--- title: Cardiac tamponade description: What cardiac tamponade is, why fluid or blood around the heart stops it from filling, what causes it and what its signs are, how it is found and treated, and why suspected tamponade needs an ambulance. type: disease aliases: - pericardial tamponade - tamponade sources: - tier: guideline org: minzdrav-rf title: Перикардиты year: 2025 url: https://cr.minzdrav.gov.ru/view-cr/746_2 - tier: guideline org: esc title: 2025 ESC Guidelines for the management of myocarditis and pericarditis year: 2025 doi: 10.1093/eurheartj/ehaf192 url: https://doi.org/10.1093/eurheartj/ehaf192 - tier: reference org: msd-manuals title: Pericarditis year: 2026 url: https://www.msdmanuals.com/professional/cardiovascular-disorders/pericarditis/pericarditis - tier: reference org: msd-manuals title: Cardiac Tamponade year: 2026 url: https://www.msdmanuals.com/professional/injuries-poisoning/thoracic-trauma/cardiac-tamponade sources_checked: 2026-10-13 review: null --- Cardiac tamponade is a life-threatening condition in which the heart is squeezed by fluid, blood, pus, clots or gas that have collected in the pericardial cavity, the space inside the sac around the heart. The cause can be inflammation, injury, rupture of the heart or aortic dissection, and the squeezing builds up quickly or gradually. When the pressure in the pericardium becomes higher than in the chambers of the heart, they cannot fill with blood properly, and the heart pumps out less blood. Without help this can lead to shock and death.

Normally the pericardium is a closed, slit-like cavity around the heart that holds up to 15–50 mL of fluid. This fluid lubricates the layers of the pericardium. Normally the pericardium does not stop the ventricles from filling freely with blood.

In tamponade, blood or other fluid collects between the layers of the pericardium, and the pressure in the pericardium becomes higher than in the chambers of the heart. The heart itself is usually not enlarged, but its atria and ventricles are small because they do not fill with enough blood. An ultrasound scan usually shows that the right chambers, the right atrium and the right ventricle, are compressed or collapse.

## Why it happens According to the ESC, the common causes are tumours, injury during medical procedures and trauma, [pericarditis](../pericarditis/) and tuberculosis (the most common cause in developing countries). Less often, tamponade occurs with systemic connective tissue diseases, an acute [heart attack](../coronary-heart-disease/), [aortic dissection](../aortic-dissection/), uraemia (severe kidney failure) and bacterial infection. Blood gets into the pericardium when the heart muscle ruptures after a heart attack, when the aorta dissects or an aortic aneurysm ruptures, and when the heart is injured. Occasionally the heart ruptures after a heart attack, usually 1 to 10 days later. Blood in the pericardium can also follow cardiac catheterisation or the placement of a pacemaker or a central venous line. In acute pericarditis with no known cause, tamponade is rare. What matters is not only how much fluid there is but also how fast it collects. If fluid (usually blood) builds up quickly, the pericardium cannot stretch in time, and even a small amount, for example 150 mL, can cause tamponade; if it builds up slowly, even 1500 mL may not. Tamponade occurs when the pressure in the pericardial space exceeds the pressure in one or more cardiac chambers: their filling is restricted, intracardiac diastolic pressure rises and cardiac output falls. Tamponade can be acute, subacute or localised. A loculated effusion can cause localised tamponade of the right or left side of the heart, which may be difficult to diagnose. The ESC lists the causes in order of relative frequency. Common: neoplasm/malignancy, iatrogenic causes and trauma, pericarditis, tuberculosis (most common in developing countries). Less common: collagen vascular diseases (systemic lupus erythematosus, rheumatoid arthritis, scleroderma), pericardial injury syndrome, acute myocardial infarction, aortic dissection, uraemia, bacterial infection, pneumopericardium. In acute idiopathic pericarditis tamponade is rare; it is typical of malignant tumours, tuberculosis and purulent pericarditis. In trauma, the cause is more often a penetrating wound than blunt trauma. If the effusion is not very large, it is the rate of fluid accumulation rather than the volume that determines whether tamponade develops: with rapid accumulation, tamponade is possible when the pericardial layers are only 10 mm apart, while with slow accumulation it may not develop even with a large effusion. ## Symptoms The main complaints are bouts of sudden severe weakness, dizziness, fainting and worsening breathlessness. The person often sits leaning forward, and the skin is pale, cold and bluish. Blood pressure falls and the pulse speeds up, as in shock, but the veins in the neck swell markedly. Sometimes tamponade is the first sign of pericarditis. The clinical picture resembles cardiogenic shock (low cardiac output, hypotension, tachycardia, dyspnoea), but the neck veins are markedly distended. Neck vein distension is less noticeable in hypovolaemia; hypotension progresses or may be absent, especially in patients with pre-existing hypertension; swelling of the face and left arm, an enlarged liver and ascites, and dyspnoea or tachypnoea without lung crackles may occur. The combination of hypotension, muffled heart sounds and distended jugular veins is called Beck's triad. The triad is considered diagnostic but may be absent or hard to recognise; it has been shown to be an unreliable indicator of tamponade. Pulsus paradoxus is a fall in systolic blood pressure of more than 10 mm Hg on inspiration during quiet breathing; the Russian Ministry of Health guideline calls it a pathognomonic sign of tamponade. According to MSD, it nearly always accompanies severe tamponade but also occurs in COPD, bronchial asthma, [pulmonary embolism](../pulmonary-embolism/), right ventricular infarction and non-cardiogenic shock. In localised tamponade, physical, haemodynamic and some echocardiographic signs may be absent. ## How it is diagnosed The doctor recognises tamponade mainly from the complaints, the person's condition and the examination. When it is suspected, a [heart ultrasound (echocardiography)](../../diagnostic/echocardiography/) is done straight away, unless even a short delay would be dangerous. Fluid in the pericardium is easy to see on ultrasound. Signs of tamponade are compressed right chambers of the heart and a widened inferior vena cava that hardly narrows on breathing in. The [ECG](../../diagnostic/ecg/) may show changes that suggest tamponade, but these signs are unreliable. Tamponade is primarily a clinical diagnosis; echocardiographic findings alone are not an indication for pericardiocentesis. Echocardiographic signs according to the ESC: a large pericardial effusion with a swinging heart, collapse of the right atrium, diastolic collapse of the right ventricle, respiratory changes of the mitral E velocity of more than 25–30% and of the tricuspid E velocity of more than 40–60%, and inferior vena cava plethora (dilatation above 20 mm with less than 50% reduction in diameter with breathing) with hepatic vein dilatation. The Russian Ministry of Health guideline adds that the heart is usually of normal size, while the chambers are small because of insufficient diastolic filling, with good systolic function. The ESC and the Russian Ministry of Health guidelines grade an effusion as mild (less than 10 mm), moderate (10–20 mm) or large (more than 20 mm). Low voltage and electrical alternans on the ECG suggest tamponade but lack sensitivity and specificity. If the diagnosis is not confirmed by clinical findings and echocardiography, right heart catheterisation may be needed: in tamponade, diastolic pressures are raised and equal in all cardiac chambers and in the pulmonary artery. ## How it is treated Everyone with signs of tamponade is admitted to hospital as an emergency. The main step is to remove the fluid from the pericardium so the heart can fill again. The simplest and fastest way is to drain it through a needle (pericardiocentesis); in tamponade this saves lives. It is usually done by an experienced doctor guided by ultrasound or X-rays. Removing even a small amount of fluid can save a life. If drainage through a needle is not possible or the pericardium contains pus, the fluid is removed surgically, for example by making a "window" in the pericardium. Then the cause of the fluid build-up is treated. The doctor decides which approach is needed. The ESC recommends pericardiocentesis guided by echocardiography, CT or fluoroscopy for cardiac tamponade (I C), and surgical pericardial drainage when percutaneous pericardiocentesis is not feasible or the effusion is purulent, to allow complete drainage and prevent constriction (I C). In the ESC algorithm, a patient with confirmed tamponade is assessed for high-risk features with a cumulative score (aetiology, clinical presentation, imaging): with high risk, pericardiocentesis with drainage is performed, and if there is no improvement, a pericardial window is created. In traumatic and bacterial pericarditis, the Russian Ministry of Health guideline prefers going straight to surgical drainage. In trauma, pericardiocentesis is a temporising measure, and a pericardial window or pericardiotomy is more definitive. In tamponade, peripheral vasodilators and diuretics are not recommended, nor is mechanical ventilation with positive airway pressure. Further treatment of the effusion is directed at its cause. ## When to call an ambulance Tamponade is life-threatening, and everyone with its signs is admitted to hospital as an emergency. Call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK) if a person who has pericarditis, a malignant tumour or tuberculosis, or who has had a chest injury, a heart procedure or a recent heart attack, develops bouts of sudden severe weakness, dizziness, fainting or worsening breathlessness. Warning signs are pale, cold skin, a bluish colour and swollen neck veins. The signs of a [heart attack](../coronary-heart-disease/) and of [aortic dissection](../aortic-dissection/), which can themselves be complicated by tamponade, are described in the articles about them. As with any heart condition, call an ambulance for fainting, chest pain or severe breathlessness: this is the site's general safety rule, repeated at the bottom of every page.