Masoud Rajabioun - Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Alireza Vajhi - Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Majid Masoudifard - Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Masoud Selk Ghaffari - Department of Clinical Sciences, Faculty of Veterinary Medicine, Islamic Azad University- Karaj Branch, Karaj, Iran.
Hakimeh Sadeghian - Tehran Heart Centre, Faculty of Medical Sciences, Tehran University, Tehran, Iran.
Mohammad Azizzadeh - Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran.

Objective- To determine the range of systolic times intervals using Pulsed-wave Doppler and m-mode echocardiography in normal, healthy Great Dane dogs. Design- Descriptive study. Animals- Thirty healthy Great Dane dogs. Procedures- This study examined ۳۰ clinically healthy Great Dane dogs by the two-dimensional, M-mode and Pulsed-wave Doppler echocardiography. The dogs were awake and unsedated. The following parameters were measured on the both Pulsed-wave Doppler and M-mode echocardiographic images: pre-ejection period (PEP), left ventricular ejection time (LVET), ratio of PEP to LVET (PEP/LVET) and the total electrical-mechanical systole (QAVC). Acceleration time of aortic flow (AT) was also measured by Doppler mode. Results- The following values have been acquired: PEP = ۰.۰۶۷ ± ۰.۰۱۰ s; LVET = ۰.۱۸۸ ± ۰.۰۱۱ s; QAVC = ۰.۲۵۴ ± ۰.۰۱۶ s and PEP/LVET = ۰.۳۵۴ ± ۰.۰۵۴ measured by Mmode echocardiography and PEP = ۰.۰۶۲ ± ۰.۰۰۹ s; LVET = ۰.۱۹۳ ± ۰.۰۰۷ s; QAVC = ۰.۲۵۶ ± ۰.۰۱۱s; PEP/LVET = ۰.۳۲۳ ± ۰.۰۵۱ and AT = ۰.۰۸۰ ± ۰.۱۰۷ s measured by Doppler echocardiography. Conclusion and Clinical Relevance- On Doppler mode, there was a significant correlation between the body weight and PEP and PEP/LVET. M-mode echocardiography showed significant correlation between the body weight and body surface area and QAVC. Results of this study revealed the importance of determination of breed-specific echocardiographic parameters and indices, and evaluating of measured values with range using same method for accurate diagnosis.

echocardiography, Systolic time intervals, Great Dane, M-mode, Pulsed- wave doppler