Which condition is NOT an indication for Calcium Channel Blockers?

Calcium channel blockers are primarily used to treat conditions related to the cardiovascular system by inhibiting calcium entry into cells, which leads to relaxation of vascular smooth muscle and decreased heart contractility. They are effective in managing angina, hypertension, and pulmonary hypertension due to their ability to dilate blood vessels and reduce heart workload.

In cases of heart failure, the use of calcium channel blockers is generally not indicated. This is because they can negatively affect the heart's pumping ability, particularly in patients with reduced ejection fraction heart failure. In such cases, these medications could worsen heart function instead of providing benefits. Therefore, while calcium channel blockers are beneficial for conditions like angina, hypertension, and pulmonary hypertension, they are not recommended for managing heart failure, making it the correct choice in this scenario.