Relationship between age and location of the apex beat among apparently healthy Nigerian children
Background: Normal location of apex beat varies with age in children. Location of apex beat is an integral part of routine cardiovascular system examination in clinical practice. However, there is paucity of literature on apex beat location in Nigerian children. Objective: The aim of this study was to locate apex beat position in apparently healthy Nigerian children from birth to ten years, and to relate the location with age. Subjects and Methods: This was a cross sectional study carried out in Sagamu, Nigeria. A sample size of two hundred and thirty-seven was calculated from a previous study. Hence two hundred and thirty-seven apparently healthy Nigerian children who satisfied the inclusion criteria were enrolled for the study. Apex beat location in the intercostal space was determined and distance of apex beat from the midline, midclavicular line and nipple lines were measured. The measured distances were related to age using linear regression and Pearson correlation. Results: The mean distance of apex beat from the midline from birth to 10 years ranged from 2.3cm to 6.4cm. The distance of apex beat from the midline increased progressively with age. In children up to the age of three years, the apex beat was in the 4th left intercostals space. In 91.7%, 51.3% and 14.3% of children aged four, five and six years respectively, the apex beat was present in the 4th left intercostal space. Above six years, it was located in the 5th left intercostals space. Conclusion: The location of the apex beat from the midline was strongly related with age Thus, the distance of apex beat from the midline can be predicted from age in months.
Keywords: Apex beat, Children, Mid-clavicular line, Nigeria, Nipple line