An unusual cause of electrical storm in a young woman.

Clinical vignette

A 35-year-old woman with a history of neurocardiogenic syncope, without cardiovascular risk factors, family history of sudden death, or usual medication, was admitted to our emergency department (ED) for recurrent syncope. Episodes were preceded by sudden onset palpitations, some at rest, without apparent situational cause. She had a recent electrocardiogram (EKG), transthoracic echocardiogram (TTE), and exercise EKC performed which were normal, at admission to the ED, she was undergoing 24 h Holter monitoring (Supplementary material online, ).

At admission, multiple episodes of tachyarrhythmias were recorded (—admission electrocardiogram).

Figure 1

Admission electrocardiogram.

Question 1

What’s the most likely diagnosis?

1.  Acute coronary syndrome;

2.  Congenital Long QT syndrome;

3.  Right ventricular arrhythmogenic dysplasia;

4.  Acquired Long QT syndrome;

5.  Short-coupled variant of torsade de pointes.

The correct answer is 5: Short-coupled variant of torsade de pointes.

Explanation:

(Supplementary material online, Figure ). All of episodes recorded were preceded by the same monomorphic, isolated, and premature ventricular contractions (PVCs) with the same shorter coupling interval (∼260 ms). The other options were excluded by basal TTE, EKG (namely normal QT interval, no Brugada pattern, or ischaemic changes), blood samples, and emergent coronary angiography.

Question 2

Which is the most appropriate treatment of this patient?

1.  Amiodarone;

2.  Lidocaine;

3.  β-blockers;

4.  Verapamil;

5.  Quinidine;

The correct answer is 4: Verapamil.

Explanation:

Given the suspected diagnosis of short-coupled variant of torsade de pointes and as suggested by 2015 European Society of Cardiology (ESC) Guidelines for the management of patients with ventricular arrhythmias, intravenous verapamil was started with successful rhythm stabilization. Although there is little evidence available, the slow calcium channel blocker verapamil seems to be the only drug with some efficacy in suppressing the arrhythmias, while amiodarone, β-blockers, and quinidine are ineffective. This supports the theory of early after-depolarizations being the trigger for torsade de pointes, since early after-depolarizations are in part, probably carried by current passing through slow calcium channels.,

Question 3

In this clinical context, which is the most appropriate intervention during hospitalization?

1.  No further intervention.

2.  Transvenous implantable cardioverter-defibrillator implantation.

3.  Subcutaneous implantable cardioverter defibrillator implantation.

4.  Catheter ablation.

5.  Pacemaker implantation.

The correct answer is 3: Subcutaneous implantable cardioverter defibrillator implantation.

Explanation:

Although verapamil is a useful drug for rhythm stabilization, it does not prevent sudden deaths, so an implantable cardioverter-defibrillator (ICD) is indicated in this patient.

As highlight by 2015 ESC Guidelines, subcutaneous-ICD should be considered as an alternative to transvenous ICD in patients with an indication for an ICD when pacing therapy for bradycardia support, cardiac resynchronization, or antitachycardia pacing is not needed. As none of the above, device therapies are needed in our patient a subcutaneous-ICD was implanted. Catheter ablation could be considered for long-term suppression/prevention of an electrical storm or recurrent ICD discharges in case of verapamil treatment failure.

Conclusion

Idiopathic ventricular arrhythmias occur in structurally normal hearts and include a heterogeneous group of patients with mean age less than patients with ventricular arrhythmias secondary to underlying heart disease. Short-coupled variant of torsade de pointes is a rare condition, triggered by PVC not followed by a compensatory pause and a short coupling interval (<300 ms), similar to an R-on-T phenomenon. Verapamil is the drug of choice for rhythm stabilization, but it is not effective in reducing the risk of sudden death. A high clinical suspicion is essential for this diagnosis as it can be lifesaving in such young patients presenting with electric storm.

Supplementary material

Supplementary material is available at European Heart Journal - Case Reports online.

Consent: The authors confirm that written consent for submission and publication of this case report including images and associated text has been obtained from the patient.

Conflict of interest: None declared.

Funding: None declared.

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