Cardiac abnormalities in severe acute dichlorvos poisoning

Patients with organophosphorus poisoning sometimes die suddenly during rigorous treatment, possibly from myocardial injury. This study sought to elucidate the mechanisms underlying organophosphorus poisoning-induced cardiotoxicity.

Prospective observational study.

Urban, tertiary teaching hospital emergency intensive care unit with 10 beds.

Forty-one patients with severe acute dichlorvos poisoning were consecutively enrolled (n = 92) at emergency intensive care unit and followed for 3 months.

Levels of serum creatine kinase isoenzyme myocardium, cardiac troponin I, acetylcholinesterase, acetylcholine, epinephrine, and norepinephrine were tested on hospital days 1, 3, and 5 and on discharge day. Electrocardiography was recorded on admission and then every other day. Transthoracic echocardiography was performed at admission, in the acute phase, before discharge, and during follow-up. Technetium 99m-sestamibi myocardial single photon emission computed tomography was conducted in four patients. Thirty-seven (90.2%) patients survived and four (9.8%) patients died during treatment. We observed sinus tachycardia in 37 (90.2%) patients and ST-T changes in 33 (80.4%) patients. Creatine kinase isoenzyme myocardium and cardiac troponin I levels peaked at day 3 postadmission and then decreased to normal levels. Serum acetylcholine, epinephrine, and norepinephrine peaked at day 1 after admission and then decreased. Echocardiography revealed marked decreases in wall motion of the interventricular septum and left ventricle in the acute phase but returned to normal in the recovery phase. The left ventricular ejection fraction improved significantly from 42 ± 5% to 59 ± 4% (p = .001). Single photon emission computed tomography showed abnormal left ventricle perfusion.

Severe acute dichlorvos poisoning is associated with reversible myocardial dysfunction, possibly through an increase in catecholamine levels.