Presentation: Patient with a catecholaminergic polymorphic ventricular tachycardia

An eight-year-old boy presents to a cardiology clinic following an episode of collapse while playing football. He has a normal cardiovascular examination, echocardiogram and resting electrocardiogram (ECG). During exercise testing, his ECG exhibits evidence of isolated ventricular premature beats, which progress to a bigeminal pattern on further exertion. The test is stopped.

• Consider genomic testing in the presence of an underlying diagnosis of catecholaminergic polymorphic ventricular tachycardia (CPVT), as suggested by either:
  • a structurally normal heart with a normal ECG but with either:
    • an unexplained exercise- or catecholamine-induced bidirectional ventricular tachycardia (VT);
    • polymorphic ventricular premature beats; or
    • a VT or ventricular fibrillation (VF) in an individual under 40 years of age;
  • a structurally normal heart in a patient who experiences exercise-induced premature ventricular contractions (PVCs) or bidirectional or polymorphic VT or VF, and has a positive family history of CPVT, where a symptomatic family member is unavailable for testing; or
  • a structurally normal heart and coronary arteries and a normal ECG in a patient with either:
    • unexplained exercise- or catecholamine-induced bidirectional VT;
    • polymorphic ventricular premature beats; or
    • a VT or VF in an individual over 40 years of age.
• Genomic testing for CPVT should be carried out in parallel with expert phenotypic assessment – for example, in an inherited cardiac conditions (ICC) clinic – and with support from clinical genetics. Note that testing may occasionally be appropriate outside these criteria following discussion at an ICC multidisciplinary team meeting.
• Referrals for genomic testing will be triaged by the genomic laboratory. Testing should be targeted at those in whom a genetic or genomic diagnosis will guide management for the proband or family.
• Testing should also be considered in first-degree relatives of a patient with confirmed CPVT whose condition is associated with an identified familial variant. This requires appropriate genetic counselling.
• If the patient fulfils diagnostic criteria as detailed in published guidelines that differ from the eligibility criteria in the National Genomic Test Directory, it is appropriate to refer to an ICC clinic for further assessment.

• Consult the National Genomic Test Directory. From here you can access the rare and inherited disease eligibility criteria for information about individual tests and their associated eligibility criteria. You can also access a spreadsheet containing details of all available tests.
  • For information about how to arrange testing in Wales, Scotland or Northern Ireland, see our dedicated Knowledge Hub resource.
• To find out which genes are included on different gene panels, see the NHS Genomic Medicine Service (GMS) Signed Off Panels Resource.
• If eligibility criteria are met, discuss the case with or refer it to your local ICC clinical service for genomic testing and family screening. You will need to provide details confirming that the patient fulfils the criteria.
• The relevant clinical indication for suspected CPVT is:
  • R129 Catecholaminergic polymorphic VT: This indication comprises small gene panel sequencing.
• Predictive testing for first-degree relatives of a patient with a known causative variant should be tested via:
  • R242 Predictive testing for known familial variant(s).
• For tests that do not include whole genome sequencing, you will need to:
  • complete a test order form (available from your local Genomic Laboratory Hub) and document consent (record of discussion) as per regional requirements; and
  • include details of the phenotype in the test order form (refer to human phenotype ontology (HPO) terms or the clinical summary) as well as the appropriate panel name(s) with associated R number.
• These tests are DNA based, and an EDTA sample (typically a purple-topped tube) is required.
• Information about patient eligibility and test indications was correct at the time of writing. When requesting a test, please refer to the National Genomic Test Directory to confirm the right test for your patient.

• NHS England: National Genomic Test Directory

References:

• Zeppenfeld K, Tfelt-Hansen J, de Riva M and others. ‘2022 ESC guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: Developed by the task force for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death of the European Society of Cardiology (ESC) endorsed by the Association for European Paediatric and Congenital Cardiology (AEPC)’. European Heart Journal 2022: volume 43, issue 40, pages 3,997–4,126. DOI: 10.1093/eurheartj/ehac262

For patients

• Arrhythmia Alliance: Catecholaminergic polymorphic ventricular tachycardia
• British Heart Foundation: Catecholaminergic polymorphic ventricular tachycardia
• British Heart Foundation: Life with sudden arrhythmic death syndrome
• Cardiac Risk in the Young
• myheart: Catecholaminergic polymorphic ventricular tachycardia
• SADS Foundation: Catecholaminergic polymorphic ventricular tachycardia