Final answer:
Cardiac Tamponade causes Pulseless Electrical Activity (PEA) by accumulating excess fluid in the pericardial space, which reduces the heart's ability to fill with blood and decreases cardiac output, potentially leading to obstructive shock and other serious complications.
Step-by-step explanation:
Cardiac Tamponade is a medical condition where excess fluid accumulates within the pericardial space, exerting pressure on the heart and hindering its ability to fully relax and refill with blood. This pressure leads to a decrease in preload, which is the volume of blood entering the right atrium during diastole. As the chambers of the heart contain less blood, cardiac output falls, ultimately leading to a form of shock known as obstructive shock.
With progression, this reduced cardiac output can deteriorate into pulmonary edema or congestive heart failure as the blood 'backs up' in the left side of the heart. Cardiac Tamponade can cause Pulseless Electrical Activity (PEA), where though electrically the heart seems to be beating, the mechanical dysfunction due to the pressure means the heart is unable to pump effectively, leading to an absence of a palpable pulse.