Implantation of a programmable atrioventricular pacemaker in a donkey with complete atrioventricular block and syncope.

Abstract

The Adams-Stokes syndrome is characterised by syncopal episodes caused by severe cardiac dysrhythmias. Bradydysrhythmias such as sick sinus syndrome or advanced atrioventricular (AV) block and tachydysrhythmias such as ventricular tachycardia can cause syncope because of variable reduction of cardiac output (Naccarelli 1984). The Adams-Stokes syndrome has been reported in horses presenting with an advanced atrioventricular block (Bosnic and Rapic 1948; Briller 1963; Taylor and Mero 1967; Reef et al. 1986). Artificial pacemakers were developed to treat bradydysrhythmias causing AdamsStokes syndrome in humans in the late 1950s. Patients with complete AV block and syncope have an improved survival rate with cardiac pacing (see Atlee 1987). Pacemaker implantation for treatment of complete AV block has been described in two horses (Taylor and Mero 1967; Reef et al. 1986). This paper describes the use of an AV sequential pacemaker in a young donkey with complete AV block and syncope. Adams-Stokes syndrome was documented by electrocardiographic and haemodynamic monitoring.