Sinus node dysfunction, junctional escape rhythm, exertional dyspnea

Patient

64-year-old man, dilated heart disease, hospitalized for asthenia and exercise intolerance;

Trace

Bradycardia with heart rate of 45 beats/minute, sinus node dysfunction with total absence of sinus P wave, likely junctional escape rhythm (regular and moderately slow QRS), with right bundle branch block pattern; retrograde conduction (negative atrial activity in inferior leads with fixed RP' interval);

Exergue

Chronotropic incompetence corresponds to a particular form of sinus node dysfunction with appearance or increase of symptoms in relation to an insufficient acceleration of the heart rate. The implantation of a controlled pacemaker (possibility of accelerating the pacing rate in response to exercise constitutes the reference treatment.