Mechanism of cardiac output gain from cardiac resynchronization therapy in patients with coronary artery disease or idiopathic dilated cardiomyopathy

The American Journal of Cardiology
T V SalukheM Henein

Abstract

The mechanisms underlying cardiac resynchronization therapy have consistently been studied at rest and remain ill defined. Peak stress total isovolumic time (t-IVT) is a major determinant of cardiac output (CO) in chronic heart failure. In this study, pharmacologic stress was used to assess the effects of atrioventricular (AV) delay shortening and ventricular resynchronization elements of cardiac resynchronization therapy. Thirty patients undergoing cardiac resynchronization therapy were studied <6 months after implantation. t-IVT and CO were measured during native activation (left bundle branch block), AV delay shortening (right ventricular dual-chamber pacing), and full resynchronization (atrio-biventricular pacing). Full resynchronization shortened peak stress t-IVT by 9.4 +/- 6.2 s/min (p <0.001) and increased peak stress CO by 0.9 +/- 0.4 L/min (p <0.001), with the effects in individual patients showing a large correlation (r = -0.64, p <0.001). In contrast, simple AV delay shortening did not shorten peak stress t-IVT nor increase peak stress CO, nor was CO at rest affected by full resynchronization or AV delay shortening. Of all measurements during native activation, the best predictor of gain in peak stress CO from full ...Continue Reading

References

Feb 1, 1995·British Heart Journal·M Y Henein, D G Gibson
Mar 22, 2001·The New England Journal of Medicine·S CazeauUNKNOWN Multisite Stimulation in Cardiomyopathies (MUSTIC) Study Investigators
Jun 14, 2002·The New England Journal of Medicine·William T AbrahamUNKNOWN MIRACLE Study Group. Multicenter InSync Randomized Clinical Evaluation
Nov 3, 2004·Journal of the American College of Cardiology·Jeroen J BaxMartin J Schalij

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Citations

Nov 12, 2013·International Journal of Cardiology·Dejan MarasMichael Y Henein
Apr 9, 2008·European Journal of Heart Failure·Alfonso MacíasIgnacio García-Bolao
Oct 9, 2012·International Journal of Cardiology·Kaushik GuhaAlison M Duncan
Oct 19, 2017·BMC Cardiovascular Disorders·Artan AhmetiGani Bajraktari

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