A patient wants to know what causes atherosclerosis. How should the nurse respond? In general, atherosclerosis is caused by

Choice A reason: Cardiac output has not fallen below normal levels. Cardiac output is the amount of blood pumped by the heart per minute. It is affected by the heart rate and the stroke volume. Angina pectoris does not directly affect the cardiac output, but it can reduce the stroke volume due to impaired ventricular filling.

Choice B reason: The vagus nerve is not stimulated. The vagus nerve is a cranial nerve that innervates the heart and other organs. It is part of the parasympathetic nervous system, which slows down the heart rate and lowers the blood pressure. Angina pectoris does not activate the vagus nerve, but it can trigger the sympathetic nervous system, which increases the heart rate and blood pressure.

Choice C reason: Myocardial stretch has not exceeded the upper limits. Myocardial stretch is the degree of tension or load on the cardiac muscle fibers. It is determined by the end-diastolic volume, which is the amount of blood in the ventricle at the end of relaxation. Angina pectoris does not cause excessive myocardial stretch, but it can impair the myocardial contractility due to ischemia.

Choice D reason: The myocardial oxygen supply has fallen below demand. This is the main cause of angina pectoris. It occurs when the coronary arteries, which supply blood and oxygen to the heart muscle, are narrowed or blocked by atherosclerosis or spasm. This creates an imbalance between the oxygen demand of the heart, which increases during exertion, and the oxygen supply, which is reduced by the obstruction.

Choice A reason: This is not a correct statement. LABAs stand for long-acting beta2-agonists, which are a class of medications that relax the smooth muscles of the airways and improve the airflow in patients with asthma or COPD. However, LABAs do not reduce the risk of asthma-related deaths, and may even increase it if used alone without an inhaled glucocorticoid, which is a type of anti-inflammatory medication.

Choice B reason: This is not a correct statement. LABAs cannot be used on an as-needed basis to treat symptoms, as they have a slow onset of action and a long duration of effect. LABAs are meant to be used as a maintenance therapy to prevent asthma exacerbations, not to relieve acute symptoms. For quick relief of symptoms, patients should use a short-acting beta2-agonist, such as albuterol or salbutamol.

Choice C reason: This is not a correct statement. LABAs are not safer than short-acting beta2 agonists, as they have similar side effects, such as tachycardia, tremors, and hypokalemia. LABAs also have a black box warning that they may increase the risk of asthma-related deaths if used without an inhaled glucocorticoid.

Choice D reason: This is the correct statement. LABAs should be combined with an inhaled glucocorticoid, as this combination has been shown to improve the asthma control, reduce the frequency and severity of exacerbations, and decrease the inflammation and airway hyperresponsiveness. The inhaled glucocorticoid also reduces the risk of adverse effects and mortality associated with LABAs.