title: Diastolic perfusion time at ischemic threshold in patients with stress-induced ischemia.
abstract: BACKGROUND
  To evaluate the relevance of diastolic perfusion time on the mechanisms underlying stress-induced ischemia, 16 patients with coronary artery disease and seven patients with syndrome X underwent five randomized stress tests (upright and supine exercise with and without therapy, transesophageal atrial pacing).
  
  
  RESULTS
  Exercise duration Time to 0.1 mV ST segment depression, heart rate, rate-pressure product, and diastolic perfusion time were evaluated for each patient during stress tests. In both groups, variability coefficients of the above-mentioned parameters were not different at rest. At ischemic threshold (0.1 mV ST segment depression) in patients with coronary artery disease, the variability coefficient of exercise duration (40.1 +/- 22.2) was significantly higher (p less than 0.0001) than those of heart rate (12.8 +/- 2.9), rate-pressure product (14.8 +/- 3.3), and diastolic perfusion time (0.39 +/- 0.1). The variability coefficient of diastolic perfusion time was also significantly (p less than 0.0001) lower than those of heart rate and rate-pressure product. Similarly, the variability coefficient of diastolic perfusion time (0.44 +/- 0.1) in syndrome X patients was significantly lower (p less than 0.0001) than those of exercise duration (28.2 +/- 9.4), heart rate (12 +/- 1.4), and rate-pressure product (14.6 +/- 1.3).
  
  
  CONCLUSIONS
  Fixed diastolic perfusion time at ischemic threshold, despite different kinds of stress tests and variability of heart rate and rate-pressure product, indicates the relevant role of diastolic perfusion time in determining myocardial ischemia.
authors.affiliation: Department of Medicine, Second Medical School, University of Naples, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Ferro
authors.forename: L
authors.initials: L
authors.lastname: Spinelli
authors.forename: C
authors.initials: C
authors.lastname: Duilio
authors.forename: M
authors.initials: M
authors.lastname: Spadafora
authors.forename: F
authors.initials: F
authors.lastname: Guarnaccia
authors.forename: M
authors.initials: M
authors.lastname: Condorelli
mesh_terms: D000328:Adult; D003326:Coronary Circulation; D003327:Coronary Disease / Q000209:etiology / Q000503:physiopathology*; D003971:Diastole; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D011897:Random Allocation; D013312:Stress, Physiological / Q000150:complications*