Signs and Symptoms of Heart Cancer

Heart cancer develops when abnormal cells in the heart muscle or surrounding tissues grow uncontrollably, forming a malignant (cancerous) tumor. Cancerous heart tumors (known as cardiac sarcomas) are extremely rare, accounting for less than 0.028% of all cancer diagnoses annually.  

Secondary heart cancer is when cancer cells metastasize (spread) to the heart from a tumor that started in nearby organs or body tissues. Secondary heart cancer is about 30 to 50 times more common than primary heart cancer. However, it is still rare, affecting approximately 10% of people with lung cancer, breast cancer, lymphoma (lymphatic system cancer), melanoma (skin cancer), and leukemia (blood cancer).  

Primary and secondary heart cancer can develop in the endocardium (the tissue that lines the heart's chambers), myocardium (the heart muscle), heart valves, and pericardium (the sac that surrounds the heart). Tumors growing in the heart and its surrounding tissues can disrupt the heart's function and structure.

In many cases, the signs and symptoms of heart cancer mimic those of more common heart and lung diseases. Symptoms can develop gradually over time or suddenly, depending on the tumor's growth rate (aggressiveness) and location within the heart.

Blood Flow Obstruction

Tumors in or near the heart valves or within the heart's chambers can obstruct blood flow, interfering with the heart's ability to pump blood efficiently. Depending on the location, cardiac tumors may block blood flow from the upper heart chamber (atrium) to the lower chambers (ventricles) or block blood flow out of the heart, disrupting the flow of oxygen-rich blood to the body's tissues. 

Symptoms of blood flow obstruction include:

• Shortness of breath, especially during physical activity
• Chest pain 
• Heart palpitations 
• Fatigue 
• Dizziness
• Fainting
• Swelling in the legs and feet

Disrupted Conduction System

The heart's electrical conduction system sets the rhythm of your heartbeat by stimulating the heart muscle contractions. Tumors in some regions of the heart can cause problems with the conduction system function. The following structures can be affected: 

• Atrioventricular (AV) node: A small area of the heart and part of the heart's electrical conduction system, helping the heart's four chambers beat in coordination 
• Septum: A wall of muscle that separates the chambers of the heart

Tumors in these areas can cause conduction problems or a "heart block," leading to symptoms such as: 

• Rapid or slow heart rate 
• Heart palpitations
• Lightheadedness or dizziness 
• Fatigue 
• Chest pain 
• Difficulty breathing during sleep 
• Fainting

Heart Muscle Dysfunction

Tumors growing in the myocardium (heart muscle) can cause the muscle to stiffen, reducing its ability to contract and effectively pump blood throughout the body. Symptoms of heart muscle dysfunction with heart cancer can mimic symptoms of heart failure and may include: 

• Shortness of breath at rest or with exertion 
• Fatigue
• Swelling in the abdomen, legs, and feet 
• Pleural effusion (fluid buildup surrounding the lungs)
• Pulmonary edema (fluid buildup in the lungs)
• Coughing

Embolus 

An embolus can occur when a small piece of a tumor breaks free from its original location in the heart and travels through the bloodstream before it gets stuck within an artery and blocks blood flow. However, blood clots and infections can also cause an embolism to form. Depending on the location of the embolus, its symptoms vary.

Common sites for an embolus with heart cancer include the brain, lungs, and limbs. 

Emboli Stroke 

An emboli stroke, or cerebral embolism, occurs when a blood clot, infection, or fragment of a cardiac tumor breaks away and travels to the brain, blocking blood flow. Symptoms of an emboli stroke depend on which area of the brain the embolus is affecting and may include:

• Numbness or weakness on one side of the body
• Confusion
• Difficulty speaking or understanding when others are talking 
• Vision problems
• Loss of coordination or balance
• Sudden, severe headaches
• Dizziness
• Trouble walking

Pulmonary Tumor Embolism 

A pulmonary tumor embolism occurs when a blood clot or piece of a heart tumor breaks free and travels to the lungs, blocking blood flow. Symptoms of a pulmonary tumor embolism develop suddenly, rapidly worsening, and may include:

• Shortness of breath 
• Rapid breathing 
• Chest pain that may worsen when coughing or taking a deep breath
• Rapid heart rate 
• Coughing up blood 
• Lightheadedness 
• Fainting 

Peripheral Embolism

A peripheral embolism is a blockage in the peripheral arteries—the vessels that supply blood to your limbs and other internal organs outside your heart and lungs. This can occur when a fragment of a cardiac tumor breaks free and becomes lodged in a peripheral artery. Symptoms depend on the location of the blockage. 

When the embolus is in a limb (arm or leg), symptoms will develop in the affected limb and may include: 

• Coldness due to lack of blood flow
• Weak or no pulse 
• Pain 
• Pale skin
• Muscle weakness
• Inability to move the affected limb 

Left untreated, additional symptoms may develop, including: 

• Blisters on the skin 
• Skin shedding 
• Ulcers (open sores) from skin erosion 
• Necrosis (tissue death) due to lack of blood flow 

When a peripheral embolism affects an internal organ, you may experience sudden and severe pain in the area of the affected organ. 

Pericardial Effusion

Tumors affecting the pericardium (the sac surrounding the heart) can cause fluid buildup, known as pericardial effusion. If a tumor irritates the pericardium or limits blood flow to the area, fluid buildup puts extra pressure on the heart. Symptoms of a pericardial effusion may include:  

• Sharp chest pain that worsens when lying down and improves when sitting
• Shortness of breath
• Decreased tolerance for physical activity
• Swelling in the limbs

Systemic Symptoms 

Primary and secondary heart cancers can cause systemic (bodywide) symptoms in response to the growing cancer. Systemic symptoms of cardiac sarcoma are flu-like and can include: 

• Unexplained weight loss
• Fever
• Chills
• Fatigue
• Weakness
• Joint pain 

Is Heart Cancer Contagious?

Heart cancer is not contagious and does not spread from person to person through direct contact, bodily fluids, or airborne particles. Like other forms of cancer, it develops due to mutations within a person's cells, not from pathogens like viruses and bacteria.

Although heart cancer is not contagious, some symptoms associated with it, such as coughing, can spread respiratory droplets that contain viruses or bacteria that can spread common respiratory infections, such as influenza (the flu), the common cold, and COVID-19. Coughing into your elbow or a tissue and washing your hands after touching shared surfaces like doorknobs can help prevent the spread of these infections. 

When to Contact a Healthcare Provider 

Early detection and diagnosis can help improve treatment outcomes in people with heart cancer. While some symptoms may seem minor, it's important to know the warning signs and seek medical attention. See a healthcare provider if you experience: 

• Shortness of breath 
• Unexplained fatigue or weakness
• Rapid or irregular heartbeats
• Unexplained swelling in the legs or abdomen 
• Persistent cough 
• Fever
• Unintentional weight loss 

Seek immediate medical attention if you experience any of the following symptoms: 

• Sudden, severe chest pain 
• Difficulty breathing or rapidly worsening shortness of breath
• Fainting 
• Cough up blood 

When in doubt, it's always better to seek medical attention for any concerning or persistent symptoms you experience. 

A Quick Review 

Heart cancer, or cardiac sarcoma, is a rare form of cancer that can cause symptoms such as shortness of breath, chest pain, and fatigue. Primary heart cancer starts in the heart, while secondary heart cancer spreads from other nearby organs, such as the lungs. 

Because symptoms of heart cancer are often vague and overlap with different conditions, the only way to know for sure if your symptoms are cancer-related is to see a healthcare provider to discuss next steps.