Atrial Functional Tricuspid Regurgitation Associated With Atrial Standstill.

We report a case of atrial functional tricuspid regurgitation with an atrial standstill in a 71-year-old woman with a history of chronic atrial fibrillation (AF). The ECG showed a flat baseline with no AF waves and regular, narrow QRS complexes, whereas the previous ECG demonstrated AF. Echocardiography revealed dilation of the right atrium and the tricuspid annulus with severe regurgitation, but mitral regurgitation was mild. No atrial contraction was detected. Bilateral ventricular function was preserved. Cardiac catheterization showed no pulmonary hypertension and an a-wave in atrial pressure tracings. During surgery, epicardial pacing was unable to capture both atria. The tricuspid valve was replaced and a pacemaker was implanted.