In order to confirm the suspected diagnosis of LQTS, Margaret undergoes a number of further investigations and tests. Whilst polymorphic ventricular tachycardia secondary to long QT may be drug induced, it is important, also, to investigate the possibility of underlying inherited LQTS.
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- Repeat ECGs (once trimethoprin discontinued): check heart rhythm is normal
- Electrolyte check: electrolyte imbalance (specifically Potassium, Magnesium and Calcium) can cause cardiac disturbances
- Holter monitor: to check heart rhythm over prolonged period
- Symptom Assessment: please see symptoms on previous page
- Family History Assessment: to ascertain whether there is a family history of syncope/sudden death
- Exercise stress test: to check for induced arrhythmias
- Genetics test: to check whether genetic cause for Margaret’s LQTS
Pulse point
LQTS can be confirmed through measurement of the QT interval on a 12 lead ECG. A number of useful calculators are available to help with this measurement we suggest you use Bazett’s Formula.
