Treating breast cancer patients with chemotherapy and radiation may increase their risk of developing cardiovascular diseases, the American Heart Association has warned.

With the advances in treatment, there has been a growing number of breast cancer survivors. However, survivors above the age of 65, were more likely to die from heart disease than breast cancer, the new study showed. Targeted therapies for breast cancers like HER-2 could cause weakening of the heart muscle, a condition known as heart failure, it said.

Other therapies could also affect the heart arteries and cause the development of coronary artery disease or blockages, the study added. Prompting attention to the fact that during treatment not only ones breast health, but also general health, including that of the heart, should be considered, the researchers suggested.

"Any patient who is going to undergo breast cancer treatment, whether they have heart disease at the beginning or not, should be aware of the potential effects of the treatments on their heart," said Indian-origin Laxmi Mehta, Associate Professor at The Ohio State University in the US.

However, it should not deter or scare patients from undergoing the cancer treatment, instead allow them to make informed decisions with their doctor on the best option available, Mehta added, in the statement published in the journal Circulation.

In some cases, post cessation of the treatment and/or the addition of heart medicines can improve heart function Administering Doxorubicin -- a chemotherapy drug -- used in breast cancer therapy can also lead to the damage of heart cells, but, giving the drug slowly, rather than all at once, may lower the risk of heart failure. Doctors were also developing more-targeted radiation to reduce risks, the statement said.

Adherence to a number of ideal heart health behaviours including being physically active, achieving, and maintaining a healthy body weight could help. Besides, eating a healthy diet, avoiding tobacco, maintaining healthy levels of blood pressure, cholesterol and blood sugar may help prevent or minimise the damage.