After a pericardiocentesis what are signs of complications that require immediate medical attention?

Multiple: Changes in the patients symptoms such as passing out, shortness of breath, or weakness. The development of a rapid pulse or of a low blood pressure. A drop in the hemoglobin and hematocrit. The development of significant problems with the heart rhythm.

Several...: If the procedure is over completed, the late concern is for recurrence of the pericardial effusion. Signs or symptoms of effusion recurrence could include: shortness of breath, chest pain, dizziness, light headedness, or anxiety.