Sinus node dysfunction, junctional escape rhythm, exertional dyspnea
This patient was symptomatic with presence of asthenia and exertional dyspnea. The exercise test revealed a marked chronotropic incompetence with dyspnea appearing at the first stages in conjunction with a near total absence of heart rate acceleration and the persistence of a junctional escape rhythm without reappearance of normal sinus activity. The presence of this chronotropic incompetence without curable cause led to the decision to implant a pacemaker (class I indication). There is indeed consensus regarding the fact that implantation of a pacemaker does not improve the survival of patients with sinus node dysfunction but does allow to reduce associated symptoms. There is therefore no theoretical indication in asymptomatic patients (class III).