Tissue Doppler Findings in Patients with Pulmonary Arterial Hypertension

Background:
Pulmonary hypertension is an untreatable condition with poor prognosis and factors such as more elevated pulmonary arterial systolic pressure and right ventricular dysfunction are associated with a worse outcome.
Objectives:
Considering the limitations of the current modalities, this study aimed to find the relationship between tissue Doppler-derived systolic and diastolic parameters and elevated pulmonary arterial pressure in order to assess the routine application of tissue Doppler imaging in evaluation of pulmonary arterial hypertension.
Patients and Methods:
This study was conducted on 100 inpatient and outpatient individuals referred to the Department of Echocardiography in Shahid Faghihi hospital, Shiraz, Iran from July 2012 to March 2013. The individuals who had preserved right ventricular function in the presence of pulmonary arterial hypertension were included in the case group. On the other hand, the patients who did not have echocardiographic signs of pulmonary arterial hypertension were enrolled into the control group. All the patients underwent a complete transthoracic echocardiogram including 2-dimensional, color flow, and spectral Doppler as well as tissue Doppler imaging using a vivid E9 system, and the desired systolic and diastolic parameters were recorded. The relationship among these parameters was evaluated by independent sample t-test using the SPSS statistical software, version 16. Besides, P < 0.05 was considered to be statistically significant.
Results:
The mean time to peak strain was significantly longer in the case group (203.98 ± 47.54 milliseconds) compared to the controls (81.20 ± 25.76 milliseconds). The mean early diastolic tricuspid inflow velocity/early diastolic tricuspid annulus velocity (E/E’a) ratio was also significantly higher in the case group (10.24 ± 6.19) compared to the controls (4.70 ± 0.80). In contrast, Isovolumic Contraction (IVC) acceleration time/IVC time ratio was reduced in the case group (0.44 ± 0.09) in comparison to the control patients (0.56 ± 0.05).
Conclusions:
In conclusion, our results suggested that increasing degrees of pulmonary artery systolic pressure affected timing of some tissue Doppler-derived intervals within the cardiac cycle, including IVC time, time to peak systolic myocardial velocity (Sm), and time to peak strain. Therefore, tissue Doppler imaging could be used in assessment of patients with suspected pulmonary arterial hypertension.