A client with angina pectoris is prescribed sublingual nitroglycerin for chest pain episodes. The nurse educates the client about its administration. Which statement by the client indicates understanding of the instructions?

A: Oxygen does not directly dilate coronary arteries; medications such as nitrates are responsible for this effect.
B: While oxygen aids in metabolic processes, it does not directly affect the heart's pumping efficiency in the context of angina pectoris.
C: Oxygen therapy increases the oxygen saturation of the blood, which can help alleviate symptoms like shortness of breath and chest pain associated with angina by ensuring that the heart muscle receives sufficient oxygen to function properly.
D: Oxygen therapy is not a treatment for preventing clot formation; this is typically managed with anticoagulant medications.

A) This choice is correct. Diaphoresis (profuse sweating) is an early sign of myocardial infarction (MI) and is caused by the activation of the sympathetic nervous system in response to the heart muscle's decreased oxygen supply. Diaphoresis is often accompanied by other symptoms such as chest pain, shortness of breath, and nausea.

B) This choice is incorrect because elevated blood pressure can occur during an acute MI, but it is not an early sign of the condition.

C) This choice is incorrect because elevated body temperature is not typically associated with an MI. It may be indicative of an infection or other inflammatory conditions.

D) This choice is incorrect because bradycardia (slow heart rate) is not an early sign of an MI. Tachycardia (rapid heart rate) is more commonly associated with an acute MI as the body attempts to compensate for the decreased cardiac output.