March 12th Question
Episodes classified as nonsustained ventricular tachycardia were noted on interrogation of a single-chamber implantable cardioverter-defibrillator. The high-frequency noise on the shock electrogram (RV coil to can) was reproducible with provocative maneuvers (Figure, arrows). Lead parameters were otherwise stable. What is the reason for VF oversensing shown in the Figure?
A. Low sensing amplitude
B. Lead fracture
C. Electromagnetic interference
D. Myopotential oversensing
E. Connection problem between lead and header
ANSWER TO MARCH 5th QUESTION
E. Place a pericardial drain
The contrast cinefluoroscopy (Figure; Movie in Data Supplement) in a right anterior oblique caudal projection shows the Watchman device seated deep within the ostium of the left atrial appendage. There is absence of any contrast leak around the polyethylene terephthalate mesh, with good apposition and seal of the mesh-covered surface with the endocardium. The tips of the feet of the nitinol frame, however, are constrained and have not expanded, caught in the trabeculations along the free wall of the left atrial appendage. There is extravasation of contrast seen from this region into the pericardial space (Figure, arrow) denoting laceration of the left atrial appendage. This is a major complication with potential for large volume bleeding, tamponade, and possibility for requirement of open chest surgery. Emergent pericardiocentesis should be performed as the most appropriate next step to control the pericardial space and drain the effusion (Option E). Anticoagulation should be reversed. After evacuating the pericardial space, and assessing hemodynamic stability, if the position, anchor, seal, and stability of the Watchman device are confirmed, the device can be released. It is not advised to capture or remove the Watchman as any manipulation can further extend the laceration, and with reversal of anticoagulation, the device itself may help ward off and limit the amount of pericardial bleeding. After a pericardial drain was inserted and anticoagulation reversed, a total 1200 cc of blood was suctioned out with hemodynamic improvement, and the Watchman device was released in this position.
I thank Dr. Daniel H. Cooper, MD for providing the tracing for March 12th Question.
The Data Supplement is available at http://circep.ahajournals.org/lookup/suppl/doi:10.1161/CIRCEP.118.006250/-/DC1.
Circ Arrhythm Electrophysiol is available at http://circep.ahajournals.org.
- © 2018 American Heart Association, Inc.