《黄帝内经·灵枢·本藏》
胸骨剑突长者，心脏多坚实；胸骨剑突瘦小而薄者，心脏脆弱。
𩩲骬长者，心下坚；𩩲骬弱小以薄者，心脆。
A person with a long xiphoid process usually has a firmer heart; while a person with a slender and thin xiphoid process has a vulnerable heart.