Patients with PICM were continuous enrolled from January 2018 to March 2020. All patients were further divided into AF subgroup and sinus rhythm subgroup. Clinical data including echocardiographic examination parameters, electrocardiogram (ECG) measurements, and New York Heart Association (NYHA) classification, were assessed before and after a his-purkinje system pacing (HPSP) upgrade. The HBP and LBBP upgrades were completed in 34 of 36 (94%), Complications including electrode dislodged, perforation, infection or thrombosis were not observed in perioperative period. During a mean of 11.52±5.40 months of follow-up. The left ventricular ejection fraction (LVEF) increased significantly (33.76±7.54 vs 40.41±9.06, P<0.001), and the QRS duration decreased (184.22±23.76ms vs 120.52±16.67ms, P<0.001) after the HBP upgrades. LVEDD reversed from 59.29±7.74 mm to 53.91±5.92 mm (P<0.001), and the NYHA functional class also improved to 2.00±0.76 from 2.55±0.91 at the first follow-up (P<0.001). The left atrium (LA) size also slightly decreased compared to the initial state (47.44±7.14mm VS 45.56±7.78, P=0.010). The threshold did not increase significantly (1.18±0.76 mv@0.4ms vs 1.26±0.91mv @ 0.4ms, P=0.581). These improvements in patients with AF were similar with those in patients without AF (P >0.05).