Long-term prognosis of successful left ventricular substrate modification of electrical storm.

Introduction: The Electrical storm (ES) subsumes a state of electrical instability of the heart, which manifests itself in repeated and potentially fatal ventricular arrhythmias (VA). We examine the long-term effects of substrate modification with regards to mortality, ventricular tachycardia (VT) recurrences and hospitalization depending on age, gender, heart function, scare location, VT documentation, postprocedural electrical stimulation (PES) and induced VTs. Methods: From 08/2008 and 09/2019 160 consecutive patients admitted for ES ablation via electroanatomical mapping were followed up until 04/2021. Results: 50/160 patients showed VT recurrences after 13.8 ± 21.7 (0.0-80.3) months, with a characteristic steep curve directly after ES and then a rapid decline leading to a plateau (first month 10/50 (20%), first year 35/50 VT recurrences (70%) Mortality rates followed a similar pattern also the initial decline was not as steep. 42 patients died during the observation period (26%) after 16.6 ± 16.1 (0.0-67.9) months after ablation day (first month (n = 7, 16.7%) first year (n = 21, 50%). Gender, age, scare localization, missing VT documentation did not worsen outcome. Induction of >3 VTs and lack of PES due to hemodynamic instability significantly decreased effectiveness. Finding the entry significantly increased long-term effects. Conclusion: Ablation of ES is safe and feasible independent of a variety of factors. Employing more sophisticated tools to understand the reentry mechanism will further improve the long-term outcome.

Transseptal use of high-density grid catheter for VT mapping and retrograde hemodynamic support with Impella pump in presence of Mitraclips.

PURPOSE: We sought to establish the technical feasibility of VT-mapping with high-density catheters in patients with Mitraclips, requiring a hemodynamic support. METHODS: A 73-year-old man with ischemic cardiomyopathy and reduced left ventricular ejection fraction (LVEF ~ 20%) was presented due to syncope and adequate shock of his ICD. Due to severe mitral valve regurgitation (MR), two Mitraclips were implanted earlier. The decision for catheter ablation was made in line with current guidelines. Given the increased PAAINESD score, the use of hemodynamic support was required. To employ an Impella pump via the retrograde transaortic approach, LV-mapping and VT-ablation were necessary to be performed via the transseptal approach, which was challenging due to the presence of Mitraclips. The MV passage with the steerable sheath was guided by a quadripolar catheter and 3D transoesophageal echo (TEE). After the 12F steerable sheath had passed the MV, the quadripolar catheter was exchanged by a high-density (HD) Grid® catheter. Hereafter, the Impella pump was placed retrogradely in the LV, and voltage-mapping of the LV and ablation was performed. RESULTS: At the end of the procedure, the Impella pump could be removed in stable hemodynamic conditions. The follow-up after 3, 6, and 12 months showed no new VT episodes. CONCLUSIONS: This case demonstrates the feasibility of the transseptal approach of VT mapping used HD Grid catheter and retrograde hemodynamic support with Impella Pump for VT treatment in patients after Mitraclips implantation. To avoid a damage of the MV and Mitraclips, 3D-TEE is advisable.

[Electrical storm : Recognition and management]. / Elektrischer Sturm : Erkennung und Beherrschung.

The electrical storm (ES) defined as ≥3 sustained episodes of ventricular tachycardia within a 24 h period comprises a wide spectrum of clinical entities. Mostly patients suffer from severe heart insufficiency and comorbidities making an immediate transfer into a heart center with multidisciplinary expertise in the treatment of ES mandatory. As these patients are often traumatized by ongoing tachycardia despite multiple cardioversions, early deep sedation and ß­blockade to break the vicious circle of sympathico-adrenergic hyperactivation is very effective. Multiple ICD discharges suggesting the diagnosis of ES are inadequate in one third of cases. Pharmacological suppression, frequency control or ablation of supraventricular tachycardias (SVT) help in most cases. In some cases "oversensing" demands optimization of ICD programming. Even so not all adequate ICD discharges, however, are necessary. Since every ICD discharge worsens the patient's prognosis, any kind of ICD discharge should be prevented as far as hemodynamically feasible. After clinical stabilization of the patient with simultaneous acquisition of ECG and testing for reversible causes of ES, ES should be terminated by external or internal cardioversion followed by urgent but elective therapy. Some cases of ES, however, may require immediate escalation of therapy with emergency ablation or revascularization sometimes with circulatory support systems. If ES still persists, a further step in escalation may be taken by cardiac sympathetic denervation. Due to the poor prognosis of patients after ES, close monitoring of the patient, preferably with telemedicine, is indicated.