Veterinary Research Communications, 31(Suppl. 1) (2007) 297–299 DOI: 10.1007/s11259-007-0051-2
# Springer 2007
Haemodynamic Effects in Healthy Horses Treated with an ACE-Inhibitor (Ramipril) A. Luciani1,2,*, C. Civitella1, D. Santori1, S. Sconza1 and C. Guglielmini1 1 Department of Veterinary Clinical Sciences, School of Veterinary Medicine, University of Teramo, Italy; 2Dipartimento di Scienze Cliniche Veterinarie, Facolta` di Medicina Veterinaria, Viale F. Crispi 212, 64100, Teramo, Italy * Correspondence: E-mail:
[email protected]
Luciani, A., Civitella, C., Santori, D., Sconza, S. and Guglielmini, C. 2007. Haemodynamic effects in healthy horses treated with an ACE-inhibitor (ramipril). Veterinary Research Communications, 31(Suppl. 1), 297–299 Keywords: ACE-inhibitor, arterial blood pressure, cardiovascular system, horse, ramipril Abbreviations: ACE, angiotensin-converting enzyme; CBC, complete blood count; CHF, congestive heart failure; DAP, diastolic arterial pressure; ECG, electrocardiography; HR, heart rate; MAP, mean arterial pressure; SAP, systolic arterial pressure
INTRODUCTION ACE-inhibitors are widely used in humans and in small animals for the treatment of CHF and systemic hypertension (Brown and Vaughan 1998; Wolfel 1998). Data regarding the haemodynamic effects and therapeutic use of these drugs are scarce for the horse. In an experimental study, it was demonstrated that the ACE-inhibitor ramipril is useful in contrasting the hypertensive effects of angiotensin I (De Luna et al. 1995). The clinical effectiveness of ramipril on the clinical signs of CHF in a horse with chronic valvular disease was described. The effects of the drug on arterial blood pressure were also demonstrated (Guglielmini et al. 2002).The aim of this study was to evaluate the haemodynamic effects of ramipril in healthy horses. MATERIALS AND METHODS Five clinically healthy horses aged between 7 and 20 years were employed in the study. Each horse underwent a clinical examination, an ECG, a complete echocardiographic and echo-Doppler examination and a CBC and serum biochemical profile and all results fell within references values. All subjects were admitted to the Veterinary Teaching Hospital, University of Teramo the day before ramipril administration to permit them to adjust to a new environment and to get used to being handled. Food was withheld 12 hours before administration of the drug. On day 1 arterial blood pressure was measured without drug administration. On the morning of days 2 to 5, 200 mg/kg of ramipril (Triatec\, Aventis Pharma) diluted in 4 litres of warm water was administrated through a naso-gastric tube. Each horse was monitored by a base-apex ECG to control the HR and by a multiparametric system (M3046A, Philips) to evaluate the SAP, DAP and MAP
297
298
using an oscillometric method. Blood pressure measurements were performed using a cuff placed at the coccygeal artery. The trend of the arterial blood pressure and the HR was measured on day 1 and then during ramipril administration (days 2–5) at the following experimental times: T0, before the drug_s administration, and then at T1, T2, T4, T6, T8, T12, T24 corresponding to 1, 2, 4, 6, 8, 12, 24 hours after administration. At each experimental time, blood pressure measurements were taken ten times with an interval of two minutes between each measurement. The mean values and the standard deviation of each experimental time and of each day of study were calculated, eliminating the highest and the lowest values. The calculated mean pressure values were increased by 0.75 mmHg for each centimetre of vertical distance between the position of the cuff and the level of the right atrium (Wagner and Brodbelt 1997). The haematological and biochemical tests and a final arterial blood pressure monitoring were performed on day 6 in order to establish possible drug side effects. Data were statistically calculated using the SPSS Base 9.0 statistical software package. A Student_s T test for paired data was employed to compare mean blood pressure and HR values on each day of the study. A value of P
