**9. Conclusion**

AF is the most common clinical arrhythmia showing progressive features. There has been evidence to suggest PV as a source of abnormal electrical activities initiating and sustaining AF. Currently, PVF recording is feasible in routine Doppler echocardiography, and is essential for evaluation of LA functioning three roles during an entire cardiac cycle such as 'booster pump', 'reservoir' and 'conduit'. This flow pattern recognition is of clinical importance not only in assessing global cardiac performance but also for obtaining considerable information with respect to the pathophysiology and management of AF. There has been a consensus with respect to the PVF pattern during ongoing AF or in patients with permanent AF. However, there has been a controversy concerning PVF profile during sinus rhythm in patients with paroxysmal AF. This indicates the anatomical and pathophysiological complexities of PV-LA junction and AF itself. Time-dependent recovery of LA contractile function (LA stunning) and neuroanatomical modification of PV-LA junction by radiofrequency catheter ablation make this controversy further complicated. In spite of such controversy and complexity, PVF recording has potential benefits to assess various stages of long-term AF progression and to manage the AF patients.
