Heart attack threatens

Cancer can also affect the heart

If the radiation is administered close to the heart during therapy, there is a risk of damage.

(Bild: ©nerthuz - stock.adobe.com)

Cancer can be treated better today than ever before. Chemotherapy and radiation may fight the tumor, but they often damage the life pump. It can promote cardiac insufficiency, arrhythmia, high blood pressure and heart attacks.

Cardiovascular disease as a result of cancer therapies - this is the phenomenon known as cardiotoxicity. "This can lead to high blood pressure, valve disease, premature calcification of the coronary arteries, cardiac insufficiency, heart attacks or arrhythmias," explains Prof. Dr. Jutta Bergler-Klein, Division of Cardiology, MedUni Vienna.

How does radiation affect the heart?

There is essentially a cardiac risk if the heart is in the so-called radiation path. In particular, the vessels surrounding the heart in the form of a ring, the coronary arteries, can be damaged. This is particularly true for the left coronary artery, as part of it runs along the front of the heart and is therefore most likely to be reached by the radiation when irradiated from the front. Studies have shown a clear correlation between the radiation dose used and cardiac events such as heart attacks in the case of damage in this area.

Prevention and therapy extremely important!
However, not only cancer drugs but also substances produced by tumors can impair heart function. Conversely, chronic cardiac insufficiency creates a permanent inflammatory state that favors the development of tumors.

Prevention and treatment of cardiovascular diseases are therefore crucial at all times, especially after a cancer diagnosis and before, during and after treatment. The primary goal must be to neither delay nor impair the vital treatment of the tumor.

Protection for the heart
Cancer patients themselves can also help to protect the heart: "Risk factors such as high blood pressure and cholesterol levels should be treated immediately. Physical activity, where possible even during chemotherapy, helps to reduce potential cardiotoxicity, for example by inactivating cell-damaging oxygen radicals and preventing muscle breakdown," explains Prof. Dr. Bergler-Klein.

The risk of coronary heart disease or valve disease is particularly high in patients with bronchial carcinoma who have to be irradiated. The radiation dose and radiation field are therefore selected as carefully as possible - especially in the case of pre-existing heart disease. Consultation between the cardiologist and oncologist is then very helpful.

Reducing the risk of radiation
For women with breast cancer, a technique called DIBH (deep inspiration breath hold) can be used to protect the heart during radiotherapy. Radiation is delivered during a moment of deep inspiration with a short breath hold, as there is then a greater distance between the breast and the heart. This means that the cardiac doses are now low, even when irradiating the left side of the chest.

Irradiation away from the heart, for example on the foot, is not critical. In this case, the heart dose is 0 Gy (=Gray: dose unit of radiation therapy), as reported on the homepage of the German Heart Foundation.