Title: Severe Cardiac Complications in Organophosphate and Carbamate Poisoning in the agriculture environment of Taiwan

Author: Sung-Yuan Hu 1,2,3

Affiliation: 1 Division of Toxicology, Department of Emergency Medicine, Taichung Veterans General Hospital; 2 School of Medicine, Chung Shan Medical Univerity; 3 National Taichung Nursing College, Taiwan, ROC

Abstract

Introduction: The most common pesticide poisoning is organophosphate (OP) and carbamate (CB) in the agriculture environment of Taiwan with a mortality rate more than 10%. The complications of OP poisoning (OPP) and CB poisoning (CBP) include central depression, respiratory failure, myocardial injury, cardiac arrhythmia, pancreatitis and electrolyte/metabolic disorders. Torsades de pointes (TDP) and acute myocardial infarction (AMI) are very rare in OPP and CBP.

Methods: Patients who were admitted to Emergency Department due to OPP and/or CBP were enrolled in retrospective cases serial study by clinical chart review between Jan 2006 and Dec 2008.

Results: There were 128 patients enrolled in this retrospective study with OPP and/or CBP. There were 100 patients with OPP and 28 patients with CBP. There were 4 patients with 2 kinds of OPP and 3 patients combined with OPP and CBP. There were 91 men and 37 women with age of 24~88 years. There were 15 patients (15/128=11.7%) with out of hospital cardiac arrest. There were 4 patients with TDP in OPP and 1 patient with AMI in CBP. Marked prolongation of QT and QTc intervals was noted in 4 OPP patients complicating with TDP. MgSO4 and xylocaine were prescribed in TDP patients and one patient received an implantation of transvenous pacemaker. ST elevation in precordial leads and cardiac enzymes in CBP patient, but coronary arterial angiography was normal. Mortality rate of OPP and/or CBP was 16.4% (21/128) in our study.

Discussion: Severe cardiac complications in OPP and CBP are very rare. The etiologies of TDP in OPP include hypoxia, electrolyte imbalances, acidosis and myocardial depression. Few cases of OPP complicating with AMI were reported and CBP complicating with AMI was not reported in previous literatures. The mechanisms of AMI in CBP might be similar to OPP complicating with AMI. Antidotes of atropine and/or PAM with respiratory and cardiovascular support were recommended.

Key words: carbamate, cardiac complication, myocardial infraction, torsades de pointes, organophosphate, poisoning