Warfarin, aspirin and microembolic signals in the acute phase of stroke in a patient with mechanical heart valves.

We report the case of a 54-year-old woman, with atrial fibrillation and mechanical heart valves, who suffered a left-hemispheric stroke while she was under warfarin. Daily bilateral simultaneous transcranial Doppler monitoring of the middle cerebral arteries showed the presence of microembolic signals (MES), whose number remained unchanged after adding aspirin 100 mg daily. We conclude that anticoagulant plus antiplatelet therapy does not influence the number of MES in the acute phase of stroke in patients with prosthetic heart valves, suggesting the gaseous origin of MES in these patients.