The authors report a case of paradoxical embolism associated with pulmonary embolism in a male patient under mechanical ventilation for chronic respiratory failure. They review the present diagnostic criteria of paradoxical embolism and insist on the determinant contribution of contrast echocardiography to the diagnosis. They also discuss the factors which make this type of patient liable to reopening of the foramen ovale and to paradoxical embolism. The clinical and gasometric characteristics of pulmonary embolism occurring in patients under mechanical ventilation are detailed.
