As you said, the EGM was stored as ATR onset. At the beginning of the tracing we see a ventricular asystole of +/- 3s, during which we observe an asynchronous LV pacing sequence at decremental output (0.5, then 0.4V). This cannot be an automatic test (PacSAfe VGAT): this algorithm provides a RVP support all along the test and does not allow loss of capture.
Therefore, it is a manual testing of the LV threshold. The test has been frozen with the RTA onset. This is a funny behavior of BS devices to store events which occured during the manual interrogation (see my comment on the last RHYTHM IQTM post).
Personally I don't go under 1V for a threshold testing in a dependant patient, since I won't program <2.5 anyway. This avoids to induce a prolonged asystole.
DR Sylvain Ploux
Sun, 20/12/2015 - 10:28
Thank you Marc for this intriguing tracing!
As you said, the EGM was stored as ATR onset. At the beginning of the tracing we see a ventricular asystole of +/- 3s, during which we observe an asynchronous LV pacing sequence at decremental output (0.5, then 0.4V). This cannot be an automatic test (PacSAfe VGAT): this algorithm provides a RVP support all along the test and does not allow loss of capture.
Therefore, it is a manual testing of the LV threshold. The test has been frozen with the RTA onset. This is a funny behavior of BS devices to store events which occured during the manual interrogation (see my comment on the last RHYTHM IQTM post).
Personally I don't go under 1V for a threshold testing in a dependant patient, since I won't program <2.5 anyway. This avoids to induce a prolonged asystole.
Don't hesitate to send your comments and EGMs!
S Ploux