[Massive pulmonary thromboembolism with left axis deviation and low voltage]

The classic electrocardiographic abnormalities observed in massive or submassive thromboembolism in the absence of preexistent cardiac or pulmonary disease are: S1Q3T3 pattern, right axis deviation, "pulmonary" P wave, ST segment depression or elevation, subepicardic ischemia and transient right bundle branch block. Left axis deviation due to pulmonary embolism was first described in 1949; this same finding and the presence of low voltage of the frontal plane owed to pulmonary embolism has been reported occasionally in the last decades, but it has had little diffusion. We report on a patient with no prior cardiac or pulmonary disease who suffered massive pulmonary thromboembolism. Electrocardiographically left axis deviation and low voltage of the horizontal plane attributed to pulmonary thromboembolism was observed. The mechanisms that originate this electrocardiographic changes in pulmonary embolism are unknown. Since the electrocardiogram is aspecific method for the diagnosis of this disorder, and the presence of the mentioned changes originate a greater difficulty in the diagnosis; we consider is important to publish it.