51 year old man implanted with a triple chamber defibrillator Consulta CRT-P in the context of an ischemic cardiomyopathy with left bundle branch block; excellent clinical response to resynchronization, a stress test (steps) is performed with the telemetry wand of the programmer placed onto the device;
The first line corresponds to an electrocardiographic recording with superimposed markers, the second line correspond to the bipolar RV EGM, the third line correspond to the atrial EGM, the fourth line correspond to the far field EGM LV tip / RV ring – anode;
This tracing illustrates with electrograms the same problem as the previous tracing. There is no reason to limit the upper tracking rate below the patients’ maximal capacity. However, this type of episode is rarely symptomatic because it is not associated with a sudden drop in the heart rate. This causes “just” the loss of biventricular pacing at peak exercise. In this patient an increase of the UTR to 140 bpm has solved the problem. This setting has been validated during a new stress test, which confirmed the persistence of biventricular pacing and capture up to the he maximal capacity of the patient. Conducting a stress test in CRT patient allows to confirm the proper functioning of the device at exercise and to ensure: 1) a good atrial sensing in patients without chronotropic incompetence, 2) a suitable adaptive rate response for patients with chronotropic incompetence, 3) that the 2 / 1 point is not reached during the effort (Rate adaptive AV delay and PVARP Auto), 4) the appropriate programming of the upper tracking rate and / or the maximum sensor rate, 5) the absence of arrhythmias during exercise (supraventricular arrhythmia, many VPC, ventricular arrhythmia, pace maker mediated tachycardia…).
