Case 122: A 77 Year-Old Woman in the Emergency Room with Dizziness
History
Diagnosis
History
A 77 year-old woman is seen in the emergency room with several days of dizziness. Her ECG recorded in the emergency room is shown below:
Diagnosis
- Ectopic Atrial Bradycardia, 37/min
- AV Dissociation with Junctional Escape, 43/min
- Conducted P-waves have 1st degree AV block
- Anteroseptal myocardial infarction
- Left Anterior Fascicular Block
- ST & T wave abnormality, consider inferolateral ischemia
Comment: This ECG was incorrectly interpreted as atrial fibrillation as the p-waves are difficult to see and the rhythm is somewhat irregular. Because the p-waves are negative in the inferior leads, this is an ectopic atrial rhythm and NOT sinus rhythm. As the atrial rate is slower than the junctional escape, one should NOT confuse this rhythm with complete heart block. The 4th p-wave is a conducted p-wave and is conducted with a PR interval of 480ms. We know it is conducted because the resultant QRS complex is early relative to the remainder of QRS complexes which are regular and likely of junctional origin.
ECG ID: E837