Online
Clinical Case Study (November 2003)
Clinical
Cardiology Series
臨床心臟科個案研究
The
content of the Clinical Cardiology Series is provided by:
Dr. Wong Shou Pang, Alexander
F.R.C.P., F.H.K.A.M.(Med.), F.H.K.C.P., Specialist in Cardiology
Dr. Li Siu Lung, Steven
M.B.,B.S.(H.K.),
M.R.C.P.(U.K.), F.H.K.A.M., F.H.K.C.P., F.R.C.P.(Glasg.), Specialist in Cardiology
臨床心臟科個案研究之內容誠蒙王壽鵬醫生及李少隆醫生提供。
A 45 year old man
with a history of heart failure presented to you with exertional dyspnea. His
coronary arteries were known to be normal and his left ventricular ejection
fraction was 35% by echocardiography. He was taking a loop diuretic and an angiotensin
converting enzyme inhibitor. Physical examination was unremarkable.
Answers
| 1. |
Is
beta-blockade therapy contraindicated?
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No.
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| 2. |
What
is the mechanism of beneficial effects of beta-blockers in chronic heart
failure?
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Beta-blockade
therapy reduces the increased sympathetic nervous system activation that
is frequently associated with heart failure. Such activation may accelerate
left ventricular remodeling, worsen myocardial function and lower the
threshold of life-threatening arrhythmias. It also inhibits the activity
of the rennin-angiotensin system and reduces atrial and ventricular arrhythmias.
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| 3. |
Which
beta-blockers have been proven to be beneficial?
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Carvedilol
(US Carvedilol, COPERNICUS, COMET trials), Metoprolol CR/XL (MERIT-HF)
and Bisoprolol (CIBIS-II) have been proven to be beneficial. Starting
dose should be low initially and gradually titrated up to maximum target
dose. If a higher target dose is not tolerated, then the highest tolerated
dose should be maintained.
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| 4. |
What
are the contraindications for beta-blockers?
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Advanced heart
block, asthma or reactive airways disease that is not related to heart
failure and requires bronchodilator therapy, a heart rate <50 bpm and
a systolic blood pressure <85 mmHg.
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| 5. |
What
are the side effects of beta-blocker therapy?
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Fatigue, depression,
dizziness, bradycardia and worsening heart failure. Beta-blockers should
not be initiated in patients with moderate to severe fluid retention.
In these patients, beta-blockers should be started when fluid overloading
problem is resolved.
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Dermatology Series
皮膚科病例研究
A 52 year old male
restaurant worker presented with mildly painful ulcer on his right ankle for
three months. The ulcer was preceded by scratching for relieving his leg itch
and enlarged progressively. He had varicose veins for over ten years. He is
a non-smoker and he enjoyed otherwise good health in the past. Physical examination
revealed a deep ulcer over his lateral malleolus measuring three centimeter
in diameter. The border was irregular and the base was yellowish. There was
purulent discharge from the wound. Brown speckled pigmentation and engorged
veins were also present. His feet were warm and pedal pulses were normal.
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The
content of the Dermatology Series is provided by:
Dr. Chan Loi Yuen and Dr. Tang Yuk Ming, William
Specialist in Dermatology & Venereology
皮膚科病例研究之內容誠蒙陳來源醫生及鄧旭明醫生提供。 |
Answers
| 1. |
What
is the clinical diagnosis? |
|
The diagnosis
is varicose ulcer. It is caused by increased venous pressure from incompetent
superficial communicating veins.
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| 2. |
What
are the clinical differential diagnoses?
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Other possible
causes for leg ulcer include arterial ulcer, infection, malignancy, vasculitis
and pyoderma gangrenosa.
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| 3. |
What
are the investigations? |
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Swab for bacterial
culture should be taken if there is purulent discharge or healing is slow.
Radiological imaging including conventional X-rays of the ankle for bone
abnormalities and Doppler ultrasonography to assess blood flow. Biopsy
of the ulcer for histopathology and cultures should be considered as appropriate
.
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| 4. |
What
are the possible complications of this condition? |
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Possible complications
include secondary bacterial infection, lymphoedema, periostitis / osteomyelitis
and contact dermatitis to topical medication.
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| 5. |
What
is the treatment?
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Factors interfering
with wound healing should be corrected and these include smoking, ankle
oedema, infection, anaemia, malnutrition and diabetes mellitus. The legs
should be elevated and trauma should be avoided. Antibiotic is required
to treat superimposed bacterial infection and analgesic to control pain.
Debridement, either mechanical or chemical, should be performed to promote
wound healing. Opinion on surgical management of varicose veins should
be seeked. Elastic compression stockings, wound dressing, topical silver
sulfadiazine cream or zinc oxide cream, skin graft may also be needed.
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