- Pericardial effusion is seen in approximately 60% of acute pericarditis cases, but cardiac tamponade is more uncommon and occurs in approximately 5% of cases.
- Cardiac tamponade occurs when the abnormal accumulation of pericardial fluid creates pressure and causes impairment in diastolic filling of the heart.
- The development of cardiac tamponade is not dependent on the quantity of fluid
Signs of Tamponade
- Beck Triad (more common in rapidly progressive Pericardial Effusions)
- Muffled heart sounds
- Hypotension
- elevated JVP
- tachypnoea
- tachycardia
- atrial arrhythmias (atrial fibrillation)
- positive hepatojugular reflux
- peripheral oedema and cyanosis.
- Kussmaul sign (a paradoxical rise in JVP on inspiration, usually JVP decrease with inspiration)
- Pulsus paradoxus
- BP drop of 20% during inspiration – Occurs in 77% of Cardiac Tamponade cases
- To measure pulsus paradoxus, the sphygmomanometer cuff is inflated above systolic pressure. Korotkoff sounds are sought over the brachial artery while the cuff is slowly deflated. Initial Korotkoff sounds are heard only intermittently during expiration. The cuff is then deflated slowly to the pressure at which Korotkoff sounds become audible continuously during inspiration and expiration. When the difference between these two levels exceeds 10 mmHg during quiet respiration, pulsus paradoxus is present.
- ECG
- Electrical alternans: Alternating QRS complex height best seen in lateral precordial leads,
- Occurs when the heart swings backwards and forwards within a large fluid-filled pericardium
