Which of the following would indicate a possible worsening of heart failure?

An increase in episodes of nocturnal dyspnea is a significant indicator of worsening heart failure. This symptom occurs when fluid accumulates in the lungs while the patient is lying down, leading to difficulty breathing during the night. It often signifies increased fluid retention and compromised cardiac function, both of which are critical concerns in managing heart failure.

While weight changes, exercise tolerance, and blood pressure stability can provide useful insights into a patient's condition, they are not as direct indicators of worsening heart failure. For example, decreased weight is generally seen as a positive sign, indicating potential fluid loss, while increased exercise tolerance suggests improved cardiac function. Stable blood pressure is also a good sign that the patient's condition may not be deteriorating. In contrast, the occurrence of nocturnal dyspnea reflects an acute change in the patient's respiratory status, prompting immediate assessment and intervention to prevent further exacerbation of heart failure.