80-year old patient with palpitations and syncope. What does the ECG show?
Describe and interpret this ECG
ECG ANSWER and INTERPRETATION
- Runs of tachycardia are interspersed with long sinus pauses (up to 6 seconds)
- The sinus rate is extremely slow, varying from 40 bpm down to around 10 bpm in places
- Sinus beats are followed by paroxysms of junctional tachycardia at around 140 bpm
- This is a good example of sick sinus syndrome leading to the tachycardia-bradycardia syndrome
- The flurries of junctional tachycardia are a compensatory phenomenon attempting to maintain cardiac output in the face of critically low sinus node rates
- The syncope likely occurred due to a long sinus pause with temporary loss of cardiac output. This patient needs a pacemaker!