ICCnotes

Clinical resource for cardiomyopathies, channelopathies, and related conditions

Cardiomyopathies
HCM
DCM
ARVC
RCM
NDLVC
Channelopathies
Long QT
Short QT
Brugada
CPVT
Aortopathies & Connective Tissue
Marfan syndrome
Loeys-Dietz syndrome
Ehlers-Danlos (vascular)
Bicuspid aortic valve
Metabolic & Storage Diseases
Fabry disease
Danon disease
Amyloidosis
Pompe disease
Neuromuscular & Syndromic
Duchenne/Becker MD
Myotonic dystrophy
Friedreich ataxia
Mitochondrial disorders

Clinical Guidelines

ESC Guidelines on Cardiomyopathies

European Society of Cardiology, 2023

View Guideline →

AHA/ACC/HRS Guideline on HCM

American Heart Association / American College of Cardiology, 2020

View Guideline →

ESC Guidelines on Ventricular Arrhythmias and SCD

European Society of Cardiology, 2022

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HRS Expert Consensus on ARVC

Heart Rhythm Society, 2019

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ESC Guidelines on Cardiac Pacing and CRT

European Society of Cardiology, 2021

View Guideline →

2023 ESC Guidelines for Management of Cardiomyopathies

European Society of Cardiology, 2023

Comprehensive evidence-based guidelines covering HCM, DCM, ARVC, RCM, and genetic/metabolic cardiomyopathies. Includes validated risk stratification tools (HCM Risk-SCD, HCM Risk-Kids) and updated diagnostic criteria.

View Guideline →

HRS/EHRA/APHRS Expert Consensus on Inherited Arrhythmias

Heart Rhythm Society, 2013

Consensus on diagnosis and management of Long QT, Brugada, CPVT, Short QT, Early Repolarization, and unexplained cardiac arrest.

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ACMG Standards and Guidelines for Genetic Testing

American College of Medical Genetics, 2024

View Guideline →

Genetic Testing

UK National Genomic Test Directory (Version 8.1, July 2025)

About These Criteria

These criteria are from the NHS England National Genomic Test Directory. Tests must be delivered by a Genomic Laboratory Hub and should only be requested where results are highly likely to change clinical management.

Important: Criteria use "OR" / "AND" logic. When multiple criteria are listed with "OR", meeting ANY ONE is sufficient. When "AND" is used, ALL criteria must be met.

R131: Hypertrophic Cardiomyopathy

Testing Method: WES or Medium Panel | Requesting Specialties: Cardiology, Clinical Genetics

Testing criteria (meet ONE OR MORE):

  • Adult with wall thickness ≥15 mm in ≥1 LV segment, NOT explained solely by loading conditions (e.g. hypertension), AND age of onset <60 years
  • Child <18 years with LV wall thickness >2 standard deviations above predicted mean (z-score >2)
  • Increased LV wall thickness ≥13 mm in ≥1 LV segment, in patient with 1st degree relative with unequivocal disease (LVH ≥15 mm), where affected family member unavailable for testing
  • Deceased individual with pathologically confirmed HCM (post-mortem DNA analysis)

Additional requirements:

  • Testing recommended when relatives will benefit from cascade testing using genetic diagnosis
  • Testing in parallel with expert phenotypic assessment in ICC, including clinical genetics support

Genes Tested (Hypertrophic Cardiomyopathy Panel - 49 genes)

MYBPC3 MYH7 TNNT2 TNNI3 TPM1 ACTC1 MYL2 MYL3 + 41 others

Note: R135 Paediatric/syndromic cardiomyopathy should be used where atypical features suggest broader gene testing needed

R132: Dilated and Arrhythmogenic Cardiomyopathy

Testing Method: WES or Medium Panel | Requesting Specialties: Cardiology, Clinical Genetics

Testing criteria (meet ONE OR MORE):

  • LVEDD >2 SD AND/OR reduced EF <45% (age/sex adjusted), AND age of onset <65 years
  • Criterion 2 (DCM with conduction): DCM with conduction defects, age of onset <65 years
  • Left and/or biventricular cardiomyopathy with variable myocardial dysfunction/fibrosis PLUS ventricular arrhythmias, after excluding inflammatory causes
  • Deceased individual with pathologically confirmed DCM/ACM, age of onset <65 years
  • Patient with DCM/ACM at ANY age if 1st degree relative has confirmed DCM/ACM

Main Genes Tested (DCM/ACM Panel)

TTN LMNA MYH7 BAG3 FLNC RBM20 SCN5A DSP PLN DES + others

Exclusions: DCM secondary to coronary disease or pressure/volume overload. Consult expert before testing DCM due to myocarditis, alcohol, peripartum, chemotherapy.

R133: Arrhythmogenic Right Ventricular Cardiomyopathy

Testing Method: Small Panel (134 genes) | Requesting Specialties: Cardiology, Clinical Genetics

Testing criteria (meet ONE OR MORE):

  • DEFINITE diagnosis by Modified Task Force Criteria (Marcus 2010), age of onset <50 years
  • Deceased with pathologically confirmed ARVC, relatives will benefit from cascade testing
  • Identification of P/LP variant would complete diagnostic Task Force Criteria

Desmosomal Genes

PKP2 DSG2 DSC2 DSP JUP TMEM43 PLN FLNC + 126 others

R127: Long QT Syndrome

Testing Method: Small Panel (76 genes) | Requesting Specialties: Cardiology, Clinical Genetics

Testing criteria (meet ONE OR MORE):

  • QTc ≥500ms in repeated 12-lead ECGs
  • LQTS risk score ≥3.5 (Schwartz 2011)
  • QTc ≥480ms in repeated ECGs AND unexplained syncope
  • QTc ≥480ms AND sudden unexplained death <60 years in 1st/2nd degree relative

Main Genes (LQTS Panel)

KCNQ1 KCNH2 SCN5A CALM1 CALM2 CALM3 CACNA1C KCNE1 KCNE2 + 67 others

Secondary causes must be excluded before testing

R128: Brugada Syndrome

Testing Method: Small Panel (13 genes) | Requesting Specialties: Cardiology, Clinical Genetics

Testing criteria (meet ONE):

  • Spontaneous Type 1 ST elevation ≥2mm in ≥1 right precordial lead
  • Type 1 ST elevation with Na-channel blocker, AND ONE OR MORE of: VF/VT, syncope, FH of SCD <45y, coved ECG in family, agonal respiration, atrial arrhythmias <30y
  • Sodium channel disease suspicion (atrial arrhythmias, sinus/conduction disease, QT prolongation)

Genes Tested

SCN5A GPD1L CACNA1C CACNB2 SCN1B + 8 others

R129: Catecholaminergic Polymorphic VT

Testing Method: Small Panel (214 genes) | Requesting Specialties: Cardiology, Clinical Genetics

Structurally normal heart, normal ECG, AND:

  • Exercise/catecholamine-induced bidirectional VT or polymorphic PVCs/VT/VF in patient <40 years, OR
  • Exercise-induced arrhythmias with positive FH of CPVT (symptomatic family member unavailable), OR
  • Same as above but age >40 years

Main Genes

RYR2 CASQ2 CALM1-3 TRDN TECRL + 209 others

R130: Short QT Syndrome

Testing Method: Small Panel (224 genes) | Requesting Specialties: Cardiology, Clinical Genetics

  • QTc ≤330ms, OR
  • QTc <360ms AND (FH of SQTS OR FH of SCD ≤40y OR VT/VF survival)

Main Genes

KCNH2 KCNQ1 KCNJ2 + 221 others

R138: Molecular Autopsy / Idiopathic VF

Testing Method: WES/Medium Panel (841 genes) | Requesting Specialties: Cardiology, Clinical Genetics

Post-mortem testing:

  • Sudden death with normal PM <40 years, OR
  • Sudden death with normal PM <60y with FH unexplained SCD <40y in 1st/2nd degree relative, OR
  • Sudden death with normal PM <60y with FH unexplained SCD <60y (relative also had normal PM)

Cardiac arrest survivors (idiopathic VF):

  • No phenotype on comprehensive evaluation (coronary, imaging, ECG provocation) AND age <45 years

Panel: 841 genes covering all ICC, channelopathies, cardiomyopathies, SCD-associated genes

General Requirements for All Tests

All testing should be:

  • Performed in parallel with expert phenotypic assessment in an Inherited Cardiac Clinic (ICC)
  • With clinical genetics support
  • Targeted at those where genetic/genomic diagnosis will guide management for proband or family

Full guidelines: National Genomic Test Directory v8.1

Genetic Counselling in Inherited Cardiac Conditions

Genetic counselling is an essential component of the care pathway for patients with inherited cardiac conditions and their families. It provides information, support, and guidance regarding genetic testing, inheritance patterns, and family screening.

When to Refer for Genetic Counselling

  • Confirmed diagnosis of inherited cardiac condition
  • Family history of inherited cardiac condition or sudden cardiac death
  • Prior to genetic testing (predictive or diagnostic)
  • After receiving genetic test results (positive, negative, or uncertain)
  • Family cascade screening
  • Reproductive planning in affected individuals

Pathway from ICC SOP Document

  • Predictive testing for Class IV/V, non-TTN variants: Can go straight to genetic counsellors without medical clinic booking (unless symptomatic)
  • Gene positive, phenotype negative family screens: Keep under specialist ICC care
  • Predictive testing negative: Discharge from service
  • TTN variants: Require clinical correlation; all patients seen in medical clinics due to complexity
Important Notes on Genetic Counselling

Who provides genetic counselling: Certified genetic counsellors or clinicians with appropriate training in genetics

Pre-test counselling is mandatory before genetic testing for inherited cardiac conditions

Post-test counselling should be provided regardless of result (positive, negative, or VUS)

Exercise Recommendations

About These Recommendations

Exercise recommendations are based on ESC and AHA/ACC guidelines. The matrix below provides a quick reference for condition-specific recommendations. Detailed guidance follows.

Exercise Recommendation Matrix

Condition Low Intensity Moderate Intensity Vigorous Intensity Competitive Sport
HCM ✓ Permitted ⚠ Restricted
Low-risk only
✗ Contraindicated ✗ Contraindicated
DCM ✓ Permitted ✓ Permitted
If LVEF >35-40%
⚠ Restricted
Stable, LVEF >50%
✗ Contraindicated
LVEF <50%
ARVC ✓ Permitted ✗ Contraindicated ✗ Contraindicated ✗ Contraindicated
LQTS ✓ Permitted ⚠ Restricted
Depends on type
✗ Contraindicated ✗ Contraindicated
Brugada ✓ Permitted ✓ Permitted
Avoid dehydration
⚠ Restricted
If asymptomatic
✗ Contraindicated
If symptomatic
CPVT ✓ Permitted ✗ Contraindicated ✗ Contraindicated ✗ Contraindicated
Marfan/TAAD ✓ Permitted ⚠ Restricted
No contact sports
✗ Contraindicated
Aortic root >40mm
✗ Contraindicated
Contact/collision
Gene +ve / Pheno -ve ✓ Permitted ✓ Permitted
Annual review
✓ Permitted
Annual review
⚠ Restricted
Shared decision

Exercise Intensity Definitions

Light/Low Intensity

  • MET: <3 METs
  • Heart rate: <50% max HR
  • Examples: Walking slowly, bowling, golf (with cart), light housework
  • Can hold conversation easily

Moderate Intensity

  • MET: 3-6 METs
  • Heart rate: 50-70% max HR
  • Examples: Brisk walking, recreational swimming, cycling on flat terrain, doubles tennis, golf (carrying clubs)
  • Can talk but not sing

Vigorous Intensity

  • MET: >6 METs
  • Heart rate: 70-85% max HR
  • Examples: Running, singles tennis, competitive cycling, football, basketball, vigorous swimming
  • Difficult to talk comfortably

Competitive Sport

  • Organized team or individual sports
  • Regular training and competition
  • Performance-focused
  • Examples: Any sport at club, regional, or national level

Detailed Condition-Specific Recommendations

Hypertrophic Cardiomyopathy (HCM)

PERMITTED

  • Low intensity recreational exercise (walking, golf with cart, bowling)
  • Moderate intensity if low-risk (recreational swimming, doubles tennis, recreational cycling)
  • Light resistance training (<50% MVC)

CONTRAINDICATED

  • All competitive sports
  • High intensity exercise (running, intense cycling, vigorous swimming)
  • High static component sports (weightlifting, gymnastics)
  • Marathon, triathlon, CrossFit

Special considerations: Avoid activities that worsen LVOT gradient (Valsalva, post-exercise). Low-risk patients (no LVOTO, thinner walls, no high-risk features) may engage in moderate-intensity activities after shared decision-making.

High-risk features (any of the following warrant exercise restriction): Prior exertional syncope/presyncope, sustained VAs or cardiac arrest, family history of SCD in young relatives, severe LVH (≥30mm), extensive LGE (≥15% LV mass), severe LVOT obstruction (>50mmHg), apical aneurysm, LVEF <50%, NSVT, abnormal BP response to exercise, or HCM Risk-SCD ≥6%.

Dilated Cardiomyopathy (DCM)

PERMITTED

  • Low intensity exercise (all patients)
  • Moderate intensity if LVEF >35-40% and stable
  • Vigorous exercise if LVEF >50%, stable, no arrhythmias
  • Competitive sport only if LVEF >50%, no LGE, normal exercise test

CONTRAINDICATED

  • Competitive sport if LVEF <50%
  • Vigorous exercise if LVEF <45% or symptomatic
  • Any exercise during acute decompensation

Special considerations: Exercise capacity improves with appropriate medical therapy. Annual assessment recommended. LMNA mutations require careful monitoring regardless of LVEF.

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)

PERMITTED

  • Low intensity recreational exercise only (walking, golf with cart)

CONTRAINDICATED

  • All competitive sports
  • Moderate-vigorous intensity exercise
  • Endurance exercise (running, cycling, swimming)

Special considerations: Exercise accelerates disease progression in ARVC ("exercise paradox"). Even moderate exercise may worsen phenotype. Strictest restrictions of all cardiomyopathies.

Long QT Syndrome (LQTS)

PERMITTED

  • Low intensity exercise (all genotypes)
  • Moderate intensity if on therapy, asymptomatic, QTc <500ms
  • LQT3: Generally more permissive (avoid rest/sleep triggers)

CONTRAINDICATED

  • All competitive sports
  • Swimming (especially LQT1)
  • High intensity exercise (especially LQT1)
  • Exercise with auditory stimuli (LQT2)

Genotype-specific: LQT1 avoid swimming/diving. LQT2 avoid loud alarms/auditory triggers. LQT3 more permissive for exercise (events at rest/sleep). All must be on adequate beta-blocker therapy.

Brugada Syndrome

PERMITTED

  • Low-moderate intensity exercise if asymptomatic
  • Vigorous exercise if asymptomatic Type 1 pattern only
  • Competitive sport possible if asymptomatic, shared decision-making

CONTRAINDICATED

  • Competitive sport if history of syncope or VF
  • Exercise in febrile illness (aggressive fever management essential)
  • Avoid dehydration and excessive alcohol

Special considerations: Events typically at rest/sleep (not during exercise). More permissive than other channelopathies for asymptomatic patients. Fever is major trigger - treat aggressively.

Catecholaminergic Polymorphic VT (CPVT)

PERMITTED

  • Low intensity exercise only if well-controlled on therapy

CONTRAINDICATED

  • All competitive sports (absolute contraindication)
  • Moderate-vigorous exercise
  • Swimming
  • Any intense physical or emotional stress

Special considerations: CPVT is exercise/catecholamine-triggered - strictest exercise restrictions. Even on high-dose beta-blockers + flecainide, avoid moderate-vigorous exercise. Compliance with therapy is critical.

Marfan Syndrome & Thoracic Aortic Aneurysm Disease (TAAD)

PERMITTED

  • Low intensity exercise (all patients)
  • Moderate intensity if aortic root <40mm
  • Non-contact sports if aortic dimensions stable

CONTRAINDICATED

  • Contact/collision sports (rugby, boxing, martial arts)
  • Isometric exercise (weightlifting)
  • Competitive sport if aortic root >40mm
  • Vigorous intensity if aortic root >40mm

Special considerations: Exercise restrictions based on aortic dimensions. Annual imaging essential. Loeys-Dietz more aggressive (lower thresholds). Avoid Valsalva maneuvers and activities that spike blood pressure.

Genotype-Positive / Phenotype-Negative (G+/P-)

PERMITTED

  • All exercise intensities if truly phenotype-negative
  • Competitive sport with shared decision-making and annual review

REQUIRES MONITORING

  • Annual cardiac assessment (ECG, echo/MRI, exercise test)
  • Shared decision-making for competitive sport
  • Some variants higher risk (e.g., specific LMNA, RYR2 mutations)

Special considerations: True phenotype-negative carriers can exercise. Annual review essential as phenotype may develop. Competitive sport decision should involve patient, cardiologist, and sports physician. Specific gene/variant risk stratification important.

General Exercise Guidance

Shared decision-making: All recommendations individualized with patient and specialist input.

Regular review: Annual reassessment of exercise capacity and recommendations.

Adequate treatment: Optimize medical therapy before exercise.

Warning signs: Stop immediately if chest pain, palpitations, breathlessness, dizziness, or syncope.

Emergency plan: Patients and families should know CPR and have access to emergency services.

Key References:

  • 2020 ESC Guidelines on Sports Cardiology and Exercise in Patients with Cardiovascular Disease
  • 2015 Eligibility and Disqualification Recommendations for Competitive Athletes (Maron et al)
  • 2020 AHA/ACC Guideline for the Diagnosis and Treatment of HCM

UK Driving Guidance

🚗 UK Driving - Patient Responsibilities

Group 1 = Car/Motorcycle | Group 2 = Bus/Lorry (HGV/PCV)

⚠️ It is the PATIENT's legal responsibility to:

  • Notify DVLA of diagnosis (online or by post)
  • Stop driving if told to do so or if condition worsens
  • Attend reviews as required (typically 1-3 years)
  • Inform car insurance of medical condition

Failure to notify DVLA may invalidate insurance and is a criminal offence.

Cardiomyopathies

HCM

Group 1: Asymptomatic can drive (notify DVLA, review 1-3yr). Symptomatic: cease until 3mo symptom-free, EF>40%, no LVOT gradient>50mmHg.

Group 2: Disqualified if syncope, LVOT>30mmHg, wall≥30mm, NSVT, abnormal BP response.

DCM

Group 1: LVEF>40% can drive (annual review). LVEF≤40%: notify DVLA, cease if symptomatic.

Group 2: LVEF>45%, no symptomatic HF, annual review.

ARVC

Group 1: No VT/VF/syncope + LVEF>40%: can drive. If VT/VF/syncope: cease until 3mo post-ablation OR ICD.

Group 2: Barred if VT/VF, cardiac syncope, or LVEF<45%.

Channelopathies

LQTS, Brugada, CPVT

LQTS Group 1: Asymptomatic + on therapy: can drive. Symptomatic: 3mo off.

LQTS Group 2: No syncope/arrest, QTc<500ms, annual review.

Brugada/CPVT: Similar - asymptomatic can drive. Group 2 barred if syncope/arrest history.

ICD Rules

Group 1: Primary prevention: 1wk off. Secondary: 6mo off. After appropriate shock: 6mo. Inappropriate shock: 2wk (if fixed).

Group 2: ANY ICD = permanent bar.

Key Points:

  • Patient responsibility: Legally required to notify DVLA and stop driving if advised. Clinicians advise but cannot notify DVLA on patient's behalf.
  • Failure to notify: Invalidates insurance, is a criminal offence (£1000 fine), and may result in prosecution if accident occurs.
  • Returning to driving: DVLA will issue new licence when medical criteria met. No re-test required unless told otherwise. Patient must reapply if licence expired.
  • Temporary licences: DVLA may issue 1, 2, or 3-year licences requiring regular review rather than standard 10-year (Group 1) or 5-year (Group 2) licences.
  • Individual variation: These are general rules - DVLA assesses each case individually. Always check current guidance.

→ Full DVLA Guidance (Official)

→ Contact DVLA (Drivers Medical Group)

Useful Websites

British Inherited Cardiac Conditions Society (BICCS)

Professional society for healthcare professionals working with inherited cardiac conditions

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Cardiomyopathy UK

Patient support charity providing information and support for people affected by cardiomyopathy

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Cardiac Risk in the Young (CRY)

Charity working to reduce deaths from young sudden cardiac death

Visit Website →

SADS UK

Support for families affected by Sudden Arrhythmic Death Syndrome

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European Society of Cardiology

Clinical practice guidelines and educational resources

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American College of Cardiology

Clinical guidelines, tools, and educational content

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ClinGen - Clinical Genome Resource

Authoritative resource for gene-disease validity and variant interpretation

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ClinVar

Database of genomic variation and its relationship to human health

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Heart Rhythm Society

Professional organization for cardiac electrophysiology and arrhythmia management

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British Cardiovascular Society

UK professional body for cardiovascular healthcare professionals

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ARVC Registry

International registry for arrhythmogenic right ventricular cardiomyopathy

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SarcomaHER Registry

International database for HCM patients and research

Visit Website →