Long QT Syndrome
OVERVIEW
- normal QT = < 440ms (two large squares) – prolonged QT > 450ms
- produces prolonged ventricular repolarisation -> predisposes to malignant ventricular arrhythmias
CAUSES
- drugs: amiodarone, TCA’s, many antibiotics, fluconazole, erythromycin, metoclopramide, quinidine, haloperidol, droperidol, methadone, ondansetron, SSRI’s
- genetic: cardiac ion channel mutation (Na+, K+)
- myocardial disease: MI, RF, 3rd degree HB, cardiomyopathy
- electrolytes: low Ca2+, low K+, low Mg2+
ASSESSMENT
HISTORY
- syncope
- exercised induced syncope
- cardiac arrest
- FHx
EXAMINATION
- may be normal
INVESTIGATIONS
- ECG: QTc >440ms (11 small squares or T wave after half the R-R distance)
- ECHO: structural heart disease
MANAGEMENT
- beta-blockade
- avoidance of increased sympathetic tone
- cardiac pacing
- treat cause
- ICD
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at The Alfred ICU, where he is Deputy Director (Education). He is a Clinical Adjunct Associate Professor at Monash University, the Lead for the Clinician Educator Incubator programme, and a CICM First Part Examiner.
He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives. He was one of the founders of the FOAM movement (Free Open-Access Medical education) has been recognised for his contributions to education with awards from ANZICS, ANZAHPE, and ACEM.
His one great achievement is being the father of three amazing children.
On Bluesky, he is @precordialthump.bsky.social and on the site that Elon has screwed up, he is @precordialthump.
| INTENSIVE | RAGE | Resuscitology | SMACC