Left Ventricular Extracellular Matrix Remodeling in Dogs with Right Ventricular Apical Pacing

Abstract

LV dyssynchrony by RV apical pacing elicits heterogeneous ECM remodeling in the LV. These findings assist in the elucidation of the pathophysiology of LV desynchronization.

Randomized placebo controlled blinded study to assess valsartan efficacy in preventing left ventricle remodeling in patients with dual chamber pacemaker — Rationale and design of the trial

“…Pacing caused significantly abnormal motion at the pacing site, and this pacing-induced dyssynchrony of left ventricle contraction was sufficient to stimulate matrix metalloproteinase-9 (MMP-9) activity. Lin et al [10] have found increased interstitial fibrosis and fragmentation of myofibrils in the left ventricle lateral wall in the right ventricle apical pacing group. Moreover there was increased activation of MMP-2, MMP-9, tissue inhibitor of matrix metalloproteinase TIMP-1 and TIMP-3 in the same area.…”

“…Though, it is highly probable that the diastolic dysfunction, observed in this study, can be mainly attributed to rapid pacing-induced ischemia, and not to direct effect of pacing. Nevertheless, two animal experiments provide probable pathophysiologic explanation for the immediate relation of pacing and left ventricle dysfunction [9,10]. Garcia et al [9] used piezoelectric sensors, that were located at pacing site and remote site, to assess myocardial contractility.…”

Perspectives on Pharmacological Prevention of Pacing Induced Heart Remodeling: Targeting Extracellular Matrix

“…There are several papers elucidating the underlying mechanisms of detrimental effect of right ventricle apical pacing [6][7][8]. Tse et al [8] have proved that patients with right ventricle apical pacing have had significantly increased perfusion defects in dipyridamole thallium myocardial scintigraphy along with regional wall motion abnormalities in radionuclide ventriculography.…”

“…The animal experimental models [6,7] provide much more detailed characteristic of consequences of pacing. Both experiments were carried out in dogs, but researchers have studied different pacing sites.…”

“…Both experiments were carried out in dogs, but researchers have studied different pacing sites. Garcia et al [6] have used atrial and left ventricle epicardial pacing in an open chest anesthetized dogs, as Lin et al [7] have used obligatory atrial synchronized right ventricle apical pacing in dogs, which have been subjected to atrioventricular node ablation. Moreover, Garcia et al [6] have used sonomicrometric sensors to monitor dyssynchrony of ventricular contraction at the pacing and remote to pacing lead areas of left ventricle, as well as left ventricle catheter to assess left ventricle pressure curve.…”