Open AccessTissue D oppler Imaging and 2‐Dimensional Speckle Tracking of Left Ventricular Function in H orses Exposed to L asalocid
Author(s) -
Decloedt A.,
Verheyen T.,
Sys S.,
Clercq D.,
Loon G.
Publication year - 2012
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/j.1939-1676.2012.00972.x
Subject(s) - medicine , doppler imaging , troponin i , cardiology , ventricular tachycardia , horse , tachycardia , sinus tachycardia , myocardial infarction , blood pressure , paleontology , diastole , biology
Background Tissue Doppler imaging ( TDI ) and 2‐dimensional speckle tracking (2 DST ) can quantify left ventricular ( LV ) function in horses. Objectives To evaluate LV function by TDI and 2 DST in horses with myocardial dysfunction after accidental ionophore intoxication. Animals Sixty‐seven horses exposed to lasalocid in feed. Methods Prospective study. Horses were included in the study if a full cardiac examination was performed, consisting of determination of cardiac troponin I ( cTnI ), electrocardiography, and echocardiography. By TDI, radial systolic velocity and strain were measured. By 2 DST , circumferential (SC) and radial ( SR ) strain at papillary muscle and chordal level and longitudinal ( SL ) strain were measured. Results Twenty horses showed signs of myocardial injury. Forty‐nine examinations were performed on these horses between day 30 and 490 after suspected onset of exposure. Five horses had increased cTnI and ventricular tachycardia and 15 had increased cTnI without ventricular tachycardia. Horses with mild myocardial damage showed few significant differences compared with a control group. Horses with severe myocardial damage showed severely decreased TDI , 2 DST and fractional shortening measurements ( P < .05), indicating impaired LV function. Long‐term follow‐up of 2 surviving horses demonstrated full recovery in 1 horse and permanent myocardial fibrosis in the other. The lowest measurements per horse (n = 20) for all TDI measurements, SL , SR at chordal level, and FS correlated significantly with maximal cTnI ( P < .05). Over all examinations (n = 49), TDI and 2 DST measurements correlated well with FS ( P < .05). Conclusions and Clinical Importance The TDI and 2 DST measurements allowed accurate detection and quantification of LV dysfunction in horses exposed to lasalocid.