Cardiotoxicity is heart damage caused by medical treatments, medications, or chemical exposure. This damage can interfere with the heart’s ability to pump blood or maintain a normal rhythm. Cardiotoxicity testing involves procedures used to detect and monitor this potential damage before it becomes a significant problem. The goal is to identify issues early, allowing for timely intervention.
Why Cardiotoxicity Testing is Performed
The purpose of cardiotoxicity testing is the early detection and prevention of heart muscle damage. For patients starting treatments with known heart-related side effects, like certain chemotherapy drugs, these tests serve as a protective measure. Monitoring allows doctors to identify subtle changes in heart function long before a person would notice any symptoms.
A part of the process involves establishing a baseline measurement of heart function before a treatment begins. This initial assessment provides a clear reference point. Subsequent tests performed during and after treatment are then compared to this baseline to accurately track any changes. This ongoing surveillance enables doctors to make informed decisions about a patient’s care.
Common Methods Used in Testing
One frequently used method for assessing heart function is the echocardiogram, or “echo.” This non-invasive procedure uses sound waves to create detailed images of the heart. It allows doctors to visualize the heart’s chambers and valves and assess how well it pumps blood. A measurement from an echocardiogram is the left ventricular ejection fraction (LVEF), which indicates the percentage of blood leaving the left ventricle with each contraction. A drop in LVEF can be an early sign of cardiotoxicity.
Another diagnostic tool is the electrocardiogram, also known as an ECG or EKG, which records the heart’s electrical activity. Small sensors attached to the skin detect the electrical signals that trigger each heartbeat. The ECG is useful for identifying irregularities in the heart’s rhythm, known as arrhythmias, which can be caused by cardiotoxic agents.
Blood tests monitor for heart damage by measuring levels of cardiac biomarkers. When the heart muscle is injured, it releases certain proteins into the bloodstream. One biomarker is troponin; elevated levels can indicate heart muscle damage has occurred. Brain natriuretic peptide (BNP) is another substance measured, as its levels can rise when the heart works harder. More advanced imaging like a multigated acquisition (MUGA) scan or a cardiac MRI may be recommended for a more detailed view.
Understanding Test Results and Next Steps
If signs of cardiotoxicity are detected, such as a drop in LVEF, an abnormal heart rhythm, or a rise in cardiac biomarkers, your medical team will discuss the best course of action. This does not always mean stopping the primary treatment. One strategy is to adjust the dosage of the medication suspected of causing the issue. In other situations, the treatment plan might be paused or switched to an alternative therapy that is less likely to affect the heart.
In addition to modifying the treatment, doctors may prescribe medications to protect heart function. These can include drugs like beta-blockers or ACE inhibitors, which help lower blood pressure and reduce the workload on the heart. The response is tailored to the individual, based on the severity of the cardiotoxicity, the type of treatment, and the patient’s overall health.
Who is at Higher Risk for Cardiotoxicity?
Certain individuals are more susceptible to developing heart-related complications from medical treatments. Factors that can increase risk include:
- Pre-existing heart conditions, such as high blood pressure, coronary artery disease, or a history of heart failure.
- Age, as older adults can be more susceptible to cardiotoxicity.
- Previous or concurrent radiation therapy to the chest area, which can affect the heart muscle and blood vessels.
- The specific treatment regimen, such as receiving high cumulative doses of a cardiotoxic drug or undergoing combination therapy with multiple such agents.
Your healthcare provider considers these factors when deciding on the necessity and frequency of cardiotoxicity testing.