Introduction: Preload-independent pulsed tissue Doppler echocardiography (TDI) and conventional pulsed Doppler echocardiography were used to assess the global left ventricular diastolic function in patients with hypertrophic cardiomyopathy (HCM). Levels of B-type natriuretic peptide (BNP) could be elevated in patients with isolated left ventricular diastolic dysfunction.
Aim: The study was to investigate the correlation between BNP levels and the parameters measured by conventional echocardiography and TDI in patients with HCM.
Patients: 32 consecutive patients with HCM (21 male, 11 female, mean age 47 +/- 14 years) were studied. Inclusion criteria were: normal sinus rhythm; ejection fraction > or = 50%; absence of moderate to severe mitral regurgitation or prosthetic mitral valve.
Methods: In addition to the conventional transmitral flow patterns (E, A, E/A, DT, IVRT) myocardial early (Ea) and late diastolic (Aa) velocities were measured at the lateral and septal border of the mitral annulus by ATL HDI 5000 ultrasound system. Ea/Aa and E/Ea ratios were calculated. NT-proBNP levels were measured by Roche-Elecsys test (immunoassay). Because the distribution of BNP values did not appear to be normal, the values were transformed into a natural logarithm (InBNP).
Results: Mean BNP level was 543 +/- 845 pg/ml. BNP levels negatively correlated with lateral Aa values (r = -0.59, p < 0.001). No significant relationship was observed between BNP levels and other echocardiographic parameters. By stepwise multiple linear regression analysis the only significant predictor of InBNP was lateral Aa value, too (r = -0.467, p < 0.05).
Conclusion: Significant correlation was found between BNP levels and a single TDI parameter characterizing left atrial systolic function, but there was no significant correlation between BNP levels and global left ventricular diastolic function characterized by either conventional echocardiographic or TDI parameters.