Trends in ablation procedures in Greece over the 2008-2018 period: Results from the Hellenic Cardiology Society Ablation Registry.

OBJECTIVE: In 2008, the radiofrequency ablation (RFA) procedures registry of the Hellenic Society of Cardiology was created. This online database allowed electrophysiologists around the country to input data for all performed ablation procedures. The aim of this study is to provide a thorough report and interpretation of the data submitted to the registry between 2008 and 2018. METHODS: In 2008, a total of 27 centers/medical teams in 24 hospitals were licensed to perform RFA in Greece. By 2018, the number had risen to 31. Each center was tasked with inserting their own data into the registry, which included patient demographics (anonymized), type of procedure and technique, complications, and outcomes. RESULTS: A total of 18587 procedures in 17900 patients were recorded in the period of 2008-2018. By 2018, slightly more than 70% of procedures were performed in 7 high-volume centers (>100 cases/year). The most common procedure since 2014 was atrial fibrillation ablation, followed by atrioventricular nodal reentry tachycardia ablation. Complication rates were low, and success rates remained high, whereas the 6-month relapse rates declined steadily. CONCLUSION: This online RFA registry has proved that ablation procedures in Greece have reached a very high standard, with results and complication rates comparable to European and American standards. Ablation procedures for atrial fibrillation are increasing constantly, with it being the most common intervention over the last 6-year period, although the absolute number of procedures still remains low, compared to other European countries.

Sudden Death After Transcatheter Aortic Valve Implantation. Are Bradyarrhythmias Always The Cause?

Transcatheter Aortic-Valve Implantation (TAVI) is considered to be highly effective in the treatment of high-risk patients with severe aortic stenosis. After TAVI, the rate of pacemaker implantation is 6.5%-40%. Some reports of sudden death after TAVI are mostly attributed to bradyarrhythmias. We report the case of three patients who experienced sudden cardiac death or aborted sudden cardiac death after TAVI. All patients were affected from ischemic heart disease with an ejection fraction of approximately 40% and underwent pacemaker implantation (PM) after the procedure due to 1rst degree atrioventricular block (AV) and left bundle branch block (LBBB). One of the patients died suddenly 30 days after the procedure. The PM interrogation revealed many episodes of non sustain ventricular tachycardias (NSVT) and one episode of ventricular fibrillation (VF) that led to death. The other two patients had syncope and during PM interrogation episodes of ventricular tachycardia >12 sec were recorded. Patients affected by ischemic heart disease undergoing TAVI, especially with borderline coronary lesions should receive particular attention in order to avoid potentially lethal ventricular arrhythmias. In addition, the physiopathologic mechanism of sudden arrhythmic death in these patients needs to be clarified.

Radiofrequency ablation procedures in Greece: initial experience and results from the national registry 2008-2010.

INTRODUCTION: In 2008 the radiofrequency ablation procedures (RFA) registry of the Hellenic Cardiological Society (HCS) was created. This is a dynamic, web-based application, which acts as the interface for storing and retrieving patients' demographic data and ablation procedures. Access to the site is permitted only to registered users. The purpose of this study is to report the results of RFA procedures performed in Greece over the 2008-2010 period. METHODS: There are 27 centers in 24 hospitals that are licensed to perform RFA in Greece. During the period 2008-2010, 3541 RFA procedures were performed in 3344 patients in 23 centers. Four centers did not contribute data at all for various reasons. It is interesting that nearly 50% of the total number of procedures were performed at 3 high volume centers (>100 cases/year). RESULTS: The most common procedure was slow pathway ablation for atrioventricular reentrant tachycardia, the second was ablation of accessory pathway related tachycardias, and the third was ablation of atrial fibrillation. Success rates were high (92.1%), the complication rate was 3% (serious complications <1%) and total relapse rate was 8.7% at six months' follow up. CONCLUSIONS: The electronic RFA registry in Greece confirmed that all RFA procedures are performed in Greece with high success and low complication rates, comparable to the European and US standards. The experience and results from the first three-year period using the registry are very interesting and encouraging, thus indicating the need for development of similar databases at the national level.

Late presentation of arrhythmogenic right ventricular cardiomyopathy: a case report.

INTRODUCTION: Arrhythmogenic right ventricular cardiomyopathy is an inherited myocardial disease affecting predominantly young people and manifests as sustained ventricular tachycardia with left bundle branch block morphology, sudden death or isolated right or biventricular heart failure. However, its first manifestation as sustained ventricular tachycardia in older patients without preceding symptoms of heart failure is infrequent. To our knowledge, our patient is among the oldest reported in the literature presenting with ventricular tachycardia because of arrhythmogenic right ventricular cardiomyopathy without preceding symptoms of heart failure. CASE PRESENTATION: We present an unusual case of a very late presentation of a right ventricular cardiomyopathy in a 72-year-old white Caucasian man. The patient was admitted with symptoms of weakness, dizziness and chest discomfort for several hours. His electrocardiogram showed a wide-complex tachycardia with left bundle branch block morphology and left axis deviation. Because of continuing hemodynamic instability, the patient was cardioverted to sinus rhythm with a single 300 J shock. His post-cardioversion electrocardiogram, cardiac echocardiogram, coronary angiogram, magnetic resonance imaging and electrophysiological study confirmed the diagnosis of arrhythmogenic right ventricular cardiomyopathy. The patient was treated with an implantable cardioverter defibrillator and discharged on sotalol. CONCLUSION: This case report demonstrates that arrhythmogenic right ventricular cardiomyopathy may have a very late presentation and this diagnosis should be considered as a potential cause of sustained ventricular tachycardia of right ventricular origin among the elderly and should be treated accordingly.

Electrical storm is an independent predictor of adverse long-term outcome in the era of implantable defibrillator therapy.

AIMS: Electrical storm (ES) is a life-threatening arrhythmia complication affecting patients treated with an implantable cardioverter defibrillator (ICD). Despite its increasing importance, existing data on prognosis and management of ICD patients affected by ES are limited and conflicting. METHODS: We prospectively studied 169 consecutive patients receiving an ICD. Thirty-two patients presented with at least one episode of ES during the period of observation (33+/-26 months). ES patients were older (64+/-9 vs. 59+/-13 years, P=0.013) with more advanced congestive heart failure (CHF) but a similar incidence of an underlying organic heart disease. RESULTS: Long-term total and cardiac mortality were both increased among ES patients. Seventeen of the 32 ES patients died as opposed to 19 of the 137 ICD patients without ES (53 vs. 14%, P<0.001). In multivariate Cox regression analysis adjusted for the main confounders, history of ES was significantly and independently associated with total and cardiac mortality (risk ratio (RR)=2.13, P=0.031 and RR=2.59, P=0.019, respectively). CONCLUSION: ES is a relatively frequent complication affecting ICD patients treated for secondary prevention of sudden cardiac death (SCD). Although the acute management of this serious arrhythmia complication is usually successful, occurrence of ES is a strong independent predictor of poor outcome in ICD patients.

Atrial standstill with subnodal conduction defect and diffuse ventricular fibrosis managed with low right atrial pacing.

In patients with congenital heart disease presenting with bradyarrhythmia, many electrophysiological abnormalities are found. This report presents a case of a man with surgically corrected single atrium and pulmonary valve stenosis, atrial standstill, delayed AV node conduction, first-degree intra- and second-degree infra-His block, who was permanently paced from a restricted excitable area of the low right atrium, as the pacing threshold was unacceptable at any ventricular site.

Paraseptal accessory connections in the proximity of the atrioventricular node and the His bundle. Additional observations in relation to the ablation technique in a high risk area.

INTRODUCTION: Paraseptal pathways, namely, accessory connections (AC) in the vicinity of the atrioventricular node (AVN) and the bundle of His, are associated with a high risk of complete atrioventricular block (AVB) during transcatheter radiofrequency ablation (RFA) in the Electrophysiology Laboratory. In previously reported series of ablation of paraseptal ACs, the coexistence of multiple ACs in this high-risk region has rarely been mentioned. METHODS AND RESULTS: We studied 15 patients undergoing RFA of paraseptal ACs 2 of whom had dual pathways with an additional midseptal pathway revealed after the elimination of the anteroseptal target AC. The fundamental goal of the pre-ablation electrophysiological mapping was the clear-cut determination of anatomical site with His bundle recording activity. This required unique pharmacological and programmed electrical stimulation manipulations in 8 patients in whom His bundle recording activity was only temporarily possible. After identifying the corresponding His bundle site, special attention was given to the ablation catheter being situated at least 3 mm away, thus recording minimal or no His bundle activity. Additional precautions were taken so that the delivered therapy was of minimal duration and powered by temperature regulation with immediate interruption in case of AVB or nodal rhythm appearance. With this therapeutic approach, 16 of the 17 paraseptal ACs were ablated successfully with the inadvertent induction of AVB in only 1 patient. In the patient with persistent ventricular preexcitation after the ablation session, modification of both the AC and the AVN was noted so that the previously easily induced reciprocating atrioventricular tachycardia was no longer so, using programmed stimulation. CONCLUSION: Transcatheter radiofrequency ablation is a feasible and effective radical therapy for patients with paraseptal ACs, provided the His bundle site has first been clearly defined and the coexistence of other nearby tracts has been excluded.