Pericardial effusion and tamponade — viva

Stem

Practice viva. The examiner describes a breathless, hypotensive patient with a large pericardial effusion, and works through the physiology of tamponade, the bedside and echocardiographic diagnosis, how urgently to drain, how to drain safely, and special settings.^[1]

Branch A — What is tamponade?

Examiner: What is cardiac tamponade, and why can a small amount of fluid cause it?^[1]

Strong answer:

• ESC 2025 defines tamponade as a pericardial syndrome occurring when the effusion impairs diastolic filling of the heart until cardiac output is reduced.^[1]
• The pericardium is relatively stiff: when fluid collects quickly, as in haemopericardium, the limit of stretch is reached with 200–300 mL, while a slowly accumulating effusion may reach 1 to 2 L first.^[1]
• ESC 2025 calls tamponade a last-drop phenomenon: a small increase in volume may precipitate it, and aspirating a small amount of fluid may greatly improve the patient.^[1]

Follow-up: Explain pulsus paradoxus.^[1]

• ESC 2025 defines it as an inspiratory fall in systolic blood pressure of at least 10 mmHg.^[1]
• It is due to exaggerated ventricular interdependence: the overall ventricular volume cannot expand, so any change in volume on one side of the heart causes the opposite change on the other.^[1]

Branch B — Bedside and echocardiographic diagnosis

Examiner: How do you make the diagnosis?^[1]

Strong answer:

• ESC 2025 calls tamponade a clinical diagnosis based on a suggestive history, symptoms and signs, with imaging confirmation by echocardiography (Table 17).^[1]
• Acute tamponade is usually associated with tachycardia and low blood pressure (under 90 mmHg), which is only slightly reduced in subacute or chronic tamponade; on examination, classical signs include neck vein distension with elevated JVP, pulsus paradoxus and diminished heart sounds, and the ECG usually shows tachycardia, low QRS voltages and electrical alternans.^[1]
• In pericarditis with tamponade, ESC 2025 lists symptoms that may include chest discomfort, fatigue and dyspnoea, and the clinical signs it lists in that setting include an enlarged cardiac silhouette on chest X-ray.^[1]
• Beck triad (hypotension, increased JVP, quiet heart sounds) was classically identified in surgical tamponade and may be lacking in medical tamponade with slowly accumulating fluid.^[1]

Follow-up: Which echocardiographic signs would you look for, and how good are they?^[1]

• Table 17: diastolic collapse of the right atrium (sensitivity 50%–100%, specificity 33%–100%) and of the right ventricle (48%–100%, 72%–100%).^[1]
• Diastolic collapse of the right atrium lasting more than 0.34 of the cardiac cycle length: sensitivity above 90%, specificity 100%.^[1]
• Inferior vena cava plethora with hepatic vein dilatation: sensitivity 97% but specificity 40%; respiratory changes of mitral E velocity above 25%–30% and tricuspid E velocity above 40%–60%, and a large effusion with swinging heart, have no figures given.^[1]

Branch C — How urgent?

Examiner: How do you decide how urgently to drain?^[1]

Strong answer:

• ESC 2025 says clinical triage has been proposed to indicate urgent management: an overall score above 6 indicates the need for urgent pericardiocentesis, and a lower score suggests delaying the intervention.^[1]
• The Figure 12 legend: immediate pericardiocentesis should be considered with more than 6 points from at least two categories (aetiology, clinical presentation, imaging), criteria based on expert consensus.^[1]
• High-scoring items include orthopnoea and a circumferential large effusion (3 points each), malignant disease, tuberculosis, pulsus paradoxus over 10 mmHg, rapid worsening of symptoms and left atrial collapse (2 points each).^[1]

Follow-up: And if the patient is unstable?^[1]

• Drainage should be performed without delay in unstable patients, preferably by needle pericardiocentesis with echocardiographic or fluoroscopic guidance.^[1]
• Avoid positive airway pressure ventilation and diuretics; temporary fluid can help to stabilise the patient while waiting for urgent pericardiocentesis.^[1]

Branch D — Draining safely

Examiner: Talk me through pericardiocentesis.^[1]

Strong answer:

• ESC 2025: pericardiocentesis (echocardiography-, CT- or fluoroscopy-guided) is recommended for cardiac tamponade, suspected bacterial or neoplastic pericarditis, or symptomatic moderate to large effusion despite medical therapy (Class I, Level C).^[1]
• Under imaging guidance a needle, usually 16–20 gauge, goes into the sub-xiphoid space; an apical or left-lateral approach might be used.^[1]
• Whenever possible, pericardiocentesis should not drain a large amount of fluid (usually under 500 mL), to prevent pericardial decompression syndrome; a drain can be left and removed when daily drainage is under 30 mL.^[1]
• It carries a variable complication risk of 4%–10%, depending on the type of monitoring, the operator's skill and the setting; the most common complications include arrhythmias, coronary artery or chamber puncture, haemothorax, pneumothorax, pneumopericardium and hepatic injury.^[1]

Follow-up: When would you choose surgery?^[1]

• Surgical pericardial drainage is recommended when percutaneous pericardiocentesis is not feasible or with purulent effusion, to allow complete drainage and prevent constriction (Class I, Level C).^[1]
• A surgical pleuro-pericardial window is recommended for relapsing pericardial effusion despite medical therapy (Class I, Level C).^[1]
• ESC 2025 also names urgent bleeding into the pericardium as a situation for a surgical approach.^[1]

Branch E — After the drain

Examiner: The fluid is out but the right atrial pressure stays high. What are you thinking?^[1]

Strong answer:

• Effusive–constrictive pericarditis: constrictive physiology uncovered after draining an effusion with tamponade.^[1]
• ESC 2025 defines it haemodynamically as right atrial pressure failing to fall by 50% or more, or to below 10 mmHg, despite intrapericardial pressure lowered to near 0 mmHg by pericardiocentesis.^[1]
• Tricuspid regurgitation or right heart failure may also keep the right atrial pressure high after effective pericardiocentesis.^[1]

Branch F — Special settings

Examiner: How does the cause change your plan?^[1]

Strong answer:

• Suspected purulent pericarditis is an indication for drainage regardless of haemodynamic status; urgent pericardiocentesis and/or a surgical window is recommended to establish a diagnosis (Class I, Level C).^[1]
• Suspected or definite neoplastic pericardial effusion: extended pericardial drainage (3–6 days) is recommended to prevent effusion recurrence (Class I, Level B).^[1]
• Suspected TB pericarditis: diagnostic pericardiocentesis is recommended when non-invasive tests have not confirmed the diagnosis, to identify the agent in pericardial fluid (Class I, Level C).^[1]
• Type A aortic dissection: ESC 2024 says to consider an emergency pericardial puncture for potential cardiac arrest from tamponade, as a temporary life-saving measure before transfer to the operating room (no class or level given).^[3]