Case Report: Junctional Bradycardia in a 42-Year-Old Male

Case Report: Numb Hand and Face

History: A 42-year-old male with a history of cryptogenic stroke on rivaroxaban (Xarelto) presents to the emergency department for 12 hours of left facial and left finger numbness. He denies any chest pain, weakness, near-syncope or other complaints. He states his usual pulse race is usually around 40.

Exam: Vital signs are normal except for a pulse of 40. Exam shows bradycardia and left arm >leg weakness but is otherwise normal. Patient states this weakness is at his baseline

Initial differential diagnosis: anginal equivalent, heart block, high vagal tone

Initial EKG

COMPUTER EKG READ:

1. Wide QRS rhythm

2. Rightward axis

3. Nonspecific intraventricular block

Do you agree with the computer? What should you do next?

EKG ANALYSIS, CASE OUTCOME & 1-MINUTE CONSULT:

EKG analysis (peer-reviewed by Dr. Stephen W. Smith of Dr. Smith’s ECG Blog): The computer read is correct but incomplete. There are no P waves and the rate is about 40 which is consistent with a junctional escape rhythm. There may be an underlying sinus rhythm that is slower than 40 which could be triggered by having the patient exercise to see if the sinus rate increases and the sinus node takes over. The QRS is wide, which means either there is also an intraventricular conduction delay or that the escape rhythm originates below the bundle of His rather than within the AV node.

Case Conclusion: Echo showed a severely dilated right atrium with atrial standstill. Since the patient was hemodynamically stable with no symptoms attributed to his bradycardia, no therapy was recommended by cardiology.

EKG ANALYSIS, CASE OUTCOME, 1-MINUTE CONSULT & CASE LESSONS:

Junctional rhythms are uncommon and when read by the computer as such are not infrequently actually program misreads of other rhythms. A “Junctional” read means the computer cannot find a P-wave, but many computers only check one or two leads for P-waves.If the provider checks all 12 leads carefully, they will often find that the rhythm is actually sinus in origin. If unsure, checking an old EKG and consideration of performing a Lewis lead tracing can help clarify the situation.

Junctional rhythms originate from the AV node or from the bundle of His. The P-wave is usually buried within the QRS but occasionally can be seen, and if so, is typically abnormal in that it is either very narrow, upside down or both. Junctional rhythms are further classified based on the rate (see highlighted area in sample page below).

Causes of junctional bradycardia include sick sinus syndrome, hyperkalemia, ischemia, prior damage from surgery or radiation, amyloidosis or collagen vascular diseases affecting the heart, hypothyroidism, Lyme disease or other causes of myocarditis, certain drug toxicities (see highlighted area in sample page below), hypoxia and high vagal tone. Treatment depends of the cause and whether or not the patient has symptoms at rest or with activity.

Source: The Emergency Medicine 1-Minute Consult Pocketbook