Focus on Falls
First Published: Investigator - March 2005
Syncope is a transient loss of consciousness (fainting) due to a lack of blood flow to the brain. One reason for this is linked to a condition called Carotid Sinus Syndrome (CSS) where the over activity of the carotid sinus can cause a pause in the heartbeat or low blood pressure leading to dizziness and blackouts.
Generally complete recovery from a syncope episode is made but the consequences can be quite serious.
The Syncope Clinic has recently been opened in conjunction with the Falls Clinic, at the Repatriation General Hospital.
Dr Zbigniew Gieroba from the Repat and Dr Arduino Mangoni from the Department of Clinical Pharmacology will commence a new study at Flinders and Repatriation Hospitals looking into a link between Carotid Sinus Syndrome and hardening of the blood vessels to the brain.
The carotid sinus is a dilated portion of one of the major arteries supplying blood to the head. The sinus nerve innervates carotid sinus with blood pressure monitoring receptors. The sinus nerve sends information into an area of the brain stem that controls blood pressure and heart rate.
“The poor understanding of the mechanisms responsible for carotid sinus syndrome doesn’t allow us to maintain satisfactory management in many patients”, said Dr Gieroba.
“This study will test our theory that patients with CSS have a hardening of the vessels that supply blood to the brain. A sudden stimulation (carotid sinus massage) of stiff vessels may provoke significant falls in blood pressure and with consequent reduction in blood flow to the brain, hence dizziness and blackouts”
It is necessary to perform carotid sinus massage in supine and 70 degree head–up tilt position. The study will involve a head-up tilt table test. The Task Force Monitor is the first of its type in Australia and the Southern Hemisphere and allows doctors to non-invasively monitor beat-to-beat blood pressure, heart rate and cardiac output.
Dr Gieroba says “If our hypothesis is correct there is a potential to manage Carotid Sinus Syndrome with medication to reduce the hardening of the vessels, such as cholesterol and or blood pressure tablets”.