title: Right ventricular myocardial isovolumic relaxation time and pulmonary pressure.
abstract: OBJECTIVE
  Non-invasive assessment of pulmonary artery systolic pressure (PASP) has several limitations. As previously described by Burstin, the right ventricular (RV) isovolumic relaxation time (IVRt) is sensitive to changes in PASP. We therefore compared RV myocardial IVRt, derived by Doppler tissue imaging (DTI), with simultaneously measured invasive PASP.
  
  
  RESULTS
  Twenty-six consecutive patients (18 males, mean age 52 +/- 12 years, range 23-75) underwent a simultaneous Doppler echocardiography, including DTI, and cardiac catheterization examination for measurement of PASP and right atrial mean pressures. IVRt was measured using the myocardial velocities by pulsed DTI at both basal and mid cavity segments of the RV free wall. As diastolic time intervals are influenced by heart rate IVRt was corrected for heart rate (IVRt/RR%). A significant correlation was found between PASP and regional IVRt/RR% at both the basal (r = 0.42, P<0.05) and mid cavity segment (r = 0.71, P<0.001). Furthermore, when only patients with normal right atrial pressures (<7 mmHg) were taken into account, the correlation coefficient improved at both basal and mid cavity segments (r = 0.74, P<0.05 and r = 0.83, P<0.01).
  
  
  CONCLUSIONS
  Pulsed Doppler-derived IVRt correlates well with PASP. The use of pulsed DTI for measurement of IVRt is simple, reproducible and easy to obtain. We propose this method as an additional non-invasive tool in the assessment of PASP.
authors.affiliation: Department of Cardiology, Heart Centre, University Hospital, Umeå, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Lindqvist
authors.forename: Anders
authors.initials: A
authors.lastname: Waldenström
authors.forename: Gerhard
authors.initials: G
authors.lastname: Wikström
authors.forename: Elsadig
authors.initials: E
authors.lastname: Kazzam
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D006328:Cardiac Catheterization; D003935:Diagnostic Techniques, Cardiovascular; D003971:Diastole / Q000502:physiology*; D018619:Echocardiography, Doppler, Pulsed; D005240:Feasibility Studies; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D011651:Pulmonary Artery / Q000502:physiology / Q000503:physiopathology*; D013997:Time Factors; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging / Q000503:physiopathology; D016278:Ventricular Function, Right / Q000502:physiology*