Your patient is a 70-year-old male who passed out at church. He is now awake but seems confused, has a respiratory rate of 20 breaths per minute, a blood pressure of 90/60 and cool, moist skin. You attach the ECG monitor to reveal what appears to be a slow heart rate. A closer examination of the ECG shows there are two P waves preceding each QRS complex and the PR interval for the conducted beats remains constant. This dysrhythmia is:

Question

Quizplus · Accepted Answer

The description of two P waves preceding each QRS complex with a constant PR interval for the conducted beats is indicative of a 2nd-degree AV block, Type II (also known as Mobitz Type II). This type of heart block is characterized by the occasional non-conduction of a P wave without a change in the preceding PR intervals, unlike in Wenckebach (Mobitz Type I) where the PR interval progressively lengthens until a beat is dropped. Sinus bradycardia would show a slow but regular rhythm with a consistent P wave before each QRS complex, and a 3rd-degree AV block would show complete disassociation between P waves and QRS complexes.

Your Patient Is a 70-Year-Old Male Who Passed Out at Church