Are heart palpitations a symptom of lung cancer?

Heart palpitations are not among the classic, common symptoms of lung cancer; typical symptoms include cough, shortness of breath, chest pain, coughing up blood, and unexplained weight loss. ^[1] Shortness of breath can occur when lung tumors block airways or when fluid builds up around the lungs or heart, which may indirectly contribute to a racing heartbeat for some people. ^[2] Overall, if palpitations happen in someone with or being evaluated for lung cancer, they are more often due to complications or treatments rather than the tumor itself. ^{[3] [4]}

What palpitations feel like

Palpitations are the sensation of a fast, pounding, or irregular heartbeat. They can be brief and harmless, or a sign of an underlying heart rhythm problem (arrhythmia). In cancer care, arrhythmias can arise from multiple causes, so it’s important to consider context and timing. ^{[3] [5]}

Possible causes in lung cancer

• Fluid around the heart (pericardial effusion) or lungs (pleural effusion): Fluid accumulation due to cancer can cause shortness of breath and chest discomfort; the strain can make the heart beat faster or feel irregular. ^[2]
• Collapsed lung (pneumothorax) or blocked airway: When a large area of lung is affected, people may feel short of breath and develop a rapid heart rate. ^[6]
• Blood clots in the lungs (pulmonary embolism): Cancer increases clot risk; palpitations can accompany breathlessness and chest pain when a clot impacts heart and lung function. [PM19]
• Direct heart involvement: Rarely, lung cancer can involve the heart muscle or pericardium, provoking serious rhythm problems like ventricular tachycardia. [PM20]
• Cancer treatments (cardiotoxicity):
  • Chemotherapy, targeted therapy, immunotherapy, and radiation can lead to heart rhythm changes, myocarditis (heart muscle inflammation), pericarditis, and heart failure, all of which may cause palpitations. ^{[3] [4]}
  • Some lung cancer regimens list abnormal heartbeat and other heart problems as potential risks, sometimes appearing within the first months of therapy. ^[7]
  • Specific agents (examples from lung cancer care) may cause bradycardia or other rhythm issues, requiring baseline and ongoing cardiac monitoring. ^{[8] [9]}
  • Tyrosine kinase inhibitors and immunotherapies have been linked to QT prolongation, myocarditis, and ventricular arrhythmias, which can present with palpitations. [PM21] [PM24] [PM25] [PM23]
• Paraneoplastic autonomic effects: Rare immune-related syndromes associated with lung cancer can disrupt the autonomic nervous system, leading to irregular heartbeats and blood pressure changes. ^{[10] [11]}

When to seek urgent care

• New palpitations with chest pain, fainting, severe shortness of breath, or coughing up blood need emergency assessment because they may signal a serious rhythm disturbance, pulmonary embolism, or significant fluid around the heart. ^[1] [PM19]
• Palpitations starting soon after a new cancer treatment warrant prompt contact with the oncology team, as some therapy-related heart problems can be uncommon but potentially severe. ^{[7] [3]}

How palpitations are evaluated

• Clinical assessment: Detailed history (timing vs. treatments), vital signs, and physical exam help identify red flags. Shortness of breath, low oxygen, or hypotension raise concern for lung or heart complications. ^{[2] [6]}
• Electrocardiogram (ECG): Detects arrhythmias, conduction changes, or QT prolongation that may be drug-induced. Baseline and repeat ECGs are often recommended in patients receiving cardiotoxic therapies. ^{[8] [9] [3]}
• Blood tests: Cardiac biomarkers (like troponins) may be used if myocarditis or heart injury is suspected during cancer therapy. [PM24]
• Imaging: Chest X‑ray or CT can check for lung collapse, clots, or fluid; echocardiogram evaluates heart function and pericardial effusion. These tests help pinpoint mechanical or inflammatory causes. ^{[6] [2]} [PM24]

Management approaches

Management focuses on the underlying cause and symptom control:

• Treat fluid or mechanical problems:
  • Pericardial effusion may require pericardiocentesis to relieve symptoms and reduce cardiac strain. [PM20]
  • Significant pleural effusions are drained to improve breathing and reduce reflex tachycardia. ^[2]
  • Pneumothorax is managed according to size and symptoms (often with oxygen or chest tube), which can reduce rapid heart rate. ^[6]
• Address pulmonary embolism:
  • Anticoagulation is standard; in selected cancer cases with bleeding risks, catheter-based thrombectomy may be considered. [PM19]
• Adjust cancer therapies:
  • If a drug causes bradycardia or arrhythmia, clinicians may pause treatment, adjust dose, avoid interacting medications, and resume with monitoring when appropriate. ^{[9] [8]}
  • For serious drug-induced arrhythmias (e.g., from EGFR inhibitors), careful rechallenge at lower dose with close monitoring has been reported in select cases. [PM21]
  • Immune‑related myocarditis or arrhythmias may require urgent immunosuppression and specialized cardiac support. [PM23] [PM24]
• Treat arrhythmias directly:
  • Medications (rate or rhythm control) are chosen to minimize interactions with cancer drugs and bleeding risk. Cardio‑oncology teams tailor therapy. [PM25]
  • Procedures like ablation or device therapy are considered for persistent or dangerous rhythms when appropriate. ^[12]
• Supportive measures:
  • Hydration, limiting stimulants (caffeine), managing pain and anxiety, and correcting anemia or thyroid issues can reduce palpitations. These steps complement targeted treatment. [PM25] [PM24]

Practical tips for people with or being evaluated for lung cancer

• Track symptoms: Note timing of palpitations relative to treatments or new respiratory symptoms; share this timeline with your care team. This often clarifies the cause. ^{[3] [8]}
• Ask about heart monitoring: If starting targeted therapy or immunotherapy, discuss baseline ECG and periodic checks; report any chest symptoms early. ^{[8] [9] [7]}
• Know the red flags: Palpitations with fainting, chest pain, severe breathlessness, or hemoptysis require emergency care. Early action can be lifesaving. ^[1] [PM19]

Bottom line

• Palpitations are not a typical, primary symptom of lung cancer but can appear due to fluid, clots, lung collapse, rare heart involvement, or most commonly effects of cancer treatments. ^{[1] [2] [3]}
• The right approach is to identify and treat the underlying cause, often with collaborative care between oncology and cardiology. Prompt evaluation is key, especially around new therapies or sudden respiratory symptoms. [PM25] ^{[8] [9]}