A meta-analysis on the prognostic significance of inferolateral early repolarization pattern in Brugada syndrome

Aims

The early repolarization (ER) pattern has been linked to an increased risk for arrhythmic death in various clinical settings. There are limited and conflicting data regarding the prognostic significance of ER pattern in Brugada syndrome (BS). The aim of this meta-analysis was to provide a detailed analysis of the currently available studies regarding the arrhythmic risk in patients with BS and ER pattern.

Methods and results

Current databases were searched until May 2015. A random-effect meta-analysis of the effect of ER pattern on the incidence of arrhythmic events in patients with BS was performed. Five studies were included comprising a total of 1375 patients with BS. An ER pattern was reported in 177 patients (12.8%). During follow-up (44.9-93 months), 143 patients (10.4%) suffered an arrhythmic event. Overall, BS patients with ER pattern displayed an increased risk of arrhythmic events compared to patients without ER (OR 3.29, 95% CI: 2.06 to 5.26, P < 0.00001; Heterogeneity: P = 0.11, I2 = 48%). Three studies provided data regarding ER pattern location. Inferior, lateral, or inferolateral ER pattern location was observed in 20.3%, 32.2%, and 48%, respectively. An inferolateral ER location conferred the higher arrhythmic risk (OR 4.87, 95% CI: 2.64 to 9.01, P< 0.00001; Heterogeneity: P = 0.85, I2 = 0%).

Conclusion

This meta-analysis suggests that the ER pattern is associated with a high risk of arrhythmic events in patients with BS. In particular, BS patients with inferolateral ER (global ER pattern) displayed the highest arrhythmic risk.

Pharmacological Provocation of Outflow-Tract Tachycardia in a Patient With Brugada Syndrome

We present a case of a symptomatic patient with Brugada syndrome, who had sustained right ventricular outflow tract tachycardia after pronounced exercise-induced ST segment elevation in V₁ and V₂. In electrophysiological study he developed right ventricular outflow tract tachycardia provoked by combined infusion of ajmaline and orciprenaline. After ablation no further arrhythmia was provoked by pharmacological stimulation.

Small or large isolation areas around the pulmonary veins for the treatment of atrial fibrillation? Results from a prospective randomized study

BACKGROUND

Pulmonary vein (PV) isolation is a promising new treatment for atrial fibrillation (AF). We hypothesized that isolation of large areas around both ipsilateral PVs with verification of conduction block is more effective than the isolation of each individual PV.

METHODS AND RESULTS

A total of 110 patients, 67 with paroxysmal AF and 43 with persistent AF, were randomly assigned to undergo either isolation of each individual PV or isolation of large areas around both ipsilateral PVs. The isolation of each individual PV was an electrophysiologically guided, ostial segmental ablation with a 64-pole basket catheter or a 20-pole circular mapping catheter (group I). Isolation of large areas was performed around the 2 ipsilateral veins with a nonfluoroscopic navigation system and a circular 20-pole mapping catheter for verification of conduction block (group II). In both groups, an irrigated-tip ablation catheter (25 to 35 W) was used to achieve complete isolation. Procedure and ablation times were longer in group II, whereas fluoroscopic time was significantly shorter (P < or = 0.001). After a follow-up period of 15+/-4 months, 27 patients in group I (49%) and 37 patients in group II (67%) remained free of symptoms of AF and had no AF or atrial flutter during repetitive Holter monitoring without antiarrhythmic drug treatment after a single procedure (P < or = 0.05).

CONCLUSIONS

The rate of success was significantly higher and fluoroscopy times were significantly lower in the group with large isolation areas around both ipsilateral PVs than in those who underwent individual PV isolation.

Platelet activation and myocardial necrosis in patients undergoing radiofrequency and cryoablation of isthmus-dependent atrial flutter

AIMS

Lower platelet activation by cryoenergy compared with radiofrequency (RF) energy was recently demonstrated immediately following ablation procedures of cardiac arrhythmias. Due to the delayed occurrence of cryolesions it is currently unknown, if cryoenergy and RF energy are associated with similar platelet activation and myocardial necrosis in the days after the procedure.

METHODS AND RESULTS

We enrolled 38 patients with common atrial flutter undergoing cavotricuspid isthmus ablation with either RF energy (n = 23) or cryoenergy (n = 13). Ten patients undergoing RF ablation and receiving aspirin served as antiplatelet control group. Troponin T and platelet surface protein expression of P-selectin were determined before and immediately after ablation as well as on day 1 and 2 thereafter. Rise in troponin T was amplified after RF ablation (0.50 +/- 0.37 microg/L) when compared with cryoablation (0.24 +/- 0.20 microg/L; P = 0.024). In patients without aspirin, a significant increase in P-selectin expression was observed on day 1 after intervention in RF ablation compared with cryoablation (80 +/- 26 vs. 63 +/- 16 arbitrary units; P = 0.048). Platelet activation was attenuated in patients receiving aspirin.

CONCLUSION

Successful ablation of atrial flutter with cryoenergy is associated with less myocardial necrosis and platelet activation compared with ablation with RF energy. Increased platelet activation following RF ablation can be attenuated by concomitant treatment with aspirin.

Pulmonary haemodynamics at rest and during exercise in patients with significant pulmonary vein stenosis after radiofrequency catheter ablation for drug resistant atrial fibrillation

AIMS

Iatrogenic pulmonary vein (PV) stenosis after radiofrequency catheter ablation for atrial fibrillation (AF) is a new pathology in cardiology. The effects of PV stenosis on the pulmonary circulation are not yet known. We provide long-term follow-up data in patients with significant PV stenosis including magnetic resonance imaging (MRI) and Swan Ganz (SG) right heart catheterization.

METHODS AND RESULTS

One hundred and seventeen patients had MRI 12-24 months after the AF ablation procedure. Eleven patients (58+/-7 years, nine males) with significant stenosis (n=9) or occlusion of the proximal PV (n=5) at this follow-up were re-examined using MRI and SG right heart catheterization at rest and during exercise (follow-up time since PV ablation 50+/-15 months). None of these underwent previous PV angioplasty. When compared with prior MRI studies, no significant changes were noted. At rest, no patient had pulmonary hypertension. At 100 W, seven patients had elevated pulmonary artery pressures, three of them probably caused, in part, by left ventricular dysfunction.

CONCLUSION

Significant stenosis/occlusions of one or two PV do not create pulmonary hypertension at rest during long-term follow-up. However, seven of the 11 patients develop pulmonary hypertension during exercise. All three patients with stenosis/occlusions of two PV were affected.

Effects of Circumferential Ostial Radiofrequency Lesions on Pulmonary Vein Activation Recorded with a Multipolar Basket Catheter

AIMS

Two different ablation procedures are performed to cure patients of atrial fibrillation (AF): (1) the electrophysiological pulmonary vein (PV) isolation, and (2) the anatomical circumferential ablation of all four PV ostia. The aim of this study was to determine the effects of circumferential radiofrequency lesions around the ostia on PV activation.

METHODS AND RESULTS

In 34 patients with drug refractory paroxysmal (N = 22) or persistent (N = 12) AF a 31-mm basket catheter (BC) was introduced transseptally in the PVs. After creating a circumferential ablation line around the PV ostia using a nonfluoroscopic 3D-navigation system, electrical isolation was achieved in 46% of the PVs, and prolongation of conduction time (+39 +/- 34 ms) was observed in 30%. PVs with persistent conduction (54%) were isolated by ablating the remaining conduction pathways using the BC. At 12 months follow-up, 62% of the patients were in stable sinus rhythm without antiarrhythmic drug therapy. Six patients had developed left atrial flutter.

CONCLUSIONS

Anatomically guided, circumferential lesions around the PV ostia resulted in isolation in only 46% of the veins. At 12 months, 62% of the patients were free of AF without antiarrrhythmic drug treatment, however, 6 patients (18%) developed left atrial flutter.

3-D-Mapping der Pulmonalvenen mit einem multipolaren Basketkatheter

BACKGROUND

Focal discharges from pulmonary veins are the major sources of paroxysmal atrial fibrillation. The aim of this study was to analyze the activation pattern of pulmonary veins during sinus rhythm and ectopy with the help of a multipolar basket catheter and to disconnect them from the left atrium by localized radiofrequency catheter ablation.

PATIENTS AND METHODS

We studied 65 patients (43 male, 22 female, mean age 54 +/- 12 years) with drug-refractory atrial fibrillation (paroxysmal n = 42, persistent n = 23). A 64-pole basket catheter (Figure 1) with a diameter of 31 or 38 mm (Constellation, Boston Scientific) was placed transseptally into the pulmonary veins to record its activation during ectopic beats and during sinus rhythm or coronary sinus pacing (Figure 2). The ablation catheter was placed as ostial as possible next to the electrodes showing the earliest pulmonary vein activation during sinus rhythm or coronary sinus pacing (Figures 3 and 4a). The radiofrequency energy was delivered with a maximum temperature of 50 degrees C and a maximum power of 30 W. In 32 patients, an irrigated-tip catheter (Thermocool, Biosense-Webster) was used. Endpoint of the procedure was the complete elimination of all distal pulmonary vein potentials during sinus rhythm (Figure 4b).

RESULTS

The mean number of procedures per patients was 1.25, mean procedure time 236 +/- 79 min, and mean fluoroscopy time 40 +/- 17 min, respectively. In 16 veins, repetitive discharges (more than three) could be recorded under stable conditions (Figures 2 and 5). In twelve of these 16 pulmonary veins (75%), the activation pattern during ectopic beats was identical in the same vein, but different from one vein to another (Figure 2). In four veins, changing activation patterns were observed in the same vein. Focal atrial fibrillation was recorded in four pulmonary veins (Figures 6 and 7). A total of 187 out of 190 mapped veins were successfully isolated at the ostium by ablating 2.3 +/- 1.1 separated conduction pathways. In 16 patients, a second EP study was performed for recurrence of atrial fibrillation. Recovery of conduction of a previously isolated pulmonary vein was identified as the primary reason for recurrence of atrial fibrillation. The second reason were ostial foci, localized proximal to the ablation line (Figure 8). COMPLICATIONS AND FOLLOW-UP: One pericardial tamponade occurred. Carbonization on the splines of the basket catheter-observed in twelve cases with use of a nonirrigated-tip catheter-was prevented by use of irrigated-tip catheters. At 12 months, 36 out of 65 patients (55%) are in sinus rhythm without antiarrhythmic drug use, 28 of 42 patients (67%) with paroxysmal atrial fibrillation. Only one pulmonary vein stenosis > 50% was detected by angiomagnetic resonance imaging 1 year after the procedure.

CONCLUSION

75% of the arrhythmogenic pulmonary veins showed a stable and specific pattern during repetitive ectopic activity. Ostial ablation of 2.3 +/- 1.1 separated conduction pathways from the left atrium into the pulmonary veins resulted in complete conduction block in 187 of 190 veins.

Feasibility and Safety of Pulmonary Vein Isolation Using a New Mapping and Navigation System in Patients With Refractory Atrial Fibrillation

Background— Ostial pulmonary vein (PV) isolation by radiofrequency (RF) catheter ablation can cure patients with atrial fibrillation (AF); however, this procedure carries the risk of PV stenosis. The aim of this study was to assess the feasibility of a new mapping and navigation technique using a multipolar basket catheter (BC) for PV isolation in patients with refractory AF and to analyze its safety with regard to PV stenosis at long-term follow-up.

Methods and Results— We studied 55 patients (mean age, 53±11 years; 40 male) with drug-refractory AF (paroxysmal, n=37; persistent, n=18). A 64-pole BC was placed transseptally into each of the accessible PVs. By use of a nonfluoroscopic navigation system, the ablation catheter was guided to the BC electrodes at the PV ostium, with earliest activation during sinus rhythm. RF was delivered by use of maximum settings of temperature at 50°C and power at 30 W. The end point of the procedure was the complete elimination of all distal and fragmented ostial PV potentials. Of 165 targeted veins, 163 were successfully isolated with a mean RF duration of 720±301 seconds per vein. At 1-year follow-up, 62% of the patients were in sinus rhythm without antiarrhythmic drugs. Contrast-enhanced magnetic resonance angiography revealed 2 PV stenoses of >25% out of 165 treated vessels.

Conclusions— The use of a multipolar BC allowed effective and safe PV isolation by combining 3D mapping and navigation. At 1-year follow-up, 62% of the patients were in sinus rhythm without antiarrhythmic drugs, and the incidence of relevant diameter reduction of the treated PVs was 1.2%.

[The place of local, low-dose, short-duration fibrinolysis in the management concept of arterial occlusive diseases]

551 angiographic therapeutic radiological interventions were studied in detail. They included 246 patients treated by local, low dose fibrinolysis with consecutive PTA, 55 interventions treated by fibrinolysis therapy alone and 250 patients treated by angioplasty. The results of low dose, low duration fibrinolysis with or without consecutive PTA was compared with the "standard" results from PTA despite the variations in the severity of the arterial occlusive disease. The indications for local fibrinolysis are discussed and the variations from the technique reported in the literature are described ("retrograde" local fibrinolysis). We have not been able to show any statistical relationship between clot lysis and duration of history or the length of vascular occlusion. Clinical improvement of at least one stage (according to Fontaine) was achieved in 85% of cases by PTA, 60% by local lysis and 74% by lysis with subsequent PTA.

[Differential effect of bleomycin on squamous epithelium at various sites]

By autoradiographic methods it was examined, whether a specific local effect on squamous epithelium can be proved in a animal model. For this purpose the proliferatory activity was considered in the epithelium of the murine tongue, of esophagus, of the skin in the area of foot and of tail as long as 72 hours after a single application of bleomycin. The result shows, that the proliferatory activity is impaired to a greater extent in the epithelium of the tongue and the esophagus in comparison on the squamous epithelium of foot and tail skin.

[Tissue specificity of the action of bleomycin. Autoradiographic studies]

The proliferative activity of different types of murine tissue up to 72 h after a single dose of bleomycin was studied via histoautoradiography to determine whether bleomycin has a tissue-specific effect. Bleomycin apparently not only has a general cytotoxic and/or cytostatic action, the strongest being on tissue with a high proliferation rate, but also, as a comparison of the effect of bleomycin on the proliferative activity of squamous epithelium (plantar region, tail, skin, esophagus, tongue) and of mucosal epithelium (stomach, ileum, colon) has indicated, the proliferative activity of squamous epithelium is impaired to a greater extent. This, therefore, distinguishes bleomycin from many other substances used in tumor therapy.

[Change of toxicity and carcinogenicity of N-methyl-N-nitrosobenzylamine in rats by methylsubstitution in the phenylresidue]

Substitution with a methyl group in the 2-, 3- or 4-position respectively of the phenyl moiety of N-methyl-N-nitrosobenzylamine results in a considerable reduction of the acute toxicity. (LD 50 of MNBA: 18 mg/kg (Druckrey et al., 1967), 2-Me-MNBA: 90 mg/kg, 3-Me-MNBA: 600 mg/kg, 4-Me-MNBA: 400 mg/kg). However, the introduction of the methyl group influences the carcinogenic activity of MNBA in rats and its organotropy, only to a small extent. Long-term administration of 5 and 15 ppm respectively of the isomeric N-nitroso compounds in the drinking water produces in all animals carcinomas of the oesophagus and the pharynx.