Over time, these increases in workload, which are mediated by long-term activation of neurohormonal systems such as the renin–angiotensin system and the sympathoadrenal system, lead to fibrosis, dilation, and structural changes in the shape of the left ventricle from elliptical to spherical.The heart of a person with heart failure may have a reduced force of contraction due to overloading of the ventricle. In a normal heart, increased filling of the ventricle results in increased contraction force by the Frank–Starling law of the heart, and thus a rise in cardiac output. In heart failure, this mechanism fails, as the ventricle is loaded with blood to the point where heart muscle contraction becomes less efficient. This is due to reduced ability to cross-link actin and myosin myofilaments in over-stretched heart muscle. Diagnosis
No diagnostic criteria have been agreed on as the gold standard for heart failure. In the UK the National Institute for Health and Care Excellence recommends measuring brain natriuretic peptide 32 (BNP) followed by an ultrasound of the heart if positive. This is recommended in those with shortness of breath. In those with worsening heart failure, both a measure of BNP and of troponin are recommended to help determine likely outcomes. Classification
One historical method of categorizing heart failure is by the side of the heart involved (left heart failure versus right heart failure).
Primary pigmented nodular adrenocortical disease (PPNAD) was first coined in 1984 by Carney et al. it often occurs in association with Carney complex (CNC). CNC is a rare syndrome that involves the formation of abnormal tumours that cause endocrine hyperactivity. PPNAD arises due to the enlargement of the cortex of the adrenal glands, resulting in Cushings syndrome that is independent of the pituitary hormone ACTH. Signs and symptoms
PPNAD is a rare cause of high cortisol levels in the blood and often manifests as ACTH-independent Cushings syndrome. The effects of PPNAD can often be cyclical so the symptoms of Cushings syndrome will not always be as severe, which may complicate diagnosis. The classic symptoms of Cushings syndrome include rapid central weight gain, a puffy red face and a buffalo hump at the back of the neck due to fat deposits. Skin changes in Cushings syndrome include thinning and bruising easily, developing striae and hyperpigmentation at skin folds. The hormonal changes can lead to hirsutism, males developing breast tissue, females no longer having periods and both sexes may become infertile. High cortisol levels can lead to psychological disturbances such as anxiety or depression and insomnia. Bone health can deteriorate, leading to an increased fracture risk in people with Cushings syndrome. PPNAD is unique as it often causes Cushings at a young age, in children and adolescents.