Cardiac tamponade is the compression of the heart caused by blood or fluid accumulation in the space between the myocardium (the muscle of the heart) and the pericardium (the outer covering sac of the heart).

In this condition, blood or fluid collects within the pericardium. This prevents the ventricles from expanding fully, so they cannot adequately fill or pump blood.

Cardiac tamponade is often associated with pericarditis caused by bacterial or viral infections. Heart surgery, dissecting aortic aneurysm (thoracic), wounds to the heart, end-stage lung cancer, and acute MI can all lead to cardiac tamponade.

Other potential causes include heart tumors, kidney failure, recent heart attack, recent open heart surgery, recent invasive heart procedures, radiation therapy to the chest, hypothyroidism and systemic lupus erythematosus.

Cardiac tamponade occurs in approximately 2 out of 10,000 people.

• Anxiety, restlessness
• Discomfort, sometimes relieved by sitting upright or leaning forward.
• Difficulty breathing
• Rapid breathing
• Fainting, light-headedness
• Chest pain
  • Radiating to the neck, shoulder, back or abdomen
  • Sharp, stabbing
  • Worsened by deep breathing or coughing
• Swelling of the abdomen or other areas
• Skin pale, gray or blue
• Palpitations

Additional symptoms that may be associated with this disease:

• Pulse, weak or absent
• Drowsiness
• Dizziness
• Low blood pressure

Although there are no specific laboratory tests that diagnose tamponade, echocardiogram is first choice to help establish the diagnosis. The heart will often sound uncharacteristically faint during examination with a stethoscope. Peripheral pulses may be weak or absent. Neck veins may be distended but the blood pressure may be low.

The heart rate may be over 100 (normal is 60 to 100 beats per minute), and breathing may be rapid (faster than 12 breaths in an adult per minute). The blood pressure may fall (pulsus paradoxical) when the person inhales deeply.

• Fluid in the pericardial sac may show on:
  • Chest x-ray
  • Echocardiogram
  • Chest CT or MRI of chest
  • Coronary angiography (may show other changes also)
• ECG changes include low voltage wave forms