Heart failure: when the heart’s strength fails

Cardiomyopathy is a disease of the heart muscle that impairs contraction, ultimately reducing the heart’s ability to pump blood.

Heart failure is one of several types of cardiomyopathy. 

The heart is an organ consisting of four chambers. It has two atria and two ventricles, on the left and on the right. 

Each ventricle serves a specific function. The right ventricle contracts and pumps blood toward the pulmonary arteries to be filled with oxygen in the lungs. 

The left ventricle contracts and pushes blood into the aorta. The oxygen-rich blood is then delivered to the organs, muscles and tissues in the body. 

Heart failure occurs when the heart is no longer able to perform the pumping function required for proper blood distribution. 

This is a relatively common condition. The first symptom is shortness of breath during exercise. This occurs because the heart is no longer able to pump enough blood to meet demand during physical activity.

There are two types of heart failure. The first is systolic heart failure, also called heart failure with reduced ejection fraction. It occurs when the heart muscle loses its ability to contract normally. This decreases the amount of blood ejected during each heartbeat.

The second is diastolic heart failure, also known as heart failure with preserved ejection fraction. In this case, the heart muscle becomes stiff and cannot relax properly. This hinders the capacity of the heart chambers to fill with blood and increases the pressure required to accomplish this.

Causes

Heart failure has many causes. 

• Coronary artery disease: the arteries bring oxygen to the heart. If one of these arteries is blocked, the heart suffers and part of the cardiac muscle dies, which decreases its force of contraction. 
• Genetic heart disease: certain mutations can alter the heart’s architecture and functioning.
• Heart rhythm and conduction disorders: These include atrial fibrillation.
• Heart valve abnormalities
• Viral or bacterial infections
• Diseases affecting other organs: such as lupus, hyperthyroidism and kidney failure.

Symptoms

People with heart failure can experience a wide variety of symptoms. 

These symptoms often do not appear right away, but tend to develop over a few weeks or months, as the heart starts to become strained. 

Patients can experience shortness of breath, especially during physical activity. 

There are also cases of excessive fatigue that is not necessarily linked to physical activity. Chest pain at rest and during physical activity can also occur. This is a sign that the coronary arteries are affected. Finally, some people experience palpitations, the sensation of a rapid or irregular heartbeat.

Edema may also develop, causing swelling in the ankles or legs.

Diagnosis

The patient should consult a primary care physician, who will make an initial diagnosis before recommending further examinations. 

An electrocardiogram is used to detect arrhythmia and indicate any additional tests that are required. 

Echocardiography is the key test used to analyze the heart’s architecture and the functioning of its various structures.

A chest X-ray is used to identify cardiac dilatation or pulmonary overload. 

Blood tests are used alongside the most common tests to identify the underlying causes of the heart failure. Certain markers, such as BNP, are specific to heart failure. Further tests may also be carried out, such as magnetic resonance imaging (MRI) for a thorough analysis of cardiac function.

Treatment

Heart failure treatment focuses on the cause. However, cardioprotective medication is also prescribed to help slow the progression of heart function deterioration: 

• Medication: Antihypertensives, diuretics, beta-blockers and sometimes anticoagulants.
• Lifestyle changes: A low-salt, Mediterranean-type diet.

Source: Reviewed by Benjamin Bouyer, MD, Cardiologist at Bordeaux University Hospital (CHU)