Where to start counting on an irregular rhythm? 

The first QRS complex of this irregular rhythm is on the dark line of the large box. Note where you start counting to determine the 6second heart rate for an irregular rhythm. 



Note, with this irregular rhythm there are at least 3 small boxes before the FIRST QRS complex AND the line of the LARGE BOX. In fact, in this example we see 4 small boxes. So you start your counting of 30 large boxes at the starting point containing that first QRS complex. 



Note, with this irregular rhythm there are NOT at least 3 small boxes before the FIRST QRS complex AND the line of the LARGE BOX. In fact, in this example we see 1 (or 1.5) small boxes. So you start your counting of 30 large boxes by MOVING BACK 1 large box. 

