title: Results of carotid sinus massage in a tertiary referral unit--is carotid sinus syndrome still relevant?
abstract: BACKGROUND
  carotid sinus hypersensitivity (CSH) is associated with syncope, drop attacks and unexplained falls in older people. However, a recent study has also reported a prevalence of 35% in asymptomatic community-dwelling older people.
  
  
  OBJECTIVE
  we conducted a retrospective observational study to investigate the haemodynamic and symptom responses of a large cohort of patients undergoing carotid sinus massage (CSM).
  
  
  METHODS
  the electronically stored haemodynamic data of 302 consecutive patients, aged 71 +/- 11 years, investigated with CSM for unexplained falls and syncope was analysed. Bilateral sequential CSM was performed in the supine and upright positions with continuous electrocardiogram (ECG) and non-invasive beat-to-beat blood pressure monitoring (Taskforce, CN Systems, Austria). CSH (CSH) was defined by maximal R-R interval > or =3 s (cardioinhibitory) and/or a systolic blood pressure drop of > or =50 mmHg (vasodepressor).
  
  
  RESULTS
  a total of 74/302 (25%) subjects had CSH, 37 (50%) of which were cardioinhibitory (CI) and 37 (50%) were vasodepressor (VD) subtypes. Subjects with positive CSM were significantly older (75.2 vs 70.2 years, P < 0.001), and more likely to be male (32% vs 19%, P < 0.01). CSH was diagnosed with right-sided CSM alone in 45 (61%) subjects and erect CSM only in 36 (49%) subjects. Symptom reproduction was more likely with the CI than the VD subtypes (82% vs 28%; P < 0.001).
  
  
  CONCLUSIONS
  CSH was diagnosed in 25% of patients investigated with CSM at our specialist unit, lower than the prevalence of 39% reported for community-dwelling older individuals. This discrepancy may be explained by selection bias and demographic differences, but raises the possibility of CSH being an age-related epiphenomenon rather than a causal mechanism for syncope, drop attacks and unexplained falls. Our observations have important implications for clinical practice and the development of future research strategies.
authors.affiliation: Institute for Ageing and Health, Wolfson Centre, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE4 5PL, UK.
authors.forename: Maw Pin
authors.initials: MP
authors.lastname: Tan
authors.forename: Julia L
authors.initials: JL
authors.lastname: Newton
authors.forename: Pam
authors.initials: P
authors.lastname: Reeve
authors.forename: Alan
authors.initials: A
authors.lastname: Murray
authors.forename: Tom J
authors.initials: TJ
authors.lastname: Chadwick
authors.forename: Steve W
authors.initials: SW
authors.lastname: Parry
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001795:Blood Pressure Determination / Q000009:adverse effects; D002346:Carotid Sinus / Q000503:physiopathology*; D003937:Diagnosis, Differential; D004244:Dizziness / Q000175:diagnosis / Q000209:etiology* / Q000517:prevention & control; D004562:Electrocardiography / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D008405:Massage; D008875:Middle Aged; D015995:Prevalence; D012017:Referral and Consultation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D013575:Syncope / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy*; D013577:Syndrome; D018667:Tilt-Table Test