title: Uses and limitations of high dose dipyridamole stress echocardiography for evaluation of coronary artery disease.
abstract: OBJECTIVE
  To compare the usefulness of high dose dipyridamole stress echocardiography with dipyridamole stress electrocardiography and exercise electrocardiography for the evaluation of coronary artery disease.
  
  
  METHODS
  Prospective investigation with coronary angiography as the criterion standard and blinded assessment of study data.
  
  
  METHODS
  Cardiology unit of a tertiary referral centre.
  
  
  METHODS
  Fifty eight patients with suspected coronary disease; three of these were excluded because of poor echogenicity at baseline (test feasibility 95%). Angiography showed normal coronary arteries in 15 and coronary disease (greater than or equal to 70% diameter stenosis) in 40.
  
  
  METHODS
  Cross sectional echocardiography and 12 lead electrocardiography during dipyridamole stress (up to 1 mg/kg) and exercise electrocardiography on a separate occasion. Wall motion was analysed with an 11-segment model developed at Hammersmith Hospital.
  
  
  METHODS
  Test sensitivity, specificity, and side effect data.
  
  
  RESULTS
  16 of 40 patients with coronary artery disease had inducible asynergy; all had multivessel disease and a tight stenosis in the vessel that supplied the abnormal segment. Exercise duration and time to 1 mm ST segment depression were significantly shorter in patients with a positive echocardiogram than in those without (both p less than 0.01). The sensitivity and specificity of dipyridamole stress echocardiography were 40% and 93% respectively; sensitivity improved to 60% when baseline (n = 18) or reversible asynergy defined an abnormal study (likelihood ratio = 9). Corresponding figures for stress electrocardiography were 38% and 80% for dipyridamole and 80% and 67% for exercise. Adverse reactions were seen in 67% of patients and included two instances of pronounced hypotension, one episode of prolonged myocardial ischaemia, and one cardiac arrest in a patient who was successfully resuscitated.
  
  
  CONCLUSIONS
  A positive high dose dipyridamole echocardiogram predicts multivessel disease and impaired coronary reserve, but low overall sensitivity and occasionally troublesome side effects limit its clinical usefulness.
authors.affiliation: Department of Medicine Clinical Cardiology Unit, Hammersmith Hospital, London.
authors.forename: P
authors.initials: P
authors.lastname: Mazeika
authors.forename: P
authors.initials: P
authors.lastname: Nihoyannopoulos
authors.forename: J
authors.initials: J
authors.lastname: Joshi
authors.forename: C M
authors.initials: CM
authors.lastname: Oakley
mesh_terms: D000328:Adult; D000368:Aged; D003327:Coronary Disease / Q000175:diagnosis / Q000000981:diagnostic imaging*; D003331:Coronary Vessels / Q000000981:diagnostic imaging*; D004176:Dipyridamole / Q000009:adverse effects; D004452:Echocardiography / Q000379:methods*; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D011446:Prospective Studies; D013312:Stress, Physiological / Q000139:chemically induced / Q000503:physiopathology
chemical_list: D004176:Dipyridamole