A nurse is providing teaching to a client about recognizing manifestations of an impending cardiac arrest. Which of the following manifestations should the nurse include in the teaching?

Profound fatigue is a well-recognized warning sign that can precede cardiac arrest, particularly in the context of acute myocardial infarction. Many patients, especially women, report overwhelming, unexplained exhaustion in the hours or days before a cardiac event. This occurs because the myocardium is receiving inadequate perfusion and the body is compensating through increased sympathetic activity, which is taxing to the system. Nurses teaching clients about impending cardiac arrest warning signs should emphasize this atypical but important symptom. Ringing in the ears, known as tinnitus, is more commonly associated with vestibular problems, ototoxic medications, or acoustic nerve issues and is not a recognized prodrome of cardiac arrest. Severe headache is a classic warning sign of hypertensive crisis or stroke, particularly hemorrhagic stroke, not cardiac arrest. Muscular aches in the leg are more characteristic of peripheral vascular disease, deep vein thrombosis, or musculoskeletal issues rather than an impending cardiac event. Recognizing profound fatigue as a potential cardiac warning sign is especially important in populations where chest pain may be absent, enabling earlier help-seeking behavior and potentially life-saving intervention.