electrocardiograms (ECGs) - Cancer Science

What is an Electrocardiogram (ECG)?

An electrocardiogram (ECG) is a non-invasive test that measures the electrical activity of the heart. It is commonly used to assess heart health, detect abnormalities, and guide treatment decisions. ECGs are crucial in the context of cancer treatment, as cancer therapies can have significant cardiovascular effects.

Why Are ECGs Important for Cancer Patients?

Cancer patients often undergo treatments such as chemotherapy, radiation, and targeted therapies, which can have cardiotoxic effects. Cardiotoxicity refers to damage to the heart muscle or its function due to toxic substances. Monitoring heart health with regular ECGs helps in early detection of cardiotoxic effects, allowing for timely interventions to mitigate risks.

How Do Cancer Treatments Affect the Heart?

Certain chemotherapeutic agents, like anthracyclines and trastuzumab, are known to cause heart damage. Radiation therapy, especially when directed towards the chest, can also affect the heart. These treatments can lead to conditions such as arrhythmias, heart failure, and myocardial ischemia.

When Should an ECG Be Performed?

An ECG should be performed at various stages of cancer treatment:

Baseline: Before starting any potentially cardiotoxic therapy to establish a reference point.
During Treatment: Regularly during the course of treatment to monitor ongoing heart health.
Post-Treatment: After completion of treatment to check for delayed cardiotoxic effects.

What Are the Key ECG Findings in Cancer Patients?

Some key ECG findings that might indicate cardiotoxicity include:

Prolonged QT Interval: This can increase the risk of life-threatening arrhythmias.
ST Segment Changes: These can indicate myocardial ischemia or infarction.
T Wave Abnormalities: These may suggest changes in the heart muscle or electrolyte imbalances.

How Is Cardiotoxicity Managed?

Upon detecting cardiotoxicity through an ECG, several steps can be taken:

Medication Adjustment: Modifying or stopping the offending agent.
Cardioprotective Agents: Drugs like beta-blockers or ACE inhibitors may be prescribed.
Lifestyle Changes: Encouraging heart-healthy behaviors such as diet and exercise.
Frequent Monitoring: Increased frequency of ECGs and other cardiac tests.

What Are the Limitations of ECGs in Cancer Patients?

While ECGs are valuable, they have limitations. They might not detect all aspects of heart damage, particularly early subtle changes. Therefore, additional tests like echocardiograms or cardiac MRI may be needed for comprehensive cardiac assessment.

Conclusion

ECGs play a crucial role in the multidisciplinary care of cancer patients by monitoring and managing the cardiovascular side effects of cancer treatments. Regular ECGs help in early detection of cardiotoxicity, allowing for timely interventions and better overall outcomes for cancer patients.