Same-day discharge after catheter ablation for routine arrhythmias: an initial experience.

AIM: Same-day discharge (SDD) in the setting of catheter ablation (CA) is not widely applied. We present our experience concerning SDD in a selected population of patients who underwent CA; the outcome was evaluated in terms of feasibility and safety. METHODS: 401 CA procedures were performed at our institution between January 2008 and December 2009 in 379 patients (65±16 years, 221 men). 336 CA procedures (84%) were considered eligible for SDD, after the exclusion of ventricular arrhythmias, atrial fibrillation, atypical atrial flutter, AV node ablation as well as procedures involving an arterial or transseptal access. Subsequently, a number of clinical and organizational exclusion criteria were applied. RESULTS: 223 patients were actually discharged on the same day of CA (56% of 401 overall CA procedures): 114 atrial flutter (AFL) and 109 supraventricular tachycardia. Many patients were excluded before CA due to a limited availability of the day-hospital facility; this occurred more frequently in the year 2008 than 2009 (45 vs. 2, P=0.0001); in the year 2009 the rate of total CA procedures which underwent SDD was of 68%. Overall, three groin hematomas occurred, all in patients ablated for AFL. Two of them were recognized during the postablation CONCLUSION: SDD can be safely performed in most patients undergoing CA for routine arrhythmias. This may result in a significant impact on daily practice in terms of both organizational improvement and subjective benefit for the patients.

Facilitation of atrioventricular reentrant tachycardia by iatrogenic right bundle branch block.

The present case report describes the diagnosis of a concealed bypass tract in the right lateral wall revealed by electrophysiologic evaluation performed in a patient with rare palpitations. A iatrogenic right bundle branch block (RBBB) caused the occurrence of an incessant atrioventricular reentrant tachycardia. The disappearance of the RBBB determined a very difficult induction of the tachycardia that, when induced, showed a shorter cycle length and ventriculoatrial interval than those observed during RBBB tachycardia. The presence of a RBBB ipsilateral to the right free wall accessory pathway provided a critical delay within the circuit thus allowing the bypass tract to recover excitability. This relevant delay also allows the sinus beat to initiate and stabilize the tachycardia thus rendering it incessant.

Allogeneic transplantation induces expression of cytomegalovirus immediate-early genes in vivo: a model for reactivation from latency.

Reactivation of cytomegalovirus (CMV) from latency is a frequent complication of organ transplantation, and the molecular mechanism by which this occurs is unknown. Previous studies have shown that allogeneic stimulation induces reactivation of human CMV (HCMV) in vitro (64). We find that transplantation of vascularized allogeneic kidneys induces murine CMV (MCMV) and HCMV immediate-early (ie) gene expression. This induction is accompanied by increased expression of transcripts encoding inflammatory cytokines, including tumor necrosis factor (TNF), interleukin-2, and gamma interferon, and by activation of NF-kappaB. TNF alone can substitute for allogeneic transplantation in inducing HCMV and MCMV ie gene expression in some tissues. Our studies suggest that reactivation is a multistep process which is initiated by factors that induce ie gene expression, including TNF and NF-kappaB. Allogeneic transplantation combined with immunosuppression may be required to achieve complete reactivation in vivo.

Unusual induction of slow-fast atrioventricular nodal reentrant tachycardia. Report of two cases.

INTRODUCTION: Generally, the induction of typical atrioventricular nodal reentrant tachycardia (AVNRT) occurs with a premature atrial stimulus that blocks in the fast pathway and proceeds down the slow pathway slowly enough to allow the refractory fast pathway time to recover. We describe two cases in which a typical AVNRT was induced in an unusual fashion. RESULTS: The first case is a 41-year-old man with paroxysmal supraventricular tachycardia. During the electrophysiology study, the atrial extrastimulus inducing the typical AVNRT was conducted simultaneously over the fast (AH) and the slow pathway (AH'). A successful ablation of the slow pathway was performed. During the follow-up no recurrence was noted. The second case is a 52-year-old woman with a Wolff-Parkinson-White syndrome due to a left posterior accessory pathway. After 5 minutes of atrioventricular reentrant tachycardia (AVRT) induced by a ventricular extrastimulus, a variability of the antegrade conduction was noted in presence of the same VA conduction. In fact, a short AH interval (fast pathway) alternated with a more prolonged AH intervals (slow pathway) that progressively lengthened until a typical AVNRT was induced. The ablation of the accessory pathway eliminated both tachycardias. DISCUSSION: A rare manifestation of dual atrioventricular nodal pathways is a double ventricular response to an atrial impulse that may cause a tachycardia with an atrioventricular conduction of 1:2. In our first case, an atrial extrastimulus was simultaneously conducted over the fast and the slow pathway inducing an AVNRT. This nodal reentry implies two different mechanisms: 1) a retrograde block on the slow pathway impeding the activation of the slow pathway from the impulse coming down the fast pathway, and 2) a critical slowing of conduction in the slow pathway to allow the recovery of excitability of the fast pathway. Interestingly, in the second case, during an AVRT the atrial impulse suddenly proceeded alternately over the fast and the slow pathway. The progressive slowing of conduction over the slow pathway until a certain point which allows the recovery of excitability of the fast pathway determines the AVNRT. This is a case of "tachycardia-induced tachycardia" as confirmed by the fact that the ablation of the accessory pathway eliminated both tachycardias.

Role of transesophageal echocardiography in evaluation of pulmonary venous obstruction by paracardiac neoplastic masses.

From 71 consecutive patients with paracardiac neoplastic masses who underwent transesophageal echocardiography (TEE), obstruction of individual right upper pulmonary venous flow by compression by contiguous mass was detected by TEE in 4 patients before and disappeared after anti-neoplastic treatments. Pulmonary vein, contiguous neoplastic mass and their relation could be clearly visualized and assessed by TEE. Pulmonary venous obstruction was assessed as moderate degree by combination of Doppler flow characteristics and diameter of pulmonary vein. Before therapy, peak velocities and time-velocity integrals in obstructed right upper pulmonary venous flow were increased, whereas deceleration times of systolic flow were prolonged. After therapy, peak velocities and time-velocity integrals were reduced and deceleration times of systolic flow were shortened, with normalization of the diameter of the right upper pulmonary veins. Thus, TEE may be used to detect and evaluate pulmonary venous obstruction by neoplastic masses and its changes after antineoplastic treatments.

Androgen metabolism in sheep.

3H-Testosterone (3H-T) plus 14C-androst-4-ene-3,17-dione (A-dione) and 3H-epi-testosterone (17alpha-hydroxy-4-androsten-3-one) (epiT) plus 14C-T were injected intravenously into two male sheep with bile fistulae, respectively. Urine and bile samples were collected at intervals for 4-8 hours and analyzed by the use of DEAE-Sephadex A-25 and Lipidex 5000 columns, TLC, and paper chromatography; the aglycones were identified by co-crystallization with authentic standards. Five fractions were obtained from urine and bile: unconjugated, glucosiduronates, sulfates, sulfo-glucosiduronates and disulfates. In urine, the major conjugates were glucosiduronates, while sulfates predominated in bile. About 80-90% of recovered radioactivity was found to be either glucosiduronates or sulfates. Among the metabolites identified, epi-T was the principal one, accounting for 10-15% of the administered doses. Conversion to 17alpha-hydroxysteroids thus appears to be a major route of metabolism of the androgens administered in sheep. Other metabolites in the glucosiduronate and sulfate fractions were androsterone, etiocholanolone (3alpha-hydroxy-5beta-androstan-17-one), 5beta-androstane-3alpha,17beta-diol, two unknown diols and polar metabolites. The results indicated that androgen metabolism is somewhat unusual in sheep, as compared with other animals and the human.