A 74-year-old man presents with palpitations, chest pain and shortness of breath. This man generally keeps well. He had a permanent pacemaker implanted 18 months ago following episodes of syncope. He was diagnosed as having complete heart block at that time. He was discovered to be in atrial flutter at his most recent cardiorespiratory appointment for pacemaker checks.
He has felt generally out of sorts for the last few weeks. He feels constantly tired and has lost his motivation for his daily walk with his dog. This morning, he felt tightness across his chest and was unable to fully catch his breath. He was aware of his heart pounding in his chest at the same time.
His vital signs were as follows:
- Blood pressure: 178/95 mmHg
- Pulse: 65 beats per minute
- Respiratory rate: 16 breaths per minute
- Temperature: 36.8°C
- SpO2 on air: 95%.
The 12-lead electrocardiogram (ECG) in Figure 1 was recorded by the paramedic crew.
ECG of a 74-year-old man with palpitations, chest pain and shortness of breath
What does the ECG show?
- The heart rhythm is irregular
- The heart rate is approximately 65 beats per minute
- There are flutter waves present – more obvious in V1
- The QRS duration is prolonged with a left bundle branch block appearance
- There is a small pacing artefact immediately prior to QRS complexes.
This is therefore a ventricular paced rhythm with appropriate left bundle branch block (LBBB) configuration. The ventricular pacing lead is in the right ventricle and this will result in an LBBB configuration. There is appropriate discordance between the QRS and ST segments/T waves. The underlying rhythm is atrial flutter.