A client diagnosed with diabetes mellitus is admitted to the emergency department (ED) and the cardiac monitor shows multifocal premature ventricular contractions (PVCs). Initial laboratory findings are as follows: The nurse recognizes that the client's PVCs are most likely caused by:

Potassium 2.8 mEq/L
Sodium 133 mEq/L
Chloride 90 mEq/L
Glucose 200 mg/dl
Magnesium 2.5 mg/dL
Calcium 8.0 mg/dL

 

A. Increase the pacemaker sensitivity: Adjusting pacemaker sensitivity is a technical function typically managed by a cardiologist or device technician. There is no indication from the information provided that the pacemaker is under- or over-sensing, so no adjustment is warranted.

B. Document that the pacemaker is regular: While the pacemaker may be functioning regularly, this statement is vague and does not accurately describe the observed pacing activity. The key observation is the spike occurring before the P wave, which requires more specific documentation.

C. Set the pacemaker to the asynchronous mode: Asynchronous pacing means the pacemaker fires at a set rate regardless of the patient's intrinsic rhythm and is generally reserved for specific situations such as during surgery or when interference with sensing is suspected. There is no evidence of pacemaker malfunction or need to override sensing in this scenario.

D. Document that the atria are being paced: A pacemaker spike immediately before the P wave indicates atrial pacing. This means the pacemaker is stimulating the atria, leading to atrial depolarization. This is the appropriate interpretation and should be documented clearly.

A. The P-P and R-R distances are equal and regular: Equal and regular spacing between P-P and R-R intervals indicates that both atrial and ventricular rhythms are regular. This is a fundamental aspect of rhythm interpretation, helping to distinguish between regular and irregular rhythms such as atrial fibrillation or sinus arrhythmia.

B. The rhythm rate using a 3-second strip: Assessing the heart rate using a 3-second or 6-second ECG strip helps determine whether the rhythm is bradycardic, tachycardic, or within normal limits, which is crucial for accurate rhythm classification.

C. The duration of the U waves: U waves are typically small and follow the T wave. Although their presence can suggest conditions like hypokalemia, they are not routinely assessed in basic rhythm identification. Evaluating U wave duration is more relevant in electrolyte imbalance analysis than in identifying rhythm type.

D. There is a QRS complex after each P wave: A consistent QRS following every P wave indicates effective conduction from the atria to the ventricles. Each atrial depolarization (P wave) should be followed by a ventricular depolarization (QRS complex) if the signal is being conducted properly through the AV node. This finding supports a diagnosis of sinus rhythm and helps rule out AV blocks, where conduction may be delayed or blocked entirely.

E. P waves are present, upright and rounded: P waves that are upright and rounded in lead II suggest the electrical impulse is originating from the SA node. Their presence and morphology are essential criteria for identifying sinus rhythm and differentiating it from atrial arrhythmias like flutter or fibrillation.