Assessment of electrocardiographic findings, serum nitric oxide, cardiac troponins and some enzymes in calves with hyperkaliemia related to neonatal diarrhoea

摘要

The aims of the present study were to characterize ECG changes in calves with hyperkaliemia due to neonatal diarrhoea and to determine concomitant variations of serum concentrations of NO and of some cardiac markers such as cardiac troponins I and T and serum enzyme AST, LDH, CK and CK-MB activities. For that; ECG examinations were performed and serum biochemical parameters were measured in 13 diarrhoeic calves developing hyperkaliemia before and 5 hours after intravenous electrolyte (NaCl and Na_2HCO_3) administration and also in 5 healthy control calves. Compared to controls, diarrhoeic and hyperkaliemic calves exhibited significant alterations in electrolyte concentrations (increases of K; Mg and P concentrations coupled to decreases of Na and C1concentrations), a significant blood accumulation of nitrogen compounds (BUN and creatinine) and significant increases in ALP, LDH, CK and GGT activities. Furthermore; the serum NO concentrations have greatly enhanced in some individuals. By contrast, the serum troponin concentrations and the heart specific CK-MB and AST activities were similar between the 2 groups whereas electrocardiography changes were evidenced in diarrhoeic calves: P wave anomalies were observed in some diseased calves and the mean amplitude and the mean duration of the QRS complex and the T wave were markedly increased. The fluid electrolyte therapy has restored the electrolyte balance and has globally improved the parameters of the cardiac function but has failed to counteractthe blood azote accumulation and the release of ALP; LDH, CK and GGT enzymes and even has aggravated the decreases in total protein and albumin concentrations and the glycaemia variations. These results suggest that the diarrhoearelated hyperkaliemia hasled to disturbances into the cardiac function without inducing severe myocardium lesions in calves but was coupled to acute renal failure.