24/09/2025

It is estimated that over one million people in the UK are living with heart failure,¹ but uncovering the underlying cause can be critical to help people receive the right care.

Heart failure occurs when the heart muscle can’t pump enough blood to meet the body’s needs for blood and oxygen.² Ultimately, the heart can’t keep up with its workload which can be due to a wide range of underlying factors.² Heart failure is a serious long-term condition that can get slowly worse over time.² Treatment for heart failure aims to control the symptoms for as long as possible and slow down the progression of the condition.²

The main symptoms of heart failure can include: ²

• Breathlessness after activity or at rest.
• Swollen ankles or legs.
• Feeling tired most of the time and finding exercise exhausting.
• Fainting or feeling lightheaded.

Other symptoms can include a persistent cough and a fast heart rate.²

While the more common causes of heart failure, such as coronary heart disease, high blood pressure, valve problems, and conditions affecting the heart muscle (cardiomyopathy) are well-known,² there are also some rare and less common causes of this debilitating syndrome. These include:

Pulmonary hypertension: Raised blood pressure in the blood vessels that supply your lungs.³

Heart Rhythm Disorders: Abnormal heart rhythms, or arrhythmias, can impair the heart's ability to pump blood efficiently.³

Cardiac Amyloidosis: A rare, complex condition in which abnormal proteins (amyloids) accumulate in the organs, including the heart, and disrupt their normal function.^3,4 

Anaemia: A lack of red blood cells carrying oxygen in your blood.³

Endocarditis: A viral infection affecting the heart muscle.³

Identifying the underlying cause of heart failure is crucial, as it can guide the most appropriate treatment approach. However, diagnosing the rare and less common causes of heart failure can be challenging, as the symptoms may be similar to more common heart conditions.⁵

Many patients see multiple doctors before finally receiving the correct diagnosis, sometimes after years of uncertainty. A study of UK data between 1987 to the present, suggests that approximately 80% of heart failure diagnoses in England are made when a patient is hospitalised, despite 37% of patients having symptoms recorded in the previous 5 years that should have triggered an earlier assessment.⁶

Early diagnosis of the underlying cause of a persons heart failure is critical to help slow disease progression, as treatments are most effective when started early.⁷ It's important for healthcare professionals to therefore investigate what is causing a patient's heart failure especially if a patient is not responding to a treatment. If the cause of heart failure remains unclear individuals may be referred for additional tests such as imaging scans,³ blood tests,3 and genetic testing.⁸

Raising awareness about rare and less common causes of heart failure and its different manifestations among both the public and healthcare providers is important. Patients should feel empowered to ask doctors about the underlying cause of their heart failure, and they shouldn’t ignore symptoms. 

Additionally, continued research and development for rare and less common causes of heart failure will be crucial. Collaborative efforts between industry, academia, and the healthcare system will be key to advancing care and the provision of accessible options for all patients.⁹

With greater awareness, earlier detection, and continued innovation, we have the opportunity to improve outcomes for those affected by the rare and less common causes of heart failure.⁹