An atrial arrhythmia characterized by disorganized atrial activity without discrete P waves on the surface EKG, but instead by an undulating baseline or more sharply circumscribed atrial deflections of varying amplitude an frequency ranging from 350 to 600 per minute.

A type of atrial arrhythmia characterized by atrial rates of between 240 and 400 beats per minute and some degree of atrioventricular node conduction block. Typically, the ventricular rate is half the atrial rate. In the EKG; atrial flutter waves are observed as sawtooth-like atrial activity. Pathophysiologically, atrial flutter is a form of atrial reentry in which there is a premature electrical impulse creates a self-propagating circuit.

The presence of chronic increased pressure in the systemic arterial system.

Increase in size of the left atrium.

A diminution of the volumetric fraction of blood pumped out of the ventricle with each cardiac cycle.

Atrial fibrosis is an hallmark of atrial structural remodelling, characterized by the aberrant activation, proliferation and differentiation of fibroblasts, and subsequent excessive synthesis and irregular deposition of extracellular matrix proteins.

An increased concentration of brain natriuretic peptide in the blood circulation.

The concentration of NT-proANP in the blood circulation is below the lower limit of normal.