Which of the following(s) is/are correct (you may choose more than one item)?
a) LVH
b) RVH
c) Right axis deviation
d) P pulmonale
e) P mitrale
f) Atrial ectopic

Options d and f are correct. This gentleman was in sinus rhythm with normal axis. The P wave amplitude increased to 4 mV and was peaked in shape. By definition, any P wave amplitude greater than 2.5 mV would be classified as P pulmonale, which signified right atrial enlargement. There was no ventricular hypertrophy. There were frequent atrial ectopics with slightly variable morphologies of P waves.

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After admission to the ward, he complained of palpitations again, ECG was done and was shown below. Blood pressure was 130/80. What was the arrhythmia?

a) Sinus tachycardia
b) Ventricular tachycardia
c) Atrial Flutter
d) Mutlifocal atrial tachycardia

Option C is correct - patient had atrial flutter with 2:1 block. The second ECG showed a ventricular rate of around 170/ min. The atrial rate was around 300/min and was saw-toothed especially in the inferior leads. Atrial arrhythmia is common in patients with COAD. It is usually difficult to convert it back to sinus rhythm during the acute exacerbation. The aim is to control the heart rate and to relieve hypoxemia so that it will convert back to sinus rhythm afterwards spontaneously. Indeed, the heart rate of this gentleman was initially controlled with diltiazem and it reverted back to sinus rhythm spontaneuously after the exacerbation of COAD subsided.

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What is the clinical diagnosis?

The diagnosis is acanthosis nigricans (AN). This patient has the pseudo-AN subtype.

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What are the different subtypes of this dermatosis?

There are five types of AN. Type 1 is the hereditary, benign AN. Type 2 is the benign AN and is associated with various endocrine disorders such as type 1 diabetes, hyperandrogenetic states, Cushing’s disease, Addison’s disease and hypothyroidism. Type 3 is the pseudo-AN and is associated with obesity. Type 4 is the drug-induced AN and may be due to nicotinic acid, stilbestrol or oral contraceptives. Type 5 is the malignant AN and usually due to adenocarcinoma, or lymphoma. In type 5, AN involvement is more extensive and severe; and can involve lips, palms and soles.

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What is the underlying mechanism?

AN is caused by hyperinsulinemia associated with insulin resistance. Insulin binds to insulin-like growth factor receptors in the skin cells, resulting in hyperplasia of skin.

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What are the investigations?

There is elevated fasting blood insulin level. Screening for diabetes should also be done. Further evaluation to rule out endocrinopathy and malignancy are usually not required in obese patients or those with limited involvement.

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What are the treatments?

Weight loss can resolve type-3 AN and has beneficial effect on other types of AN. Improvement may be obtained with topical keratolytics, tretinoin, corticosteroids, dermabrasion, laser and cryotherapy. More severe form of AN may be treated with isotretinoin or acitretin. It should be noted that patients with AN are at a higher risk of atherosclerosis and subsequent cardiovascular disease, hypertension, dyslipidaemia and impaired glucose tolerance.

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