Atrial compliance determines the nature of passive atrial stretch and plasma atrial natriuretic factor in the conscious dog

Abstract

Very high atrial appendage wall stresses are required to increase plasma atrial natriuretic factor markedly. Atrial stretch and the release of atrial natriuretic factor are non-linearly related. The stimulus for atrial natriuretic factor release is related to the exponential changes in atrial function due to the underlying atrial compliance relationship.

Effect of saline administration on left atrial pressure during transcatheter mitral valve repair

“…Further volume administration during clip placement exhausts this compensation and effectively overwhelms the distensibility of the enlarged, remodeled, and chronically fibrosed atrium, resulting in increased LAP as part of the exponential LAP‐volume relationship. This observation reflects not only the pathophysiology of chronic mitral regurgitation but also the findings of prior studies, including, for instance, a noted increase in v‐wave amplitude secondary to acute volume loading in acute mitral regurgitation . Such intraprocedural change in v‐wave pressure may very well, however, be influenced by other concomitant factors apart from intravascular volume status and left atrial compliance, including, for instance, left ventricular diastolic function, filling pressure, and afterload.…”

The transverse four-chamber view for the assessment of atrial tissue deformation in the fetus

“…Within these thickened regions, most myocytes lie parallel to the long axis of the muscle bundles, while in LA wall myofiber orientation varies with depth [ 25 ]. Filling pressure is lower and compliance higher in RA than in LA, which allows more absolute movement of RA than of LA tissue [ 26 ]. Due to reduced atrial compliance, LA tissue reflects passive “manipulation” more intensely than RA tissue, yielding more distorted strain curves with several smaller peaks.…”