PEA causes when it is the presenting rhythm ('primary PEA') are usually due to conditions that affect which?

PEA causes when it is the presenting rhythm ('primary PEA') are usually due to conditions that affect which?

• A. Contractility or ejection, or preload
• B. Blood pressure only
• C. Left ventricular hypertrophy
• D. Valve stenosis

Answer: (A)

PEA is organized electrical activity without a palpable pulse, so the problem lies in the heart’s ability to pump. When this rhythm presents, stroke volume is lost because the pump isn’t working well or the heart isn’t adequately filled. That points to issues with preload (venous return), contractility (how strongly the heart contracts), or the ease of ejection (how well blood is pushed out). So conditions that acutely diminish filling (e.g., low blood volume, tamponade) or depress myocardial contractility (ischemia, massive electrolyte or acid-base disturbances) commonly cause primary PEA. Chronic structural changes like left ventricular hypertrophy or valve stenosis can contribute to poor output over time, but they’re not the immediate mechanism behind the presenting PEA. Blood pressure status alone doesn’t explain it, since PEA hinges on the heart’s mechanical output despite electrical activity.

PEA is organized electrical activity without a palpable pulse, so the problem lies in the heart’s ability to pump. When this rhythm presents, stroke volume is lost because the pump isn’t working well or the heart isn’t adequately filled. That points to issues with preload (venous return), contractility (how strongly the heart contracts), or the ease of ejection (how well blood is pushed out). So conditions that acutely diminish filling (e.g., low blood volume, tamponade) or depress myocardial contractility (ischemia, massive electrolyte or acid-base disturbances) commonly cause primary PEA. Chronic structural changes like left ventricular hypertrophy or valve stenosis can contribute to poor output over time, but they’re not the immediate mechanism behind the presenting PEA. Blood pressure status alone doesn’t explain it, since PEA hinges on the heart’s mechanical output despite electrical activity.