Introduction: Pulmonary hypertension syndrome (PHS) begins with pulmonary hypertension that leads to ventricular hypertrophy especially right ventricular hypertrophy (RVH), tricuspid valve insufficiency and right ventricular failure followed by ascites and death. So we decided to evaluate the electrocardiographic changes and the effect of cardiac ventricular hypertrophy on the electrocardiogram wave during the development of PHS.
Methods: 300 one day old cockerels were divided into three groups; control, T3 and cold. The T3 and cold groups made susceptible to PHS by a standard defined method. At different ages electrocardiogram were taken randomly from 10 chickens of each group, then they weighed, killed and their ventricles weighed.
Results: The voltage of R and S waves were greater in the groups made susceptible to PHS (P<0.05), and the duration of QRS complex was also greater in these groups at 42 day old (P<0.05). Both ventricles hypertrophied in T3 and cold. The voltage of R wave had positive and the voltage of S wave had negative correlation with ventricular weight, before being sever the mortality of ascites (P<0.05). After the peak of mortality, the R wave had negative correlation with the ratio of right ventricle/total ventricle (RV/TV; a major index in PHS), and the S wave had positive correlation with the RV/TV and right ventricle/ body weight (P<0.05).
Conclusion: Since the ECG wave are changed before and after the severity of PHS, should be more careful in its prediction by the electrocardiogram.