Background: The incidence of atrial fibrillation among adults increase with increasing age. Surgical series report a prevalence rate of 75% with valvular heart disease. In children, little is known or published about its true incidence, but with increased morbidity during valve surgery.
Objectives: To determine the prevalence of atrial fibrillation among pediatric patients with RHD. It is further intended to identify the factors that predispose the occurrence or AF in these patients.
Methods: This is a retrospective study reviewing 360 children less than 19 years of age diagnosed with RHD based on 2Decho, chest radiograph, and EKG. Predefined criteria were used to diagnose the valvular lesions by M-Mode, 2D-Echo and doppler measurements of Left atrial and left ventricular diameter, mean transmitral gradient and quantification of regurgitant lesions. Data were reported as mean standard deviation for continuous variables and percent prevalence for discrete or dichotomized variation. Group difference were assessed by the Student's t test for
continuous variables. Stepwise regression analysis was used to determine the independent association of clinical characteristics and echocardiographic variables with AF.
Results: Thirty-nine percent (39.4%) among children with rheumatic heart disease had Atrial Fibrillation, seventeen percent of which was chronic. 48.8% with Mitral Stenosis had AF, the frequency is increased to 61% when Mitral stenosis is in combined with MR, and TR. Majority of patients with moderate to severe MR had AF. Univariate analysis of 9 echocardiographic variables disclosed left atrial diameter, LVEED diastolic diameter (LVEDD), Pulmonary artery pressure (PAP),
MV area, presence of calcification and mean diastolic mitral gradient as factors significantly associated wit h the development of A F (p value < 005) RV systolic pressure of at least 50 + 23 mmHg and MV area by planimetry were highly predictive or developing AF (p=0.0002 and p =0.022, respectively). By multivariate analysis or the 9 variables, however, yielded only five namely;. LA diameter, MV Area by pressure half time (PHT), LVESD, presence of calcification and PA pressure as significant predictors of atrial fibrillation among children with rheumatic heart disease (p < 0.05).
Conclusion: Atrial Fibrillation among children with rheumatic heart disease occurs in 48%. The most important predictor or atrial fibrillation among these patients are: LA diameter, MV area by PHT, LV end systolic diameter, presence or calcification, and PA pressure.