The heart is a muscular organ that pumps blood containing oxygen and nutrients to organs through the circulation system of arteries. If this is pump is damaged, it no longer works efficiently and as a result, the supply of blood to the body's other organs is reduced. Meanwhile, a back log of pressure occurs in the circulation system that leads to pressure on the heart itself and in turn this leads to a build up of fluid in the lungs and lower limbs. At least 1% of the UK population is affected by heart failure and it accounts for 5% of hospital admissions.
If the heart is not working as effectively as it should, patients notice a lack of energy, reduced exercise levels and increased fatigue. Ankle swelling or oedema, may also be an associated feature due to excess fluid in the tissues not being circulated properly. The skin is left feeling spongy so if pressure is applied with a finger, a small indentation can be felt that resolves in a few seconds. Shortness of breath can also occur, especially when lying down, due to the fluid causing lung congestion, preventing adequate oxygenation of the blood.
As heart failure progresses, so can the extent of the oedema caused by fluid swelling. Lower limbs can be affected first, with the fluid spreading upwards towards the thighs, scrotal area in males, and even the lower back and abdomen.
Symptoms of heart failure usually occur over a prolonged period of time and may initially be unnoticed. However, they become a problem when one's daily activities begin to be affected. The condition is usually stable but can be interspersed with episodes of acute symptoms.
Anything that affects the heart muscle can cause a problem with the ability to work efficiently. The causes include:
Coronary artery disease- narrowing of the arteries supplying the heart caused by cholesterol plaques, that reduces the oxygen supply and causes angina (myocardial ischaemia).
Heart attack- if the coronary artery is blocked suddenly, part of the heart muscle dies (myocardial infarction) leaving a residual scar and weakness in that part of the pump.
Hypertension- high blood pressure can cause the arteries to stiffen and narrow, increasing the risk of coronary artery disease. It also has the direct effect on the heart muscle itself by thickening it, making it less flexible and reducing its overall ability to pump efficiently.
Valvular heart disease- if the valves that help maintain the direction of blood flow are damaged (e.g. stiffening and calcification over time, infection such as endocarditis, or after a heart attack), there is an additional strain on the pumping action of the heart.
Cardiomyopathy- this is when the heart muscle is damaged directly by toxins such as alcohol, viruses, abnormal thyroid function or it may be inherited.
A variety of tests can be used to make the diagnosis of heart failure, including an ECG, chest X-ray and blood tests. However, an echocardiogram (ultrasound of the heart) is the best bedside test that can visualise the heart muscle, identify any weaknesses and highlight valve problems.
The aims of treating heart failure are to improve the overall pumping action of the heart and also alleviate the patient's symptoms. These can be achieved in a variety of ways, including medication that helps remove fluid from the body (diuretics) and others that help the heart muscle (angiotensin-converting enzymes, angiotensin-receptor blockers). Your cardiologist will tailor the most suitable regimen for you, as well as investigating for underlying causes and arranging for necessary tests, e.g. an angiogram if appropriate to evaluate coronary artery disease as a cause.