Speckle Tracking Imaging in Patients with Pulmonary Hypertension

Abstract

Background: Right ventricular (RV) systolic dysfunction is a strong predictor of mortality in pulmonary hypertension (PH). The goal of this study was to investigate whether right atrium (RA) and RV myocardial strain related to PH using speckle tracking echocardiography provide a superior estimation of RV systolic function than 2-dimensional (2D)-echo.

Methods: This cross-sectional study analyzed 22 patients with a diagnosis of PH stratified by right heart catheterization, and they were compared to a control group of 22 age- and sex-matched healthy subjects.

Results: Global longitudinal peak systolic strain measured in the RV free wall from the apical 4 chamber view was -15% vs. -14.5% when measured from the subcostal view (p = 0.99). Mean longitudinal strain during reservoir phase, and longitudinal strain rate during atrial reservoir and passive conduit function was significantly impaired measured in the right atrial free wall in patients with PH.

Conclusions: This study showed impaired LV contractility in patients with PH assessed by speckle tracking strain. RV free wall longitudinal strain does not correlate with any of the measurements of RV systolic function obtained by 2D echocardiography. A major strength of RV longitudinal strain is its ability to assess the RV function without the limitations of 2D parameters. The subcostal RV strain is a feasible and accurate alternative to conventional RV strain from the apical view in patients with poor acoustic apical 4-chamber windows. The RA strain and strain rates values may be a valuable additive to assess right-sided heart function.

Keywords: Pulmonary hypertension; Right atrial function; Right ventricular function; Strains.

Figure 1. RVFWSL assessment by speckle tracking echocardiography in a normal subject. (A) RVFWSL in the apical 4-chamber view (−24%), and (B) RV longitudinal peak systolic strain of the inferior wall in the subcostal view (−25%). Note the good correlation between both views.

RVFWSL: right ventricular free wall longitudinal peak systolic strain, AVC: aortic valve closure, RA: right atrium, RV: right ventricular, LA: left atrium, LV: left ventricular.

Figure 2. RVFWSL obtained from a patient with pulmonary hypertension, showing the impairment of myocardial strain: (A) RVFWSL in the apical 4-chamber view (−4.66%), and (B) RV longitudinal peak systolic strain of the inferior wall in the subcostal view (−4.66%). Note the good correlation between both views.

RA: right atrium, RV: right ventricular, RVFWSL: right ventricular free wall longitudinal peak systolic strain.

Figure 3. Assessment of RVFWSL. (A) Normal subject (−24%). (B) Patient with pulmonary hypertension (−13.3%).

RVFWSL: right ventricular free wall longitudinal peak systolic strain, AVC: aortic valve closure, RA: right atrium, RV: right ventricular, LA: left atrium, LV: left ventricular.

Figure 4. Assessment of RA function in a normal subject. RA longitudinal strain determined by 2-dimensional speckle tracking was obtained from the RV-focused apical 4-chamber view. The RA was automatically divided into 3 segments (basal = yellow line; medial = blue line; apical = green line) The white dotted line represents the average strain of the 3 segments of the lateral wall of the RA.

AVC: aortic valve closure, RA: right atrium, RV: right ventricular, LV: left ventricular, LA: left atrium, A: reservoir function, B: conduit function, C: contractile function.

Figure 5. RASr, pRASRr, pRASRcd and pRASRct.

RASr: right atrial strain during reservoir phase, pRASRr: peak right atrial strain rate during reservoir phase, pRASRcd: peak right atrial strain rate during passive conduit phase, pRASRct: peak right atrial strain rate during contraction phase, MC: mitral closure, AO: aortic opening, AC: aortic closure, MO: mitral opening, AS: atrial systole, IVC: isovolumic contraction, VS: ventricular systole, IVR: isovolumic relaxation, ED: early diastole, Diast: diastasis, LSR = longitudinal strain rate, Pump = atrial contraction, ECG: electrocardiogram.