Table 7: Endocrine disorders associated with cardiomyopathies

Syndrome: Acromegaly
Causes
Growth hormone and insulin-like growth factor 1 excess
Symptoms and signs
Tachycardia and hypertension, diabetes, rhythm disturbances Biventricular hypertrophy and diastolic dysfunction
Diagnosis
Nonsuppressibilty of serum growth hormone levels following glucose loading
Treatment
Surgery or pharmacotherapy may improve cardiovascular morbidity
Syndrome: Adrenal insufficiency (Addison's disease)
Causes
Lack of ACTH
Symptoms and signs
Hypotension, hypokalemia, syncope, bradycardia, prolonged QT, low voltage and heart failure
Diagnosis
Decrease response of the adrenal cortex to ACTH
Treatment
Replacement of the deficient steroid hydrocortisone
Syndrome: Cushing's disease
Causes
Excess production of glucocorticoids and androgens
Symptoms and signs
Hypertension, central obesity, proximal muscle weakness, myocardial infarction, stroke and cardiomyopathy
Diagnosis
Lack of appropriate suppression of cortisol secretion by dexamethasone
Treatment
Treat specific cause
Syndrome: Hypothyroidism (myxedema)
Causes
Low production of T3 and T4
Symptoms and signs
Cardiac dilation, bradycardia, weak arterial pulses, angina, hypotension, distant heart sounds, low voltage and peripheral edema
Diagnosis
TSH, free T4
Treatment
Hormone replacement
Syndrome: Hyperthyroidism
Causes
Excess production of T3 and T4
Symptoms and signs
Tachycardia, wide pulse pressure, hyperkinetic cardiac apex, high CO heart failure
Diagnosis
TSH, free T4
Treatment
Treat thyroid disease. Be careful with the use of beta-blockers
Syndrome: Pheochromocytoma
Causes
Catecholamine-producing tumour
Symptoms and signs
Hypertension 'paroxysmal', sweating, acute pulmonary edema, tachycardia, LVH, short PR interval, ST abnormalities, heart failure, myocarditis
Diagnosis
metanephrine levels
Treatment
Phenoxybenzamine hydrochloride, beta-blockers and surgery
ACTH, adrenocorticotropic hormone;
LVH, left ventricular hypertrophy;
T3 and T4, triiodothyronine (T3) and thyroxine (T4);
TSH, thyroid-stimulating hormone.