Chemotherapy side effects: A cause of heart disease?

Chemotherapy side effects may include an increased risk of heart disease, especially weakening of the heart muscle (cardiomyopathy). Certain types of chemotherapy also increase the risk of heart attack, especially during infusion of the medication. Fortunately, heart disease associated with chemotherapy is relatively rare — and not all chemotherapy drugs carry the potential side effect of heart damage.

It's important to note that some newer anti-cancer treatments — such as trastuzumab (Herceptin) for breast cancer — may cause heart damage as well, although the effect is often temporary and reversible.

If your doctor is considering using a chemotherapy drug that may affect your heart, you may undergo heart function testing before starting treatment. During treatment, you may need periodic heart monitoring as well. If you have a pre-existing heart condition, such as cardiomyopathy, your doctor may suggest a different type of chemotherapy.

Generally, the risk of heart disease associated with certain chemotherapy drugs increases with the total lifetime amount of the drug you receive. To minimize the risk of heart damage, your doctor will carefully monitor the amount of each type of chemotherapy drug you receive. If you experience significant breathing problems such as shortness of breath with minimal exertion or chest pain during chemotherapy, report it immediately to your health care team.

In addition, some cancers require radiation therapy. If the area of your body receiving radiation includes your heart, you have an increased risk of cardiomyopathy, coronary artery disease and heart attack. The combination of radiation and chemotherapy can further increase your risk of heart damage. However, your doctor can take steps to reduce these risks as much as possible.