Patent foramen ovale, dialysis and microembolization

Abstract

BACKGROUND: Haemodialysis (HD) circuits are known to produce microemboli. Patent foramen ovale (PFO) may be important in HD patients by allowing right to left intracardiac shunting of microemboli (blood clots or microbubbles), which may pass into the cerebral circulation. METHODS: We undertook bubble contrast transthoracic echocardiography to identify PFO in HD patients and in a control population of peritoneal dialysis patients. We interrogated draining arteriovenous fistulae to confirm that microemboli are created during HD. We then undertook transcranial Doppler scanning of the middle cerebral artery before and during dialysis, with and without Valsalva augmentation, to detect cerebral mi..