Online Clinical Case Study (November 2016)

Clinical Cardiology Series

The content of the November Cardiology Series is provided by:
Dr. TAN GuangMing
MBChB, MRCP, FHKCP, FHKAM (Med), Specialist in Cardiology
Dr. CHEUNG Shing Him, Gary
MBBS, MRCP, FHKCP, FHKAM (Med), Specialist in Cardiology

A Case of Recurrent Syncope

60 year-old gentleman with history of smoking, hypertension, diabetes and hyperlipidemia admitted due to near syncope. He had complained of recurrent near syncope for a few years, especially when looking up and also to left. There was no preceding chest pain, palpitation or shortness of breath. Basic cardiovascular and neurological exam did not reveal any abnormality, except marked bilateral upper arm blood pressure (BP) difference on repeat measurements. Left arm BP was 110/60mmHg, and right arm BP was 160/80mmHg. Blood test was essentially normal. ECG showed normal sinus rhythm. Plain CT brain did not show any intracranial lesion. Doppler ultrasound of the extracranial arteries was ordered, and the Doppler from left vertebral artery was shown below.

1. What is the differential diagnosis?
A. Vertebrobasilar insufficiency
B. Cardiac arrhythmia
C. Benign positional vertigo
D. Subclavian steal syndrome
E. All of the above
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What investigation would you order?
A. Magnetic resonance angiography of the vertebral artery
B. 24 hours Holter study and echocardiogram
C. Dix-Hallpike maneuver
D. Magnetic resonance angiography of the subclavian artery
E. Electroencephalogram

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What does the Ultrasound Doppler suggest?
A. Vertebral artery stenosis
B. Normal flow at vertebral artery
C. Carotid artery stenosis
D. Vertebral artery systolic reversal on exercise
E. More information is needed

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4 How would you manage this patient?
A. Percutaneous transluminal angioplasty of the vertebral artery
B. Pacemaker
C. Percutaneous transluminal angioplasty of the left subclavian artery with stenting
D. Surgical bypass (carotid-subclavian bypass) of the left subclavian artery
E. Both C and D are acceptable
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  Answer: 1.D, 2.D, 3.D, 4.E

This patient's symptoms of recurrent syncope and the significant bilateral upper arm BP difference suggested of subclavian steal syndrome. CT angiography of upper limb confirmed significant stenosis at the ostium of the left subclavian artery. He underwent percutaneous transluminal angioplasty of the left subclavian artery with one bare metal stent placed (Fig 1). He remained symptoms free after and there was no more bilateral upper limb blood pressure deference on follow-up.

Subclavian steal syndrome constitutes a compromised vertebrobasilar circulation, secondary to retrograde flow to the arm from the contralateral vertebral artery resulting in a 'stealing' of blood from the posterior cerebral circulation (Fig 2). Typically it is caused by a significant stenosis or occlusion of the left subclavian artery at site proximal to the left vertebral artery. Subclavian artery stenosis most commonly caused by atherosclerosis but other etiologies include arteritis, post-radiation, compression syndromes and fibromuscular dysplasia. The incidence of subclavian artery stenosis can be as high as 11-18% in patients with documented peripheral artery disease and the left subclavian artery is four times more likely to be affected than the right or innominate arteries. Most of the cases are asymptomatic. The major symptoms of subclavian artery stenosis are upper limb claudication, and steal syndrome either from vertebrobasilar circulation such as in our case, or from left internal mammary artery in patients with history of coronary bypass. The most important sign to look for in patients with subclavian artery stenosis is bilateral upper arms blood pressure difference. A difference of more than 10mmHg can be used to delineate hemodynamic significance and justify further investigation. The investigations of choice are CT angiography and/or magnetic resonance angiography of the subclavian artery. Indications for treatment include disabling upper limb claudication, digital embolization; vertebrobasilar insufficiency from steal syndrome, and anginal symptoms from coronary steal via left mammary graft. Both surgical bypass either with axillary-axillary bypass or carotid-subclavian bypass, and percutaneous transluminal angioplasty with stenting of the subclavian artery are acceptable treatment options for symptomatic subclavian artery stenosis.

Fig 1.

Fig 2.


  1. Reivich M, Holling H, Roberts B et al. Reversal of blood flow through the vertebral artery and its effect on the cerebral circulation. N. Engl. J. Med. 265, 878-885 (1962).
  2. Bates MC, Broce M, Lavigne PS, Stone P. Subclavian artery stenting: factors affecting long-term outcome. Catheter. Cardiovasc. Interv. 61(1), 5-11 (2004).
  3. Burahma AF, Bates MC, Stone PA et al. Angioplasty and stenting versus carotid-subclavian bypass for the treatment of isolated subclavian artery disease. J. Endovasc. Ther. 14(5), 698-704 (2007).
  4. Patel SN, White CJ, Collins TJ, et al. Catheter-based treatment of the subclavian and innominate arteries. Catheter Cardiovasc Interv 2008; 71: 963-968.

Dermatology Series 皮膚科病例研究

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

Abnormal Genital Growth?


A 39 year-old man complained some growth on the penis. He cannot remember clearly the duration of onset. It seemed to start one to two months after having one-night-stand with girl met at a Pub. Physical examination revealed multiple small papules along the corona of the glans penis, otherwise, it was asymptomatic.


1. What are the differential diagnoses?
The differential diagnoses includes Genital Warts (GW), Molluscum Contagisum (MOL) and Penile Pearly Papules (PPP).

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2. What is the diagnosis?
The diagnosis is Penile Pearly Papules (PPP).

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3. What investigation would you like to order?
PPP is a clinical diagnosis and no investigation or test is needed to arrive the diagnosis. However, aceto-white test that is to apply acetic acid on the lesion in order to observe any white colour change can be used to help to differentiate PPP from GW. A white colour change suggested GW though it is not pathognomonic. In difficult cases, skin biopsy can help.

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4. What is the underlying pathophysiology?
PPP is a normal variant without any association with sexually transmitted infections and malignant potential. Some studies suggested PPP is more common in uncircumcised men.

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5. How do you treat this patient?
PPP is required no treatment because of its normal variant in nature and asymptomatic. Reassurance for anxious patients is necessary. Fractional ablative CO2 laser may be offered for cosmetic reasons. Cryotherapy shows only equivocal results in studies.

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