Friction Rub (Heart)

What is Friction rub (heart)?

A pericardial friction rub is a harsh, grating sound heard with a stethoscope when the inflamed layers of the pericardium (the sac surrounding the heart) rub against each other during the cardiac cycle. The sound is usually described as “scratchy” or “squeaky,” and may be heard during both systole and diastole, often best with the patient leaning forward and exhaling fully.

It is not a disease itself but a clinical sign that indicates irritation or inflammation of the pericardial surfaces. Because the pericardium contains only a thin layer of fluid, any inflammation (pericarditis) or abnormal contact between the visceral and parietal layers can generate this audible friction.

Sources: Mayo Clinic; American Heart Association (AHA) ¹.

Common Causes

Pericardial friction rubs can arise from many different conditions. The most frequent causes include:

• Acute viral pericarditis – Coxsackievirus, echovirus, adenovirus.
• Post‑myocardial infarction (Dressler) syndrome – Autoimmune reaction weeks after an MI.
• Autoimmune diseases – Systemic lupus erythematosus, rheumatoid arthritis, scleroderma.
• Uremic pericarditis – Accumulation of toxins in advanced kidney failure.
• Traumatic injury – Blunt or penetrating chest trauma, cardiac surgery.
• Neoplastic involvement – Metastatic breast, lung, or lymphoma spreading to the pericardium.
• Radiation therapy – Damage to pericardial tissue after treatment for thoracic malignancies.
• Hypothyroidism – Rarely causes serous pericardial effusion with rub.
• Bacterial or tuberculous pericarditis – Especially in immunocompromised patients.
• Post‑cardiac catheterization or pacemaker implantation – Small pericardial irritation.

Associated Symptoms

While the friction rub itself may be painless, most patients present with additional signs that point to pericardial inflammation:

• Sharp or stabbing chest pain that worsens when lying flat and improves when sitting up or leaning forward.
• Fever, chills, or recent viral illness.
• Shortness of breath, especially with exertion.
• Palpitations or a sense of “fluttering” in the chest.
• Fatigue or generalized weakness.
• Swelling of the legs or abdomen if a significant pericardial effusion develops.
• Syncopal episodes (rare) if tamponade develops abruptly.

When to See a Doctor

Because a friction rub may herald serious cardiac disease, prompt evaluation is essential. Seek medical attention if you notice:

• Chest pain that is new, worsening, or does not improve with position changes.
• Fever >100.4°F (38°C) combined with chest discomfort.
• Shortness of breath at rest or with minimal activity.
• Palpitations accompanied by dizziness, light‑headedness, or fainting.
• Sudden swelling of the abdomen, legs, or neck veins.
• A known recent heart attack, chest trauma, or recent cardiac procedure.

Diagnosis

Diagnosing a pericardial friction rub involves a combination of history, physical examination, and targeted investigations:

1. Physical examination

• Stethoscope placed at the left lower sternal border, patient sitting up, leaning forward, and breathing fully.
• The rub is usually triphasic (three components) – two systolic and one diastolic – giving a “scratch‑scratch‑scratch” quality.

2. Electrocardiogram (ECG)

• Acute pericarditis often shows diffuse ST‑segment elevation and PR‑segment depression in multiple leads.
• Differentiates from myocardial infarction, which shows localized changes.

3. Echocardiography (Echo)

• Assesses for pericardial effusion, tamponade physiology, or wall motion abnormalities.
• Can detect thickened pericardium or constrictive features.

4. Blood tests

• Complete blood count (CBC) – look for leukocytosis.
• C‑reactive protein (CRP) and erythrocyte sedimentation rate (ESR) – markers of inflammation.
• Cardiac enzymes (troponin) – may be mildly elevated in pericarditis.
• Renal function, thyroid studies, autoimmune panels (ANA, RF) based on suspicion.

5. Imaging & other studies

• Chest X‑ray – may reveal an enlarged cardiac silhouette if fluid is present.
• CT or MRI of the chest – helpful for identifying neoplastic or tuberculous pericardial disease.
• Pericardial fluid analysis – obtained via pericardiocentesis only when large effusion or tamponade is present.

Treatment Options

Treatment is directed at the underlying cause, controlling inflammation, and preventing complications.

1. Anti‑inflammatory therapy

• NSAIDs (e.g., ibuprofen 600‑800 mg every 6–8 h) are first‑line for viral or idiopathic pericarditis.
• Aspirin (650–1,000 mg every 6 h) may be used in patients who cannot take NSAIDs.
• Typical course: 1–2 weeks, then taper based on symptom resolution and CRP.

2. Colchicine

• 0.5 mg twice daily for 3 months (adjust for weight & renal function) reduces recurrence risk by ~50 % ².

3. Corticosteroids

• Reserved for refractory cases, autoimmune pericarditis, or when NSAIDs/colchicine are contraindicated.
• Prednisone 0.2–0.5 mg/kg daily with a slow taper over 4–6 weeks.

4. Treatment of specific etiologies

• Antibiotics for bacterial pericarditis.
• Anti‑tuberculous therapy for TB pericarditis.
• Dialysis or intensified renal clearance for uremic pericarditis.
• Immunosuppressive agents (hydroxychloroquine, azathioprine) for systemic autoimmune disease.

5. Procedural interventions

• Pericardiocentesis – emergent drainage of large effusion or tamponade.
• Pericardiectomy – surgical removal of the pericardium in chronic constrictive pericarditis.

6. Home care & supportive measures

• Rest and avoidance of strenuous activity for at least 2 weeks (longer if symptoms persist).
• Apply low‑dose ibuprofen with meals to reduce gastric irritation.
• Hydration and a balanced diet; avoid excessive alcohol which may worsen inflammation.
• Follow‑up appointments to repeat ECG/echo and monitor CRP.

Prevention Tips

Because many causes are not fully preventable, focus on modifiable risk factors:

• Maintain up‑to‑date vaccinations (influenza, COVID‑19) to lower viral infection risk.
• Control chronic conditions: diabetes, hypertension, and especially chronic kidney disease.
• Practice good hand hygiene and avoid close contact with people who have active respiratory infections.
• If you have an autoimmune disease, adhere to disease‑modifying therapy and routine rheumatology follow‑up.
• Quit smoking – it increases the risk of viral infections and impairs healing.
• After cardiac surgery or procedures, follow post‑operative instructions meticulously to limit pericardial irritation.

Emergency Warning Signs

References

1. Mayo Clinic. Pericarditis. https://www.mayoclinic.org. Accessed June 2026.
2. Imazio M, et al. Colchicine for the treatment of pericarditis: A systematic review and meta‑analysis. European Heart Journal. 2020;41(8):795‑804.
3. American Heart Association. Pericardial Diseases. https://www.heart.org. Accessed June 2026.
4. National Institute of Health (NIH). Pericarditis. https://www.ncbi.nlm.nih.gov. Accessed June 2026.
5. World Health Organization. Tuberculosis and pericardial disease. https://www.who.int. Accessed June 2026.