Title:Lovak pitvarremegésének gyógykezelése szájon át adott kinidin-szulfáttal - Esetismertetések
SUMMARY Background: Atrial fibrillation is a relatively common and significant arrhythmia in horses, but the Hungarian literature lacks the information about its clinical presentation, diagnosis and therapy.Objectives: To present five cases of atrial fibrillation treated with orally admin-istered quinidine sulphate. Materials and methods: Descriptive clinical report. Results and discussion: Five adult horses with suspected atrial fibrillation based on cardiac auscultation were referred for further investigation and therapy. Four of them showed exercise intolerance, as well. Based on previous physical examinations, haematology and biochemistry, systemic diseases were excluded. On presentation, all horses were bright, alert and responsive, and they did not show signs of congestive heart failure. Atrial fibrillation was confirmed by resting electrocardiography using base-apex lead in all cases. Echocardiography revealed normal findings in three horses, mild left ventricular dilation and aortic regurgitation in one animal, and moderate aortic root and left ventricular dilation in another one. Fractional shortening of the left ventricle was decreased in this horse. Cardioversion with oral quinidine sulphate, administered via a nasogastric tube was attempted in four cases. This treatment was successful after two or three doses in two horses which remained in sinus rhythm until discharge from the hospital. Follow-up electrocardiography four to eight weeks later revealed sinus rhythm in both cases. One horse converted back to sinus rhythm after six doses of quinidine and two doses of oral digoxin, but later atrial fibrillation recurred. One horse started to show moderate colic signs and tachycardia after the third dose of quinidine, therefore the treatment was ceased. The last case which was doing only very light work, was not treated by the request of the owner. Our findings highlight the importance of performing cardiac auscultation and ECG on horses with exercise intolerance.