Heart failure

What happens in heart failure

The heart has two jobs: to pump blood to the body and to fill with new blood between beats. In heart failure one or both of these jobs are impaired. As a result, organs do not receive enough blood during exertion, and blood “backs up” in front of the heart: fluid leaves the vessels and collects in the lungs (causing dyspnea) and in the legs or abdomen (causing swelling).

Doctors classify the condition by the ejection fraction (EF), the percentage of blood the left ventricle ejects with each contraction, measured by echocardiography. The normal value is about 55–60%.

• Reduced EF (40% or less): the muscle does not contract strongly enough.
• Preserved EF (50% or more): the muscle contracts well but is stiff and cannot fill properly; often after long-standing hypertension, diabetes, age or excess weight.
• Mildly reduced EF (41–49%).

Heart failure exists even when the EF is normal, so the diagnosis is never based on a single percentage, but on symptoms, examination and other findings. The left side (dyspnea), the right side (swelling, a bloated abdomen) or both may be mainly affected.

What the symptoms are

Symptoms usually start gradually and are often put down to age or poor fitness:

• Dyspnea when walking or exerting yourself that used to pass without difficulty; as it worsens it appears at rest too.
• Difficulty breathing when lying down (sleeping with more pillows) or waking at night short of breath.
• Fatigue and reduced ability to exert yourself.
• Edema (swelling) of the ankles and legs, which leaves a dent when pressed; sometimes the abdomen too.
• Rapid weight gain (for example more than 2 kg in 3 days) from fluid build-up.
• A dry cough at night, loss of appetite, passing more urine at night, palpitations.

These signs can also have other causes (lung disease, kidney disease, anemia, thyroid) and need to be assessed, not self-treated.

Causes

Heart failure is the result of another condition, so looking for the cause is an essential part of the diagnosis:

• Coronary artery disease and a previous heart attack, which damage the muscle.
• Long-standing arterial hypertension, which stiffens or thickens the muscle.
• Valve disease.
• Cardiomyopathies (diseases of the muscle itself), some of them familial.
• Prolonged, fast arrhythmias.
• Diabetes, obesity, excess alcohol, some cancer medicines (see cardio-oncology), thyroid disease, anemia, sleep apnea.

How the diagnosis is made

The cardiologist takes the history of symptoms, previous illnesses and medicines; listens to the heart and lungs, measures blood pressure and weight and looks for edema. Then, depending on the case:

• ECG for the rhythm and signs of a previous heart attack or thickening of the wall.
• Echocardiography is the central exam: it shows the EF, the size of the chambers, the thickness of the wall and the valves.
• Blood tests: natriuretic peptides (BNP or NT-proBNP) rise when the heart is under strain; a very low value makes the diagnosis less likely. They also rise with age, atrial fibrillation and kidney failure, so they are interpreted in context. Kidney function, electrolytes, hemoglobin, thyroid and iron are also measured.
• When needed: chest X-ray, tests for ischemia or the coronary arteries, cardiac MRI and catheterization. These are performed at specialized centers and recommended only when they affect the decision.

The results are interpreted together; a single test or exam rarely suffices.

How it is treated

The aims are to relieve symptoms, prevent hospital admissions and prolong life. Treatment is tailored to the type of heart failure and its cause.

• Medicines. When the EF is reduced, combinations of four groups that have been shown to prolong life are usually used: ACE inhibitors or ARNI (or ARB), beta blockers, mineralocorticoid receptor antagonists and SGLT2 inhibitors. Diuretics remove excess fluid and relieve dyspnea and swelling, but do not themselves affect prognosis. When the EF is preserved, the emphasis is on SGLT2 inhibitors, diuretics and treatment of hypertension, diabetes, atrial fibrillation and other causes. Doses are adjusted gradually with checks of the kidneys and potassium.
• Treating the cause: revascularization in coronary disease, intervention on the valves, rhythm control.
• Specialized devices and procedures in selected patients (defibrillators, cardiac resynchronization, valve interventions), decided by specialized centers.
• Daily care: weigh yourself every morning after urinating and on the same scale; moderate salt (avoid salty and processed food); fluids as your doctor advises (restriction is not needed for everyone); no smoking and no excess alcohol; regular, measured physical activity; flu and pneumococcal vaccines; taking medicines regularly.

Avoid anti-inflammatories such as ibuprofen and diclofenac without asking your doctor: they retain water and can worsen heart failure. Do not change medicine doses yourself.

Follow-up and when to contact your doctor

Check-ups assess symptoms, weight, blood pressure, kidney function, potassium and the need for new tests, including a repeat echocardiogram when the clinical picture changes or after a change in treatment. Bring your list of medicines, weight diary and previous results; say whether usual activities have become harder.

Contact your doctor without waiting for the routine check-up if weight rises quickly (more than 2 kg in 3 days), dyspnea or edema increase, you cannot sleep lying flat, or dizziness and a fall in blood pressure appear.