Persistent atrial standstill developed in a patient with rheumatic heart disease: Electrophysiological and histological study

Abstract

A case with persistent atrial standstill is presented which developed from atrial fibrillation associated with rheumatic combined valvular heart disease. In addition to clinical and electrocardiographic findings, electrophysiological and histological studies by using microelectrode technique and electron microscopy, respectively, were carried out on specimens from the right atrial appendage resected at mitral valve surgery. Scattered but severe loss of myocardial cells in the atria and deterioration of the action potential of these poorly sustained myocardial cells were confirmed. The suggestive evidence is also shown that the deteriorated action potential observed by micro-electrode technique in this case may be composed of calcium current.

Left Bundle Pacing in a Patient with Atrio-Ventricular Canal Defect Presenting with Atrial Standstill and Junctional Bradycardia

“…Atrial standstill is a rare condition defined by the lack of atrial electrical and mechanical function, and it may be intermittent or permanent, partial or total, and congenital or acquired (myocardial disease or metabolic/toxic). [1][2][3]6 Myocardial causes of acquired atrial standstill include surgical myocardial injury, 7,8 acute myocarditis, 9,10 myocardial infarction, 11 cardiac sarcoidosis, 12 mitral valve stenosis, 13 rheumatic heart disease, 14 and muscular dystrophy. 15 Histologically, atrial standstill is characterized by fibroelastosis and fatty infiltration in the atrium.…”