Two potentially fatal surprises in the preoperative assessment of an asymptomatic young adult. / Duas surpresas potencialmente fatais em avaliação pré-operatória de adulto jovem assintomático.

Isolated left ventricular non-compaction is a rare disease classified as a primary genetic cardiomyopathy and is characterized by heart failure, systemic embolism and ventricular arrhythmias. The diagnosis is established by Doppler echocardiography. We report the case of an asymptomatic young adult, with no history of heart disease, who underwent preoperative assessment for low-risk orthopedic surgery. The electrocardiogram showed left bundle branch block, which prompted further investigation with Doppler echocardiography, cardiac computed tomography angiography and cardiac magnetic resonance imaging. A diagnosis of isolated left ventricular non-compaction and pulmonary embolism was made. Some aspects of preoperative assessment in low-risk surgical patients are discussed.