Atrial standstill: an indication for rate responsive pacing.

Atrial standstill (atrial paralysis) is a rare reason for permanent bradycardia. A case of atrial standstill is presented. A 35-year-old man had suffered from bradycardia since his childhood. For 2 years he had complaints (diminishment of his working capacity, and dyspnea occurred with effort) as well. On admission, a slow (38/min) junctional escape rhythm could be detected. There were no signs of atrial mechanical activity (atrial contraction) according to chest x ray, echocardiography, and the atrial pressure curve. The electrophysiological study revealed that the atria could not be electrically stimulated, and no P wave (A wave) could be recorded on right atrial electrograms. The patient received a rate responsive pacemaker. After pacemaker implantation, he became symptom-free; his working capacity improved markedly and his heart size decreased. Owing to the permanent bradycardia and the lack of atrial stimulation, the atrial standstill represents an indication for ventricular rate responsive pacing. Atrial standstill, permanent bradycardia, and the inability to stimulate the atrium are indications for ventricular rate responsive pacing.