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Cardiac Inherited Diseases Service

Contact Details

Starship Child Health, Central Auckland

Phone (09) 307 4949 ext 23634
Fax (09) 307 2899
Mobile Clinical Coordinator: 021 825 389

Louise Monson CIDG team support administrator (General Enquiries)

Jackie Crawford CIDG National Clinical Coordinator (Clinical Enquiries)

Cellphone: 021 825 389


2 Park Road Grafton Auckland 1023
Jackie Crawford Cardiac Inherited Disease Coordinator Cardiac Inherited Disease Registry N.Z. Level 3 Cardiac Services Dept Auckland Hospital P.O. Box 92189 Auckland 1030 New Zealand
(09) 307 4949 ext 23634
(09) 307 2899
Clinical Coordinator: 021 825 389

What is CIDG and CIDRNZ?

CIDG is a national network of specialist clinicians and scientists working to prevent sudden death due to inherited heart diseases.  The Cardiac Inherited Disease Registry N.Z. (CIDRNZ) is an ethically approved national clinical registry designed to track registrants (individuals and families with known cardiac inherited disease) or cases of young sudden death typically 1 - 40 yrs (referred by the Forensic Pathologists/Coroner). 

Each CIDG member has their own employing hospital or District Health Board. Aside from the coordinators based within ADHB, Waikato DHB and Capital and Coast DHB, CIDG does not receive individual funding, but works within existing clinical systems to facilitate clinical screening for families across the country.

Which conditions does CIDG deal with?

The commonest familial heart conditions are long QT syndrome (LQTS), Brugada syndrome (BRS) and Hypertrophic Cardiomyopathy (HCM). CIDG also coordinates nationally the family and genetic investigation for sudden unexpected natural deaths in 1-40 year olds. CIDG works closely with the national forensic and coronial services.

Who leads CIDG?

The national clinical leader is Professor Jon Skinner, children's heart rhythm specialist, at Starship Children's Hospital.

Which doctors belong to CIDG?

A group of Clinicians from each region belong to CIDG. The majority are Cardiologists (heart doctors), Paediatricians, Geneticists and Pathologists. A current list is available on the CIDG 

Is this just for children?

No, CIDG facilitates family screening for all family members. The heart tests are usually performed locally, in your local hospital. Children sometimes have specialised heart tests at the Starship Hospital and test results can be copied and sent to other specialists for opinion.


  • Dr Tim Hornung, Paediatric Cardiologist
  • Prof Jonathan Skinner, Paediatric Cardiologist
  • Assoc Prof Warren Smith, Adult Cardiologist

Referral Expectations

Anybody can refer to CIDG for advice, including the patients themselves. The coordinator will help them link to a local clinician with the necessary expertise.  We hold a weekly case meeting and discuss cases from around New Zealand, to provide Specialist opinion and advice.

Pathologists dealing with a sudden death who require advice should call Dr. Skinner in the first instance via the hospital switch board, or relay a question via the Clinical Coordinator (; information for review can be sent to our team support/administrator (

Any clinician is welcome to phone or write for advice regarding their patients or families. It is almost always appropriate for the patient to be seen by a local specialist first.

Regarding written requests, please include as much detail about the family and the clinical presentation, including test results (particularly ECGs) necessary to permit an informed response.

Common Conditions / Procedures / Treatments

Electrocardiogram (ECG)

An ECG is a recording of the heart's electrical activity. Electrode patches are attached to the skin to measure the electrical impulses given off by the heart. It is not painful and takes about ten minutes. The result is a trace that can be read by a doctor.  It can give information about risk of heart rhythm disturbance - such as the length of the QT interval.

Exercise ECG or Exercise Test (ETT)

An ECG done when resting may be normal even when heart problems are present. 

During an exercise ECG the heart is made to work harder and signs of heart disease may be unmasked.  This test involves walking on a treadmill while the heart is monitored.  The treadmill gets faster with time but can be stopped at any time.  This test is supervised and interpreted by a doctor. 

The test is helpful to detect many forms of inherited heart disease, especially long QT syndrome and CPVT (catecholaminergic polymorphic ventricular tachycardia). These conditions can sometimes cause sudden collapse and sudden death in young people, and are difficult to diagnose - the exercise test can help.


Echocardiography is also referred to as cardiac ultrasound. This test is performed by a specially trained technician. It is a test that uses high frequency sound waves to generate pictures of the heart.  During the test, the patient will generally lie on their back; gel is applied to their skin to increase the conductivity of the ultrasound waves. A technician then moves the small, plastic transducer over the chest. The test is painless and can take from 10 minutes to an hour.
The machine then analyses the information and develops images of your child's heart. These images are seen on a monitor. This is referred to as an echocardiogram.
Echocardiography can help in the diagnosis of many heart problems including hypertrophic cardiomyopathy or dilated cardiomyopathy.

Cardiac Arrhythmias

The heart rate is controlled by a complex electrical system within the heart muscle which drives it to go faster when you exert yourself and slower when you rest.  A number of conditions can affect the heart rate or rhythm.  Heart rate simply refers to how fast the heart is beating.  Heart rhythm refers to the electrical source that is driving the heart rate and whether or not it is regular or irregular.

Some common terms
  • Sinus rhythm is the normal rhythm
  • Arrhythmia means abnormal rhythm
  • Fibrillation means irregular rhythm or quivering of one part of the heart
  • Bradycardia means slow heart rate
  • Tachycardia means fast heart rate
  • Paroxysmal means the arrhythmia comes and goes
The most common of these in inherited heart disease is ventricular tachycardia.  The usual presenting symptom is sudden collapse with loss of consciousness, particularly during or after exercise and also at night, when there may also be a seizure (fit). These can usually be prevented with regular medication such as a beta blocker.  Sometimes a defibrillator pacemaker is needed.
The most common form of this is called heart block.  This is because messages from the electrical generator of the heart don't get through efficiently to the rest of the heart and hence it goes very slowly or can pause.  Symptoms of the heart going too slowly include feeling tired, breathless or fainting.
Tests to diagnose what sort of arrhythmia is present include:
  • an electrocardiogram (ECG).  This trace of the heart's electrical activity gives the diagnosis of the source of the arrhythmia. This is often normal at rest and more extensive testing is needed to try and catch the arrhythmia especially if it is intermittent.
  • an Ambulatory ECG. This can be performed with a Holter monitor which monitors the heart for rhythm abnormalities during normal activity for an uninterrupted 24-hour period. During the test, electrodes attached to the chest are connected to a portable recorder - about the size of a paperback book - that's attached to a belt or hung from a shoulder strap.
Most treatments for tachycardias consist of medication to stop the abnormal rhythm or make it slower if and when it occurs. 
If bradycardia is diagnosed, a pacemaker may be fitted. This requires a small operation where a battery powered device is placed under the skin with wires that lead to the heart and provide it with electrical stimulation to prevent it from going too slowly. 

Genetic Testing

In some forms of inherited heart diseases, genetic tests can be helpful when trying to identify which family members may be at risk of developing or carrying the condition.

Testing for long QT syndrome and hypertrophic cardiomyopathy is available.

It involves a blood test, from which the lab extracts DNA. The lab looks at the genes linked to the condition suspected. The DNA from the first family member to be tested has to undergo a sequencing of the genes - in effect looking for spelling errors in a number of genes. The test is highly specialised and time consuming. In 2010 a result is usually available within 3 months.

Once a mutation (spelling error) is found in one of the genes, this can be looked for in the other family members. This test is quicker - results take about 6 weeks.

Each person having the test must be counselled carefully first, by a specialist or clinical geneticist or associate, and the patient must give their informed consent, either via the CIDG network,or the clinical genetics service.

GPs and patients themselves may not order such tests.

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