Clinical Teaching Case
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Transcript of Clinical Teaching Case
Clinical Teaching Case
Anthony Battad MD, FRCPCUniversity of Manitoba
Disclosures
• None
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”• QTc = 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%CisaprideAmiodorone – 0.34 %Erythromycin – 0.18 %IbutilideTerfenadineQuinidine – 0.45 %ClarithromycinHaloperidol – 0.14 %Fluoxetine – 0.03 %
Digoxin – 0.1 %ProcainamideTerodilineFluconazoleDisopyramideBepridilFuroseamide – 0.1 %ThioridazineFlecainideLoratidine
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 β-
blocker therapy