[Studies on the electocardiographic parameters of dairy cow [Holstein]]

ABSTRACT

Standard, augmented limb Leads, unipolar [V[10]] and bipolar precordial [Base-apex] leads electrodigrams [ECG] were recorded from 50 healthy dairy cows hept in dairy farm of the School of Agriculture, Shiraz University. The ECGs were analyzed for rhythm, rate, ECG configurations, intervals, amplitudes and vectors. The most significant findings in this study were. The most significant findings in this study were 1. The great variability of QRS complexes in all leads but V[10] and base-apex. 2. Cardiac rhythm was regular in all animals examined. However, slight sinus arrhythmia was observed on a few ECGs. 3. Variations in the forms of P, QRS, T and ECG intervals, and amplitudes given in Tables [1-5]. 4. The mean heart rate was 74 beats per minute. [Range 57-93 bpm] 5. Study of vectors in transvers, horizental and sagittal planes indicated that a] atrial depolarization directed dextrad, caudad and ventrad. b] ventricular depolarization directed dextrad, craniad and slightly dorsad, c] ventricular repolarization directed dextrad, ventrad and slightly caudad. Comparing he main vectors of QRS complex and T-wave showed that the direction of ventricular repolarization [T] is on the opposite direction of depolarization [QRS]. This study demonstrated that there are slight discrepancies between our findings and information reported by others on dairy cows. These may be due to using different breeds, ages and management conditions