Effects of radiotherapy on heart

  Radiation therapy may involve any part of heart.

  Among them, pericardial involvement is the most frequent.

  Radiotherapy can result in myocardial fibrosis. Fibrosis of tissue adjacent to the conduction system

      may result in a wide spectrum of ECG abnormalities.




Abnormal ECG findings may be seen after radiotherapy:

  Inverted T waves in leads V1-V4:

            -
the most common ECG change after radiotherapy

            - seen early after radiotherapy

            - usually reversible

  Bundle branch block (mostly right)

  All types of atrioventricular (AV) block

  Sick sinus syndrome

  Abnormal Q waves

  Loss of QRS voltages

  QT-interval prolongation




References

  Cancer Treatment Reviews 2011;37:391-403.

  Cardiology in Review 2005;13:80-86.

  Cancer 1986;57:929-934.

  Pacing Clin Electrophysiol 1991;14:1112-1118.

  J Am Coll Cardiol 2003;42:743-749.





ECG 1a. The ECG above belongs to a 53 years-old woman.
It was recorded 6 months before undergoing mastectomy for left breast cancer.
Her ECHOcardiogram was normal (no structural heart disease).

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ECG 1b. The ECG above belongs to the same woman. It was recorded 6 months after chemotherapy and radiotherapy
Newly developed left bundle branch block (LBBB) is seen. Her ECHOcardiogram did not show cardiac dilation.

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ECG 1c. The ECG above belongs to the same woman. It was recorded 2 years after the ECG 1b.
LBBB persists. Her ECHOcardiogram still does not show cardiac dilation.

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ECG 2. The ECG above belongs to 63 years-old woman with normal coronary arteries.
She had undergone left mastectomy for breast cancer.
The above ECG was recorded 5 years after radiotherapy.
Inverted T waves in leads V1-V4 are the most common ECG changes developing after radiotherapy.

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ECG 3. The ECG above belongs to 70 years-old woman who had received chemotherapy and radiotherapy for breast cancer.
Low voltage is seen.

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