Korean Journal of Veterinary Research 1993;33(4):735-746.
 Studies on electrocardiogram of the normal Korean native cattle II. Wave forms and amplitudes of the unipolar precordial chest leads In-hyuk Choi1, Soo-young Kim1, Nam-soo Kim1, Doo-seok Suh2 1College of Chonbuk National University2College of Chonnam National University 정상적(正常的)인 한우(韓牛)의 심전도(心電圖)에 관(關)한 연구(硏究) II. 흉부단극유도(胸部單極誘導)의 파형(波形)과 전위(電位) 최인혁1, 김수용1, 김남수1, 서두석2 1전북대학교 수의과대학2전남대학교 수의과대학 Abstract Electrocardiographic parameters of amplitude and the shape of waves on the unipolar precordial chest leads in the normal Korean native cattles have been measured with a 3 channel electrocardiograph built in a computed and analysis. The study was conducted on 98 heads of mean age of 17.6 months. The wave forms of P, T and QRS complex wave in all leads showed various types. The parameters of the amplitude in the wave types showed the most frequency in each lead that were analyzed as follow : 1. In P wave, amplitudes of positive type showed a frequency of 92.9% and 93.9% in leads $CV_6LU$ and $CV_6LL$ that were $83.8{pm}31.0{mu}V$ and $76.0{pm}30.7{mu}V$, and negative type showed a frequency of 97.9% in lead V 10 that were $-80.2{pm}29.4{mu}V$, respectively. But the plate type in leads $CV_6RU$ and $CV_6RL$ showed frequency of 48% and 58.3%, respectively. 2. Average amplitude of the QRS complex were in a range of $277.0{pm}154.0{mu}V$ to $648.2{pm}146.2{mu}V$(mean of $418.8{pm}139.4{mu}V$) in all leads that were manifested the Low-Voltage QRS complex(below 1 mV in unipolar precordial leads). Average amplitudes of each wave type in the QRS complex were $-250.0{pm}139.8{mu}V$ and $-399.2{pm}226.8{mu}V$ in the QS group types that showed a frequency of 50.0% and 82.5% in the leads $CV_6LU$ and $CV_6LL$, respectively. And average amplitudes of the R group types showed a frequency of 85.6%, 56.1% and 75.8% in the $CV_6RU$, $CV_6RL$ and $V_{10}$ that were $321.5{pm}142.1{mu}V$, $271.6{pm}139.9{mu}V$ and $552.4{pm}132.7{mu}V$, respectively. 3. In T waves, Amplitudes of the positive type showed a frequency of 60.2%, 46.9% and 83.7% in leads of $CV_6LL$, $CV_6RU$ and $CV_6RL$ that were respectively $184.7{pm}93.7{mu}V$ $103.7{pm}64.43{mu}V$ and $111.8{pm}39.3{mu}V$, the negative type showed a frequency of 62.2% and 93.7% in leads $CV_6LU$ and $V_{10}$ that were $142.2{pm}82.1{mu}V$ and $-280.3{pm}107.2{mu}V$, respectively. 4. Average amplitude of ST segment were $3.7{pm}33.1{mu}V$, $0.9{pm}23.1{mu}V$, $10.9{pm}28.6{mu}V$, $5.8{pm}28.3{mu}V$ and $-34.7{pm}48.4{mu}V$ in leads $CV_6LL$, $CV_6RU$, $CV_6RL$, $CV_6LU$ and $V_{10}$ respectively. Key Words: Korean native cattle, Electrodiagram, Unipolar precordial chest leads