What is the best position to hear a pericardial friction rub?

Best Position to Hear a Pericardial Friction Rub

The pericardial friction rub is best heard with the patient sitting upright and leaning forward while briefly holding their breath. 1

Optimal Auscultation Technique

Patient Positioning

• Have the patient sit upright and lean forward while briefly holding their breath to maximize detection of the friction rub 1
• This position brings the heart closer to the anterior chest wall and minimizes interfering lung sounds, allowing for better detection 1
• One case report noted that the sound was more pronounced in the left lateral decubitus position, though this is not the standard recommended position 2

Auscultation Location

• Listen along the left lower sternal border, which is the optimal location in approximately 84% of cases 3
• The friction rub is typically auscultated along the lower left sternal border as the pathognomonic physical finding of acute pericarditis 4

Respiratory Considerations

• The rub tends to be louder during inspiration than expiration in many cases 3
• However, in approximately 35% of cases, there is no respiratory predilection 3
• Having the patient briefly hold their breath helps eliminate lung sounds that might obscure the rub 1

Important Clinical Caveats

Transient Nature

• Perform multiple auscultatory examinations because friction rubs can be transient and may disappear and reappear during the course of pericarditis 1
• The rub is highly specific but only audible in approximately one-third of patients with acute pericarditis 1, 5
• One study found pericardial friction rubs in up to 85% of patients, though this higher detection rate likely reflects multiple examinations 5

Characteristics to Listen For

• The friction rub is typically triphasic (present in 56% of patients with sinus rhythm), though biphasic and monophasic patterns also occur 3
• The sound is often described as "sandpaper-scratching" in quality 2
• In some cases, the rub may be palpable (23% of cases in one study) 3

Common Pitfalls

• Do not rely on a single negative examination to exclude pericarditis, as the rub can be intermittent 1
• Extension of the neck does not have a dependable effect on rub intensity and should not be used as a maneuver 3
• The presence of pericardial effusion does not exclude a friction rub—10 patients in one study had audible rubs despite effusion, including 5 with tamponade 3