The Framingham Heart Study criteria are 100% sensitive and 78% specific for identifying persons with definite congestive heart failure. ESC algorithm
The ESC algorithm weights these parameters in establishing the diagnosis of heart failure:

Staging
Heart failure is commonly stratified by the degree of functional impairment conferred by the severity of the heart failure (as reflected in the New York Heart Association  (NYHA)  Functional Classification.) The NYHA functional classes (I–IV) begin with class I, which is defined as a person who experiences no limitation in any activities and has no symptoms from ordinary activities. People with NYHA class II heart failure have slight, mild limitations with everyday activities; the person is comfortable at rest or with mild exertion. With NYHA class III heart failure, a marked limitation occurs with any activity; the person is comfortable only at rest. A person with NYHA class IV heart failure is symptomatic at rest and becomes quite uncomfortable with any physical activity. This score documents the severity of symptoms and can be used to assess response to treatment.
An arsenical keratosis is a growth of keratin on the skin caused by arsenic,: 725  which occurs naturally in the earths crust and is widely distributed in the environment, Arsenical compounds are used in industrial, agricultural, and medicinal substances. Arsenic is also found to be an environmental contaminant in drinking water (well water) and an occupational hazard for miners and glass workers. : 640   Arsenic may also causes other conditions including: Bowens disease, cardiovascular diseases, developmental abnormalities, neurologic and neurobehavioral disorders, diabetes, hearing loss, hematologic disorders, and various types of cancer. Arsenical keratoses may persist indefinitely, and some may develop into invasive squamous cell carcinoma. Metastatic arsenic squamous cell carcinoma and arsenic-induced malignancies in internal organs such as the bladder, kidney, skin, liver, and colon, may result in death. Signs and symptoms
Books talk about diffuse ketarosic neoformations in palms and plants, which can evolve into basal cell carcinoma. These neoformations are usually yellowish. Pathophysiology
Arsenite impairs nucleotide excision repair, and it may also affect gene expression by increasing or decreasing DNA methylation. The high affinity of arsenic for sulfhydryl groups makes keratin-rich cells (e.g., epidermal keratinocytes) a sensitive target for arsenic-induced toxicity. Arsenic has been shown to alter epidermal keratinocyte differentiation processes, induce overexpression of growth factors, and enhance proliferation of human keratinocytes. Treatment
A chelating agent (e.g., dimercaprol) may be helpful to correct acute arsenic exposure, but it has minimal or no effect for patients who had arsenic exposure a long time ago.