Electrical storm - still an extremely poor prognosis. Do these acute states of life-threatening arrhythmias require a multidirectional approach from the start?

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.

Effective treatment of electrical storm by a wearable cardioverter defibrillator in a patient with severely impaired left ventricular function after myocardial infarction: a case report

Background

The implantation of cardioverter defibrillators (ICDs) is an established therapy in the prevention of sudden cardiac death in patients with systolic dysfunction after myocardial infarction. To avoid immediate implantation of an ICD, wearable cardioverter defibrillator vests (WCD) can be used to protect patients against malignant rhythm disorders, while at the same time drug-based heart failure therapy has to be initiated. This drug therapy can improve left ventricular ejection fraction and primary prophylactic cardioverter defibrillator implantation may not be necessary. However, the recent Vest Prevention of Early Sudden Death Trial (VEST) questioned the regular use of the WCD in this setting.

Case presentation

A 47-year-old Caucasian man with severely impaired left ventricular function early after myocardial infarction was prescribed a WCD as primary prophylaxis to prevent sudden cardiac death. Seven days after the patient was supplied with a WCD, the patient suffered from an electrical storm with recurrent ventricular tachycardia (VT), which was successfully terminated 17 times by the WCD. On coronary angiography, the formerly infarct-related right coronary artery had TIMI (Thrombolysis in Myocardial Ischemia Trial) III flow, and a remaining stenosis in the left anterior descending artery (LAD) was stented, which did not stop recurrent VT. In the electrophysiology (EP) study, a focus was mapped in the left inferior ventricle, which was ablated. This stopped the VT. A second radio-frequency (RF) ablation in the same area was necessary after 14 days. Finally, a permanent cardioverter defibrillator was implanted.

Conclusion

We report the case of a patient who survived recurrent episodes of VT early after myocardial infarction by effective defibrillation with a WCD. The WCD is a useful device to bridge time until a final decision for implantation of a defibrillator.

Chronic kidney disease impairs prognosis in electrical storm

Background

The study sought to assess the prognostic impact of chronic kidney disease (CKD) in patients with electrical storm (ES). ES represents a life-threatening heart rhythm disorder. In particular, CKD patients are at risk of suffering from ES. However, data regarding the prognostic impact of CKD on long-term mortality in ES patients is limited.

Methods

All consecutive ES patients with an implantable cardioverter–defibrillator (ICD) were included retrospectively from 2002 to 2016. Patients with CKD (MDRD-GFR < 60 ml/min/1.73 m²) were compared to patients without CKD. The primary endpoint was all-cause mortality at 3 years. Secondary endpoints were in-hospital mortality, cardiac rehospitalization, recurrences of electrical storm (ES-R), and major adverse cardiac events (MACE) at 3 years.

Results

A total of 70 consecutive ES patients were included. CKD was present in 43% of ES patients with a median glomerular filtration rate (GFR) of 43.3 ml/min/1.73 m². CKD was associated with increased all-cause mortality at 3 years (63% vs. 20%; p = 0.001; HR = 4.293; 95% CI 1.874–9.836; p = 0.001) and MACE (57% vs. 30%; p = 0.025; HR = 3.597; 95% CI 1.679–7.708; p = 0.001). In contrast, first cardiac rehospitalization (43% vs. 45%; log-rank p = 0.889) and ES-R (30% vs. 20%; log-rank p = 0.334) were not affected by CKD. Even after multivariable adjustment, CKD was still associated with increased long-term mortality (HR = 2.397; 95% CI 1.012–5.697; p = 0.047), as well as with the secondary endpoint MACE (HR = 2.520; 95% CI 1.109–5.727; p = 0.027).

Conclusions

In patients with ES, the presence of CKD was associated with increased long-term mortality and MACE.

[Electrical storm : Recognition and management]

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 β‑blockade 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.