The fifth intercostal space in the left midclavicular line is an important landmark for cardiac examination, during which the strongest point of the apical beat needs to be found in order to determine the size of the heart. The strongest point of the apical beat is usually located in the left midclavicular line between the fifth ribs, generally in the midclavicular line in the position of 0.5-1 cm, you can find the strongest point of the apical beat, if the beat point moves outward, it is suggestive of the heart of the heart border enlargement. Therefore, patients with enlarged heart borders need to undergo further cardiac percussion to determine the extent of the heart and perform appropriate tests to identify the heart enlargement and the cause of the enlargement.