ECG images

This is an EKG taken from a 78 year old woman who developed atrial fibrillation and congestive heart failure with a ventricular pacemaker. An atrial lead was implanted and the same pacemaker was transferred to this lead producing atrial pacing. This resulted in improvement in the patient's symptoms.
Note that this pacer does not sense the third complex which is a PVC (perhaps the retrograde p wave arrived too late to be sensed) but does sense the last complex which is a spontaneous supraventricular beat.