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.

Catheter ablation of multiple, surgically created, atrioventricular connections following Fontan-Björk procedure.

An increased incidence of Wolff-Parkinson-White (WPW) syndrome with tricuspid atresia has been reported. Although atrioventricular accessory pathways may develop across suture lines after the Fontan-Björk procedure, the presence of multiple acquired accessory pathways has only been described rarely. We report on a case of a female with tricuspid atresia who underwent the Fontan operation at 5 years of age. One year later, she developed a WPW pattern. Narrow complex tachycardias started at the age of 18. An electrophysiological study revealed the presence of three accessory pathway connections at the surgical anastomosis level. All of them were successfully ablated and there were no recurrences.

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)

Negative flecainide test in Brugada syndrome patients with previous positive response.

Class I antiarrhythmic drug infusion has been established as the standard test to unmask Brugada syndrome. This report presents two patients with Brugada syndrome with positive flecainide response which was not reproducible in a subsequent test.

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.

Superior vena cava flutter: electrophysiology and ablation.

INTRODUCTION: Reentry within a major thoracic vein has been suggested as a cause of atrial arrhythmias. However, little is known about these potential reentrant circuits. METHODS AND RESULTS: Atypical atrial flutter was induced and mapped in 67 out of 225 atrial flutter ablation procedures. Reentry around the superior vena cava (SVC) was suspected in three patients. The suspected SVC flutter was induced and terminated by pacing in all patients. Fusion was demonstrated during flutter entrainment by subeustachian isthmus pacing in all of them. The postpacing interval following entrainment by pacing from different sites of the right atrium (RA) or coronary sinus was longer than the flutter cycle length. Macroreentry within the SVC was demonstrated both by sequential activation and a postpacing interval matching the flutter cycle length when pacing from different sites around the SVC in all patients. Atrial-venous-atrial electrogram sequence was demonstrated following flutter entrainment by atrial pacing. Flutter was terminated by an electrical stimulus delivered to the SVC, which was not propagated to the trabeculated RA, in one patient, and linear radiofrequency application from the distal SVC to the posterior wall of the RA, or to the superoseptal portion of the crista terminalis, in the other two. CONCLUSION: Macroreentry within the SVC is a distinctive mechanism responsible for rapid atrial activation, which is different from other reported flutter mechanisms, such as upper loop reentry. SVC longitudinal radiofrequency application can eliminate the arrhythmia without the need for complete electrical disconnection of the vein.

Atrial fibrillation triggered by postinfarction ventricular premature beats in a patient with Wolff-Parkinson-White syndrome.

The mechanism by which atrial fibrillation is initiated in patients with accessory pathways is not fully understood. Retrograde conduction of ventricular premature beats to the atrium, causing the arrhythmia, is a very rare cause. We report a patient with Wolff-Parkinson-White syndrome (WPW), without previous tachycardias, who presented multiple episodes of paroxysmal atrial fibrillation after having a myocardial infarction. During the electrophysiological (EP) study the patient presented two spontaneous episodes of atrial fibrillation initiated by ventricular premature beats conducted to the atria through the accessory pathway. After successful catheter ablation of the accessory pathway the patient did not present arrhythmia recurrences.

Reconstrucción anatómica digital (NavX®) como guía de ablación / Ablation guided by digital anatomic reconstruction (NavX)

No disponible

No disponible

[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.

Cardioverter defibrillator implantation in a pregnant woman guided with transesophageal echocardiography.

This report describes a 28-year-old pregnant woman with mitral valve prolapse and sudden cardiac death due to a ventricular fibrillation who underwent an ICD implantation guided by tranesophageal echocardiography.