The nurse is caring for a 24 year old post-partum client with a diagnosis of cardiomyopathy. The nurse understands that which of the following types of cardiomyopathy can be associated with childbirth?

A. "The diaphragmatic nerve overdrives the rapid rhythm:" The phrenic (diaphragmatic) nerve controls the diaphragm for breathing and plays no role in cardiac rhythm regulation. It is unrelated to the autonomic control of heart rate or supraventricular tachycardia (SVT) management.

B. "Vagal stimulation decreases peripheral vascular resistance:" Vagal stimulation primarily affects the heart by decreasing the rate and conduction through the AV node. Its effect on vascular resistance is minimal, making this explanation inaccurate in the context of SVT treatment.

C. "The vagus nerve increases the heart rate, overdriving the rhythm:" The vagus nerve has a parasympathetic effect, slowing down the heart rate, not increasing it. Overdrive pacing is a different concept and not related to vagal maneuvers like carotid massage.

D. "The vagus nerve slows the heart rate": The carotid sinuses in the neck contain baroreceptors that are sensitive to pressure. Massaging these sinuses stimulates the vagus nerve to release acetylcholine, which in turn slows conduction through the AV node and may terminate episodes of SVT. This response demonstrates an accurate understanding of the purpose of the procedure.

A. surgery has caused an episode of supraventricular tachycardia: While stress or surgery can trigger arrhythmias, the ECG shown demonstrates a sinus tachycardia pattern (narrow QRS complexes with identifiable P waves before each QRS), not supraventricular tachycardia (SVT), which typically has a very rapid, regular rhythm often without visible P waves.

B. is febrile which is causing the heart rate to be elevated: The client has a temperature of 102°F (38.8°C), which can increase metabolic demand and lead to sinus tachycardia. Fever is a common and expected cause of elevated heart rate, especially when accompanied by infection, such as the client’s post-op wound infection.

C. is in heart failure and the heart rate is elevated to compensate: There is no evidence from the scenario (no dyspnea, crackles, edema, or reduced BP) that supports heart failure. The elevated HR is more directly related to the fever and infection, not cardiac decompensation.

D. probably has a low oxygen saturation causing an increased respiratory rate: The respiratory rate is slightly elevated (22/min), but there is no mention of hypoxia or oxygen saturation levels. Tachycardia secondary to hypoxia would require clinical indicators of respiratory distress or desaturation, which are not demonstrated.