Chemotherapy and Heart Palpitations: Causes, Risks, and Coping Strategies

Yes chemotherapy and several other cancer treatments can cause heart palpitations by triggering changes in heart rhythm (arrhythmias). ^[1] These rhythm changes may occur alongside other heart-related effects of treatment, such as cardiomyopathy (weakened heart muscle), myocarditis (heart muscle inflammation), pericarditis (inflammation around the heart), and pericardial effusion (fluid around the heart). ^[2] Palpitations can also stem from vasospasm (sudden vessel tightening), coronary artery narrowing, elevated blood pressure, or blood clots, all of which have been associated with cancer therapies. ^[3]

Which Treatments Are Linked to Palpitations and Arrhythmias?

Multiple chemotherapy and targeted agents are associated with arrhythmias or QT interval prolongation (a change in the heart’s electrical cycle that can cause palpitations). ^[4] Specific agents reported with arrhythmia risk include fluoropyrimidines like 5‑fluorouracil and capecitabine, certain tyrosine kinase inhibitors (e.g., dasatinib, nilotinib, ponatinib), methotrexate, bendamustine, and others. ^[5] Some regimens also carry risks of ischemia (reduced blood flow) and QTc prolongation, which warrant monitoring with ECGs and electrolytes. ^[4]

Anthracyclines (e.g., doxorubicin, epirubicin) and HER2‑targeted therapies (e.g., trastuzumab, pertuzumab) can affect heart function, which may indirectly contribute to rhythm symptoms such as palpitations. ^[6] Fluoropyrimidines like 5‑fluorouracil are notable for causing chest pain and a spectrum of cardiac events including arrhythmias in a subset of people soon after infusion. ^[7]

Why Palpitations Happen During Cancer Treatment

Arrhythmias can be triggered by direct effects on the heart’s electrical system, inflammation, reduced blood supply, QT interval changes, or metabolic shifts such as low potassium or magnesium. ^[4] The overall risk depends on your baseline heart health, the specific drugs and doses used, prior radiation to the chest, and combinations of therapies. ^[8]

Red‑Flag Symptoms: When to Seek Medical Help

Contact your care team promptly if you notice fast or irregular heartbeats, chest pain or pressure, or new shortness of breath with activity. ^[9] These symptoms can signal treatment‑related effects on the heart that may need urgent evaluation and adjustment of therapy. ^[10] Cancer treatments can raise heart risks during therapy and even years later, so early reporting helps prevent complications. ^[11]

Practical Coping Strategies

1. Track symptoms and timing

• Keep a log of when palpitations occur (during infusion, at night, after exertion), what you were doing, and any triggers like caffeine or dehydration. ^[9]
• Share this with your oncology team to guide testing (e.g., ECG, labs for electrolytes) and medication adjustments. ^[4]

2. Optimize hydration and electrolytes

• Aim for steady fluid intake and balanced nutrition to maintain potassium and magnesium, which support stable heart rhythm. ^[4]
• Your team may check and correct low levels if palpitations persist. ^[4]

3. Review medications and stimulants

• Limit caffeine, nicotine, decongestants, and energy drinks, which can worsen palpitations. ^[4]
• Ask about potential interactions (e.g., drugs that prolong QT) and whether timing around chemo days can help. ^[4]

4. Gentle activity and rest

• Light, regular exercise like walking may reduce fatigue and stress, but pause if you feel lightheaded, chest pain, or severe palpitations. ^[12]
• Use short, planned rest breaks to avoid overexertion while maintaining daily activity. ^[12]

5. Stress‑reduction techniques

• Breathing exercises, mindfulness, or guided relaxation can reduce the awareness and frequency of benign palpitations. ^[12]
• Consider brief sessions before infusion days to ease anticipatory stress. ^[12]

6. Monitoring and follow‑up

• Some regimens benefit from baseline and interval heart tests (e.g., ECG, echocardiogram) to detect rhythm or function changes early. ^[13]
• High‑risk treatments or symptoms may call for closer ECG monitoring and electrolyte checks, especially during the first treatment cycles. ^[4]

Medical Evaluation and Treatment Options

Your team may order an ECG, blood tests, and possibly an echocardiogram to assess for arrhythmias, QT prolongation, ischemia, or reduced heart function. ^[4] If a treatment is identified as the likely cause, options may include dose adjustments, changing infusion method, switching drugs, or adding cardiac medications (e.g., beta‑blockers) when appropriate. ^[7] For regimens with known QT risk, protocols often include baseline and early ECG checks and correction of low potassium or magnesium. ^[4]

Prevention and Heart‑Healthy Care During Treatment

A pretreatment heart risk assessment and baseline left ventricular ejection fraction (LVEF) can help tailor cancer therapy while protecting heart health. ^[13] Ongoing collaboration between oncology and cardio‑oncology teams can optimize survival and quality of life while reducing cardiovascular risks from therapy. ^[6] Long‑term heart care nutrition, activity, blood pressure control, and regular follow‑up supports recovery and survivorship. ^[14]

Bottom Line

Palpitations can be a side effect of chemotherapy and other cancer treatments, often reflecting arrhythmias or related cardiac effects. ^[1] Report fast or irregular heartbeats, chest discomfort, or new breathlessness promptly so your team can evaluate and manage them early. ^[9] With symptom tracking, lifestyle adjustments, and appropriate monitoring, most people can continue treatment safely while protecting their heart. ^{[4] [13] [6]}