Clinical Teaching Case
Anthony Battad MD, FRCPC
University of Manitoba

• None
Disclosures

The case of Ms. LM
• 55 year old aboriginal female:
– DM II with variable glucose control
– HTN, Dyslipidemia
– Femoral artery aneurysm (2003) – no sequelae
– Hypothyroidism
• Meds: amlodipine, metoprolol, L-thyroxine, glyburide, metformin, pioglitazone

Case…
• 8 Aug – presents to Pauingassi Nursing Station with “chest heaviness”
– Discharged home without specific treatment
• 9 Aug – unprovoked syncope with transient
LOC at home
– Still has 4/10 chest heaviness
• EKG done and faxed to St. Boniface Hospital

EKG – Aug 9

Striking Features?
Deep T wave inversion
Prolonged QT

Case…
• Patient urgently transferred to St. Boniface
Hospital ER
• In ER, V-fib arrest: 3-4 minutes CPR  restoration of pulse, BP, sinus rhythm
• Rhythm strip is not torsade de pointes

EKG – Aug 9 (ER-post arrest)
594 msec
Wellen’s sign

Repeat EKG – Aug 10
720 msec biphasic
Wellen’s sign

Case…
• 10 Aug – cardiac cath: no significant stenoses
• 11 Aug – echo: mild LV dilation, EF = 50 – 60%
• 12 Aug – cardiac MRI: normal
• 12 Aug – CT Head: nil acute
• 14 Aug – EP consult
• 15 Aug – ICD placed

Case…
• 25 Aug – discharged home
• Final Diagnosis: Prolonged QT, likely congenital
– note normal QT on an EKG 2 years prior
• Advise given for EKG screening to family members

Prolonged QT
• > 450 msec men
• > 470 msec women
• > 500 msec “very abnormal”
• QT c
= QT ÷ √ R-R

Prolonged QT
• Congenital
– Jervell & Lange-Nielson
Syndrome
– Romano-Ward
Syndrome
– Idiopathic
• Acquired
– Metabolic: hyperkalemia, hypocalcemia, hypomagnesemia, starvation, anorexia
– Anti-arrythmics: quinidine, amiodorone, sotalol
– Anti-histamines: terfenadine, astemizole
– Psychotropics: TCA, haloperidol
– Other meds: SSRI, methadone, protease inhibitors, levofloxacin, voriconazole

Top 20 Drugs
Sotalol – 4.7%
Cisapride
Amiodorone – 0.34 %
Erythromycin – 0.18 %
Ibutilide
Terfenadine
Quinidine – 0.45 %
Clarithromycin
Haloperidol – 0.14 %
Fluoxetine – 0.03 %
Digoxin – 0.1 %
Procainamide
Terodiline
Fluconazole
Disopyramide
Bepridil
Furoseamide – 0.1 %
Thioridazine
Flecainide
Loratidine
Dapro (2001), Eur Heart J

Clinical Features
• Palpitations
• Syncope
• Seizures
• Sudden cardiac death – Torsade de Pointes 
V-fib arrest

Diagnosis
• Single ECG not 100 % sensitive
– “average” QT
– Ambulatory monitoring
• Certain features for congenital QT
• EP not part of routine testing

Management: ACC/AHA/ECS
• Lifestyle modification
– Avoid QT prolonging drugs
– Avoid strenuous exercise
• Beta Blockers (+/-) DDD pacing to reduce QT
• Implantable Cardiac Defibrillator (ICD)
– Sustained VT and/or syncopal event while on βblocker therapy