L. Mont

Outcomes after radiofrequency catheter ablation of atrial tachycardia

The purpose of this study was to evaluate the efficacy, safety, and clinical benefit of radiofrequency catheter ablation (RFCA) in a large series of patients with atrial tachycardia (AT). The determinants of success or failure of RFCA in AT remain unclear. We evaluated the results of radiofrequency ablation in 73 women and 32 men (mean age 48 +/- 19 years) with AT. Mapping techniques were based on identification of the earliest endocardial atrial electrogram recorded during AT. AT originated from the right atrium in 91 patients and from the left atrium in 14. The cardiac ventricles were dilated in 12 patients. AT ablation was successful in 80 patients (77%) regardless of the site of origin. Age, gender, rate of tachycardia, temperature achieved during application, or presence of tachycardiomyopathy were not significant determinants of acute success by univariate analysis. There was a significantly higher acute success rate of ablation in patients with paroxysmal (88%, 45 of 51) and permanent (71%, 30 of 42) forms than in patients with repetitive forms of AT (41%, 5 of 12) (p <0.005). The mean local endocardial electrogram time (relative-to-surface P-wave onset) was -47 +/- 17 ms at successful ablation sites and -29 +/- 21 ms at unsuccessful sites (p <0.03). Ablation was unsuccessful in 25 cases. Thus, RFCA of AT can be performed with a high acute success rate. Patients with repetitive forms and those with multifocal origin had a lower acute success rate. The highest incidence of recurrences was found in anterior right atrial foci.

Accessory pathway localization by QRS polarity in children with Wolff-Parkinson-White syndrome.

AP Localization by QRS Polarity in Children. Introductions: Location of the accessory pathway (AP) in Wolff‐Parkinson‐White (WPW) syndrome can be determined accurately by the QRS polarity on resting ECG. These ECG characteristics may be different in children, and no algorithm has yet been tested.

Endurance athletes: exploring the limits andbeyond

See doi:10.1016/S1095-668X(03)00282-3for the article to which this editorial refers Humans have always tried to push back the limits imposed by their physical characteristics. Competitive sports are in themselves a continuous struggle tosurpass these established limits. As physicians, we are frequently asked not only to identify and treat diseases, but to define what is and what is not healthy behaviour. The paper by Heidbuchel and co-workers poses a fundamental question to medical practitioners: what are the reasonable limits for the practice of sport? The general population has the perception that athletes are the healthiest members of society, since they are capable of such impressive physical performance. However, the cardiological community has been interested in the inherent risk of sport for many years. Although …

ACE2 and ACE in acute and chronic rejection after human heart transplantation

OBJECTIVES The authors sought to evaluate cardiac activity of angiotensin-converting enzyme (ACE) and ACE2 after heart transplantation (HT) and its relation with acute rejection (AR) and chronic allograft vasculopathy (CAV). BACKGROUND The renin-angiotensin system is altered in heart failure and HT. However, ACE and ACE2 activities in post-HT acute and chronic rejection have not been previously studied. METHODS HT patients (n = 45) were included when appropriate serial endomyocardial biopsies (EMB) and coronary angiography were available for analysis. In 21 patients, three post-HT time points were selected for CAV study in EMB tissue: basal (0-3 wks), second (2-3 months) and third (4-5 months). At 10 years post-HT, CAV was evaluated by coronary angiography (CA) and patients were grouped by degree of CAV: 0-1, non-CAV (n = 15) and 2-3, CAV (n = 6). For the AR study, 28 HT patients with evidence of one EMB rejection at grade 3 and two EMB grade 1A and/or 1B rejections were selected. RESULTS Post-HT, ACE2 activity was increased in the CAV group, compared to non-CAV. Patients with AR showed increased ACE, but not ACE2, activity. CONCLUSIONS Our results suggest that early post-HT cardiac ACE2 activity may have an important role in CAV development. In contrast, ACE activity was increased in AR. The renin-angiotensin system seems to be altered after HT and strategies to balance the system may be useful.

Trastornos del ritmo cardíaco: un reto para el radiólogo

La alteracion del ritmo cardiaco o arritmia puede presentarse con o sin enfermedad cardiaca subyacente. La mayoria de cardiopatias dan lugar a arritmias, pero tambien otras enfermedades, como por ejemplo de causa metabolica, alteraciones electroliticas, drogas y farmacos pueden dar lugar asimismo a alteraciones del ritmo cardiaco en corazones previamente sanos. La clinica puede ser desde asintomatica, como un hallazgo casual en una exploracion de rutina, hasta la muerte subita como unica manifestacion clinica. Ante la sospecha clinica de una arritmia se ha de confirmar esta mediante la realizacion de un estudio Holter y un estudio electrofisiologico. A continuacion se ha de descartar una cardiopatia asociada. La ecocardiografia es la primera tecnica de imagen que se debe de realizar, la tomografia computarizada multidetector y la resonancia magnetica (RM) son tecnicas mas recientes en el campo de la cardiologia, y que poco a poco van tomando posiciones e indicaciones precisas. Dentro del terreno de la arritmologia la RM tiene su indicacion en dos campos muy concretos: la fibrilacion auricular y la displasia arritmogenica del ventriculo derecho.

943 Impact of underlying cardiopathy on left ventricular remodelling after cardiac resynchronization therapy

, p<0.02), in the office diastolic blood pressure (83.0±6.2 vs 77.0±7.5 mm Hg, p<0.008) and heart rate (76.1±14.0 vs 66.3±9.7 bpm, p<0.02). No differences were found in left ventricular diameters, volumes, mass, meridional and circumferential end-systolic stress, total peripheral resistence, stroke volume and cardiac output. The relative wall thickness (RWT) was significantly increase in black (0.42±0.04 vs 0.36±0.05, p<0.0001), suggesting a tendency to a concen- tric remodelling. The left systolic function estimated by conventional param- eters was unchanged. Doppler analysis of tissue kinetics showed a signifi- cant increase in black subjects of septal S and E waves, as peak velocity (pv) and time velocity integral (tvi), when compared with white subjects. The MPI in black subjects was significantly increase (0.46±0.05 vs 0.39±0.05, p<0.0003), due to a significant prolongation of ICT (62.1±19.1 vs 51.4±9.9 msec). A significant correlation between MPI and RWT (r=0.54, p<0.001) and left ventricular mass (r=0.54, p<0,001) respectively were demonstrated. Besides, MPI correlate with Spv (r=0.55, p<0.001) and Stvi (r=0.38, p<0.001) waves. In conclusion our data confirm that MPI is increase in black healthy subject and is geometry-dependent, in contrast with current literature. Besides, we found correlations between MPI and systolic indexes derived from DTE. These findings also suggest that racial differences in left ventricular perfor- mance and systolic function exist even in absence of other conventional echocardiographic changes.