Aníbal Rodríguez

Use of Irbesartan to Maintain Sinus Rhythm in Patients With Long-Lasting Persistent Atrial Fibrillation A Prospective and Randomized Study

Background—Data from studies of angiotensin-converting enzyme inhibitors provide evidence that the renin-angiotensin-aldosterone system plays a role as a mediator of atrial remodeling in atrial fibrillation. The present study has evaluated the effect of treatment with the angiotensin I type 1 receptor blocker irbesartan on maintaining sinus rhythm after conversion from persistent atrial fibrillation. Methods and Results—To be included in the present study, patients must have had an episode of persistent atrial fibrillation for >7 days. The patients were then randomized and scheduled for electrical cardioversion. Two groups of patients were compared: Group I was treated with amiodarone, and group II was treated with amiodarone plus irbesartan. The primary end point was the length of time to a first recurrence of atrial fibrillation. From a total of 186 patients assessed in the study, 154 were analyzed with the use of intention-to-treat analysis. Seventy-five patients were randomly allocated to group I and 79 to group II. After 2 months of follow-up in the intention-to-treat analysis, the group treated with irbesartan had fewer patients with recurrent atrial fibrillation (Kaplan-Meier analysis, 84.79% versus 63.16%, P =0.008). The Kaplan-Meier analysis of time to first recurrence during the follow-up period (median time, 254 days [range, 60 to 710]) also showed that patients treated with irbesartan had a greater probability of remaining free of atrial fibrillation (79.52% versus 55.91%, P =0.007). Conclusions—Patients treated with amiodarone plus irbesartan had a lower rate of recurrence of atrial fibrillation than did patients treated with amiodarone alone.

Use of Irbesartan to Maintain Sinus Rhythm in Patients With Long-Lasting Persistent Atrial Fibrillation

Background— Data from studies of angiotensin-converting enzyme inhibitors provide evidence that the renin-angiotensin-aldosterone system plays a role as a mediator of atrial remodeling in atrial fibrillation. The present study has evaluated the effect of treatment with the angiotensin I type 1 receptor blocker irbesartan on maintaining sinus rhythm after conversion from persistent atrial fibrillation. Methods and Results— To be included in the present study, patients must have had an episode of persistent atrial fibrillation for >7 days. The patients were then randomized and scheduled for electrical cardioversion. Two groups of patients were compared: Group I was treated with amiodarone, and group II was treated with amiodarone plus irbesartan. The primary end point was the length of time to a first recurrence of atrial fibrillation. From a total of 186 patients assessed in the study, 154 were analyzed with the use of intention-to-treat analysis. Seventy-five patients were randomly allocated to group I an...

Prospective study of Streptococcus milleri hepatic abscess.

Thirty-seven cases of microbiologically demonstrated pyogenic hepatic abscess were observed in a prospective study over a seven-year period. Biliary disease was the most common source of liver abscess (42%).Streptococcus milleri was the most common cause of hepatic abscess, accounting for 51% of the cases. Hepatic abscess is due toStreptococcus milleri clinically distinct from other forms of pyogenic liver abscess due to its torpid nature and the longer duration of its symptoms [42 vs. 11 days]. Occult hepatic abscess should be suspected if the blood culture is positive forStreptococcus milleri, since 28% of bacteremia cases due toStreptococcus milleri stem from hepatic abscesses. It is important to distinguishStreptococcus milleri from other members of the viridans streptococci group, which are frequently isolated as contaminants, but only exceptionally cause hepatic abscess. Unlike other pyogenic hepatic abscesses, those caused byStreptococcus milleri are frequently monomicrobial (79%). In the present study, empirical therapy of pyogenic hepatic abscess always included a drug that is effective againstStreptococcus milleri.

Randomized Comparison of Efficacy of Cooled Tip Catheter Ablation of Atrial Flutter: Anatomic Versus Electrophysiological Complete Isthmus Block

MADRID, A.H., et al.: Randomized Comparison of Efficacy of Cooled Tip Catheter Ablation of Atrial Flutter: Anatomic Versus Electrophysiological Complete Isthmus Block. There is a subset of patients with failed ablation of the cavotricuspid isthmus (CTI) using standard catheters and with 10% of the patients having recurrences. The purpose of this study was to compare the cooled and standard ablation with regard to acute successful electrophysiological achievement of bidirectional isthmus block and the subacute anatomic characteristics of the lesions. This randomized, experimental study compares the effects of ablation on the isthmus using a cooled catheter with those of a standard ablation catheter in 16 pigs. In 12 animals, CTI block was achieved after ablation (8/8 cooled and 4/8 standard). In two animals, it was not possible to achieve complete isthmus block and two had persistent slow conduction (all four using the standard catheter). After 1 week, the animals were slaughtered. The size of the lesion was greater with the irrigated tip catheters. Transmural lesions were found in 14 animals. A complete line of anatomic isthmus block was not documented after the first line in six animals, four with the standard and two with the cooled catheter. A conduction block was never present across gaps ≥ 5 mm. In conclusion cooled catheters achieved a complete line of electrophysiological and anatomical block in a significantly higher percentage than the standard catheters.

Learning Process for Transseptal Puncture Guided by Intracardiac Echocardiography

We prospectively analyzed the learning process for transseptal catheterization guided by intracardiac echocardiography, in 50 patients who underwent radiofrequency ablation for left atrial arrhythmias. In 20 patients the intracardiac echocardiography catheter was positioned in the right atrium to visualize the fossa ovalis and the tenting of the fossa caused by the Brockenbrough needle. In the other 30 patients, the intracardiac echocardiography catheter was positioned so that it impinged upon the fossa ovalis, and the needle was advanced alongside the intracardiac echocardiography catheter under fluoroscopic guidance in two orthogonal projections. In all but one patient, transseptal catheterization was performed successfully on the first attempt. The learning process for transseptal puncture guided by intracardiac echocardiography was uncomplicated, resulting in a procedure that is safe and effective. The intervention is simplified by positioning the echocardiography catheter at the fossa ovalis and using this as a reference point for fluoroscopic monitoring of the progress of the Brockenbrough needle.

An Automatic Algorithm Based on Morphological Stability During Fast Ventricular Arrhythmias Predicts Successful Antitachycardia Pacing in ICD Patients: A Multicenter Study.

Different types of ventricular arrhythmias (monomorphic ventricular tachycardia [VT], polymorphic VT, or ventricular fibrillation) can be detected by implantable cardiac defibrillators (ICDs) in fast VT zone. The efficacy of antitachycardia pacing (ATP) depends on the type of the treated arrhythmia. We hypothesized that an automatic algorithm based on morphological affinity of ICD far‐field electrograms during tachycardia can predict ATP success and the need of shock.

Multi-client emulation platform for performance testing of high density 802.11 networks

During the last years the world has witnessed the great success of the IEEE 802.11 standard with an exponential increase in the number of Wi-Fi networks deployed around the globe. This fact was also accompanied by a great evolution of the technology, originally created for a few clients and today supporting thousands of users in a single wireless LAN. One of the most important verticals for Wi-Fi today is education, with several one-to-one programs running around the world, such as the nationwide Plan Ceibal in Uruguay. The present paper describes the development of an 802.11 portable multi-client testing platform, which enables the emulation of a typical high density classroom scenario to test the wireless infrastructure. The prototype was successfully validated for two different laptop models used by Plan Ceibal, considering both throughput and lower network layers performance. The results indicate this might be the first step towards an open platform to enable active in-site Wi-Fi performance testing for large scale scenarios.

Estudio de las características anatomopatológicas y la seguridad de las lesiones producidas en la aurícula con dos diferentes sistemas de catéteres de punta irrigada en un modelo experimental

Introduccion y objetivos Evaluar la seguridad y eficacia de las lesiones producidas en la auricula por diferentes sistemas de irrigacion de cateter. Se estudiaron las caracteristicas anatomopatologicas de las lesiones producidas por 2 sistemas de punta irrigada, con circuito cerrado o abierto. Metodos Este estudio se realizo en 16 cerdos (29-57 kg) aplicando pulsos de radiofrecuencia de 60 s y 3 niveles de energia (15, 25, 50 Watios) y dos sistemas diferentes de irrigacion: abierto y cerrado. Como control se empleo un grupo de 4 cerdos, a los que se habia realizado ablacion con cateter estandar. Se ubicaron los cateteres en la auricula derecha lateral alta y baja donde se realizaron las aplicaciones. Los animales fueron sacrificados al septimo dia para estudio anatomopatologico. Resultados Se produjeron un total de 27 lesiones con cateteres irrigados (11 en circuito cerrado y 16 abierto) y 6 con estandar en el grupo control. No se encontraron diferencias significativas entre las lesiones producidas con los dos sistemas evaluados, aunque las lesiones del sistema cerrado fueron ligeramente mayores. Las lesiones producidas con cateteres irrigados fueron siempre superiores a las del grupo control. La transmuralidad en la pared auricular libre es frecuente con ambos sistemas irrigados. No observamos ningun caso de perforacion de la pared auricular. Conclusiones No se observaron diferencias significativas en el tamano de las lesiones producidas con los dos sistemas de irrigacion. Estos datos del modelo animal pueden aportar informacion util para la realizacion de procedimientos de ablacion de taquicardias auriculares en humanos.