Usefulness of right ventricular isovolumic relaxation time in predicting systolic pulmonary artery pressure

Abstract

Objective Assessment of usefulness of right ventricular isovolumic relaxation time measured by Tissular Doppler imaging in predicting systolic pulmonary artery pressure. Methods 30 patients, 10 males and 20 females were included in the study. The mean age was (43.7 ± 14.96) years and SPAP was (52.77 ± 23.19) mmHg. 6 patients were hypertensive, 8 patients were diabetic, Referral diagnoses were valvular heart disease (n = 8), cardiomyopathy (n = 3) and coronary artery disease (n = 19) at Bab Al-She‘reya University Hospital – Al-Azhar University – Cairo – Egypt, from April 2009 to November 2009. Patients were classified according to systolic pulmonary artery pressure (SPAP) measured invasively through right heart catheterization into two groups: Group I – Patient with systolic pulmonary artery pressure less Than 40 mmHg and this group include 10 patients (normal group). Group II – Patient with systolic pulmonary artery pressure equal or more than 40 mmHg and this group include 20 patients (pulmonary hypertensive group) . All the patients had been subjected to the following: Informed consent, Brief history taking, Transthoracic echo-Doppler study with standerd views to calculate ESPAP and Tissue Doppler Imaging (TDI) taking the following parameters: – Right ventricular isovolumic relaxation time (r IVRT’) &peak systolic tricuspid annular excertion(S)’. Results An analyzable Doppler tricuspid diastolic signal could not be obtained in 2 patients. all of them were in the group of patients without PAH, which means that TR was not recordable in 20% of patients in this group. All patients of the PAH group had an analyzable tricuspid regurgitant jet, there were extremely significant statistical positive correlation between SPAP measured invasively through right heart catheterization and r IVRT’ measured by tissue Doppler imaging. (P value 0.0001, r = 0.80).this correlation improved maximally when patients with elevated RAP(above 8 mmhg) and patients with right ventricular dysfunction(S′ 11.5 Cm/S) are excluded (P value 0.0001, r = 0.91). Receiver-operating characteristics (ROC) curve for predicting a SPAP of 40 mmHg or higher showed That rIVRT’ > 38 ms predicts pulmonary hypertension with 100% sensitivity, 90%specificity, while a rIVRT’ 38 ms excluded pulmonary hypertension with 100% negative predictive value. Conclusions Although there is extremely positive correlation between SPAP measured invasively through right heart catheterization and that estimated from peak tricuspid regurge velocity there are difficulties in assessment of TR specially in obese and COPD patients. rIVRT’ appears to be helpful in evaluating SPAP, a normal rIVRT’ 38 ms can exclude PAH with a high negative predictive value. A prolonged rIVRT’ is indicative of PAH but cannot affirm it by itself.