What is the obvious conflict noted in the ECG in relation to the information given?

Despite the marked concentric left ventricular hypertrophy noted in the echocardiogram, the ECG showed no feature of left ventricular hypertrophy (LVH) and in fact, the ECG was somewhat in low voltage.

Echocardiographic demonstration of thick left ventricular walls with concomitant low voltage on ECG is characteristic of cardiac amyloidosis. On the other hand, hypertrophic obstructive cardiomyopathy (HOCM) and hypertensive heart disease usually show distinct changes of LVH on ECG.

Abdominal fat aspirate has been the single most useful diagnostic procedure with good sensitivity and safety. Biopsy of rectum, gingival, bone marrow, liver, kidney and various other tissues has also been used. If the abdominal fat aspirate is negative, endomyocardial biopsy may be helpful.

Treatment of cardiac amyloidosis is in general unsatisfactory and ineffective. Digoxin should be used with caution because these patients are particularly sensitive to digoxin and even normal doses may lead to serious arrhythmias due to selective binding of digoxin to amyloid fibrils in the myocardium. Similarly nifedipine may lead to exacerbation of congestive heart failure due to an enhanced negative inotropic effect. Careful use of low doses of diuretics and vasodilators may provide some symptomatic relief but hypotension could be a problem. For those with a conduction problem, permanent pacemaker implantation may prevent significant bradycardia. Cardiac transplantation has been performed but in general the results are inferior.

What are the items of equipment?

These are two liquid nitrogen spray units. Each unit is also called a cryojet or cryogun. They are used to perform cryotherapy to freeze skin lesions.

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What is the mechanism of action?

Liquid nitrogen is the most commonly used cryogen. Its boiling point is -196^oC. Heat transfer from the skin lesion to the liquid nitrogen applied on top of it causes freeze damage to the skin lesion. Liquid nitrogen can be delivered to the target skin lesion by various methods. The spray method using the cryojet and nozzles of different sizes is most commonly used. The dipstick method using a cotton-tipped applicator is the original method to apply liquid nitrogen. However the temperature and freezing achieved on the skin lesion is not as low or sufficient when compared with the spray method.

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What are the common skin conditions treated by this method?

Cryotherapy is the first-line treatment for viral warts, seborrhoeic keratosis and actinic keratosis. Many other benign skin lesions can be treated by cryotherapy and these include skin tags, haemangioma, molluscum contagiosum, keloid, sebaceous hyperplasia, epidermal naevus, dermatofibroma and myxoid cyst. It may also be used for treating some cases of superficial basal cell carcinoma and in situ squamous cell carcinoma, but careful follow-up is required.

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What are the possible complications?

Cryotherapy is a safe procedure with low incidence of adverse effects. These include pain, blister formation, wound and infection. Scarring and hypo- and hyper-pigmentation may develop as late complications. Rare complications include extensor tendon rupture (if cryotherapy is performed on dorsum of finger) and nerve damage.

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What are the contraindications?

Contraindications for cryotherapy include patients with cold intolerance, cold urticaria, cryoglobulinemia, history of pyoderma gangrenosum and Raynaud’s Disease. Cryotherapy to eye margin lesions should be avoided.

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