Nonembolic, hemodynamic blood flow disturbances in the middle cerebral arteries in patients with paroxysmal atrial fibrillation without significant carotid stenosis

Objectives The aim of the present study was to evaluate whether patients with paroxysmal atrial fibrillation (AF) without symptoms of cerebral ischemia or significant carotid stenosis have reduced blood flow through the middle cerebral arteries (MCAs), as well as to assess differences between blood flow through the MCAs during AF and after cardioversion. Patients and methods A total of 65 subjects were included in the study: 30 patients consecutively admitted to the University Hospital in Szczecin, Poland, with an episode of AF and 35 healthy volunteers with normal sinus rhythm. All individuals underwent transcranial Doppler ultrasonography (TCD) with assessment of mean blood flow velocity (MV) in the MCAs. Results There were no significant differences in MCA MV values between patients with AF and controls. In patients in whom pharmacological cardioversion was successful within 24 h of hospital admission, MV values before and after cardioversion differed significantly in both MCAs. Conclusion In conclusion, AF adversely affects cerebral circulation leading to hemodynamic blood flow disturbances that might result in changes in MV values of the MCAs but which are usually insufficient to develop clinical symptoms of brain ischemia