Results: Patients undergoing high-intensity focused ultrasound had a high rate of late postoperative percutaneous ablation (37.5%) after surgical intervention (P < .001 vs the other groups). At last follow-up, freedom from atrial fibrillation and need for ablation click here was as follows: classic maze procedure, 90%;high-intensity
focused ultrasound, 43%; left atrial maze procedure, 79%; biatrial maze procedure, 79%; and pulmonary vein isolation, 69% (P < .001 between groups). For those with atrial fibrillation, mapping and ablation were performed in 23.6% (n = 27), and all patients with high-intensity focused ultrasound had failure of the box lesion around the pulmonary veins. Of those with just the left atrial maze procedure or pulmonary BLZ945 vein isolation, the right atrium was the source for failure in 75% (6/8).
Conclusions: Patients undergoing high-intensity focused ultrasound had a high need for postoperative ablation and low freedom from atrial fibrillation. The classic
maze procedure had the best results. Left atrial ablation might allow failure from right atrial foci. Matching the technology and lesion set to the patient yields good results and can be applied in 95% of patients. We suggest others obtain late catheter ablation to correct remaining atrial fibrillation, and add to the paucity of late data regarding failure mode. (J Thorac Cardiovasc Tryptophan synthase Surg 2010; 139: 860-7)”
“Rats were trained to fear an auditory conditioned stimulus (CS) by pairing it with a mild electric shock (the unconditioned stimulus, or US) delivered to one eyelid. After training, the CS elicited two different conditioned fear responses from rats: a passive freezing response, and an active turning response. The balance between these two modes of conditioned
responding depended upon the rat’s recent history of encounters with the US. If rats had not recently encountered the US, then they responded to the CS by freezing. But after recently encountering the US, rats exhibited CS-evoked turning responses that were always directed away from the trained eyelid, even if the US had recently been delivered to the opposite (untrained) eyelid. This post-encounter turning behavior was not observed in rats that had been trained with unpaired presentations of the CS and US, indicating that even though CS-evoked turning was selectively expressed after recent encounters with the US, it was nonetheless a conditioned Pavlovian fear response that depended upon a learned association between the CS and US. Further supporting this conclusion, pharmacological inactivation experiments showed that expression of both freezing and turning behaviors depended upon lateralized circuits in the amygdala and periaqueductal gray (PAG) that are known to support expression of Pavlovian fear responses.