May 1, 2021Open Access
Ver artículo completoDetrimental Immediate- and Medium-Term Clinical Effects of Right Ventricular Pacing in Patients With Myocardial Fibrosis
Resultado clave
Right ventricular pacing in patients with myocardial fibrosis, compared to those without, was associated with greater medium-term decline in LV ejection fraction (-12.3% vs -6.7%; P=0.012).
Diseño del estudio
Tipo
Observational (n=84)
PICO estructurado
Does right ventricular pacing worsen left ventricular function in patients with myocardial fibrosis compared to those without?
P
Población
84 patients with LV ejection fraction ≥40%. Includes 34 patients with a dual-chamber device and preserved atrioventricular conduction, and 50 patients with high-grade atrioventricular block.
I
Intervención
Right ventricular (RV) pacing (immediate forced RV pacing or 6 months of RV pacing)
C
Comparador
Intrinsic atrioventricular conduction (immediate) or baseline pre-implantation (medium-term), stratified by presence or absence of myocardial fibrosis on late gadolinium enhancement CMR
O
Resultado
Changes in LV end-systolic volume index and LV ejection fractionsurrogate
Myocardial fibrosis detected on CMR identifies patients at high risk of immediate and medium-term deterioration in LV function following right ventricular pacing.
Resumen
Background: Long-term right ventricular (RV) pacing leads to heart failure or a decline in left ventricular (LV) function in up to a fifth of patients. We aimed to establish whether patients with focal fibrosis detected on late gadolinium enhancement cardiovascular magnetic resonance (CMR) have deterioration in LV function after RV pacing. Methods: We recruited 84 patients with LV ejection fraction ≥40% into 2 observational CMR studies. Patients (n=34) with a dual-chamber device and preserved atrioventricular conduction underwent CMR in 2 asynchronous pacing modes (atrial asynchronous and dual-chamber asynchronous) to compare intrinsic atrioventricular conduction with forced RV pacing. Patients (n=50) with high-grade atrioventricular block underwent CMR before and 6 months after pacemaker implantation to investigate the medium-term effects of RV pacing. Results: The key findings were (1) initiation of RV pacing in patients with fibrosis, compared with those without, was associated with greater immediate changes in both LV end-systolic volume index (5.3±3.5 versus 2.1±2.4 mL/m 2 ; P 1.1 g of fibrosis with 90% sensitivity and 70% specificity. Conclusions: Fibrosis detected on CMR is associated with immediate- and medium-term deterioration in LV function following RV pacing and could be used to identify those at risk of heart failure before pacemaker implantation.