 [ Symptoms ] my blood tests came back abnormal how can i correct this [ Disease ] while it is possible for people to experience muscle stimulation from pacemakers it is typically the diaphragm as it lies close the the right ventricle which is actually being paced while i can not diagnose the cause of your muscle twitching in this forum i would guess that left pectoralis stimulation would be pretty unlikely particularly if it does not seem related to your heart rate always helpful to get checked out by your doctor if you have any concerns