Improved Left Ventricular Relaxation During Short-term Right Ventricular Outflow Tract Compared to Apical Pacing

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

“…19 Several recent studies have suggested a potential advantage of using an alternative RV pacing site instead of the apex, specifically placement along the mid to upper infundibular tract. 20,21 In addition, some have suggested that simultaneous RV stimulation at both the apex and outflow tract can led to sufficient resynchronization effect to potentially obviate the need for an LV lead. 22 The latter hypothesis is particularly attractive given the complexity of LV lead placement.…”

Permanent Cardiac Pacing in Adults with High Grade Atriovetricular Block and Preserved Left Ventricular Function: Optimal Mode and Site of Pacing

“…This finding was attributed to the fact that the detrimental effects of RVA pacing become evident after several months, especially in patients with preserved LV systolic function. The RV septal pacing also resulted in shorter isovolumic relaxation than RV apical pacing (Yu et al, 2007), implicating better diastolic function that has been invasively demonstrated by Kolettis et al (Kolettis et al, 2000) at the cardiac catheterization laboratory. In fact despite the beneficial features of reducing electrical and mechanical dyssynchrony , different studies failed to demonstrate a positive effect on indices of LV structure and 85 function and did not confirm the above mentioned clinical outcomes, at least during the 3-18 months after implantation (Bourke et al, 2002;Victor et al, 2006;Kypta et al, 2008;Dabrowska-Kugacka et al, 2009;Gong et al, 2009;Cano et al, 2010) Kypta et al (Kypta et al, 2008) randomized 98 patients with atrioventricular block (AVblock) undergoing pacemaker implantation to positioning the ventricular lead in the high or mid septum (n =53) or in the apex (n = 45) of the right ventricle.…”

“…Right Ventricular Apical permanent pacing could have negative hemodynamic effects. Initially, attention was directed to RV outflow tract/septum pacing and His/para-Hisian pacing in patients with LV dysfunction ( Mera et al, 1999;Schwaab et al, 1999;Buckingham et al, 1997;Buckingham et al, 1998;de Cock et al, 1998) and latter in preserved LV function patients (Giudici et al, 1997;Karpawich & Mital, 1997;Kolettis et al, 2000;Bourke et al, 2002;Tse et al, 2002;Occhetta et al, 2006;Victor et al, 2006;Yu et al, 2007;Kypta et al, 2008;Flevari et al, 2009;Ng et al, 2009;Dabrowska-Kugacka et al, 2009;Takemoto et al, 2009;Gong et al, 2009;Rosso et al, 2010;Verma et al , 2010;106:806-9;Leong et al, 2010;Cano et al,. 2010;Yoshikawa et al, 2010) while subsequently biventricular stimulation began to emerge as an appealing alternative proposal (Yu et al, 2009;Simantirakis et al, 2009;Doshi et al, 2005).…”

“…A pacing site that is in closer proximity with the proximal portion of His bundle at the RV septum should lead to a narrower QRS which in turn might reflect a lesser degree of activation delay compared with RVA pacing (Mera et al, 199;Schwaab et al, 1999;Tse et al, 2002) and less dyssynchrony, as demonstrated by multiple echocardiographic techniques (Tse et, 2002;Flevari et al, 2009;Takemoto et al, 2009;Gong et al, 2009;Leong et al, 2010;Cano et al, 2010). Pacing on the right ventricular (RV) septum, at high (septal RVOT pacing) (Giudici et al, 1997;Kolettis et al, 2000;Bourke et al, 2002;Tse et al, 2002;Dabrowska-Kugacka et al, 2009;Gong et al, 2009;Leong et al, 2010;Yoshikawa et al, 2010), mid (Yu et al, 2007;Cano et al, 2010;Muto et al, 2007) or lower (Flevari et al, 2009) septal pacing position has been introduced as a potentially favorable alternative to RVA pacing to preserve a more physiologic ventricular activation. Previous investigations of alternative pacing sites have yielded inconsistent results (Mera et al, 1999;Giudici et al, 1997;Bourke et al, 2002;Victor et al, 2006;Kypta et al, 2008;Dabrowska-Kugacka et al, 2009;Tse et al Europace 2009;Victor et al, 1999) which may be attributable, in part, to the fact that the pacing site was determined on a topological rather than functional basis (Giudici & Karpawich, 1999).…”

“…Results from acute and chronic studies are summarized in table 1 and show mixed results with a tendency toward better hemodynamic outcome when pacing at these alternative sites (Giudici et al, 1997;Kolettis et al, 2000;Tse et al, 2002;Yu et al, 2007;Flevari et al, 2009;Takemoto et al, 2009;Yoshikawa et al, 2010;Yu et al, 2009;de Cock et al, 2003). AF: atrial fibrillation; AV : atrioventricular; AVNA: AV node ablation; AVB: atrioventricular block; DDD: dual chamber pacing; HRA: high right atrium ; NA: not available; PSP: Peak systolic pressure; RVS: right ventricle septum; RVOT: right ventricle outflow tract; RVA: right ventricle apex; SSS: sick sinus syndrome; VA: ventricular asynchrony; VRR : ventricular rate regularization; VVI: single chamber ventricular pacing; * the study population included only children; § LVEF ≤45% in 12 patients; ¥ LVEF <40% in 14% of patients; ¤ LVEF<40% in 1 patient.…”