Hawthorn has been used as an herbal remedy since ancient times. The herb contains flavonoids which have antioxidant properties. These compounds are believed to protect the heart muscle cells from damage caused by free radicals. Hawthorn may be helpful in treating angina pectoris or chest pain due to coronary artery disease. It can also be useful in preventing cardiac arrhythmias such as palpitations, fainting, irregular heartbeat, and shortness of breath. Hawthorn is often recommended for people who suffer from high blood pressure, congestive heart failure, and cardiac insufficiency. 90 Veggie Caps.