The nurse is caring for a client whose sudden onset of sinus bradycardia is not responding adequately to atropine.
What might be the treatment of choice for this client?

Choice A rationale

For a client in acute heart failure following a myocardial infarction, the administration of 0.9 percent sodium chloride is often contraindicated or requires extreme caution. Acute heart failure involves the heart's inability to pump effectively, leading to pulmonary congestion and systemic fluid volume excess. Adding isotonic saline, which remains in the extracellular space, can worsen pulmonary edema and increase the workload on the failing left ventricle. The nurse should clarify this order to prevent further respiratory distress and cardiac strain.

Choice B rationale

Bumetanide is a potent loop diuretic used to rapidly reduce fluid volume in patients with acute heart failure and pulmonary congestion. A dose of 1 mg IV bolus every 12 hours is a standard intervention aimed at promoting diuresis and reducing preload. This helps clear fluid from the lungs and improves oxygenation. The nurse would monitor urine output and electrolyte levels, specifically looking for hypokalemia, as loop diuretics cause the kidneys to excrete potassium along with water and sodium.

Choice C rationale

Monitoring serum potassium is a critical and appropriate action for a patient with heart failure and a recent myocardial infarction. Potassium levels must stay within 3.5 to 5.0 mEq/L to maintain cardiac electrical stability. Many heart failure treatments, including diuretics and ACE inhibitors, significantly alter potassium levels. In the context of an injured myocardium following an infarct, any electrolyte imbalance can trigger lethal arrhythmias. Therefore, obtaining baseline and serial potassium levels is a standard of care that does not require clarification.

Choice D rationale

Morphine sulfate is frequently used in the treatment of acute heart failure and myocardial infarction. Beyond its analgesic properties for chest pain, morphine acts as a vasodilator, which reduces both preload and afterload. This effect decreases the myocardial oxygen demand and helps alleviate the anxiety associated with dyspnea. A dose of 2 mg IV bolus every 2 hours as needed is a common and appropriate prescription to manage symptoms and improve hemodynamics in the acute phase of cardiac distress.

Choice A rationale

Orthopnea refers to shortness of breath that occurs when lying flat and is typically a hallmark sign of chronic heart failure or pulmonary edema. While an acute myocardial infarction can lead to acute heart failure, orthopnea is not considered a classic or universal presenting symptom of the initial ischemic event itself. Assessment focuses on signs of sympathetic nervous system activation and direct cardiac distress rather than positional breathing difficulties.

Choice B rationale

Headaches are not a characteristic clinical manifestation of an acute myocardial infarction. While a patient might experience a headache due to high blood pressure or as a side effect of nitroglycerin administration, it does not stem from the underlying myocardial ischemia or necrosis. The primary pain associated with an MI is located in the chest, jaw, or arms, reflecting the dermatomal distribution of cardiac sensory nerves during an oxygen mismatch.

Choice C rationale

Diaphoresis is a common finding during an acute myocardial infarction due to the massive activation of the sympathetic nervous system. When cardiac output drops or pain becomes intense, the body initiates a fight or flight response, leading to profuse sweating. This is often described as a cold and clammy sensation. This compensatory mechanism is a key diagnostic indicator that helps clinicians distinguish significant cardiac events from less severe causes of chest pain.

Choice D rationale

Tachycardia occurs as the heart attempts to compensate for reduced stroke volume and myocardial injury. The sympathetic nervous system releases catecholamines like epinephrine and norepinephrine, which increase the heart rate to maintain systemic perfusion. During an acute MI, the body senses a decrease in effective circulating volume or oxygen delivery, triggering this rapid heart rate. Monitoring for tachycardia is essential as it also increases myocardial oxygen demand, potentially worsening the underlying ischemia.

Choice E rationale

Nausea and vomiting are frequent manifestations of an acute myocardial infarction, particularly those involving the inferior wall of the heart. This occurs due to a vasovagal reflex or the proximity of the diaphragmatic surface of the heart to the gastrointestinal tract. Pain and systemic stress also slow gastric motility, contributing to gastrointestinal upset. Recognizing nausea as a potential cardiac symptom is vital, especially in populations like women or the elderly.