The patient’s cardiac rhythm suddenly changes on the monitor.

There are no P waves, instead there are fibrillatory waves before each QRS complex.

How would the nurse interpret the rhythm?

Choice A Rationale:

Atrial Flutter is a rapid, regular atrial rhythm characterized by a "sawtooth" pattern on the ECG. It is caused by a reentrant circuit in the atria, usually involving the cavo-tricuspid isthmus. The atrial rate in atrial flutter is typically between 250 and 350 beats per minute. However, the ventricular rate is often slower due to varying degrees of AV block.

Key differentiating features: Atrial flutter has a regular, sawtooth pattern on ECG, while ventricular fibrillation is irregular and chaotic. Atrial flutter usually has a slower ventricular rate than ventricular fibrillation.

Choice B Rationale:

Ventricular Tachycardia (VT) is a rapid heart rhythm that originates in the ventricles. It is defined as three or more consecutive ventricular beats at a rate greater than 100 beats per minute. VT can be either non-sustained (lasting less than 30 seconds) or sustained (lasting more than 30 seconds).

Key differentiating features: VT has a regular or slightly irregular rhythm with wide QRS complexes, while ventricular fibrillation is irregular and chaotic with no discernible QRS complexes. VT may have a pulse, while ventricular fibrillation is pulseless.

Choice C Rationale:

Atrial Fibrillation (AF) is a common heart rhythm disorder characterized by rapid, irregular atrial electrical activity. This results in an irregular and often rapid heart rate. AF can be caused by a variety of factors, including high blood pressure, heart valve disease, coronary artery disease, and hyperthyroidism.

Key differentiating features: AF has an irregular, disorganized rhythm with no discernible P waves, while ventricular fibrillation is irregular and chaotic with no discernible QRS complexes. AF may have a pulse, while ventricular fibrillation is pulseless.

Choice D Rationale:

Ventricular Fibrillation (VF) is a life-threatening heart rhythm that is characterized by rapid, disorganized electrical activity in the ventricles. This results in the heart muscle quivering instead of pumping blood effectively. VF is a medical emergency that requires immediate treatment with cardiopulmonary resuscitation (CPR) and defibrillation.

Key features: VF is characterized by an irregular, chaotic rhythm with no discernible QRS complexes on the ECG. It is also pulseless, meaning that there is no palpable pulse.

Choice A rationale:

Assessing lung sounds is important for evaluating respiratory status, but it is not the priority assessment before administering digoxin. Digoxin does not have a direct effect on the respiratory system, and changes in lung sounds would not necessarily indicate a contraindication to its administration.

However, in patients with heart failure, which is a common indication for digoxin, auscultating lung sounds can provide valuable information about fluid status and the effectiveness of treatment. Therefore, while not the priority assessment, lung auscultation remains a relevant part of the overall assessment of a patient receiving digoxin.

Choice B rationale:

Assessing systolic blood pressure is important for monitoring hemodynamic status, but it is not the most critical assessment before administering digoxin. Digoxin does not directly affect blood pressure, and changes in blood pressure would not necessarily indicate a contraindication to its administration.

However, in patients with hypertension, which can be a factor in heart failure, monitoring blood pressure is essential for managing overall cardiovascular health. Therefore, while not the priority assessment, blood pressure measurement remains an important aspect of care for patients receiving digoxin.

Choice C rationale:

Assessing the brachial pulse for 30 seconds can provide a general assessment of heart rate and rhythm, but it is not as accurate as assessing the apical pulse for a full minute.

The apical pulse is the most reliable way to assess heart rate and rhythm, especially in patients with irregular heartbeats or those taking medications that can affect heart rate, such as digoxin.

Therefore, assessing the apical pulse for a full minute is essential to ensure accurate assessment of the patient's cardiac status before administering digoxin.

Choice D rationale:

Assessing the apical pulse for 60 seconds is the priority assessment before administering digoxin. This is because digoxin is a cardiac glycoside that affects the heart's electrical conduction system and can slow the heart rate. It is essential to assess the patient's heart rate and rhythm before administering digoxin to ensure that it is safe to do so.

A slow heart rate (bradycardia), irregular heart rhythms (such as atrial fibrillation), or certain heart block conditions can be contraindications to digoxin administration or require dosage adjustments.

By accurately assessing the apical pulse for a full minute, the nurse can identify any potential contraindications or concerns and ensure the safe administration of digoxin.