Time irreversibility is a fundamental property of nonequilibrium systems. It is significant to measure the trend of change of time irreversible index under different physiological and pathological state of electrocardiosignal. We analyzed and tested the heart rate variability (HRV) signals of the normal sinus rhythm, atrial contraction, sinus bradycardia in the MIT-BIH standard database using the multiscale time irreversiblity method. It was shown that the time irreversiblity index of the normal heart rhythm, atrial premature beats and bradycardia were in the decreasing trend. The results would be helpful to clinical diagnosis as a secondary means.