Effects of lead on systolic and diastolic cardiac functions.

In this paper, both systolic and diastolic cardiac functions were evaluated in 54 lead exposed and 24 non-exposed workers by Doppler echocardiography. With regard to systolic cardiac function, the results suggested that cardiac systolic function increased in exposed groups as a compensatory response for the effect of lead on myocardium. To study left ventricular diastolic function, 2.5 MHz pulsed Doppler analyses of transmitral flow velocity were performed from apical four-chamber view. The results showed that time-related parameters were comparable among all groups, but blood flow velocity through the mitral valve and Doppler area fractions changed significantly in lead-exposed groups as evidenced by increased value A, decreased value E and E/A ratio. The decrease of diastolic cardiac function was more significant in lead intoxication group. It was also observed in this study that the activity in serum of the MB isoenzyme of creatine phosphokinase (CPK-MB), one of the indices of myocardial damage, was significantly higher in exposed group than that in control (P < 0.05), and a positive correlation was found between CPK-MB activity and Pb-B. It denoted that the increasing of lead burden leads to more release of CPK-MB from the myocardial cells and suggested the existence of slight myocardial damage, which, conceivably, might cause harm to diastolic cardiac function.