I In nt tr ro od du uc ct ti io on nCarbon monoxide (CO) can cause functional and morphological alternations of the heart mainly due to myocardial hypoxemia and direct action of CO on the heart. 1)2) CO has about 250-fold higher affinity for hemoglobin as compared to oxygen and forms carboxyhemoglobin (CO-Hb). In the presence of CO-Hb, a leftward shift of the oxygenated hemoglobin dissociation curve observed and leads to impairment of tissue oxygen delivery and makes cellular hypoxia.
1)CO induced cardiotoxicity has many clinical manifestations including arrhythmias, pulmonary edema and heart failure, and myocardial infarction. Echocardiography is known as the most useful method in the detection the presence of cardiac toxicity and assessment of its severity. We report a case with transient severe left ventricular dysfunction after intentional exposure to CO. The patient was early detected with an echocardiographic exam and treated with conventional treatment including high concentration of oxygen.
C Ca as se eA 28-year-old man was admitted to our emergency room for altered mentality due to intentional exposure to CO. On his arrival, blood pressure was 104/80 mmHg, the pulse 126 beat per minute, axillary temperature 37.7°£C and the respirations were 32 breaths per minute. On blood analysis, AST/ALT 37/29 IU/L, CK 412 U/L, CK-MB 6.9 ng/mL, troponin I 0.96 ng/mL, N-terminal pro B-type natriuretic peptide 451.5 pg/mL, and CO-Hb 27.7%. The patient was intubated and treated with high concentration of oxygen therapy. A radiograph of the chest showed pulmonary edema and mild cardiomegaly (Fig. 1A). An electrocardiogram revealed sinus tachycardia of heart rate 120 per minute. Transthoracic echocardiogram showed global hypokinesia of left ventricle with severe systolic dysfunction ( Fig. 2A and B). He was treated with diuretics, angiotensin converting enzyme inhibitor and urine alkalinization. Cardiac enzymes were elevated to CK 5,994 U/L, CK-MB 38.6 ng/mL, and troponin I 11.7 ng/mL on the third admission day. CK level was elevated to 15,951 U/L due to rhabdomyolysis and normalized with urine alkalinization. The follow-up chest radiograph showed normalized cardiac size and disappearance of pulmonary edema (Fig. 1B). The echocardiography Carbon monoxide (CO) is one of well known chemical asphyxiants which cause tissue hypoxia with prominent neurologic and cardiovascular injury. Cardiac dysfunction after CO poisoning can be presented as two clinical patterns. One is transient global left ventricular (LV) dysfunction and the other is LV dysfunction with regional wall motion abnormalities. In this case report, we present a case with transient LV systolic dysfunction caused by intentional exposure to CO. After conservative treatment including high concentration of oxygen, the patient recovered completely without any complication.