What results from increased afterload during the heart's ejection of blood?

Increased afterload refers to the added pressure the heart must work against to eject blood during systole. When afterload is elevated, the heart has to exert more force to push blood into the aorta. This demanding work results in a decrease in cardiac output, particularly if the heart is unable to compensate adequately for the increased pressure.

The relationship here is based on the principles of hemodynamics: as afterload increases, the stroke volume (the amount of blood ejected with each heartbeat) may diminish if the heart cannot produce sufficient contractile force. Therefore, the increased resistance during ejection can lead to reduced efficiency in the heart's pumping mechanism, ultimately resulting in a decreased cardiac output.

Higher afterload can also lead to changes in blood pressure, but while blood pressure may temporarily increase due to the increased resistance, the overall effect on the heart's ability to pump blood effectively translates to decreased cardiac output, emphasizing the importance of the heart's workload in relation to afterload.