Question

identify this rhythm

sinus bradycardia with pjc
sinus rhythm with pvc
sinus rhythm with pac
junctional tachycardia
sinus tachycardia

Explanation:

Analyze the underlying rhythm

• The baseline rhythm shows upright P waves in the lead shown, preceding each normal QRS complex.
• The R-R intervals between the regular beats are approximately 28 small boxes (about 5.6 large boxes).
• Heart rate calculation: \(300 / 5.6 \approx 54\text{ bpm}\), which is less than \(60\text{ bpm}\), indicating sinus bradycardia.

Identify the premature beat

• The third QRS complex occurs early (prematurely).
• This premature beat has a narrow QRS complex identical to the sinus beats, indicating it originates above the ventricles (supraventricular).
• There is no preceding P wave before this premature QRS complex, but an inverted P wave is visible immediately following it (retrograde conduction), which is characteristic of a junctional origin.
• This represents a Premature Junctional Contraction (PJC).

Match with the options

• The combination of a underlying sinus bradycardia rate (\(<60\text{ bpm}\)) and a premature junctional beat matches "Sinus Bradycardia with PJC".

Answer:

• (A) Sinus Bradycardia with PJC (Correct answer)
• (B) Sinus Rhythm with PVC
• (C) Sinus Rhythm with PAC
• (D) Junctional Tachycardia
• (E) Sinus Tachycardia