Figure Legends:
Figure1:    Baseline 12 lead ECG showing atrial fibrillation. Black arrow show irregularly irregular atrial fibrillatory waves on ECG rhythm strip II (black arrows)
Figure 2: (A) Pre-cardioversion TEE showing left atrium (LA), LA appendage body (LAA) with an elongated accessory lobe (LAAA - A & B). Pulsed Wave Doppler measurement showing variable appendage velocities upto 30 cm/second in the main body and accessory lobe of the LA appendage ((yellow arrows – C & D).
Figure 3: 12 lead ECG showing sinus bradycardia at 55 beats per minute following external direct current cardioversion with 200 joules. Sinus p wave are shown with black arrows
Figure 4: Post-cardioversion TEE images of the left atrium (LA), left atrial appendage (LAA) and its accessory lobe showing progressively dense thrombus formation in the LA appendage accessory lobe from A through D. Thrombus increases progressively in echogenicity immediately post cardioversion (A) upto 3 minutes post cardioversion (D). Pulsed Wave Doppler in the LA appendage post cardioversion show near absence of velocities in the appendage body (yellow arrows E) and accessory lobe (yellow arrows F).
Figure 5: Post-cardioversion successive TEE mages of the left atrium (LA), left atrial appendage (LAA) and its accessory lobe after injection of Lumason image enhancing agent. A filing defect is present at the site of thrombus in the LA accessory lobe (yellow arrow A) with progressive uptake of contrast by the thrombus (yellow arrows B and C). C is the biplane view of the appendage and accessory lobe in B color mode showing long axis view on the left and its orthogonal short axis view on the right showing accessory lobe thrombus with contrast uptake (yellow arrows C).
Video 1:  Pre-cardioversion TEE video showing a dilated left atrial appendage (LAA) and an elongated LA appendage accessory lobe with contractile function and without thrombus.
Video 2: Post-cardioversion TEE video demonstrating LA appendage (LAA) and appendage accessory lobe becoming more elongated (due to stuning) and with a thrombus within it (white arrow).
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