Case 124: A 39-Year-Old Woman with a Left Atrial Myxoma
History
Diagnosis
ECG 2
ECG 2 Diagnosis
History
A 39-year old woman is postoperative day one from the resection of a left atrial myxoma:
Diagnosis
- Sinus rhythm with complete heart block and junctional escape rhythm
- Atrial rate 66/min, ventricular rate 53/min
- Acute pericarditis
During her operation, tbe large atrial myxoma (4.5 cm in diameter) was noted to be attached to the atrial septum below the fossa ovalis. Removal of the tumor required resection of the lower atrial septum, the atrial wall near the coronary sinus, and the area of the Koch’s triangle, which explains the development of her AV block.
ECG 2
The patient was followed for 6 days with epicardial pacing, and she continued to have complete AV block. When ventricular pacing
was turned off, she went into junctional escape rhythm at a rate of 40-50/min. An AV sequential pacemaker (DDD) was implanted:
ECG 2 Diagnosis
- DDD pacemaker (AV sequential pacemaker)
- Sinus rhythm (62/min) with AV sequential ventricular pacing
In fusion, a chamber is activated in part by the pacemaker, in part spontaneously. In pseudo fusion, the pacemaker stimulus occurs relatively late. The area where the lead tip is implanted has been already spontaneously activated and is refractory. We see the pacemaker spike, but no pacing occurs.
ECG ID: E324