Case presentation
An 88-year-old man came to the cardiology clinic with dizziness on
exertion for two months. He had long standing hypertension and a
baseline right bundle branch block (RBBB). Blood pressure was 140/70
mmHg and pulse rate was 40 beats/min at presentation. Systemic
examination was unremarkable. Electrocardiogram (ECG) recorded in the
clinic showed complete heart block. Subsequently, a dual chamber
permanent pacemaker (AttestaTM, Medtronic,
Minneapolis, MN, USA) was implanted with the ventricular lead placed at
the apex. The device was programmed to the DDDR mode, with a 60 bpm
lower rate limit, 130 bpm upper tracking rate, mode switch ON, 140 and
120 ms paced and sensed AV intervals, 0.7 and 2.3 mV atrial and
ventricular sensitivities, and atrial and ventricular pacing
amplitude/pulse width of 1.0 V/0.4 ms and 1.0 V/0.4 ms, respectively. A
12-lead electrocardiogram recorded after pacemaker implantation is shown
in Figure 1. What are the abnormalities in this electrocardiogram? What
are the immediate concerns regarding pacemaker functionality?