Objectives To assess differences in blood flow
momentum (BFM) and kinetic energy (KE) dissipation in
a model of cardiac dyssynchrony induced by electrical
right ventricular apical (RVA) stimulation compared with
spontaneous sinus rhythm.
Methods We cross-sectionally enrolled 12 consecutive
patients (mean age 74±8 years, 60% male, mean left
ventricular ejection fraction 58%±6 %), within 48 hours
from pacemaker (PMK) implantation. Inclusion criteria
were: age>18 years, no PMK-dependency, sinus rhythm
with a spontaneous narrow QRS at the ECG, preserved
ejection fraction (>50%) and a low percentage of PMKstimulation (<20%). All the participants underwent a
complete echocardiographic evaluation, including left
ventricular strain analysis and particle image velocimetry.
Results Compared with sinus rhythm, BFM shifted from
27±3.3 to 34±7.6° (p=0.016), while RVA-pacing was
characterised by a 35% of increment in KE dissipation,
during diastole (p=0.043) and 32% during systole
(p=0.016). In the same conditions, left ventricle global
longitudinal strain (LV GLS) significantly decreased from
17±3.3 to 11%±2.8% (p=0.004) during RVA-stimulation.
At the multivariable analysis, BFM and diastolic KE
dissipation were significantly associated with LV GLS
deterioration (Beta Coeff.=0.54, 95% CI 0.07 to 1.00,
p=0.034 and Beta Coeff.=0.29, 95% CI 0.02 to 0.57,
p=0.049, respectively).
Conclusions In RVA-stimulation, BFM impairment and
KE dissipation were found to be significantly associated
with LV GLS deterioration, when controlling for potential
confounders. Such changes may favour the onset of
cardiac remodelling and sustain heart failure.
