Online Clinical Case Study (August 2015)

Clinical Cardiology Series
臨床心臟科個案研究

The content of the August Cardiology Series is provided by:
Dr. WU Kwok Leung MBBS(HK), MRCP(UK), FHKCP, FHKAM(Med), Specialist in Cardiology

八月臨床心臟科個案研究之內容承蒙胡國樑醫生提供。

A Patient with Syncope

A 90-year-old lady who had past medical history of diabetes mellitus was admitted for syncope. Her blood pressure was 97/45mmHg and her pulse was 28 beats per minute.

1. What is the ECG diagnosis?
A. Sinus bradycardia.
B. Junctional bradycardia.
C. First degree heart block.
D. Second degree heart block.
E. Third degree heart block.
  E
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  This was her cardiac monitoring strip in the midnight which was presented to you by the nursing staff:

   
2.

What was the diagnosis?
A. Prolonged QT interval leading to Torsades de Pointes.
B. Prolonged QT interval leading to ventricular fibrillation.
C. Prolonged QT interval leading to atrial fibrillation.
D. Artefacts.
E. Asystole at the end of cardiac monitoring strip.

  A
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3. What treatment should be given in the acute phase?
A. Intravenous dopamine.
B. Intravenous dobutamine.
C. Intravenous magnesium sulfate and transvenous temporary pacing wire insertion.
D. Synchronized electrical cardioversion.
E. External chest compression.
  C
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4. What should be the long term treatment?
A. Percutaneous coronary intervention.
B. Permanent pacemaker implantation.
C. Radiofrequency ablation.
D. Transesophageal Echocardiogram.
E. Holter study.
  B
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Discussion:
The initial ECG showed bradycardia with A-V dissocation. Therefore the diagnosis was third degree (complete) heart block. The use of AV nodal blockade agents and electrical disturbances should be excluded. In particular the QT interval (a measure of the time between the start of the Q wave and the end of the T wave) of this case was significantly prolonged. It measured around three and a half middle squares in the initial ECG (3.5 x 0.2 seconds = 0.7 seconds).

Definitions of normal QT interval vary from <= 0.4 seconds to <= 0.4 seconds.

The patient then lapsed into Torsades de Pointes due to prolonged QT interval. Long QT intervals predispose the patient to an R-on-T phenomenon, where the R wave representing ventricular depolarization occurs during the relative refractory period at the end of repolarization (represented by the latter half of the T-wave). Drugs that increase patient's tendency towards Torsades de Pointes should be withdrawn. The only effective treatments during the acute phase were administration of intravenous magnesium sulfate and transvenous temporary pacing wire insertion. Ventricular fibrillation might develop before successful transvenous cannulation for temporary pacing wire insertion. In such case patient requires electrical defibrillation, not synchronized electrical cardioversion.

In this case, the cause of prolonged QT interval leading to Torsades de Pointes was third degree heart block. The definitive long term treatment should be implantation of permanent pacemaker.

References:

  1. Lesson III. Characteristics of the Normal ECG Frank G. Yanowitz, MD. Professor of Medicine. University of Utah School of Medicine. Retrieved on Mars 23, 2010.
  2. "Drugs That Prolong the QT Interval or Induce Torsades de Pointes". Point of Care Quick Reference. March 11, 2010.
  3. Link, MS; Atkins, DL; Passman, RS; Halperin, HR; Samson, RA; White, RD; Cudnik, MT; Berg, MD; Kudenchuk, PJ; Kerber, RE (2 November 2010). "Part 6: electrical therapies: automated external defibrillators, defibrillation, cardioversion, and pacing: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care". Circulation 122 (18 Suppl 3): S706–19.
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Dermatology Series 皮膚科病例研究

The content of the August Dermatology Series is provided by:
Dr. LEUNG Wai Yiu, Dr. TANG Yuk Ming, William, Dr. CHAN Hau Ngai, Kingsley, and Dr. KWAN Chi Keung
Specialists in Dermatology & Venereology
八月皮膚科個案研究之內容承蒙梁偉耀醫生鄧旭明醫生陳厚毅醫生關志強醫生提供。

A gentleman with rapidly growing wart

A 56-year-old gentleman presented a “wart” which has been growing steadily on his right thigh for years but growing rapidly in the past three months. It gets itchy or inflamed occasionally after minor trauma. He does not have any complaints of other skin problems. On examination, there is an approximate 3-cm waxy, weatherbeaten appearance nodule on his right thigh, and a slightly swollen red flare in the surrounding skin.

Answers

1. What is the clinical diagnosis?
The diagnosis is irritated seborrheic keratosis. Seborrheic keratoses is commonly found in the trunk and all sun-exposed areas such as face, extremities and scalp. Lesion around the neck and waist can catch on clothing and becomes irritated.
 

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2. What are the differential diagnoses?
It includes viral warts, cutaneous horn, actinic keratoses and squamous cell carcinoma.
 

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3. What are the causes of this skin disease?

The precise cause of the development of seborrheic keratoses is unknown. However, human papilloma virus and epidermal growth factor have been suggested as a possible etiology due to its verrucous appearance and association with various internal malignancies.

 

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4. What investigations should be performed?

No investigation is necessary in most patients unless a sudden appearance of multiple seborrheic keratoses (Leser-Trelat sign) occurs, which is associated with the development of adenocarcinoma of the gastrointestinal tract and hematological malignancies. Dermoscopy may be used to assist in the diagnosis. A skin biopsy could be considered in doubtful or suspicious lesions. Relevant investigations should be performed if there are any associated internal malignancies suspected.

 

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5. How would you treat it?
 

Seborrheic keratoses is harmless and do not need treatment unless it is cosmetically undesirable or becomes irritated or inflamed where lesions catch on clothing. Surgical removal such as curettage and cautery and shave excision is often adopted for large or irritated lesions. Cryotherapy and laser therapy are also effective for solitary thinner lesions.

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