Right atrium contractility and right ventricular diastolic function assessed by pulsed Tissue Doppler Imaging can predict brain natriuretic peptide in adults with acquired pulmonary hypertension

Abstract

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.

Introduction

The elevated right atrial (RA) pressure and right ventricular (RV) dysfunction are associated with increased mortality in patients with chronic pulmonary hypertension (PH) [1], [2]. Although RA and RV show adaptive responses and dynamic changes in order to maintain RV filling and cardiac output [3], few studies have focused on RA contractility and RV diastolic function in adult patients with acquired chronic PH, because assessment of these parameters is difficult due to the complicated morphological remodeling.

To evaluate RA contractility and RV dysfunction, right side heart catheter examinations is the most accurate technique available [4] but cannot be routinely performed in daily practice because of its invasive nature. Therefore, alternative, non-invasive methods are needed to assess RA contractility and RV dysfunction in such patients.

Pulsed Tissue Doppler Imaging (TDI) [5], [6], [7], [8], [9], [10], [11] is a very useful and easy technique to assess RA as well as RV function. Some studies have reported that RV systolic function is initially preserved with RV pressure overload, but that diastolic dysfunction occurs as a consequence of myocardial hypertrophy and remodeling [12]. Both RV contractility and RV stiffness are also very important factors for right heart failure in patients with chronic PH, and TDI is a useful technique in this situation to assess RV diastolic function.

Elevated serum levels of brain natriuretic peptide (BNP) [13], [14], [15], [16], [17], [18], [19], [20], [21] are also associated with poor prognosis in patients with PH [22], [23], which is greatly influenced by volume overload, age, and renal function [24]. Here, we evaluated RA contractility and RV diastolic function in adult subjects with acquired chronic PH and normal electrocardiographic sinus rhythms by pulsed TDI and assessed their relationship with serum BNP using multiple regression analysis.