads (STELs), peak creatine kinase (CK) and symptom to wire-crossing (STW) time were independent risk factors for LVSD. Peak CK had the strongest predictive value for LVSD. LVSD is an independent adverse factor for long-term prognosis in patients with AAW-STEMI discharged after PPCI. Conclusions: Age, HR at admission, number of STELs, peak CK, and STW time may be used to identify patients with a high risk of heart failure (HF) in a timely manner and initiate early standard therapy for patients with AAW-STEMI whose LAD artery was completely occluded and reperfused by PPCI. Incident LVSD in the acute phase after AAW-STEMI was significantly associated with a trend toward increased mortality at follow-up.

Background The aim of this study was to perform a retrospective analysis of patients with acute anterior wall ST-segment elevation myocardial infarction (AAW-STEMI) whose left anterior descending (LAD) artery was completely occluded and reperfused by primary percutaneous coronary intervention (PPCI) and to determine the influencing factors and prognostic value of left ventricular systolic dysfunction (LVSD) in the acute phase of acute myocardial infarction (AMI). Methods A total of 304 patients with AAW-STEMI were selected. The selected patients were divided into two groups: the preserved left ventricular ejection fraction (pLVEF) group (LVEF ≥ 50%, n = 185) and the reduced left ventricular ejection fraction (rLVEF) group (LVEF < 50%, n = 119). The influencing factors of LVSD and their predictive value for LVSD were analyzed. Patients were followed up by examining outpatient records and via telephone. The predictive value of LVSD for the cardiovascular mortality of patients with AAW-STEMI was analyzed. Results Age, heart rate (HR) at admission, number of ST-segment elevation leads (STELs), peak creatine kinase (CK) and symptom to wire-crossing (STW) time were independent risk factors for LVSD (P < 0.05). The receiver operating characteristic (ROC) analysis showed that the peak CK had the strongest predictive value for LVSD, with an area under the curve (AUC) of 0.742 (CI, 0.687 to 0.797) as the outcome. At a median follow-up of 47 months (interquartile range, 27 to 64 months), the Kaplan‒Meier survival curves up to 6-year follow-up revealed a total of 8 patients succumbed to cardiovascular disease, with 7 (6.54%) in the rLVEF group and 1 (0.56%) in the pLVEF group, respectively (hazard ratio: 12.11, [P = 0.02]). Univariate and multivariate Cox proportional hazards regression analysis demonstrated that rLVEF was an independent risk predictor of cardiovascular death in patients with AAW-STEMI discharged after PPCI (P < 0.01). Conclusions Age, HR at admission, number of STELs, peak CK, and STW time may be used to identify patients with a high risk of heart failure (HF) in a timely manner and initiate early standard therapy for incident LVSD in the acute phase of AAW-STEMI reperfused by PPCI. A trend toward increased cardiovascular mortality at follow-up was significantly linked to LVSD.