Abstract

ZOCALO, Yanina et al. Terapia de resincronización cardíaca: importancia de los cambios vasculares periféricos en la reducción de la poscarga ventricular y mejora de la eficiencia ventricular. Rev.Urug.Cardiol. [online]. 2012, vol.27, n.1, pp.28-43. ISSN 1688-0420.

Introduction: cardiac resynchronization therapy (CRT) would associate vascular changes that could contribute to CRT’s benefits and to understand differences in patients’ capability to respond to the therapy. However, when evaluating CRT’s working mechanisms and defining responders or non-responders only structural-functional cardiac changes are considered. Aims: 1) to evaluate CRT short-term effects on cardiac energetics and afterload, and 2) to analyze the meaning of the peripheral vascular changes in the ventricle performance after-CRT. Methods: cardiac and aortic echographies were done in 25 patients (age: 61±12 years; 14 men) before and after CRT. Standard structural, functional parameters and dyssynchrony indices were evaluated. Central pressure was derived using a transfer function and the diameter calibration method. Calculus: cardiac output, afterload, net arterial load and its determinants (central and peripheral components). Results: CRT resulted in an increase in cardiac output and arterial compliance, and in a reduction in peripheral vascular resistances, aortic impedance and ventricular volumes (p<0,05). The cardiac and vascular changes associated with CRT determined an afterload reduction (-19%). Without a reduction in peripheral vascular resistances, CRT would result in an afterload increase (~44-56%) and in a reduction in the ventricle efficiency. Conclusion: early after CRT central and peripheral arterial biomechanics improved, with a reduction in net arterial load. Simultaneous ventricular and vascular changes explain CRT benefits. An enhanced ventricular performance and cardiac output without peripheral vascular changes would result in detrimental changes in the ventricle’s working conditions (increased afterload)

Keywords :  ARTERIES;  BIOMECHANICS; CARDIAC ELECTROPHYSIOLOGY; HEART FAILURE; VASCULAR PERIPHERAL RESISTANCE; CARDIAC RESYNCHRONIZATION THERAPY.

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