Congestive heart failure (CHF) is a complex clinical syndrome where the heart's inability to efficiently pump blood results in compromised function. This can be caused by a variety of factors, including thiamine deficiency, and is characterized by a group of signs and symptoms known as a syndrome. The inability of the heart to adequately meet the body's metabolic needs can lead to increased filling pressure and reduced blood flow. This condition, known as decompensatio cordis or heart failure, can cause fatigue and reduced exercise tolerance. It is a common health concern with high rates of morbidity and mortality. There is a wide range of literature available on this topic, including books like "Decompensatio cordis" by J. Pool, published in 1986.