McGill Case 246

This case report is kindly provided by Michael Rosengarten from McGill and is part of the McGill Cases. These cases come from the McGill EKG World Encyclopedia. Previous Case: McGill Case 245 | Next Case: McGill Case 247

This is an interesting example of time dependent capture. Note the the venticular pacemaker captures for several beats but then fails to capture. Capture is restored when the pacer spike falls near to a conducted sinus beat. The underlying rhythm shows a lengthening of the pr interval before a p wave fails to conduct. This suggests a Mobitz I A/V block.