Which of the following is NOT a symptom of left-sided heart failure?

Left-sided heart failure primarily affects the heart's ability to pump blood effectively, leading to a backup of fluid in the lungs and subsequently causing symptoms related to pulmonary congestion. Common symptoms include shortness of breath, especially when lying flat (orthopnea), chronic cough due to fluid in the lungs, and pulmonary edema, which is the accumulation of fluid in the air sacs of the lungs.

Dizziness upon exertion, while it can occur in some cases due to decreased cardiac output or other health issues, is not a hallmark symptom directly linked to left-sided heart failure. The primary symptoms focus more on respiratory complaints and fluid overload, rather than exertional dizziness, which may relate to other conditions affecting cardiovascular or neurological stability. Therefore, dizziness upon exertion is not characteristic of left-sided heart failure, making it the correct choice here.