Which of the following symptoms indicates arterial hypotension in a patient with cardiac arrest?

In the context of cardiac arrest, the presence of unresponsiveness and pulselessness is a direct clinical manifestation of arterial hypotension. During cardiac arrest, the heart is unable to effectively pump blood, leading to a significant drop in blood pressure and ultimately resulting in the absence of a pulse. This state indicates that blood flow to vital organs is severely compromised, which aligns with the definition of hypotension. Unresponsiveness occurs because the brain, lacking adequate blood flow and oxygen, cannot function properly, and pulselessness signifies that the heart is not generating sufficient cardiac output to sustain circulation.

The other symptoms mentioned do not specifically indicate arterial hypotension. Severe headaches can result from numerous causes, including tension or migraines, but are not directly related to cardiac arrest. A rapid heart rate may occur in response to various conditions, such as anxiety or blood loss, but during cardiac arrest, the heart typically fails to maintain a pulse rather than exhibiting tachycardia. Excessive sweating is a nonspecific symptom that can be associated with many conditions, including pain or anxiety, but it does not directly relate to the state of arterial blood pressure in the context of cardiac arrest.