Practical procedure - Needle pericardiocentesis ( figure 7).

With the patient attached to a cardiac monitor, a cannula is slowly inserted immediately to the left of the xiphisternum aiming for the tip of the left scapula and is constantly aspirated until blood appears. The tamponade can be aspirated (often with dramatic improvement in the patient's signs) and the cannula left in place for further aspiration.

A thoracotomy may be required to stop the bleeding. Widening of the QRS complex, ST segment changes or multiple ventricular dysrhythmias indicate myocardial damage and unlimited aspiration of blood unaccompanied by clinical improvement is indicative of ventricular aspiration.