Vasodilator therapy-induced pacemaker syndrome

Disabling presyncopal attacks were provoked in a patient with a sinus nodal disorder and cardiac pacemaker by treatment with antianginal vasodilators. At cardiac catheterization a severe fall in aortic pressure was documented during ventricular pacing, when desynchronized atrial contractions coincided with ventricular systoles. After withdrawal of the medication, no obvious changes in arterial pressure were associated with ventricular pacing, and the patient became free of dizziness. Vasodilating drugs may provoke episodic hypotension with characteristic features of the pacemaker syndrome.