Cardiac injury in organophosphate poisoning after acute ingestion

Sparse data and conflicting evidence exist on the prevalence and prognosis of organophosphate (OP)-related cardiac toxicity. We aimed to characterize the cardiac abnormalities of OP after an acute cholinergic crisis in adults without previous cardiovascular conditions.

We did a prospective observational study in a tertiary-care hospital of north India (Postgraduate Institute of Medical Education and Research, Chandigarh) in 74 patients aged ≥ 13 years admitted with acute OP poisoning after self-ingestion. A systemic evaluation, including clinical characteristics, electrocardiography, and echocardiography, was performed to estimate the prevalence and prognosis of cardiac injury. A rate-corrected QT interval was calculated using Bazett's method, and >440 milliseconds was used to define prolongation.

Chlorpyrifos was the most commonly ingested OP (n = 29). The patients had a similar occurrence of hypotension (n = 10) and hypertension (n = 9) at admission, and electrocardiography demonstrated sinus tachycardia in 38 (51.3%) and sinus bradycardia in one case. During the hospital stay, 3 out of 74 patients had a prolonged rate-corrected QT interval (457, 468, and 461 milliseconds), and one patient developed supraventricular tachycardia. Eight (10.8%) patients developed the intermediate syndrome, and six (8.1%) died. None of the hemodynamic or electrocardiographic abnormalities was associated with in-hospital mortality or intermediate syndrome development on univariant analysis. Baseline echocardiography at hospital discharge was performed in 27 patients (admitted during 2018) and normal in all except mild tricuspid regurgitation in one. At a 6-month follow-up, 23 cases were available for cardiovascular screening (including echocardiography) and had a normal evaluation.

Cardiac toxicity is uncommon after acute OP self-ingestion and lacks prognostic significance.