Short-Term Effects of Right-Left Heart Sequential Cardiac Resynchronization in Patients With Heart Failure, Chronic Atrial Fibrillation, and Atrioventricular Nodal Block

Abstract

Background-Single-site ventricular pacing in patients with heart failure, atrial fibrillation, and severe atrioventricular (AV) nodal block risks the generation of discoordinate contraction. Whether altering the site of stimulation can offset this detrimental effect and what role sequential right ventricular-left ventricular (RV-LV) stimulation might play in such patients remain unknown. Methods and Results-Nine subjects with heart failure (ejection fraction, 14% to 30%), atrial fibrillation, and AV block were studied by pressure-volume analysis. Ventricular stimulation was applied to the RV (apex and outflow tract), LV free wall, and biventricular (BiV) at 80 and 120 bpm. BiV improved systolic function more than either site alone (dP/dt max , 810Ϯ83, 924Ϯ98, 983Ϯ102 mm Hg/s for RV, LV, BiV, respectively; PϽ0.05), although LV pacing was significantly better than RV pacing. However, only BiV improved diastolic function (isovolumic relaxation) over RV or LV alone. Similar results were obtained for both heart rates. RV pacing site did not alter the BiV effect, and concomitant stimulation of both RV sites did not improve function over each alone. Finally, varying RV-LV delay revealed optimal responses with simultaneous pacing. Conclusions-Simultaneous BiV pacing acutely enhances both systolic and diastolic function over single-site RV or LV pacing in congestive heart failure patients with atrial fibrillation and advanced AV block. Sequential RV-LV stimulation offers minimal benefit on average and should perhaps be considered only in targeted subsets such as nonresponding patients.

The effect of repolarization duration on the indices of the pump function of the heart ventricles in animals with different types of activation of the myocardium under ectopic excitation of ventricles

“…The ectopic excitation of the RV apical area more expresses the inotropic effect on the pump function in both ventricles in dogs. At that, parameters of cardiac hemodynamics were significantly lower at pacing of the RV apex that corresponds to the data of other authors [6,[15][16][17][18][19][20]. In amphibians the indices of the pump function of the heart decreased at ventricular pacing (base and apex).…”

“…Many studies report that only LV pacing leads to the increase of the duration of contraction and thus, reduces velocity of isovolumic relaxation of the ventricle [18,26]. In the present study we found out that ventricular pacing in dogs and amphibians decreases isovolumic indices (dP/dt max and dP/dt min ).…”

Identification of the Right Ventricular Pacing Site for Cardiac Resynchronization Therapy (CRT) Guided by Electroanatomical Mapping (CARTO)

“…Hay et al reported the results of a comparison of the acute hemodynamic effects of BVP using RVA and RVOT/septal sites in 6 patients with AF and found no differences. 23 In their study, however, details of the septal sites were not clarified. We consider that the septal sites of the RV are important sites for BVP and clearly demonstrated in our study that the RV septal pacing site was important for better hemodynamic outcomes with BVP.…”

Change in Blood Pressure Just After Initiation of Cardiac Resynchronization Therapy Predicts Long-Term Clinical Outcome in Patients With Advanced Heart Failure

“…[17][18][19][20] It is well known that aortic pulse pressure directly correlates with cardiac output at a constant heart rate and vascular load, 21 so most studies have examined pulse pressure as a measurement variable. However, a significant correlation between the changes in pulse pressure and clinical outcome was not found in those studies [17][18][19][20] and none have reported that a rise in SBP predicts the short-and long-term clinical outcome after CRT.…”

“…19,[22][23][24] Molhoek et al studied patients with and without chronic AF and showed that their clinical parameters improved after 6 months of CRT and the rate of non-responders was greater among patients with AF. 22 Delnoy et al showed that the benefit of CRT in patients with chronic AF and HF was similar to that in patients with SR, and that long-term survival after CRT did not differ between the AF and SR groups.…”