Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 32 1 2010 03 21 Cardiac Biochemical, Electrical and Functional Alterations in a group of Untrained Males after one bout of Maximal Isometric Exercise 26 32 EN Hassan Pourrazi Journal Article 2010 05 19 Background and Objectives: Recently, exercise-induced biochemical's, electrical and functional changes of cardiovascular system are used as a diagnostic measurement in the field of cardiology. Therefore, this study was conducted to investigation the above parameters in a group of untrained males after one bout of maximal isometric exercise (MIE). Materials and Methods: In this prospective study, we entered 17 healthy untrained young male volunteers. They performed a dead-lift exercise on the maximal voluntary contraction (MVC) for 30 second. Rate-pressure product (RPP), serum CK-MB and ECG monitoring were recorded before and immediately after one bout of maximal isometric exercise in each participant. Data were expressed as means ± S.E and analyzed by paired t-test and Pearson´ correlation coefficient at α≤0.01. Results: The results indicate that all functional indices (HR, SP & RPP) and serum CK-MB were statistically increased in the participants (aged = 22.47±1.54 year; BF% = 17.01 ± 1.03) after the training protocol. Indeed, T wave and QT interval were significantly changed after MIE but ST segment was not changed after the protocol. Thus, the results indicate meaningful linear correlation between and RPP and CK-MB (r=0.73; P<0.0003) and between T wave changes with RPP (r=-0.66; P <0.002) and CK-MB (r=-0.52; P <0.01). Conclusion: Based on the present findings, it can be concluded that the rate-pressure product can be used as a simple and noninvasive method for estimating cardiac strain during isometric exercises.