Relationship between N-terminal B-type Natriuretic Propeptide and Echocardiographic Assessment of Right Ventricular Function in Children after Surgical Repair of Tetralogy of Fallot

Aim: To examine the relationship between plasma levels of N-terminal proB type natriuretic peptide (NTproBNP) value in patients after surgical correction of Tetralogy Fallot with the dimensions of the right heart chambers, the volume load of the right heart chamber and the severity of pulmonary regurgitation

Methods: The research include 39 patients aged 1-17 years, 1±17 years after the primary surgical correction of the tetralogy Fallot, divided into two groups: Group I- patients who underwent surgical correction less than 10 years ago beginning of the study and Group II-patients who underwent operative correction in a period longer than 10 years before beginning of the study. Patient histories, measured NT-proBNP levels and transthoracic echocardiography parameters were analysed.

Results: 39 patients participated in the study, with an average age of 9.1±4.63 years, and a range of 1 to 17 years. Of the mentioned number of patients, 20 (51.3%) underwent surgery less than 10 years ago, on average 4.85 years ago, while 19 (48.7%) respondents underwent surgery more than 10 years ago, on average 11.74 years ago. In relation to the gender distribution of the respondents, it was determined that in the group of respondents who underwent surgery within 10 years, 18 (90%) respondents were female. In the group of respondents who underwent surgery more than 10 years ago, 11 (57.9%) respondents were female. It was found that there is a significant statistical difference in gender representation between the two investigated groups (x2=5.267; p=0.022). Of the 20 subjects who were operated on within 10 years, 7 of them (35%) use some form of therapy, while among the subjects who were operated on 10 years or more ago, 2 of them (10.5%) use some form of therapy. No significant statistical difference was found in the frequency of therapy consumption (x2=3.288; p=0.070). Dysrhythmias were not found in any patient. Pericardial effusion was also not found in any patient. In relation to the elapsed time since the operation, significantly higher values of PVR were found in subjects who had the operation performed ten or more years ago (p=0.022). Significantly higher values of FS-RVOT (%) (p=0.009) and significantly higher values of RV-FAC (%) were also determined; p=0.012. A significant correlation between the value of NTproBNP and the E”/A” index was determined, r=0.468; p=0.037. The relationship was evaluated as a medium-strong relationship, with a positive sign.

Conclusions: Quantification of right heart function is possible and should be routinely performed using a combination of different parameters. Increased plasma NT-proBNP levels in patients after surgical repair of ToF are related to RV systolic and dyastolic dysfunction, evaluated by 2D-, M-mode and TDI.

Keywords: Tetralogy Fallot, Right Heart, NTpro BNP, Echocardiography.