Carotid sinus hypersensitivity in asymptomatic older persons: implications for diagnosis of syncope and falls.
BACKGROUND
Carotid sinus hypersensitivity is the most commonly reported cause of falls and syncope in older persons. Recent guidelines recommend 5 to 10 seconds of carotid sinus massage in supine and upright positions with beat-to-beat monitoring. The aim of this study was to determine the prevalence of carotid sinus hypersensitivity in (1) an unselected community sample of older people and (2) a subsample with no history of syncope, dizziness, or falls using recently standardized diagnostic criteria.


METHODS
One thousand individuals older than 65 years were randomly sampled from a single general practice register; 272 participants underwent supine and upright carotid sinus massage with continuous heart rate and phasic blood pressure monitoring. Carotid sinus hypersensitivity was defined as asystole of 3 seconds or greater and/or a drop in systolic blood pressure of 50 mm Hg or greater.


RESULTS
Carotid sinus hypersensitivity was present in 107 individuals (39%); 24% had asystole of 3 seconds or greater during carotid sinus massage; and 16% had symptoms (including syncope) with carotid sinus hypersensitivity. Age (odds ratio, 1.05; 95% confidence interval, 1.00-1.09) and male sex (odds ratio, 1.71; 95% confidence intervals, 1.04-2.82) were the only predictors of carotid sinus hypersensitivity. In 80 previously asymptomatic individuals, carotid sinus hypersensitivity was present in 28 (35%) and accompanied by symptoms in 10. The 95th percentile for carotid sinus massage response was 7.3 seconds' asystole and a 77-mm Hg drop in systolic blood pressure.


CONCLUSIONS
Carotid sinus hypersensitivity is common in older persons, even those with no history of syncope, dizziness, or falls. The finding of a hypersensitive response should not necessarily preclude further investigation for other causes of syncope.
Institute for Ageing and Health, University of Newcastle upon Tyne, England. s.r.j.kerr@ncl.ac.uk
Simon R J
SR
Kerr
Mark S
MS
Pearce
Carol
C
Brayne
Richard J
RJ
Davis
Rose Anne
RA
Kenny
D000058:Accidental Falls / Q000517:prevention & control / Q000706:statistics & numerical data; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D002340:Carotid Artery Diseases / Q000150:complications* / Q000503:physiopathology; D002346:Carotid Sinus / Q000503:physiopathology*; D003937:Diagnosis, Differential; D004562:Electrocardiography; D004739:England / Q000453:epidemiology; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D015994:Incidence; D008297:Male; D016017:Odds Ratio; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D013575:Syncope / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D018667:Tilt-Table Test