The global burden of atrial fibrillation (AF) is enormous for cases, physicians, & healthcare systems. Substantial scientific efforts and resources are committed to elucidating the mechanisms behind AF, its natural progression, & efficient treatments. AF istypically classified into five distinct patterns depending on the onset, progression, and resolution of AF episodes, first diagnosed AF, paroxysmal AF, persistent AF, long-standing persistent AF, permanent AF. Atrial structural remodeling or exacerbation of atrial cardiomyopathy are generally defining features of the transition from paroxysmal to non-paroxysmal AF. The duration of rhythm monitoring and the presence of a substrate are both important factors in determining the rate of AF development. AF is both a risk factor and a hallmark of atrial cardiomyopathy, that couldclarify the absence of a temporal correlation among AF & stroke. Atrial remodeling influences major clinical difficulties in AF (i.e. avoidance of thromboembolic consequences & AF development).
In the existence of a structurally normal valve, functional MR develops when there is a mismatch between the tethering forces exerted by the heart (as a result of global and/or focal LV dilation, papillary muscle displacement, and/or dysfunction) & the closing forces exerted by the heart (as a result of decreased LV contractility and/or synchronicity).