Online Clinical Case Study (September 2016)

Clinical Cardiology Series

The content of the September Cardiology Series is provided by:
Dr. WONG Chi Yuen
MBBS (HK), MRCP (UK), FHKCP, FHKAM (Medicine), Specialist in Cardiology
Dr. CHUI Shing Fung
MBChB (CUHK), MRCP (UK), FHKCP, FHKAM (Medicine), Specialist in Cardiology


Drug-induced ECG changes

A 60-year-old gentleman with diabetic neuropathy complained of bilateral lower limb numbness. He was prescribed amitriptyline for symptom control. He did not have any prior cardiovascular diseases. His pre-treatment ECG is shown in Figure 1.

Figure 1

After 2 weeks of treatment, patient's symptoms improved. Another ECG was performed which is shown in Figure 2. He did not report any cardiac symptoms such as chest pain, shortness of breath, palpitation or syncope. His family history was unremarkable regarding cardiovascular diseases and sudden cardiac death.

Figure 2

1. What is shown in the ECG in Figure 2?
A. Right bundle branch block
B. ST-segment elevation myocardial infarction
C. Prolonged QT interval
D. Type I Brugada ECG pattern
E. Atrial fibrillation
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The following drugs have been reported to induce similar ECG changes except:
A. Flecainide
B. Cocaine
C. Procainamide
D. Digoxin
E. Fluoxetine

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What is the appropriate management for this gentleman?
1. Withdraw amitriptyline and consider alternative treatment
2. Electrophysiology study
3. Amiodarone
4. Implantable cardioverter-defibrillator (ICD)
A. 1 only
B. 1 and 3 only
C. 1, 2 and 3 only
D. 1, 2 and 4 only
E. All of the above

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Answer 1: D
The ECG shown in Figure 2 is Type 1 Brugada ECG pattern.

Brugada pattern findings on a surface ECG have some form of a pseudo-right bundle branch block and persistent ST segment elevation in leads V1 to V2.

While three different patterns of ST elevation were initially described and were used in clinical practice for years, subsequent consensus is that there are two distinct patterns of ST.

In the type 1 Brugada ECG pattern, the elevated ST segment (≥2 mm) descends with an upward convexity to an inverted T wave (Figure A).

In the type 2 Brugada ECG pattern, the ST segment has a "saddle back" ST-T wave configuration, in which the elevated ST segment descends toward the baseline, then rises again to an upright or biphasic T wave (Figure B).

(A Bayes de Luna , J Brugada , A Baranchuk , et al. Current electrocardiographic criteria for the diagnosis of Brugada pattern: a consensus report. J Electrocardiol 2012; 45: 433-442.)

The widened S wave in left lateral leads (V5, V6) that is characteristic of RBBB is absent in Figure 2.

Answer 2: D
The characteristic Brugada pattern ECG abnormalities may be exposed by a sodium channel blocker, such as flecainide or procainamide. Other medications and toxins that can unmask or modulate the Brugada ECG pattern are beta blockers, certain antidepressants (e.g. amitriptyline or fluoxetine), lithium, local anesthetics, and alcohol and cocaine.

A website ( has been established that identifies drugs that have been associated with adverse events in Brugada syndrome.

Answer 3: A
Diagnosis of Brugada syndrome combines the typical Type 1 Brugada ECG pattern with clinical presentation suggesting ventricular arrhythmias. These presentations including aborted sudden cardiac arrest, syncope, palpitation, documented ventricular arrhythmia.

Treatment for patients diagnosed with the Brugada syndrome is primarily focused around prevention of sudden cardiac arrest and the termination of any ventricular tachyarrhythmias with an implantable cardioverter-defibrillator (ICD). Initial pharmacologic therapy for ventricular tachyarrhythmia prevention has been tried in the Brugada syndrome with relatively little success, so ICD implantation should be the first line therapy for nearly all patients.

The clinical significance of drug-provoked ECG changes in the absence of symptoms, family history of Brugada syndrome, or family with Brugada ECG is undetermined. It is believed that the overall risks of arrhythmic events in these patients are low and close clinical follow-up may be sufficient for management.

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Dermatology Series 皮膚科病例研究

Dermatology Series for September 2016 is provided by:
Dr. CHAN Hau Ngai, Kingsley, Dr. TANG Yuk Ming, William, Dr. Dr. KWAN Chi Keung, LEUNG Wai Yiu and Dr. CHANG Mee, Mimi
Specialists in Dermatology & Venereology


The below figure shows a medication commonly used in a dermatology clinic.


1. What is this medication?
The medication is botulinum toxin type A. It is a neurotoxic protein produced by the bacterium Clostridium botulinum and related species. It can be used for both medical and cosmetic use.

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2. What is the mechanism of action?
The Botulinum toxin block release of neurotransmitter, by inhibiting the acetylcholine release causing temporary reduction in muscle activity.

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3. What are the medical diseases that can be treated by this medication?
Botulinum toxin can be used dermatologically to treat hyperhidrosis. It can also be used to treat neurological illness like cervical dystonia and migraine. Moreover, it can be used to treat eye conditions, for example: blepharospasm, strabismus, etc.

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4. What are the cosmetic diseases that can be treated by this medication?
Apart from treating medical illnesses, Botulinum toxin have been approved to treat different cosmetic conditions - to improve wrinkles temporarily for example crow's feet lines and frown lines between the eyebrows.

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5. What are the possible complications?
Botulinum toxin injection is usually a very safe office procedure. Possible adverse effect or complication may occur if injected over wrong site or with incorrect dosages or the medication may diffuse to other affected area, which include: asymmetry of facial expression, drooping of eyelid, double vision, bruising, swelling, or redness at the site of injection, headaches. Serious complication of Botulinum toxin injection though very rare may occur which include: dysphagia, respiratory failure, death, etc.

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