Evaluation of right intraventricular dyssynchrony by two-dimensional strain echocardiography in patients with pulmonary arterial hypertension.
BACKGROUND
Right ventricular (RV) function has major prognostic implications for patients with pulmonary arterial hypertension (PAH). Intraventricular dyssynchrony might play an important role in RV dysfunction in these patients.


METHODS
Thirty-six patients with PAH without right bundle branch block (mean age 44 +/- 14 yr, 24 women) and 39 controls (mean age 43 +/- 18 yr, 26 women) were evaluated. Global and segmental RV longitudinal deformation parameters were recorded by 2-dimensional strain echocardiography from apical 4-chamber views using a 6-segment RV model. The standard deviation of the heart rate-corrected intervals from QRS onset to peak strain for the 6 segments (RV-SD(6)) was used to quantify right intraventricular dyssynchrony.


RESULTS
RV-SD(6) was significantly higher in patients with PAH compared with controls (63 +/- 21 vs 25 +/- 15ms, P < .001). Dyssynchrony in patients with PAH was found to derive mainly from delayed contraction of the basal and mid RV free wall. In patients with PAH, RV-SD(6) was strongly correlated with RV fractional area change (beta = -.519, P = .002), RV myocardial performance index (beta = .427, P = .009), and RV global strain (beta = .512, P = .002); in models controlling for RV systolic pressure, RV size, and QRS duration, RV-SD(6) was still an independent predictor of RV fractional area change (beta = -.426, P = .005) and RV global strain (beta = .358, P = .031). RV function was significantly worse in the subgroup of patients with PAH (n = 25) with RV-SD(6) > 55 ms (the upper 95% limit in controls).


CONCLUSIONS
Right intraventricular dyssynchrony, as quantified by 2-dimensional strain echocardiography, is prevalent in PAH and is associated with more pronounced RV dysfunction. The clinical implications of these findings remain to be determined in follow-up studies.
Division of Cardiology and the Division of Pulmonary, Allergy, and Critical Care Medicine, Emory University Hospital, Atlanta, Georgia, USA.
Andreas P
AP
Kalogeropoulos
Vasiliki V
VV
Georgiopoulou
Sharon
S
Howell
Maria-Alexandra
MA
Pernetz
Micah R
MR
Fisher
Stamatios
S
Lerakis
Randolph P
RP
Martin
D000328:Adult; D004452:Echocardiography / Q000379:methods*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications* / Q000000981:diagnostic imaging*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018497:Ventricular Dysfunction, Right / Q000150:complications* / Q000000981:diagnostic imaging*