Low Blood Lead (Pb) and Prolonged P Wave as Cardiotoxicity Indicator in 12-Lead Resting Electrocardiogram among Malaysian Adult

Background Cardiovascular diseases are the major causal factor of morbidity and death rate in the world. Premature death is believed to be associated with heavy metals exposure that should be identified as early at the reversible stage. In electrocardiogram, the P wave is among the suitable indicator. Method This is a cross sectional study among a population in Selangor, one of the major state in Malaysia. It was carried out from January to December 2012 using purposive sampling to obtain blood samples and electrocardiogram reading. Data on sociodemography was obtained using a standardised validated questionnaire adopted for PURE study. Results A total of 287 respondents was enrolled in the study, the majority of women aged between 35 to 70 years old. Nearly 52.8 % of them have asymptomatic abnormal prolonged P wave. The median of blood Pb was 1.9g/L (1.0 3.3g/L). The area under curve (AUC) analysis using receiving of curve (ROC) revealed that the concentration of blood Pb of more than 2.9 g/L associated with prolonged P wave. This point may be used as the cardiotoxicity cut off point of blood Pb among the respondents. The limit was so much lower than the standard of 100.0g/L that have been adopted purposely to protect neurobehavioural problems. Conclusion The present legislation limit of blood Pb is not protecting the population from the cardiotoxicity risk. The limit should be reviewed again in reducing premature death and CVDs problems.