Treatment of acute malignant arrhythmias / electrical storm has been/should be commenced in the following steps:

Please note: DPP6 is NOT Brugada Syndrome. However, treatment of arrhythmia is very similar.

    • Defibrillate/resuscitate if necessary
    • Admit to specialised cardiac care unit or intensive care unit
      • For multiple (≥2) polymorphic VT/VF ≤24u (incl. ICD shocks):
        • A) Start isoprenaline i.v. (start 0,02mcg/kg/min, goal >100bpm / PVC-suppression. For VF-storm start with 1-2 mcg bolus).
        • B) Start quinidine (orally, in case of storm 1x600mg starting dose, generally followed by 3 times/day 200mg, 300-1600mg/day). Please know that some formulations of quinidine can be crushed and subsequently admitted through a gastric tube.
        • C) Monitor/telemetry and record 12 lead ECG of PVCs!
        • D) Please know that isoprenaline and quinidine are currently the only drugs considered therapeutic in DPP6 VF. (We have one case on a combination of high dose bepridil/cilostazol). Other Antiarrhythmic drugs, e.g. amiodarone, have been ineffective in VF-storm cases (which were fatal).
        • E) Treating coinciding (and possibly triggering) fever (with paracetamol) and sedation have been useful in some patients
        • F) Turning of the anti-tachycardia/shock therapy of the ICD is generally only relevant for conscious shocks and should not be considered lightly (due to generally faster respons times of ICDs and examples of unsuccessful manual resuscitation after programming shock therapy off).
      • For solitary Polymorphic VT/VF (incl. ICD shock).
        • A) Start quinidine orally (generally 3 times/day 200mg, 300-1600mg/day). Periodically check quinidine plasma levels, thrombocyte levels and liver function. Generally aim at quinidine plasma levels of 1-3 µg/mL or 3.5-11 µmol/L. Please note that low dosages and lower plasma levels of quinidine in adults (i.e. <600mg per day) may be sufficient
      • For repeated PVT/VF episodes (on adequate quinidine): consider ablation of trigger PVC in a specialised centre.
      • Please ask for guidance and inform the Amsterdam University Medical Centers on events in DPP6 patients.

Background on DPP6

Familial idiopathic ventricular fibrillation (IVF) is a severe disease entity and is notoriously difficult to manage because there are no clinical risk indicators for premature cardiac arrest. Previously (Alders et al.), we identified a link between familial IVF and a risk haplotype on chromosome 7q36 (involving the arrhythmia gene DPP6). In following evaluations (Postema et al., Xiao et al., Ten Sande et al., Bergeman et al.) further insights are shared.

The most important elements of the DPP6 risk haplotype.

  • The DPP6 risk haplotype represents a classic short-coupled IVF phenotype.
  • Patients at risk are only identified through genetic screening, either in cascade screening or in genetic evaluations in cases of unexplained cardiac arrest. There are no characteristic ECG or imaging abnormalities identifying patients at risk.
  • Currently, the DPP6 risk haplotype appears to be a Dutch founder mutation which is (yet) only found in The Netherlands.
  • There is a characteristic male/female and age difference concerning the risk of VF (see e.g. Bergeman et al.). These risk characteristics are translated into treatment decisions regarding primary prevention ICDs.
  • There can be some right ventricular enlargement on Cardiac MR but this didn’t show much clinical relevance yet (see .e.g. Ten Sande et al.).
  • There are currently no specific triggers apart from fever in some severe DPP6 cases. Also anaesthesia or labour are not considered specific triggers, nor are certain drugs (as opposed to, e.g., Brugada syndrome, Long QT syndrome or Catecholaminergic Polymorphic VT).
  • Please do inform us on the result of your emergency arrhythmia case to help building up experience. You can reach us through the contact page and we can discuss the case thereafter by email or otherwise.
  • A patient card with a short summary of treatment in case of arrhythmia can be found here – patients and their family members are advised to carry this card with them.