PowerPoint Presentation

L. Wu, MD; C.P. Allaart, MD, PhD; G.J. de Roest, MD; M.L. Hendriks, MA; A.C. van Rossum, MD, PhD; C.C. de Cock MD, PhD

ACC Scientific Sessions, San Francisco, CA9 March 2013

The influence of right ventricular pacing on response to biventricular stimulation -An acute pressure-volume loop study-VUmc Basispresentatie1I would like to thank the organizing committee for the invitation to present my research. I will talk about the influence of RV pacing on the response to Biv pacing.Cardiac resynchronization therapyStandard therapy in end-stage heart failureLV only versus biventricular pacing

Leclercq et al. JACC 2002Thibault et al., Circ 2011Kass et al., Circ 1999

p=0.001Hemo staafVUmc Basispresentatie2Cardiac resynchronization therapyContribution RV only pacing?Detrimental effects on LVIn LBBB patientsHigher degree of mechanical dyssynchrony Decrease in contractility

Thambo et al., Circ 2004Sweeney et al., JACC 2006Auricchio et al., JACC 2002Tops et al., JACC 2009

But the contribution of RV stimulation remains controversial. RV pacing is associated with detrimental effects on the LV. It is known that in patients with a conventional pacemaker, RVA pacing causes remodeling of the LV, asymmetrical hypertrophy of the septum, impaired cardiac output and LVEF. In patients with reduced EF, RV pacing gives a larger electrical delay. And in the presence of a conduction delay, this delay is even larger. In LBBB patients, RV pacing causes an even higher degree of mechanical dyssynchrony and a decrease in contractility. CRT has a high non-response rate, maybe this high non-response rate is partially caused by the effects of RV pacing. A theory for CRT response is that fusion of the activation wave fronts can cause a better hemodynamic response (dP/dtmax). Fusion means that there is an activation wave front from the patients intrinsic RBB and the LV paced wave front. We expect that patients with a normal AV-delay will need LV only pacing to achieve fusion. While patients with a long AV-delay needs biventricular pacing, as you can see here. We believe we should focus on the role of RV pacing, to see what the effect of RV pacing is in CRT patients.AimTo investigate the influence of RV pacing on hemodynamic response during biventricular stimulation

Therefore the aim of our study is to investigate the influence of RV pacing on hemodynamic response during biventricular pacing. MethodsPatients eligible for CRTTemporary pacing leadsConductance measurements

RA leadRV leadPL lead

Conductance catheterTemporary pacing leads were placed at the PL site, in the RV and in the RA. A conductance catheter was introduced into the LV cavity to measure pressure and volumes throughout the whole cardiac cycle, during intrinsic rhythm and during the different pacemodalities, as you can see in this movie. Here you see the PV loop during Biv pacing and now you see the PV loop without pacing.Pressure-volume loop

BaselineRV onlyLV onlyBiventricular

Here you see an example of one patient. Here you see the PV-loop on the X-axis you see the volume and on the Y-axis you see the pressure. The first one is a baseline loop, then a loop during RVA pacing, PL and PLRVA pacing. The grey surface of the PV-loop is the stroke work. What you can see is that the SW changes during the different pacing modes. Also the form of the PL-loop changes. In this case you see that the SW of PLRVA pacing is larger than during RVA and PL pacing.

Haage en JongewaardResultsBaseline characteristicsn=59Age (yrs)6710Male39 (66%)QRS (ms)15421Ischaemic, n36 (61%)NYHA, nI / II / III / IV0 / 14 / 45 / 0NT-pro BNP (ng/L)16371375LVEDV (ml)294151LVESV (ml)232142LVEF (%)2213In total, 59 patients were included with a mean age of 67, mostly male, prolonged QRS complex and decreased LVEF

Acute effect of pacing on SW p=NSp