Functional or structural?
Least but not last is the evaluation of the underlying substrate that can lead to the clinical appearance of AFL. Atrial myopathy is the phrasing to highlight the presence of a progressive atrial disease which promotes areas of fibrosis and scars. If one considers that patients in AFL group were older and with larger atrial volume, it is conceivable that the myopathic process influences the conduction properties of the atrium and, thus it is not surprising to find prolonged RACT. Comorbidities such as systemic hypertension, OSA, ischemic disease can greatly affect the cardiac electrophysiology and specifically of the atrium; these pathologic clinical aspects were significantly associated to the AFL patients suggesting an undoubtable role in favoring the formation of the ideal pathophysiological substrate for reentry circuits.
After several decades of investigational studies and a great wealth of data collected about the typical atrial flutter, we are still here to be nicely fascinated by the basic electrophysiology and surprised of how much is still to be learned as to improve our understanding of this common cardiac arrhythmia. In the era dominated by novel technologies and sophisticated softwares supporting 3D mapping systems used in many EP labs, the continuous investigation of the electrophysiologic properties of cardiac tissue should not be disregarded. but carefully stewarded.