Introduction
It is well known that long-term right ventricular paving (RVP) might lead to a long QRS duration (QRSd) and left ventricular (LV) dyssynchrony and consequently result in LV systolic dysfunction. And more and more studies have demonstrated that conventional pacing sites (i.e., the apex or septum) could increase mortality and hospitalization of heart failure in pacemaker-dependent patients [1-3]. However, the incidence of PICM remains relatively high, and no response to cardiac resynchronization therapy (CRT) for these patients. And the biventricular pacing upgrade is still not the optimal recommendation (IIb) for these patients in recent guidelines [4].
What would help those patients with PICM? His-Purkinje system pacing, including HBP and LBBP, was chosen as an alternative procedure in patients with indications of bradycardia or heart failure [4]. The safety and efficiency have been confirmed by recent publications [5-7]. However, studies focusing on the outcome of HBP and LBBP upgrades in PICM patients are extremely rare [8, 9]. It is unknown whether this is an effective procedure in patients with PICM and AF. We consequently performed this study to investigate the clinical outcome of HBP and LBBP upgrades in these patients.
Methods and results
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).