S3 .The third heart sound (S3, or ventricular gallop) is low-pitched and best heard at the apex with the stethoscope bell.是什么意思_S3 .The third heart sound (S3, or ventricular gallop) is low-pitched and best heard at the apex with the stethoscope bell.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句