The effect of frequent ventricular premature beats originating from the right ventricular outflow tract on left ventricular diastolic functions and their relationship with serum N-terminal proBNP levels

Objectives: We investigated the effect of frequent ventricular premature beats (VPB) originating from the right ventricular outflow tract (RVOT) on diastolic functions and the relationship between VPBs and serum N-terminal pro-brain natriuretic peptide (NT-proBNP) levels.
Study design: The study included 33 symptomatic patients (10 males, 23 females; mean age 40±8 years) with normal left ventricular functions, who had frequent VPBs originating from the RVOT on 24-hour Holter monitoring. All the patients underwent 2D transthoracic echocardiography and Doppler analyses and mitral inflow patterns and serum NT-proBNP levels were evaluated. The results were compared with those of 30 healthy individuals (9 males, 21 females; 37±9 years).
Results: Compared to the controls, the patients had a longer isovolumetric relaxation time (IVRT) (p<0.0001) and E-wave deceleration time (EDT) (p<0.0001), a smaller ratio of early diastolic wave to atrial wave (E/A) (p=0.001), and higher NT-proBNP levels (p=0.016). While the mitral inflow pattern was normal in all the controls, it was associated with impaired relaxation in 13 patients. Patients with diastolic dysfunction (n=13) had higher NT-proBNP levels (p=0.03) and greater VPB counts (p=0.001) than those without diastolic dysfunction (n=20). The number of VPBs was inversely correlated with the mitral E/A ratio, and positively correlated with EDT, IVRT, and NT-proBNP levels.
Conclusion: Frequent VPBs from the RVOT cause deterioration in diastolic functions in patients without structural heart disease. Considering a parallel rise in NT-proBNP levels with the VPB count, NT-proBNP measurement can be used as a predictor of diastolic dysfunction in symptomatic patients.

Keywords: Echocardiography, Doppler, heart ventricles; natriuretic peptide, brain/metabolism; ventricular function, left; ventricular premature complexes