Pre-syncope during exercise in a patient with a permanent pacemaker and hypertrophic obstructive cardiomyopathy
A 71-year-old male with a history of hypertrophic obstructive cardiomyopathy and dual chamber pacemaker implantation for symptomatic 2:1 AV block, presented to A&E with dizzy spells and near syncope during exercise. A pacemaker check was performed in A&E with the device function deemed satisfactory. The patient was later referred for an exercise test to rule out exertion induced arrhythmias and assess pacemaker behaviour during exercise. Figure 1 shows the EGM recorded during the exercise test at approximately 10 minutes of exercise which was associated with symptoms of pre-syncope and lethargy. The device settings are displayed below.
LR/UR: 60/130 bpm.
Paced/Sensed AV delay: 180/140 ms
PVAB: 150 ms Partial +
Mode switch: On
Sensitivity thresholds: Atrial 0.3 mV, Ventricular 0.9 mV
EGM recorded 10 minutes into exercise at the time of symptoms. Channel 1 shows the Can to RV ring EGM with event marker channels. Channel 2 shows a poor quality atrial EGM and Channel 3 shows the RV tip to RV ring EGM.