Final answer:
The correct option is (A). Stroke volume is increased by a decrease in venous compliance, as it results in increased venous return and end-diastolic volume. This occurs through the Frank-Starling mechanism. Factors such as increased afterload, decreased contractility, and decreased coronary blood flow typically decrease stroke volume.
Step-by-step explanation:
Stroke volume (SV) is increased by (A) A decrease in venous compliance. Venous compliance refers to the capacity of veins to expand in response to increased blood volume. A decrease in venous compliance means that veins are less able to expand, which can lead to an increased venous return to the heart, thereby increasing the EDV (end-diastolic volume) and subsequently the stroke volume through the Frank-Starling mechanism. In contrast, factors such as an increase in afterload, a decrease in contractility, and a decrease in coronary blood flow typically lead to a decrease in stroke volume. Furthermore, an increase in heart rate does not directly increase stroke volume; it raises cardiac output by increasing the number of heartbeats per minute.
The subject of this question involves understanding the relationship between venous return, compliance, and factors that influence stroke volume and cardiac function. While afterload is the resistance the heart must overcome to eject blood, it is typically associated with a decrease in stroke volume if it is elevated. Stroke volume is critically dependent on the balance between preload, contractility, and afterload.