Restoration of sinus rhythm after prolonged atrial fibrillation or, to a lesser degree, atrial flutter often results in depressed left atrial (LA) contractility despite normal electrical activity. Echocardiography performed after restoration of sinus rhythm, regardless of the mode of conversion, frequently shows an increased early mitral inflow velocity and depressed or absent filling due to atrial contraction which may persist for days to weeks. This pattern usually manifests as a result of severe left ventricular diastolic dysfunction as in restrictive cardiomyopathy. Recently, it has been shown in an animal model that this trans-mitral filling pattern is largely due to increased LA pressure as a result of depressed LA mechanical function rather than impaired left ventricular compliance, which has led some to refer to this pattern as “pseudorestrictive.” We present an illustrative case of “pseudorestrictive” trans-mitral Doppler flow pattern: a fifty-nine-year-old woman presented for elective radiofrequency ablation (RFA) of typical, counter-clockwise, isthmus-dependent, atrial flutter. Spontaneous conversion to sinus rhythm occurred the evening before the procedure, obviating the need for pacing or direct current cardioversion during the electrophysiologic study. Bi-directional isthmus block was confirmed after RFA and no recurrence of the atrial arrhythmia was observed. Standard transthoracic echocardiographic examinations (TEE) were performed 5, 10, and 30 days after RFA. Diastolic parameters included mitral inflow early filling velocity (E), filling velocity due to atrial contraction (A), E deceleration time (DT), E/A ratio, left atrial diastolic and systolic filling velocities (PVd and PVs respectively), and PVs/PVd ratio. TTE initially demonstrated a restrictive filling pattern (E = 1.2 m/s, A = 0.24 m/s, E/A = 5.0, DT = 154 msec, PVs = 24 cm/s, PVd = 101 cm/s, PVs/PVd = 0.24) which was not altered by left ventricular pre-load reduction (Valsalva maneuver) consistent with grade IV diastolic dysfunction. Moderate mitral and tricuspid regurgitation and moderate pulmonary hypertension (59 mm Hg) were also noted. At ten days post RFA pulmonary artery pressure returned to normal. Subsequent (30 day) TTE demonstrated a normal diastolic filling pattern (E = 0.95 m/s, A = 0.73 m/s, E/A = 1.3, DT = 192 msec, PVs = 52 cm/s, PVd = 54 cm/s, PVs/PVd = 0.96). The left ventricular systolic ejection fraction (68% ± 4%) and heart rate (74 bpm ± 6 bpm) did not vary significantly between the examinations.