ABSTRACT
The first Maze procedure (now referred to as the “Maze-I” procedure) was performed on September 25, 1987.1 There were two problems with the pattern of the Maze-I procedure:
1. One of the roof lesions crossed the “sinus tachycardia region” of the sino-atrial (SA) node where all sinus tachycardia originates. This region of the “atrial pacemaker complex”2 lies immediately anterior to the junction of the SVC with the right atrium. Obliterating it with a surgical lesion led to the inability of several patients to generate an appropriate chronotropic response to exercise postoperatively as they usually could generate a heart rate of no more than 110 beats per minute.
