Abstract
Mechanical cardiac alternans is usually associated with left ventricular dysfunction. Atrial alternans has been described on invasive assessment of atrial action potentials, however cannot be detected clinically. Herein we report a patient who had transthyretin type cardiac amyloidosis with prior history of recurrent atrial fibrillation requiring ablations as well as ablation for atrial flutter and a recent history of cardioversion for atrial flutter. The patient presented with diastolic heart failure and recurrent atrial flutter and was referred for a TEE guided cardioversion. Mechanical left and right atrial alternans was seen on Doppler interrogation of both atrial appendages with velocities corresponding to the flutter P wave on the ultrasound ECG monitor. The patient was successfully cardioverted with the TEE probe in situ. Post cardioversion TEE showed resumption of normal albeit reduced mechanical atrial function in the left atrium and preserved right atrial function in tissue Doppler imaging. Our case demonstrates the mechanical phenomenon of atrial alternans in both atria on TEE with disappearance of atrial alternans during sinus rhythm suggesting rate related atrial alternans likely related to atrial stiffness from amyloid infiltration and as well as possibly scar formation from prior ablations.
Key words: Atrial alternans, transesophageal echocardiography, Doppler ultrasound, cardiac amyloid, atrial flutter