This 16yr old patient has a dual chamber pacemaker implanted for congenital complete heart block and has been getting dizzy episodes on exercise. This ECG is from his exercise test. What’s the problem?
This is actually normal pacemaker behaviour, when the patient exercises and he reaches the upper tracking rate in this case 185ppm, the pacemaker will inhibit any further rate rise by exhibiting wenkebach or 2:1 block of the ventricular rate .In this case increasing the upper rate to 200ppm resolved his symptoms. It is worth noting that not all manufacturers have pacemakers that are able to have the upper tracking rate programmed this high so caution is advised that the upper tracking rate will be adequate when choosing a pacemaker to be implanted in a young or fit patient.