part of cardiac pacemaker cell differentiation cardiac muscle cell fate commitment cardiac pacemaker cell fate commitment The commitment of cells to pacemaker cell fates and their capacity to differentiate into pacemaker cells. Pacemaker cells are specialized cardiomyocytes that are responsible for regulating the timing of heart contractions. pacemaker cell fate commitment 2009-09-29T11:54:22Z GO:0060927 biological_process dph