14th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 2000

Jan. 29 - Feb. 5, 2000
Marilleva, Trento, Italy

RT-32

Pacemaker current in human ventricular myocytes: modulation and role in arrhythmogenesis

Laura Sartiani, Elisabetta Cerbai, Petra DePaoli, Alessandro Mugelli.
Department of Preclinical and Clinical Pharmacology, University of Firenze, Italy

Introduction

Human ventricular myocytes (HuVM) isolated from failing human hearts show altered electrophysiological properties, ranging from a prolonged action potential duration (APD) to the presence of the pacemaker current, I_f (for reviews see Cerbai et al¹ and Tomaselli and Marban²). All these alterations are thought to contribute to life-threatening arrhythmias occurring in heart failure.

In previous studies^3,4 we have shown that in myocytes isolated from the hypertrophied heart of old spontaneously hypertensive rats (SHR), a predictive model of the alterations occurring in human failing cardiac myocytes, b-adrenoreceptors (AR) stimulation affects APD, steepness of diastolic depolarization (DD) and amplitude of I_f. In this paper we report the effect of a- and b-AR stimulation in HuVM in order to get insight into the proarrhythmic role of catecholamines in the human failing heart.