Role of syncope in predicting adverse outcomes in patients with suspected Brugada syndrome undergoing standardized flecainide testing.

Aims: Sensitivity to flecainide testing results in suboptimal findings in patients with Brugada syndrome (BrS), leading to safety concerns. Because cardiac syncope effectively predicts outcomes in BrS, we aimed to explore its predictive value in a large cohort of negative and positive responders (NR and PR) to standard flecainide testing. Methods and results: We analysed the data of 251 consecutive patients, 177 NR vs. 74 PR, to flecainide testing, performed according to standard recommendations. Cardiac syncope was defined as syncope presenting without prodromal symptoms and in the absence of any specific situation. Comparing PR with NR, there were no differences regarding age (39 ± 15 vs. 44 ± 13 years; P = 0.052), male gender (70.1% vs. 66.2%; P = 0.553), and family history of sudden cardiac death in relatives younger than 45 years (27% vs. 27%; P = 1). Cardiac syncope was more frequent in PR (12.2% vs. 4%; P = 0.022), and previous sudden cardiac arrest (SCA) was documented only in PR (5.4% vs. 0%; P = 0.007). During the follow-up period (6.2 ± 3.3 years), one NR, who had previously experienced cardiac syncope, developed SCA 3 months after flecainide testing. Following resuscitation, a type I electrocardiogram was spontaneously recorded. The follow-up event rate was higher in patients with cardiac syncope, both in PR and in NR (P < 0.001 both). In a multivariate analysis, cardiac syncope was the unique variable that predicted adverse outcomes (hazard ratio 14.9, 95% confidence interval 1.84-121.25; P = 0.011). Conclusions: In patients with false-negative responses to the provocative testing with flecainide, cardiac syncope predicts SCA, allowing a more extensive and individualized evaluation.

Exposición de las cardiólogas intervencionistas a radiaciones ionizantes durante el embarazo. ¿Realmente es necesario? / Radiation exposure to the pregnant interventional cardiologist. Is it really necessary?

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The inferior radiolucent area within the cardiac silhouette: validation as a landmark for coronary sinus catheterization.

BACKGROUND: Catheterization of the coronary sinus (CS) plays a preponderant role in device implantation and electrophysiology. Nevertheless, catheterization of this structure can be time-consuming and is related to operator experience. An inferior radiolucent area of the cardiac right anterior oblique (RAO) view has been suggested as a landmark to guide CS catheterization. However, the true relationship of this area with the CS ostium (CSO) has not been studied. METHODS: Thirty-five consecutive patients who underwent right coronary angiography were prospectively enrolled in the study. Fluoroscopic images of the heart in the right anterior oblique, both immediately before and during the venous phase of right coronary angiography, were recorded and digitally stored. Postprocedure measurements of the inferior radiolucent area within the cardiac silhouette and, subsequently, the distance of this area to the CSO, were performed by two independent observers. RESULTS: A radiolucent area of 9.5 +/- 3.0 x 11.0 +/- 3.4 mm was identified in the inferior annulus by the two evaluators in all patients. No significant differences in the dimensions of this area were found between the two observers. The CSO was 9.6 +/- 7.2 mm superior and 0.1 +/- 9.0 mm posterior to the radiolucent area and no statistically significant differences were found between the two observers. CONCLUSION: An inferior radiolucent area can be identified within the cardiac silhouette in most patients in the RAO view. This area is slightly anterior and inferior to the CSO and can be used for catheterization guidance of this latter structure.

[Post-infarction ventricular tachycardia with a QRS complex narrower than 140 ms: characterization and catheter ablation]. / Taquicardia ventricular postinfarto de QRS inferior a 140 ms: caracterización y ablación con catéter.

Typically, sustained monomorphic ventricular tachycardia (SMVT) in patients with a previous myocardial infarction (MI) is characterized by a wide QRS complex. However, occasionally patients present with SMVT and a narrow QRS complex (N-SMVT). We studied retrospectively the incidence of N-SMVT (i.e., QRS interval <140 ms) in patients with a previous MI and inducible SMVT who underwent electrophysiological evaluation. Of the 135 consecutive patients with inducible SMVT, 8 (5.9%) presented with inducible N-SMVT. The mean QRS complex duration in patients with N-SMVT was 126 (8) ms. Radiofrequency ablation was successful in 5 out of 6 patients (83%). One of the remaining two received an implantable defibrillator, while the other was given amiodarone. Findings during radiofrequency ablation showed that the reentry circuit was located in the left septum in 4 out of the 5 patients (80%). N-SMVT is relatively uncommon, but the success rate of radiofrequency ablation is high. The reentry circuit is most often located in the septum.

Taquicardia ventricular postinfarto de QRS inferior a 140 ms: caracterización y ablación con catéter / Post-infarction ventricular tachycardia with a QRS complex narrower than 140 ms: characterization and catheter ablation

Las taquicardias ventriculares monomórficas sostenidas (TVMS) en pacientes con infarto de miocardio (IM) previo presentan, habitualmente, un complejo QRS ancho. Sin embargo, en ocasiones se han descrito TVMS de complejos QRS «estrechos» (TVMS-E). Se analizó retrospectivamente la incidencia de TVMS-E (QRS < 140 ms) en pacientes con IM previo y TVMS inducidas en el estudio electrofisiológico. De 135 pacientes consecutivos con TVMS inducibles, 8 (5,9%) presentaron al menos una TVMS-E. La duración media del QRS de las TVMS-E fue de 126 ± 8 ms. La ablación con radiofrecuencia (ARF) fue eficaz en 5/6 pacientes (83%). De los restantes, en uno se implantó un desfibrilador y en el otro se indicó amiodarona. El resultado de la ARF evidenció una localización septal izquierda del circuito en 4/5 pacientes (80%). Las TVMS-E son relativamente raras pero la eficacia de la ARF es elevada; el septo es la localización más frecuente del circuito (AU)

Typically, sustained monomorphic ventricular tachycardia (SMVT) in patients with a previous myocardial infarction (MI) is characterized by a wide QRS complex. However, occasionally patients present with SMVT and a narrow QRS complex (N-SMVT). We studied retrospectively the incidence of N-SMVT (i.e., QRS interval <140 ms) in patients with a previous MI and inducible SMVT who underwent electrophysiological evaluation. Of the 135 consecutive patients with inducible SMVT, 8 (5.9%) presented with inducible N-SMVT. The mean QRS complex duration in patients with N-SMVT was 126 (8) ms. Radiofrequency ablation was successful in 5 out of 6 patients (83%). One of the remaining two received an implantable defibrillator, while the other was given amiodarone. Findings during radiofrequency ablation showed that the reentry circuit was located in the left septum in 4 out of the 5 patients (80%). N-SMVT is relatively uncommon, but the success rate of radiofrequency ablation is high. The reentry circuit is most often located in the septum (AU)

Syncope following cardioverter defibrillator implantation in patients with spontaneous syncopal monomorphic ventricular tachycardia.

AIMS: We sought to determine the incidence, mechanisms, and time to syncope recurrence in patients with spontaneous syncopal monomorphic ventricular tachycardia (SyMVT) treated with an implantable cardiac defibrillator (ICD). METHODS AND RESULTS: Incidence and causes of syncope following ICD implantation in consecutive patients (n=26) with spontaneous SyMVT were compared with those found in consecutive patients (n=50) with spontaneous non-syncopal monomorphic ventricular tachycardia (NSyMVT). Patients with SyMVT had a higher incidence of syncope (46% patients) than those with NSyMVT (2% patients) at 31+/-21 and 34+/-23 months follow-up, respectively (hazard ratio, 0.19; 95% confidence interval, 0.04-0.42; P=0.0001). Among the former, four patients (15%) had non-arrhythmic syncope and eight patients had arrhythmic syncope (31%), which was associated with either ICD proarrhythmia (seven episodes of VT acceleration or VF degeneration by ATP or low/high-energy shocks in three patients) or spontaneous VT and VF (five episodes in five patients). Median time to the first arrhythmic syncope was 376 days. Arrhythmic syncope presented after a first non-syncopal VT recurrence in six patients (75%). CONCLUSION: Syncope following ICD implantation is common in patients with SyMVT in contrast to patients with NSyMVT. Late syncope presentation supports reassessment of driving restrictions in this setting.

[Ventricular tachycardia ablation guided by LocaLisa system in patients with structural heart disease]. / Ablación de taquicardias ventriculares guiada mediante sistema LocaLisa en pacientes con cardiopatía estructural.

INTRODUCTION: The ablation of ventricular tachycardia is limited by a number of factors that reduce the effectiveness of this intervention in patients with structural heart disease compared to other types of arrhythmia. Recent years have seen the development of several nonfluoroscopic navigation techniques that facilitate the mapping of complex arrhythmogenic substrates. One such technique, the LocaLisa system, has not previously been tested for the ablation of ventricular tachycardia. PATIENTS AND METHOD: A total of 32 patients with structural heart disease were treated at our center with ablation for sustained ventricular tachycardia. In 10 patients the LocaLisa system was used to visualize the catheters during the procedure. We compared the results in the LocaLisa group with those in a control group of 22 patients treated with conventional fluoroscopy-guided ablation. RESULTS: The success rate of ablation was 75% (9/12 procedures) in the LocaLisa group and 68% (17/25 procedures) in the control group (P=NS). In the LocaLisa group, mean total duration of the procedure (243 +/- 84), duration of ablation (86 +/- 56) and fluoroscopy time (46 +/- 19) did not differ significantly from those in the control group (244 +/- 72 min, 79 +/- 58 min, and 43 +/- 27 min, respectively). In the LocaLisa group the trend toward greater hemodynamic intolerance in ventricular tachycardia approached significance (42% in the LocaLisa group vs 24% in the control group, P=.05) and the number of mapping procedures performed during sinus rhythm was significantly higher in the former (33% in the LocaLisa group vs 4% in the control group, P=.03). With the LocaLisa system it was possible to locate and reposition the ablation catheter accurately at the target endocardial sites, as confirmed by electrographic recordings and fluoroscopic verification. CONCLUSIONS: The LocaLisa system helps to delineate the reentry circuit and facilitates accurate catheter repositioning in patients with structural heart disease and ventricular tachycardia.