Background The electrical ventricular storm (ES) is a life-threatening condition. The treatment is based on addressing the triggering cause, influencing reversible factors, patient sedation, and antiarrhythmics. Suppressing the massive sympathetic surge is a keystone in the emergent management. Stellate ganglion block (SGB) might serve this purpose. Purpose To show the efficacy of ultrasound-guided SGB in the management of ES. Methods Retrospective analysis of case series. All ES patients in whom SGB was used. SGB was performed after the initial failure of reversible factors modification + sedation + antiarrhythmics. We compared the mean VA burden 2 days before vs. 7 days after SGB (to show the long effect of SGB). 31 patients (5 females). Procedure date between 01.03.2017 and 21.11.2018. Mean LVEF 27±9%. Etiology: 74% ischemic vs. 26% non-ischemic cardiomyopathy. Antiarrhythmic treatment: amiodarone 27 pt. (87%), trimecaine 3pt (10%), digoxin 2 pt. (6%), beta-blocker 28 pt. (90%). Results The ES management including SGB resulted in a significant decrease (92%) in VA burden (mean 26,0 episodes/day vs. 0,6 episodes/day; p<0.001). Separately, ATP episodes were reduced by 99%, external or ICD shocks by 76%. There was no need for general anesthesia as a last resort in refractory ES. 30-days mortality 12,9%. No significant adverse events have been noticed, 10 pt. (32,3%) have developed Horner syndrome, which always disappeared in 24 hours. Conclusion Ultrasound-guided SGB in the management of ES is safe and very effective. Randomized prospective studies are required to precisely determine the effect of SGB.

Szmek B, Neuwirth R, Fiala M. Transaortální ablace incesantní komorové tachykardie po náhradě aortální chlopně mechanickou protézou. Cor Vasa 2010;52:643-645. V kasuistice prezentujeme případ mladé pacientky po náhradě aortální chlopně pro závažnou regurgitaci při infekční endokarditidě, u které byl pooperační průběh komplikován vznikem incesantní pravidelné tachykardie se štíhlým komplexem QRS. Pro přechodnou pooperační AV blokádu II. stupně, která neumožňovala nasazení antiarytmik, bylo provedeno elektrofyziologické vyšetření s nálezem komorového původu arytmie. Fokus ve výtokovém traktu levé komory v blízkosti Hisova svazku byl následně odstraněn radiofrekvenční ablací retrográdním přístupem přes mechanickou protézu. Klíčová slova: Aortální chlopeň -Mechanická náhrada -Komorová tachykardie -Katetrová ablace Szmek B, Neuwirth R, Fiala M. Transaortic ablation of incessant ventricular tachycardia after aortic valve replacement by a mechanical prosthesis. Cor Vasa 2010;52:643-645.We present the case of a young lady who underwent aortic valve replacement for serious regurgitation due to infectious endocarditis and in whom the postoperative course was complicated by incessant regular tachycardia with a narrow QRS complex. Because of a transient postoperative second-degree AV block, which precluded antiarrhythmic therapy commencement, she underwent an electrophysiological study demonstrating ventricular origin of the arrhythmia. The focal source in the left ventricular outfl ow tract was subsequently eliminated by radiofrequency ablation using the retrograde approach through the mechanical prosthesis.

Funding Acknowledgements Type of funding sources: None. Introduction Electrical cardioversion (DCCV) is a long-used and proven method for the acute termination of atrial fibrillation episodes. The methodology for optimal performance of DCCV with the highest level of effectiveness while maintaining maximum safety is still under investigation. To validate our proposed methodology for performing DCCV, we have initiated the PROTOCOLENERGY clinical trial, which is currently ongoing. Objective To test the effect of conducting a clinical trial on the effectiveness of cardioversion in patients who were not included in the study for any reason. Methodology A retrospective analysis of the DCCV registry from the indications of persistent atrial fibrillation (long-term persistent excluded) from 2015-8/2022. Statistical comparison of the demographics and overall effectiveness of the DCCV cohort before and after study initiation and comparison of the cohort, enrolled and not enrolled since study initiation (no interim analysis of the study cohort proper). Heart rate 1 min after the last discharge is assessed. Cohort A total of 2402 procedures were analyzed in 829 women (34.5%) and 1573 men (65.5%) aged 67 (+/-10) years, with CHADSVASC score of 3,0 (+/− 1), BMI 31.2 (+/-7.7). Results DCCV efficiency in the whole cohort was 91.1%. Before the study, SR was achieved in 90% of the 1981 patients; since the start of the clinical trial, DCCV efficacy increased to 96.4% (in a cohort of 421 patients) (p &lt;0.001). There was no statistically significant effect in efficacy between patients included in the clinical trial (312 pt.) and those not included (109 pt.) (96.5% vs. 96.3% p=0.944). Conclusion The presented data suggest an effect of developing and controlling the methodology of DCCV performance in a clinical trial on increasing the efficacy of DCCV, even in the cohort of patients not enrolled in the clinical trial. That phenomenon is called the HAWTHORNE effect and is related to the improvement of the outcome of the investigated phenomenon due to the influence of the actual investigation. In this case, probably due to strict adherence to the study protocol ( paddle pressure during DCCV, cardioversion in expiration, adherence to predetermined cardioversion energies, etc. even in patients not included in the study).