Clinical Teaching Case Anthony Battad MD, FRCPC University 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 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 β- blocker therapy