Oertzenweg 19 b
14163 Berlin
+49 30 838 62299 / 62300
pferdeklinik@vetmed.fu-berlin.de
An 8-year-old warmblood mare was referred to the Equine Clinic of the Freie Universitaet Berlin because of irregular heart rhythm and multiple syncope. The clinical examination revealed a regular heartbeat (38bpm) with a holosystolic heart murmur, grade III/VI on the left side and I/VI on the right side, punctum maximum on the left side over the mitral valve and on the right side over the tricuspid valve. Furthermore, jugular vein pulsation and a prolonged capillary refill time was obvious. A 24-hour continuous ECG revealed a regular rhythm with complete dissociation of the atrial and ventricular activity with an atrial rate of 62bpm and ventricular rate of 38bpm. Later on, the horse developed tachycardia and intermittent asystole. An echocardiography including B-mode, M-mode, color flow and continuous wave Doppler revealed valvular regurgitation of the mitral valve, tricuspid valve and pulmonic valve. The heart’s dimensions, especially on the right side, were enlarged. Furthermore, the horse suffered from lung edema and edema formation on the ventral chest. Congestive heart failure with concomitant third degree AV block and, later on, a ventricular tachycardia with intermitted asystole was diagnosed. The initiated treatment was unrewarding. Due to the grave prognosis, the horse was euthanized. Necropsy revealed chronic, multifocal to coalescing, lymphoplasmacytic and fibrosing epicarditis, myocarditis and endocarditis as well as a mitral valve dysplasia and severe, diffuse subendocardial fibrosis.