A case of electrical storm in a liver transplant patient

[Electrical storm in the emergency room: clinical pathways]

In patients with structural heart disease, occurrence of an electrical storm (ES) is associated with increased mortality acutely and during medium term follow-up. Depending on the underlying heart disease and baseline type of arrhythmia, different clinical pathways have to be followed to reach sustained freedom from ventricular arrhythmia recurrences. Trigger elimination, sympathetic blockade (initially using betablockers and sedation), antiarrhythmic therapy with amiodarone and catheter ablation, treatment of heart failure and invasive hemodynamic support are cornerstones of the treatment. We present an algorithm which may help to organize an optimized treatment for each ES patient, implementing invasive treatment options like coronary angioplasty, catheter ablation and invasive circulatory support. Further studies are necessary to evaluate medium term outcome of such a structured therapy.

Successful conversion of post-cardiac surgery electric storm in a child

BACKGROUND

The management of ventricular electrical storm can prove to be a challenge for the clinician given its complexity and life threatening consequences.

CASE CHARACTERISTICS

8-year-old boy with repeated life-threatening polymorphic ventricular tachycardia following aortic valve replacement surgery.

INTERVENTION

Defibrillated 45 times in addition to multiple antiarrhythmic drugs.

OUTCOME

Conversion to stable sinus rhythm with normal neurological outcome.

MESSAGE

Electric storm can be controlled by combination of multiple intravenous antiarrhythmic drugs.

Use of beta-blockers for the treatment of cardiac arrest due to ventricular fibrillation/pulseless ventricular tachycardia: a systematic review

INTRODUCTION

Advanced Life Support guidelines recommend the use of epinephrine during Cardiopulmonary Resuscitation (CPR), as to increase coronary blood flow and perfusion pressure through its alpha-adrenergic peripheral vasoconstriction, allowing minimal rises in coronary perfusion pressure to make defibrillation possible. Contrasting to these alpha-adrenergic effects, epinephrine's beta-stimulation may have deleterious effects through an increase in myocardial oxygen consumption and a reduction of subendocardial perfusion, leading to postresuscitation cardiac dysfunction.

OBJECTIVE

The present paper consists of a systematic review of the literature regarding the use of beta-blockade in cardiac arrest due to ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT).

METHODS

Studies were identified through MEDLINE electronic databases research and were included those regarding the use of beta-blockade during CPR.

RESULTS

Beta-blockade has been extensively studied in animal models of CPR. These studies not only suggest that beta-blockade could reduce myocardial oxygen requirements and the number of shocks necessary for defibrillation, but also improve postresuscitation myocardial function, diminish arrhythmia recurrences and prolong survival. A few case reports described successful beta-blockade use in patients, along with two prospective human studies, suggesting that it could be safe and effectively used during cardiac arrest in humans.

CONCLUSION

Even though the existing literature points toward a beneficial effect of beta-blockade in patients presenting with cardiac arrest due to VF/pulseless VT, high quality human trials are still lacking to answer this question definitely.

β-Blockers for the treatment of cardiac arrest from ventricular fibrillation?

More than 160,000 people suffer sudden cardiac death each year in the US. It is estimated that ventricular fibrillation (VF) is the initial rhythm in approximately 30% of these cases. Ventricular fibrillation that does not respond to the first few defibrillation attempts is associated with mortality rates of up to 97%. Currently, no pharmacological intervention has been shown to increase long-term survival in patients with shock-refractory VF. The purpose of this review article is to evaluate whether beta-blocker administration during the resuscitation of cardiac arrest from VF or pulseless ventricular tachycardia (VT) improves outcome. We searched the MEDLINE and EMBASE databases for human clinical trials, animal experimental trials, review articles, case reports and abstracts published between 1966 and September 2006. No human prospective randomized controlled trial has studied the effects of beta-blocker administration during VF directly. Prospective trials of anti-arrhythmics with beta-blocking properties have been published, as well as several case reports/case series and experimental animal studies. The evidence thus far suggests that beta-blockade during resuscitation from VF may be associated with increasing rates of resuscitation, greater post-resuscitation survival, and improved post-resuscitation myocardial function. These positive effects on outcome may be mediated by a decrease in the oxygen requirements of the fibrillating heart, thus improving the overall balance between myocardial oxygen supply and demand during resuscitation. While no significant detrimental effects directly related to low dose beta-blockade during VF have been reported in the studies reviewed, concerns relating to possible loss of myocardial contractility and hypotension remain. To this day, high quality human trials are lacking. Preliminary human studies are needed to assess the effects of beta-blockers in the treatment of cardiac arrest from ventricular fibrillation or pulseless VT further.