For those with irregular heartbeat accompanied by chest tightness, treat with Cinnamon Twig Decoction minus Peony Root. This is due to the weakness of yang qi, which fails to govern the blood, leading to irregular heartbeat, presenting as intermittent pulse and chest tightness. The decoction has the effect of warming yang and promoting circulation. Since chest tightness is a sign of yin exuberance, Peony Root is removed.