Disease of the month: Heart failure

Heart failure is an impairment of the heart’s function, Paul Gyseman clarifies its causes and the insurance implications

Heart failure is described as the condition where the heart is unable to pump sufficient oxygenated blood through the arterial system to the major organs and tissues, therefore impacting upon their ability to function. It is generally a condition that affects the elderly. However, younger people with congenital or premature heart conditions may well suffer with heart failure as a consequence of their underlying illness.

Causes of heart failure & Anatomy

The most common causes of heart failure are coronary artery disease, cardiomyopathy (disease of the heart muscle), hypertension (high blood pressure) heart valve disease, congenital heart disease and alcoholism or drug abuse.

The heart, in its simplest form, can be described as a pump that is constructed of muscle and fibers, consisting of four chambers that are separated by valves to ensure blood flows in the right direction. The two upper chambers are known as the atria, or ‘filling’ chambers and the lower two, the ventricles. It is the ventricles that pump blood through the arterial system, the right ventricle pumps blood through the lungs and the left ventricle pumps blood to the rest of the body.

The heart monitors its activity and rhythm by having a natural ‘pacemaker’ set into the right atrium that acts a bit like a battery. It emits a ‘charge’ every minute or so that travels through the heart’s electrical pathway, ensuring that the heart beats in time, regularly and in sequence.

Signs & symptoms

When we are talking about heart failure, we can describe three variations. Right sided heart failure, left sided heart failure or congestive heart failure (both sides) which causes a build up of fluid within the body known as oedema. The lungs are particularly affected by this, as are the lower extremities (feet, ankles, legs) which often become swollen with fluid.

Other major symptoms include frequent coughing, shortness of breath, enlarged liver, abdominal swelling, dizziness and general fatigue.

Left ventricular function – the action chamber

The main pumping chamber of the heart is the left ventricle, which has the onerous duty of pumping blood to the whole body. The functional performance of this chamber can be measured using cardiac techniques and the label used to describe the functional performance is known as the ejection fraction. Simply put, it is the volume of blood ejected with each heart beat (systolic function) as a fraction of the total volume when at rest (diastolic function). Normal ejection fraction measurements in healthy individuals is anything above 50% but unfortunately those who suffer with heart disease and have heart failure – meaning that their ejection fraction will be lower, or much lower than 50%. Generally speaking, the lower the ejection fraction, the worse the prognosis.

Coronary heart disease, being one of the biggest killers in the UK eventually leads to heart failure – a long-term consequence of those who have suffered a myocardial infarction (heart attack), or other forms of coronary heart disease such as angina pectoris, where the arteries feeding the heart muscle become narrowed or blocked. Some who suffer large heart attacks will have permanent damage to the left ventricle and the lower ejection fraction, therefore the worse their heart failure will be.

Cardiomyopathy comes in several types, but all are due to an abnormal thickening of the heart muscle itself, which in turn narrows the outflow tract from which blood passes through, and is a precursor to abnormal heart rhythms known as arrhythmias. Ventricular arrhythmias are particularly nasty and can cause sudden death in extreme cases.

One of the long-term complications of high blood pressure is the constant abnormally high pressure on the heart to pump, and therefore heart failure develops over time. One of the reasons why it is so important to have blood pressure checks and take treatment when prescribed, is to assist in reducing the load on the heart’s pumping action.

Disease of the heart valves or heart defects from birth can lead to heart failure over time. The main valves affected are the mitral valve and the aortic valve and these valves either become narrowed, therefore do not open properly (stenotic) or do not close properly (incompetent). In both cases, blood does not flow through the valves properly and causes increased pressure in the heart which leads to heart failure, especially if left untreated.

Diagnosis and investigations

Heart failure is often diagnosed by taking a detailed medical history and a clinical medical examination, supported by x-rays, MRI scans, ECGs and echocardiograms. Clinical findings may reveal abnormal heart sounds, murmurs, crackling noises from the lungs, especially when there is shortness of breath and an enlarged liver.

An echocardiogram may reveal abnormal (hypokinetic) or lack of (akinetic) movement of the left ventricular walls and provide a reasonable estimate of the ejection fraction.

Chest x-rays may show abnormal shadowing due to fluid build up in the lungs (oedema) and heart size and an ECG will be able to give an indication of the heart’s rhythm, size and if any ischaemia (narrowing of arteries) is present.

Treatment

Heart failure is usually treated by lifestyle changes and medication. Gentle exercise, such as walking, cycling or swimming in the form of cardiac rehabilitation, is generally recommended.

Drugs such as diuretics (water tablets) are often prescribed to reduce the fluid and salt content within the body. ACE inhibitors, calcium channel blockers and vasodilators help with lowering blood pressure, reducing the strain of the heart’s pumping action and allowing blood vessels to expand. Cholesterol lowering drugs (statins) have also been shown to assist heart failure patients.

Surgery is usually required where heart valves need fixing or replacing, or where congenital heart defects exist. Blocked arteries can be treated with angioplasty or by-pass surgery where applicable.

At the severe stage, known as end-stage heart failure, only a heart transplant would be of benefit.

Underwriting implications

For serious or critical illness (CI) and any disability related products, heart failure applicants would be uninsurable. However, many applicants are able to get quoted for life cover, albeit with a moderate or heavy rating.

Clearly, the medical history with full details of the underlying illness would be required from the GP, alongside any hospital reports with details of most recent follow-ups and ejection fraction results. Other co-morbidities would need to be assessed too.

Paul Gyseman is director of underwriting & claims at PruProtect