title: Orthostatic blood pressure test for risk stratification in patients with hypertrophic cardiomyopathy.
abstract: BACKGROUND
  Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden cardiac death (SCD) in young adults, mainly ascribed to ventricular tachycardia (VT). Assuming that VT is the major cause of (pre-) syncope in HCM patients, its occurrence is essential for SCD risk stratification and primarily preventive ICD-implantation. However, evidence of VT during syncope is often missing. As the differentiation of potential lethal causes for syncope such as VT from more harmless reasons is crucial, HCM patients were screened for orthostatic dysregulation by using a simple orthostatic blood pressure test.
  
  
  METHODS
  Over 15 months (IQR [9;20]) 100 HCM patients (55.8±16.2 yrs, 61% male) were evaluated for (pre-)syncope and VT (24h-ECGs, device-memories) within the last five years. Eighty patients underwent an orthostatic blood pressure test. Logistic regression models were used for statistical analysis.
  
  
  RESULTS
  In older patients (>40 yrs) a positive orthostatic test result increased the chance of (pre-) syncope by a factor of 63 (95%-CI [8.8; 447.9], p<0.001; 93% sensitivity, 95%-CI [76; 99]; 74% specificity, 95%-CI [58; 86]). No correlation with VT was shown. A prolonged QTc interval also increased the chance of (pre-) syncope by a factor of 6.6 (95%-CI [2.0; 21.7]; p=0.002).
  
  
  CONCLUSIONS
  The orthostatic blood pressure test is highly valuable for evaluation of syncope and presyncope especially in older HCM patients, suggesting that orthostatic syncope might be more relevant than previously assumed. Considering the high complication rates due to ICD therapies, this test may provide useful information for the evaluation of syncope in individual risk stratification and may help to prevent unnecessary device implantations, especially in older HCM patients.
authors.affiliation: Klinik und Poliklinik für Allgemeine und Interventionelle Kardiologie, Universitäres Herzzentrum Hamburg, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Münch
authors.affiliation: Krankenhaus Reinbek, Abteilung für Kardiologie, Hamburger Strasse 41, 21465, Reinbek, Germany.
authors.forename: Ali
authors.initials: A
authors.lastname: Aydin
authors.affiliation: Institut für Medizinische Biometrie und Epidemiologie, Universitätsklinikum Hamburg Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Suling
authors.affiliation: Klinik und Poliklinik für Allgemeine und Interventionelle Kardiologie, Universitäres Herzzentrum Hamburg, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Voigt
authors.affiliation: Klinik und Poliklinik für Allgemeine und Interventionelle Kardiologie, Universitäres Herzzentrum Hamburg, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Blankenberg
authors.affiliation: Klinik und Poliklinik für Allgemeine und Interventionelle Kardiologie, Universitäres Herzzentrum Hamburg, Martinistr. 52, 20246, Hamburg, Germany.
authors.forename: Monica
authors.initials: M
authors.lastname: Patten
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000503:physiopathology*; D016757:Death, Sudden, Cardiac / Q000209:etiology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment / Q000379:methods