Heart failure and its causes

Heart failure is a complex clinical syndrome of symptoms and signs that suggest impairment of the heart as a pump to support physiological circulation. As a result, the cardiac output is insufficient to meet the demands of the body. Initially, patients may tolerate small declines in cardiac output as various compensatory measures are activated to redress the balance. 

Over time, however, these compensatory measures become deleterious to heart function and lead to worsening cardiac output, resulting in further activation and additional stress on a failing heart. The main systems activated in response to reduced systemic perfusion are the renin-angiotensin-aldosterone system, sympathomimetic nervous system and the natriuretic peptide system (NPS). 

There are many reasons why a patient may develop heart failure. Common causes include heart attacks (because of damage to heart muscle), undetected and uncontrolled high blood pressure, heart valve disease, disease of the cardiac muscle itself and sometimes excess alcohol or toxicity from other medications.

Symptoms

Recognising the main symptoms of heart failure will help to identify people not yet diagnosed or assess symptom control for those known to have heart failure. Typical symptoms of heart failure include: 

• Shortness of breath (dyspnoea) at rest or on exertion
• Cough with frothy sputum
• Swelling of the feet and legs secondary to fluid retention (oedema)
• Difficulty sleeping at night – unable to lie flat in bed and night-time waking due to breathlessness or cough (known as paroxysmal nocturnal dyspnoea)
• Chronic lack of energy
• Swollen or tender abdomen with loss of appetite
• Increased urination at night
• Confusion or impaired thinking/memory
• Fast heart rate or palpitations.