[Myocardial injury in the course of carbon monoxide poisoning]

Abstract

Carbon monoxide still remains one of the most common causes of fatal poisonings. Mechanisms of carbon monoxide toxic effects are complex and lead to hypoxia of body tissues. The most sensitive to tissue hypoxia are: the central nervous system and the cardiovascular system.The most characteristic cardiac symptoms of carbon monoxide poisoning are: stenocardial symptoms, hypotonia, myocardial dysfunction and arrhythmia (atrial fibrillation, tachycardia, bradycardia). Carbon monoxide connects with high affinity to metallo-proteins mainly to hemoglobin impairing oxygen transport in the body and to myoglobin, interfering with its function as oxygen reservoir among others in myocardium. Connecting to cytochrome oxidase in mitochondria it blocks the chain of electron transport which results in impairment of cellural respiration and formation of free radicals. Carbon monoxide has also relaxation effect against the smooth muscles of blood vessels, and thrombogenic effect. It is particularly adverse in patients with ischemic heart disease. In case of carbon monoxide poisoning one should always search for features of myocardial injury- as far as screening is concerned the most important ones are ECG and screening for cardiac troponin. Depending on the course of poisoning other laboratory (e.g. BNP) or imaging (echo-cardiography. scintiscanning, coronarography) tests may also prove to be useful.