Cardiac Toxicity From Cancer Treatments - An Overview

Introduction

Cardiotoxicity associated with cancer treatment refers to damage to the heart and cardiovascular system (including heart valves and arteries) that can occur during or after cancer treatment. Chemotherapy and radiation therapy, as well as newer cancer treatments such as immune system therapies, can cause or exacerbate cardiovascular adverse effects such as high blood pressure, irregular cardiac rhythms, and heart failure. Cardiotoxicity symptoms during cancer treatment might cause stoppage or cessation of treatment, lowering its effectiveness. Symptoms may appear years after cancer treatment. As therapeutic advances have resulted in more cancer patients living longer lives, researchers are examining how side effects such as cardiotoxicity affect cancer survivors.

What Is Cardiotoxicity?

Cardiotoxicity refers to cardiac damage caused by some cancer treatments or medications. It can emerge years after cancer therapy, particularly in individuals who got cancer treatment as children. Certain cancer treatments pose an increased risk of cardiotoxicity. Cardiotoxicity may impair the heart's ability to pump blood throughout the body as it should. In severe situations, it can progress to cardiomyopathy, a heart muscle disorder that makes it difficult for the heart to pump blood.

Who Is Affected By Cardiotoxicity?

Cardiotoxicity can harm anyone who has undergone cancer treatment. It is more frequent in those who have taken specific medicines or had chest radiation therapy. It is also rather prevalent in adults who received cancer therapy as children. It is difficult to estimate the exact rate of cardiotoxicity in adults who received cancer treatment as adults. However, other groups believe that up to 20 percent of this population may have heart issues, with seven percent to ten percent developing cardiomyopathies or heart failure.

What Are the Signs of Cardiovascular Toxicity?

Symptoms of heart issues caused by cardiotoxicity include:

• Abdominal hypertrophy (distension).

• Chest discomfort.

• Dizziness.

• Cardiac palpitations.

• Dyspnea (shortness of breath).

• The legs swell and retain fluid (edema).

How Is Cardiotoxicity Detected?

Cardiotoxicity can be diagnosed by monitoring the heart's pumping function and assessing the function of heart valves. The left ventricular ejection fraction measures how much blood pumps out of the lower left heart chamber (left ventricle) each time the heart contracts. Doctors employ specific tests to examine the heart's pumping and valve function, including:

1. Echocardiogram: The most commonly used imaging tool for diagnosing cardiotoxicity is the echocardiogram. Echocardiograms employ electrodes and ultrasounds to detect heartbeat and visualize blood flow through the heart.

2. Cardiac MRI: Some specialists consider cardiac magnetic resonance imaging the gold standard for detecting cardiotoxicity. It employs magnets, radio waves, and a specialized computer to generate comprehensive images of the heart's architecture and assess how blood flows through it.

3. Cardiac Stress Test: This test assesses the heart's response to severe exertion. One can walk on a treadmill or ride a stationary bike while hooked to a machine that monitors heart rate and blood pressure.

4. The Multigated Acquisition Scan: This analyzes the function of the heart's ventricles. It employs a harmless radioactive tracer that appears clearly on an imaging scan. The physician assesses how the tracer flows through the bloodstream and computes the ejection percentage.

5. Cardiac Computed Tomography Scans: Cardiac tomography employs several X-rays from different angles to create a detailed heart image. This test may be most useful for patients who fear they have cardiotoxicity after chest radiation therapy.

Is It Possible for Radiation to Cause Cardiotoxicity?

An estimated 50 percent of cancer patients receive radiotherapy, which, along with the discovery of new chemotherapeutic medicines, has significantly improved the prognosis for numerous forms of cancer. However, late cardiovascular consequences are usually observed after radiation. The majority of clinical data on radiation-induced heart disease are based on investigations of people who had breast cancer or Hodgkin's disease and experienced symptoms during or after treatment. Pericardial disease is usually related to radiotherapy, but additional problems, such as myocardial fibrosis and cardiomyopathy, accelerated heart disease, conduction abnormalities, and valve dysfunction, can develop months or years later. The radiation dose mostly determines the level of cardiotoxicity, the region of the heart exposed, and the specific technique used. Other risk variables include the patient's age at the time of exposure, with younger patients (under 20) being more vulnerable to cardiac injury.

How Can Cardiotoxicity Be Treated?

Depending on the existing medication regimen, the doctor may advise to discontinue or reduce the dose of certain medications. Physicians may also prescribe drugs to help the heart function more efficiently, such as:

• ACE inhibitors, such as Lisinopril and Fosinopril sodium, help to widen arteries and enhance blood flow.

• Beta-blockers, such as Metoprolol or Atenolol, boost blood flow while slowing the heart rate.

• Digoxin, or digitalis, reduces heart rate and helps it beat more efficiently.

• Diuretics, such as Furosemide, can help the body eliminate extra fluid.

• Vasodilators, such as Isosorbide dinitrate, dilate blood vessels, allowing blood to flow more efficiently.

How Can One Lower the Risk of Cardiotoxicity?

There is no way to prevent cardiotoxicity. If one has been diagnosed with cancer, one should consult with a physician about the potential health risks and advantages of therapies. Regular cardiac imaging during cancer therapy can improve the chances of detecting cardiotoxicity early. Detecting heart problems early can improve the chances of properly treating them.

When Should One Go to Visit a Doctor?

If one has any of the following signs indicating a significant heart problem, proceed to the nearest emergency center:

• Heart palpitations or a racing sensation that persists or continues.

• Dizziness, lightheadedness, or fainting.

• Rapidly developing shortness of breath or chest pain.

• Swelling of the throat or lips.

• Unusual swelling in the legs or feet.

• Weight gain of more than three pounds in one week.

Conclusion

Chemotherapy and radiotherapy are widely used in clinical practice, which has raised concerns about their possible severe cardiovascular consequences in cancer survivors, such as cardiomyopathy, ischemia, arrhythmias, hypertension, pericardial disease, and thrombosis. There is no consensus on standardized cardiac function monitoring in these individuals, and there are no acceptable models for predicting the risk of cardiotoxicity. Cancer drug specialists appreciate the need to understand the processes of cardiotoxicity. Careful monitoring and assessment of cardiac risk are critical in these patients, and the long-term implications of various treatments warrant additional investigation. To this purpose, it is becoming increasingly vital to form dynamic collaborations between oncologists and cardiologists to minimize mortality and improve patients' quality of life while retaining therapeutic effectiveness. To summarize, cardiotoxicity caused by cancer treatment should be viewed as a multidisciplinary challenge, with approaches encompassing basic research, oncology, and cardiovascular medicine.