Purpose: We evaluated right atrial (RA) contractility and right ventricular (RV) diastolic function in adult patients with acquired chronic pulmonary hypertension (PH) by pulsed Tissue Doppler Imaging (TDI) and assessed their relationship with serum brain natriuretic peptide (BNP).
Materials and methods: Systolic myocardial wave (Sa), early diastolic myocardial wave (Ea), and late diastolic myocardial wave (Aa) at the tricuspid annulus were recorded in 77 consecutive patients with acquired PH. Early (E) RV inflow waves were recorded from 4-chamber views. RV Aa was regarded as the parameter of RA contractility and RV E/Ea was taken as the parameter of RV diastolic function using TDI.
Results: All subjects had elevated BNP (mean 188.9 +/- 244.0 pg/dl) and pulmonary arterial systolic pressure (PASP) estimated at 62.9 +/- 26.7 mm Hg. BNP levels were positively correlated with RV E/Ea, Aa and PASP (r = 0.47, p < 0.0001 and r = 0.35, p < 0.01, respectively) but negatively with Aa (r = -0.29, p < 0.05). Next, all predictor variables were used in a multiple regression model with serum BNP values as dependent variables, refined to include 3 predictors: RV E/Ea, Aa, and PASP, which were all found to influence serum BNP values (p < 0.0001) by the formula Y = 34.1X1**-19.11X2**+2.95X3* (**p < 0.001, *p < 0.01) where Y = BNP, X1 = E/Ea of RV, X2 = Aa, and X3 = PASP (standard regression coefficients were 0.37, -0.34 and 0.34, respectively).
Conclusion: Serum BNP correlates with RA contractility and RV diastolic dysfunction by RV TDI in adults with acquired PH. Increased BNP may be related to decreased RA systolic function and RV diastolic function in these patients.