Aorto-cardiac fistulas in seven horses

• Published in: Veterinary radiology & ultrasound 1998-01, Vol.39 (1), p.22-31
• Main Authors: Marr, C.M, Reef, V.B, Brazil, T.J, Thomas, W.P, Knottenbelt, D.C, Kelly, D.F, Baker, J.R, Reimer, J.M, Maxson, A.D, Crowhurst, J.S
• Format: Article
• Language: English
• Subjects: Age Factors; aneurysm; Animals; AORTA; Aortic Aneurysm - diagnosis; Aortic Aneurysm - pathology; Aortic Aneurysm - veterinary; Aortic Diseases - diagnosis; Aortic Diseases - drug therapy; Aortic Diseases - pathology; Aortic Diseases - physiopathology; Aortic Diseases - veterinary; Aortic Rupture - diagnosis; Aortic Rupture - pathology; Aortic Rupture - veterinary; aorto-cardiac fisula; arrhythmia; ARTERE; ARTERIAS; ARTERIES; BLOOD CIRCULATION; BLOOD VESSELS; CABALLOS; CHEVAL; CIRCULACION SANGUINEA; CIRCULATION SANGUINE; COEUR; CORAZON; DEBIT; Diagnosis, Differential; ECHOCARDIOGRAPHY; Echocardiography - veterinary; ECHOGRAPHIE; ECHOGRAPHY; ECOGRAFIA; ELECTROCARDIOGRAFIA; ELECTROCARDIOGRAPHIE; ELECTROCARDIOGRAPHY; Electrocardiography - veterinary; Exercise Tolerance; Female; Fistula - diagnosis; Fistula - drug therapy; Fistula - pathology; Fistula - physiopathology; Fistula - veterinary; FISTULATION; FISTULISATION; FISTULIZACION; FLOW RATE; FRECUENCIA CARDIACA; FREQUENCE CARDIAQUE; GASTO; HEART; Heart Atria - pathology; Heart Diseases - diagnosis; Heart Diseases - drug therapy; Heart Diseases - pathology; Heart Diseases - physiopathology; Heart Diseases - veterinary; Heart Murmurs - pathology; Heart Murmurs - physiopathology; Heart Murmurs - veterinary; HEART RATE; Heart Septum - pathology; HEART SOUNDS; Heart Ventricles - pathology; horse; Horse Diseases - diagnosis; Horse Diseases - drug therapy; Horse Diseases - pathology; Horse Diseases - physiopathology; HORSES; JUGULAR VEIN; Male; PULSATION; Pulse - veterinary; SINTOMAS; Stress, Physiological - physiopathology; Stress, Physiological - veterinary; Survival Rate; SYMPTOME; SYMPTOMS; Tachycardia, Ventricular - physiopathology; Tachycardia, Ventricular - veterinary; Treatment Outcome; VAISSEAU SANGUIN; Vascular Fistula - diagnosis; Vascular Fistula - drug therapy; Vascular Fistula - pathology; Vascular Fistula - physiopathology; Vascular Fistula - veterinary; VASOS SANGUINEOS; ventricular tachycardia; VIBRACIONES; VIBRATION
• ISSN: 1058-8183; 1740-8261
• DOI: 10.1111/j.1740-8261.1998.tb00321.x

This report describes the history, clinical, electrocardiographic and echocardiographic findings, treatment, outcome, and post‐mortem findings in seven horses with aorto‐cardiac fistula. Affected horses included 5 stallions, one gelding and one mare; 2 each of the Thoroughbred, Arabian and Standardbred breeds and one Thoroughbred‐cross with a mean ± s.d. age of 12 ± 4 years, range 6–18 years. The presenting sings were acute distress (four horses), exercise intolerance (two horses) and the lesion was detected during a routine examination in one horse. Five horses had monomorphic ventricular tachycardia on admission and one other had a history of this arrhythmia. Five horses had a characteristic continuous murmur loudes in the right fourth intercostal space. Echocardiography (six horuses) and/or post‐mortem examination (four horses) revealed the horses had aorto‐cardiac fistulas arising from the right aortic sinus in all five horses in which the site was recorded. Two horses had ruptured aneurysmall dilatations of the aortic wall at this site. Fistulas extended into the right ventricle in four horses; the right atrium in two horses, the left ventricle in one horse, and five horses had dissecting tracts in the septal myocardium. Horses survived for periods ranging from 24th to 4 years. Aorto‐cardiac fistula should be considered in the differential diagnosis for horses presenting with acute distress, bounding arterial pulse, a right‐sided continuous murmur and/or monomorphic ventricular tachycardia, particularly in middle‐aged or older stallions. Echocardiography is the technique of choice for confirming the diagnosis and demonstrating accompanying cardiac changes.