Comparison of St-Segment Duration and Morphology between Clinically Healthy and Diarrheic Holstein Dairy Calves

Several diarrheic (n=52) and clinically healthy (n=21) calves were randomly selected and assigned into 3 age groups, comprising newborn calves (18 to 72 hours; n=31), 15 (n=30) and 30 days old (n=12). Electrocardiograms were recorded on a bipolar base apex lead, using limb lead I and duration, amplitude and morphology of the STsegment were assessed from successive beats. Serum concentration of sodium, potassium, magnesium and ionized calcium were also determined in all studied animals. ST-segment duration had not significant differences among any groups. Elevation of ST-segment was detected in 75% of healthy newborn calves (amplitude was 0.10±0.03 mV in elevated ST-segments). The ST-segment was elevated in a percent of diarrheic calves; there was elevation in 78.9% (0.14±0.04 mV), 34.6% (0.11±0.04 mV) and 57.1% (0.11±0.04 mV) in newborn, 15 and 30 days old diarrheic calves, respectively. Serum potassium, calcium and magnesium concentrations in all studied diarrheic calves were higher than healthy calves, significantly. It may be stated the electrolyte imbalances in diarrheic calves can induce alterations in ST-segment morphology and the results of the current study may interpret the alterations of ST-segment morphology in diarrheic calves.