Dong-In Shin

Incidence of asymptomatic intracranial embolic events after pulmonary vein isolation: comparison of different atrial fibrillation ablation technologies in a multicenter study.

OBJECTIVES We compared the safety of different devices by screening for subclinical intracranial embolic events after pulmonary vein isolation with either conventional irrigated radiofrequency (RF) or cryoballoon or multielectrode phased RF pulmonary vein ablation catheter (PVAC). BACKGROUND New devices specifically designed to facilitate pulmonary vein isolation procedures have recently been introduced. METHODS This prospective, observational, multicenter study included patients with symptomatic atrial fibrillation referred for pulmonary vein isolation. Ablation was performed using 1 of the 3 catheters. Strict periprocedural anticoagulation, with intravenous heparin during ablation to achieve an activated clotting time >300 s, was ensured in all patients. Cerebral magnetic resonance imaging was performed before and after ablation. RESULTS Seventy-four patients were included in the study: 27 in the irrigated RF group, 23 in the cryoballoon group, and 24 in the PVAC group. Total procedure times were 198 ± 50 min, 174 ± 35 min, and 124 ± 32 min, respectively (p < 0.001 for PVAC vs. irrigated RF and cryoballoon). Findings on neurological examination were normal in all patients before and after ablation. Post-procedure magnetic resonance imaging detected a single new embolic lesion in 2 of 27 patients in the irrigated RF group (7.4%) and in 1 of 23 in the cryoballoon group (4.3%). However, in the PVAC group 9 of 24 patients (37.5%) demonstrated 2.7 ± 1.3 new lesions each (p = 0.003 for the presence of new embolic events among the 3 groups). CONCLUSIONS The PVAC is associated with a significantly higher incidence of subclinical intracranial embolic events. Further study of the causes and significance of these emboli is required to determine the safety of the PVAC.

Postablation asymptomatic cerebral lesions: Long-term follow-up using magnetic resonance imaging

BACKGROUND Catheter ablation of atrial fibrillation (AF) is complicated by cerebral emboli resulting in acute ischemia. Recently, cerebral ischemic microlesions have been identified with diffusion-weighted magnet resonance imaging (MRI). OBJECTIVE The clinical course and longer-term characteristics of these lesions are not known and were investigated in this study. METHODS Of 86 patients, 33 (38%) had new asymptomatic cerebral lesions documented on MRI after catheter ablation for AF; 14 of these 33 (42%) underwent repeat MRI at different time intervals (2 weeks to 1 year) during follow-up, and clinical symptoms as well as size and number of residual lesions were documented. RESULTS In postablation cerebral MRI, 50 new lesions were identified (3.6 lesions/patient) in 14 patients. No patient presented any neurological symptoms. Distribution of the lesions was predominantly in the left hemisphere (60%) and the cerebellum (26%); 52% of the lesions were small (≤3 mm maximum diameter), 42% were medium (4 to 10 mm) and 3 lesions (6%) had a maximum diameter >10 mm. Follow-up MRI after a median of 3 months revealed 3 residual lesions in 3 of 14 patients corresponding to the large acute postablation lesions (>10 mm). The remaining 47 of 50 (94%) of the small or medium-sized lesions were not detectable at follow-up evaluation. CONCLUSIONS Most asymptomatic cerebral lesions observed acutely after AF ablation procedures were ≤10 mm in diameter. 94% of all lesions healed without scarring at follow-up >2 weeks after ablation. The larger acute lesions produced chronic glial scars. Neither chronic nor acute lesions were associated with neurological symptoms.

Catheter Ablation of Electrical Storm in a Collaborative Hospital Network

An electrical storm (ES) is defined as multiple ventricular arrhythmia episodes leading to implantable cardioverter defibrillator interventions. Although conventional rhythm stabilization might be of help acutely, ES involves high mortality and morbidity. We evaluated the effect of catheter ablation strategies in the setting of an interhospital collaborative network on the recurrence of ventricular arrhythmia episodes and mortality in patients with ES. Consecutive patients presenting for invasive treatment of ES from December 2007 to December 2009 were included. All patients underwent catheter ablation of ventricular arrhythmia. The strategies were adapted to the individual cardiac pathologic features. The follow-up examination constituted periodic implantable cardioverter defibrillator interrogation. A total of 32 patients were included. Of the 32 patients, 29 (91%) had monomorphic ventricular tachycardia and 3 ventricular fibrillation. The mean number of implantable cardioverter defibrillator-treated episodes within 7 days before ablation was 16 ± 11. Of the 32 patients, 27 underwent ablation within 24 hours after admission, and 5 underwent acute ablation within 8 hours. In 3 patients, epicardial ablation was performed. In all but 2 patients (6%), the clinical arrhythmia was successfully ablated. During a median follow-up of 15 months, 10 patients (31%) had recurrences of sustained ventricular arrhythmia, including 2 patients (6%) with recurrent ES. Three patients (9%) died during the follow-up period. In conclusion, catheter ablation effectively suppressed ventricular arrhythmia midterm recurrences in patients presenting with ES. Catheter ablation is complex in these severely sick patients. The recurrence rate of ventricular arrhythmia appears to be 31% and the mortality rate to be 9%. Collaborative hospital networks to increase the prompt availability of ES ablation might help to optimize the ES outcome.

Plasma levels of NT-pro-BNP in patients with atrial fibrillation before and after electrical cardioversion

In mehreren Studien wurden natriuretische Peptide (ANP, BNP) bei Patienten mit persistierendem Vorhofflimmern vor und nach elektrischer Kardioversion ermittelt. Häufig bestand bei den untersuchten untersuchten Patienten jedoch additiv eine Herzinsuffizienz, welche die Interpretation der natriuretischen Peptide hinsichtlich des Vorhofflimmerns erschwert. Ziel dieser Studie war es, die Serumkonzentrationen von NT-pro-BNP, welches das stabilere Abspaltungsprodukt von pro-BNP darstellt, bei Patienten mit persistierendem Vorhofflimmern, aber normaler linksventrikulärer Ejektionsfraktion, vor und nach elektrischer Kardioversion zu bestimmen. Es wurden NT-pro-BNP-Plasmaspiegel von 34 konsekutiven Patienten vor, wenige Minuten nach und 11 Tage nach elektrischer Kardioversion bestimmt. Alle Patienten wiesen nach echokardiographischen oder lävokardiographischen Kriterien eine normale linksventrikuläre Ejektionsfraktion auf. Im Vergleich zu einem gesunden Kontrollkollektiv zeigte sich das NT-pro-BNP mit einem Medianwert von 1086 pg/ml vs. 66,9 pg/ml signifikant erhöht (p<0,001). Nach einer mittleren Beobachtungszeit von 11 Tagen wiesen Patienten mit anhaltendem Sinusrhythmus einen Abfall des NT-pro-BNP von 1071 pg/ml zu 300 pg/ml auf (p<0,001). Im Gegensatz dazu wiesen Patienten mit einem Vorhofflimmern Rezidiv eine Erhöhung der NT-pro-BNP-Plasmaspiegel von 1570,5 pg/ml zu 1991 pg/ml auf (n.s. p=0,13). Die NT-pro-BNP-Spiegel vor elektrischer Kardioversion zeigten bei Patienten mit oder ohne Rezidiv keinen signifikanten Unterschied (p=0,23). Patienten mit Vorhofflimmern und normaler linksventrikuärer Ejektionsfraktion zeigten im Vergleich zu einer gesunden Kontrollgruppe ein signifikant erhöhtes NT-pro-BNP. Nach elektrischer Kardioversion war bei Patienten mit Sinusrhythmus ein signifikanter Abfall des NT-pro-BNP nachweisbar, während bei Patienten mit Rezidiv eines Vorhofflimmerns ein erhöhtes (n.s.) NT-pro-BNP messbar war. Da Patienten mit Sinusrhythmus oder Rezidiv eines Vorhofflimmerns vor Kardioversion kein signifikant unterschiedliches NT-pro-BNP aufwiesen, scheint NT-pro-BNP keinen prädiktiven Wert für das Auftreten eines Rezidivs zu besitzen. Plasma levels of brain natriuretic peptide (BNP) have been examined in studies on patients with persistent atrial fibrillation, both before and after electrical cardioversion. Studied patients often showed a comorbidity with congestive heart failure, which complicates interpretation of measured BNP values as a natriuretic peptide. The aim of this study was to examine plasma levels of N-terminal fragment pro-brain natriuretic peptide (NT-pro-BNP), which is the more stable but inactive cleavage product of pro-BNP in patients with atrial fibrillation, but normal left ventricular ejection fraction, before and after electrical cardioversion. NT-pro-BNP plasma levels of 34 consecutive patients were measured before, shortly after and 11 days after electrical cardioversion. All patients showed a normal ejection fraction after echocardiographic or laevocardiographic criteria. At baseline, all patients showed elevated NT-pro-BNP compared to a healthy control group (1086 vs. 66.9 pg/ml, p<0.001). After a mean follow-up time of 11 days in patients with persistent restored sinusrhythm, NT-pro-BNP decreased from 1071 pg/ml at baseline to 300 pg/ml (p<0.001). In contrast, patients with recurrence of atrial fibrillation showed increased levels from 1570.5 pg/ml at baseline to 1991 pg/ml (p=0.13; n.s.). Recurrence of atrial fibrillation was independent from height of NT-pro-BNP levels at baseline (p=0.23). Atrial fibrillation in patients with a normal left ventricular ejection fraction is associated with elevated NT-pro-BNP plasma levels, which decrease when a persistent sinus-rhythm can be restored by electrical cardioversion. On the other hand, NT-pro-BNP seems to increase (n.s.) when recurrence of atrial fibrillation occurs. Finally, NT-pro-BNP is no valid predictor for long-term success of sinus-rhythm restoration by electrical cardioversion.

nMARQ Ablation for Atrial Fibrillation: Results from a Multicenter Study

nMARQ is a multipolar catheter designed to simultaneously ablate at multiple sites around the pulmonary vein (PV) circumference with a single radiofrequency application. We sought to define the safety and efficacy of atrial fibrillation (AF) ablation with the nMARQ catheter.

Catheter ablation of electrical storm.

Electrical storm (ES) is defined as the occurrence of ≥ three distinct episodes of ventricular arrhythmia (VA) in patients with implanted defibrillators within 24 h. Whereas conventional strategies for acute rhythm stabilization may be effective in some patients the occurrence of ES impairs survival and predicts recurrent VA. Catheter ablation in the setting of ES is complex and involves decisive strategies for individualized ablation approaches adapted to the patient’s cardiac abnormalities. Success rates have been documented to be between 79 and 94% in larger studies and effective ablation improves survival and freedom from any VA. Ablation should be considered early in the treatment plan and availability may be improved by interhospital collaboration with highly experienced VA intervention centers.

Cardiogenic shock due to thrombotic thrombocytopenic purpura.

Wir berichten über einen kardiogenen Schock im Rahmen einer thrombotisch thrombozytopenischen Purpura (TTP) bei einem 49-jährigen Mann. Klinisch manifestierte sich die Diagnose einer TTP anhand einer Thrombozytopenie und einer mikroangiopathisch-hämolytischen Anämie. Zugleich wies der Patient EKGVeränderungen mit signifikanten ST-Streckenhebungen in den anterioren und inferioren Ableitungen auf. In der Koronarangiographie konnten keine relevanten Stenosen, jedoch ein verlangsamter Koronarfluss mit konsekutiver myokardialer Ischämie nachgewiesen werden. Klinisch zeigte sich der Patient in einem kardiogenen Schock. Trotz intensivmedizinischer Maßnahmen verstarb der Patient an einer elektromechanischen Entkopplung sechs Stunden nach stationärer Aufname. In der durchgeführten Autopsie zeigte sich der histologische Befund einer ausgeprägten diffusen myokardialen Nekrose aufgrund einer mikrovaskulären Thrombose. Während die TTP häufig zu einer kardialen Beteiligung führt, ist eine klinisch relevante Ischämie eine Rarität. We report the case of a 49-year-old man with thrombotic thrombocytopenic purpura (TTP) leading to cardiogenic shock. Laboratory data were typical for TTP with thrombocytopenia and microangiopathic hemolytic anemia. The electrocardiogram recorded significant ST-segment elevations in the anterior and inferior leads. In addition’ coronary angiography showed normal epicardial coronary arteries with slow flow. The patient died due to electromechanical dissociation six hours after admission. During autopsy typical features of thrombotic thrombocytopenic purpura were found. Histological preparation of the heart showed a diffuse myocardial necrosis due to microvascular thrombosis. Cardiac involvement is common in TTP but extended myocardial necrosis has been reported in only a few cases.

Usefulness of a limited linear ablation of post-myocardial infarction ventricular tachycardia using a standardized approach based on sinus rhythm mapping.

The ablation of ventricular tachycardia (VT) can be achieved using anatomically guided approaches using differentiated mapping and ablation techniques. The aim of this study was to evaluate the efficacy of limited linear ablation in the VT exit region identified during sinus rhythm mapping alone. One hundred fifteen consecutive patients presenting for ablation of post-myocardial infarction VT were included. After induction of the target VT during invasive electrophysiology, left ventricular substrate mapping during sinus rhythm to identify scar and border zone on the basis of endocardial bipolar voltage was performed. The exit site of the target VT was regionalized by a simplified vector pace mapping approach and targeted using limited linear ablation within the scar border zone. Seventy-seven percent of all inducible VT was successfully ablated. In 71 patients (62%), no sustained VT was inducible at the end of ablation procedure (complete success). During a median follow-up period of 16 + or - 10 months, 89 patients (77%) had no documented sustained ventricular arrhythmia. Seven patients (2%) had recurrences of the initially ablated VT, and 16 (14%) had new-onset VT. Patients with complete success had a significantly lower number of ventricular arrhythmia reoccurrences than patients with incomplete ablation success (11% vs 37%, p = 0.002). In conclusion, postinfarct VT was effectively ablated in 97% of patients without mapping during ongoing VT using a simplified regional linear ablation approach targeting the scar border zone. Freedom from any ventricular arrhythmia was achieved in 77% of patients during midterm follow-up.

Pulmonary vein isolation using a novel decapolar over-the-wire mapping and ablation catheter

Recently, a novel radiofrequency (RF) ablation system has been developed to perform pulmonary vein (PV) isolation. The system consists of a decapolar, steerable, over-the-wire mapping and ablation catheter combined with a multichannel RF generator that delivers energy in a temperature-controlled, power-limited fashion in both uni- and bi-polar modes. Using this technique, long continuous ablation lesions can be created within the left atrial antrum around the PV ostium. Electrical disconnection of PVs can be achieved in 93% of targeted PVs. Medium-term success is reported as 79.5% of patients with paroxysmal atrial fibrillation (no atrial fibrillation episodes detected during intensive holter monitoring). Ablation procedures using the novel technique are reported to be short (mean procedure duration: 84–201 min), including RF application duration of up to 40 min. Procedure-related complications are rare (1.8%) but the included total patient numbers are small and further studies on larger patient populations are needed.

Wolff–Parkinson–White syndrome associated with persistent left superior vena cava

Priv.-Doz. Dr. med. Marc Horlitz ()) · Philipp Schley Anja Thiel · Dong-In Shin · Michael Müller · Rolf Michael Klein Hartmut Gülker HELIOS Klinikum Wuppertal Universitätsklinikum der Universität Witten/Herdecke Herzzentrum Wuppertal, Kardiologie Arrenberger Str. 20 42117 Wuppertal Tel.: 02 02/8 96-57 08 Fax: 02 02/8 96-57 07 E-Mail: mhorlitz@wuppertal.helios-kliniken.de A highly symptomatic young female patient with a Wolff-Parkinson-White (WPW) syndrome underwent radiofrequency catheter ablation. The surface ECG indicated an accessory pathway in a left posterior location. Achieving a good ablation site underneath the posterior mitral valve was not feasible by a retrograd transaortal approach. Therefore, the mapping catheter was advanced to the proximal coronary sinus (CS) via femoral vein access. Since the CS ostium appeared dilated, contrast angiography was performed, revealing a persistent left superior vena cava (PLSVC) draining into a significantly enlarged CS (Fig. 1). Recurrent episodes of atrial fibrillation with rapid preexcited ventricular rate occurred during the procedure (Fig. 2). In this anatomically challenging situation, the optimal ablation site was identified within the proximal CS. The preexcitation disappeared during successful ablation. The existence of other cardiac anomalies could be excluded by magnetic resonance imaging (Fig. 3). PLSVC is an uncommon anomaly, estimated to be present in 0.3–0.5% of the population [2]. It results from an embryological defect involving failure of the left cardinal vein to degenerate [3]. Commonly, this malformation is hemodynamically insignificant, and simultaneous complete absence of the right superior vena cava is rare [5]. However, because of the large