What is Cardiotoxicity?
Cardiotoxicity (pronounced kaar·dee·ow·taak·si·suh·tee) is damage to the cardiovascular system that is caused by cancer treatments including chemotherapy and radiation therapy. Cancer treatments such as chemotherapy and radiation therapy can be lifesaving, but they can also have damaging side effects to the heart and cardiovascular system. This type of damage is called cardiotoxicity or toxicity in the heart. It weakens the heart. A weakened heart can lead to serious heart problems if not caught early and treated.
Types of Heart Problems Caused by Cardiotoxicity
Arrhythmia or abnormal heart rhythm
Cardiomyopathy – the heart pumps less efficiently, which decreases the amount of blood and oxygen sent to the organs and may increase risk for blood clot and heart attack
Congestive heart failure – develops when cardiomyopathy gets to the point of causing symptoms because the heart can’t pump enough blood, which can damage your organs and cause fluid to build up in your lungs
Coronary artery disease – narrowing or blocking of coronary arteries usually caused by plaque build up
Hypertension or high blood pressure – when blood pressure is too high and left untreated it can lead to heart attack, stroke and other health problems
Hypotension or low blood pressure – when blood pressure is too low, it can cause dizziness or lightheadedness, nausea, fainting and other symptoms
Myocarditis – swelling or inflammation of the heart muscle, which causes an abnormal heartbeat, can weaken the heart muscle and lead to cardiomyopathy
Peripheral vascular disease – narrowing or blocking caused by plaque build-up outside of the coronary arteries
Valve disease – narrows or weakens the valves, which causes blood flow abnormalities through the valves
Causes & Risk Factors of Cardiotoxicity
Not all cancer treatments can damage the heart. Those with the most common potential to damage to the cardiovascular system include:
- Chemotherapy – certain drugs
- Radiation therapy – especially to the chest
- Targeted or molecular therapy
- Monoclonal antibodies
- Drugs to prevent cancer recurrence
Who’s at Risk for Cardiotoxicity?
Those with an increased risk of heart issues following cancer treatment are people who:
- Are 60 years or older, children and women
- Received high doses of anthracyclines
- Had high-dose radiation therapy to the chest
- Had combination therapy of anthracyclines and chest radiation therapy
- Received anthracyclines or trastuzumab and have a history of smoking, high blood pressure, diabetes, obesity or heart problems
- Received anthracyclines followed by trastuzumab
A cardio-oncologist will use diagnostic testing to determine if you are at risk of developing heart disease from cancer treatment.
The most common diagnostic tests include:
- Echocardiogram (Echo) – this ultrasound of the heart gives a comprehensive evaluation of cardiac structures and blood flows through those structures. When performed at the beginning of cancer treatment and at different times during cancer treatments this test can evaluate changes that could lead to a change in treatment plan. A cardio-oncologist may prescribe medication to protect the heart.
- Electrocardiogram(EKG) – records the heart’s electrical signal and can indicate changes in the heartbeat.
- Blood tests – to measure the level of proteins in the blood and risk of heart disease.
- Additional advanced-testing options may be used if necessary.
Other specialists who may be involved in diagnosing and treating patients with cardiotoxicity include:
- Exercise physiologists, physical therapists and occupational therapists
The cardio-oncologist will review the results of your tests and determine if cardiotoxicity treatment is needed. Very often, cardiovascular function improves once the cancer treatment is done.
A personalized treatment will be developed for you that may include medications such as aspirin, statins, beta blockers, ACE inhibitors, diuretics and others. Other treatment strategies for cardiotoxicity include cardiac rehabilitation, nutrition counseling and other strategies.
The cardio-oncologist will monitor your health and adjust treatment as necessary. The goal is to avoid interrupting your cancer treatment and protect the heart at the same time. If necessary, the cardio-oncologist will work with your oncology team to identify alternative treatments for your specific needs.
Chris Fine, MD, FACC
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