Focal AF is amenable to radical cure by RF ablation within the PV. The primary purpose of this study was to compare lesion characteristics for irrigated versus standard ablation using three power settings for PV isolation in pigs. Secondary analyses were the comparisons of ablation time and temperature characteristics, and evaluation of short-term safety in the pig model. In 20 pigs from 25 to 35 kg in weight, transseptal catheterization was performed and then the ablation catheter was advanced into the PV. RF energy was delivered to the ostium of the PV until its isolation was achieved. The animals were euthanized 1 week after ablation for pathological examination. Electrophysiological isolation of the PV was achieved, although it was difficult to achieve a complete circumferencial lesion in the ostium of the PV. Both of these catheters can produce transmural necrosis, even using 15 W of power. The authors did not see any stenosis of the PV. This might be due to the low energy delivery and the short follow-up. Pulmonary hemorrhage was present in two animals with 50 W of power, high energy output is dangerous for the ablation of the PV.

Background: the inhibition of the renin-angiotensin system has demonstrated both experimental and clinical effects in preventing atrial fibrillation. However, there is still uncertainty about the role of these drugs in clinical practice. Objectives: The objective of this review has been to assess the effects of angiotensin II type-1 receptor blockers (ARBs) and/or angiotensinconverting enzyme inhibitors (ACEIs) for preventing atrial fibrillation. Search strategy: we searched the Cochrane controlled Trials Register

INTRODUCTION: The doctor-patient relationship has undergone several reinterpretations over the centuries being based on attentive listening primarily, a characteristic that has been neglected in many current contexts. Such a doctor-patient relationship is essential for understanding the pathological condition under analysis and, also, for understanding this patient as a human being, which will give greater dignity to this moment that is so intimate, yet so essential in medical practice. Thus, literature can be used as a tool to encourage the human development of professionals and students and subsequently reflect in this important relationship. DEVELOPMENT: Currently, there is a noticeable weakening of the doctor-patient relationship, mainly due to the exacerbated cult of technicism and the depreciation of the cultural, such as the various segments of literature, when, in fact, each of these aspects have their space and should complement each other. With this in mind, there is a greater distancing between doctor and patient, which ends up damaging the image of the clinical examination shaped by what should be a co-protagonism between these two individuals. Because of this, the doctor becomes increasingly insensitive and, therefore, the patient becomes increasingly unreachable, which hinders the proper promotion of health and future well being of this person. So, literature can be inserted as a tool that will stimulate the change of this context, either by the contact of the doctor with recurring themes in his daily life from the perspective of his patients or by the acquired self-knowledge capable of making him understand the vulnerability of human beings, including his own. Furthermore, another important function that the literature can provide is to facilitate data collection itself - through language or even by actions performed by the professional - which will have important consequences on that patient's prognosis. CONCLUSION: Doctors and students in this area should provide the greatest possible comfort for the patient who is in the state of vulnerability that the disease provides and this can be achieved more easily and efficiently with the use of the literature associated with technicism in a way wich they become complementary and encompass the various segments inherent to human beings.

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lar model reproducing experimental observed atrial cellular properties. Sustained AF, typical and atypical flutter could be reproduced using a burst-pacing protocol. Based on a model of chronic AF, surgical/ radiofrequency (RF) ablation lines were implemented by making the cardiac cells located on the ablation lines non conductive. Several published ablation patterns were implemented in the computer model and their results compared to clinical data. We thus evaluated the standard Maze llI procedure and less invasive patterns involving fight and/or left ablation lines. Success rate, time to AF termination and AF reinitiation capacities were assessed for each studied pattern. Results: among all simulated ablation patterns, the most efficient is the Maze llI procedure with a 100% success rate (no significant difference compared with the clinical success of 98% published by Cox in 1993). We observed that the most complex ablation patterns led both to the best success rate and shortest time to AF termination. Ablation patterns involving lines in the right or left atrium led to success rates in the range 60-65% while those combining lines in both atria showed an increased rate in the range from 80-100%. For example, a simplified Maze pattern led to success rate of 88% (comparable to success rate of 92% in our clinical experience using RF ablation). However, some specific ablation lines such as those connecting pulmonary veins and mitral valve annulus appear more sensitive to gaps simulating non-transmurality; this resuks in a lower performance generally manifested by the appearance of uncommon flutter after ablation. Conclusions: this simulation study confirms the good performance of the standard Maze llI procedure in treating chronic AF. It suggests that less invasive patterns need to include ablation lines in both atria and that discontinuities in specifically located ablation lines lead to a decrease in success rate. 566A prospective and comparative study of different techniques for atrial fibrillation ablation