Learn about Heart Failure, its Prevention, and Treatment

Glossary and Related Links


ACC/ AHA stages

The stages in the progression of heart failure that appeared in the ACC/AHA (American College of Cardiology/American Heart Association) heart failure guidelines in 2001.

ACE inhibitor

By inhibiting the enzyme (ACE) that changes angiotensin I into the blood pressure raising substance angiotensin II, this drug lowers blood pressure and reduces the burden on the heart. It is used not to lower blood pressure, but to treat heart failure.
ACE: Angiotensin Converting Enzyme

Acute exacerbation

The sudden worsening of symptoms.

Aldosterone antagonists

These drugs stimulate sodium and water excretion in the kidneys, suppress potassium excretion, and increase urine volume. The excretion of excess water in the body results in lower blood pressure and decreased swelling. These drugs are also used to treat heart failure by suppressing the effects of aldosterone, which causes a phenomenon called fibrosis that damages heart muscles. The drugs thereby prevent cardiac muscle disorders and heart enlargement.


This drug lowers blood pressure by blocking the receptors of angiotensin II (a substance in the body that raises blood pressure by constricting blood vessels) and lowering the resistance of peripheral blood vessels. It is usually used to treat high blood pressure. It is also used to treat heart failure when ACE inhibitors cannot be used due to side effects.
ARB: Angiotensin II Receptor Blocker


A condition in which the pulse becomes irregular and causes palpitations or declined heart function. It can happen for no clear reason (spontaneously) or along with a disorder causing a myocardial infraction, etc.


Someone who is asymptomatic experiences no subjective symptoms such as pain or discomfort.


Beta blockers

These drugs relax an overworked heart. They are also used to treat angina and atrial fibrillation.

BNP concentration

BNP is a hormone excreted by the ventricles to protect the heart. Normal BNP concentration is 18.4pg/ml or lower. This value is used to diagnose the severity of heart failure and judge the effectiveness of treatments.
BNP:B-type natriuretic peptide


Cardiac MRI

A method of examining the heart through non-invasive imaging. A cardiac MRI is a way not only to evaluate the heart's size and function, but also to evaluate conditions not shown by other examination methods.
MRI: Magnetic Resonance Imaging

Cardiac rehabilitation

Conducted to encourage early recovery, improve quality of life (QOL) through increased exercise tolerance, and prevent aggravated heart failure and rehospitalization. Generally categorized based on whether it is done on a bed, in a hospital ward, or in a rehabilitation room.


This term refers to diseases of the heart muscle itself, and is generally divided into 3 types: dilated, hypertrophic, and restrictive.
Idiopathic dilated cardiomyopathy, hypertrophic cardiomyopathy, and restrictive cardiomyopathy are designated as incurable diseases.

Cardiopulmonary exercise test

This exam simultaneously evaluates heart, lung, and bone function during exercise (bicycle pedaling). ECG, blood pressure, and levels of oxygen and carbon dioxide during breathing are measured. The results of this test are used to decide the appropriate amount of exercise during heart failure treatment.

Cardiotonic drugs

These drugs strengthen the heart's contractions. They are normally used to boost the heart's ability to pump out blood (contract).

Chronic kidney disease

A condition in which the kidney functions are chronically declining due to high blood pressure, diabetes, etc. It is diagnosed by the glomerular filtration rate (GFR), which measures the filtration function of an important part of the kidneys called the glomerulus. Chronic kidney disease is a state of continuous kidney abnormalities indicated by a GFR 60% or less of a healthy person's (60ml/minute/1.72m2 or less), or protein in the urine.


An abbreviation for "chronic kidney disease."
(Refer to the chronic kidney disease section.)

Congenital heart diseases

Heart diseases present at birth. These include ventricular septal defect, tetralogy of Fallot, and atrial septal defect, but the most common one in Japan is ventricular septal defect, in which there is a hole in the ventricular septum dividing the heart's left and right ventricles.


An abbreviation for "cardiopulmonary exercise test."
(Refer to the cardiopulmonary exercise test section.)



A disease in which the amount of glucose (sugar) in the blood increases because the blood sugar lowering substance insulin is not working properly.

Digitalis preparations

These drugs strengthen heart contractions and adjust the heartbeat if it has become too fast. They are also used to regulate the pulse in cases of atrial fibrillation and tachyarrhythmia.


A drug that expels excess fluids from the body to reduce the burden on the heart and decrease swelling.


Exercise tolerance

This term indicates the amount of exercise someone can tolerate.


Guidelines for diagnosis and treatment of acute and chronic heart failure

Jointly created by the Japanese Circulation Society and the Japanese Heart Failure Society. These are treatment guidelines for doctors to diagnose and treat illnesses during actual examinations.



The condition of a liver that has become enlarged for some reason. In the case of heart failure, the liver is swollen caused by the congestion of blood vessels. It is diagnosed by touch to see if the liver is lower than the bottom of the rib cage.

High blood pressure

An illness in which either systolic blood pressure (the top value), diastolic blood pressure (the bottom value), or both values are higher than 140/90mmHg.



Refers to a state in which something has changed to the point of no return. Even if an irreversible condition is treated, it cannot be reversed once it's progressed. (⇔Reversibility)


Jugular vein distention

A symptom often seen with heart failure, this is the condition of a swollen vein in the neck caused by an overburdened heart. It can be confirmed in a half-seated position with the upper body raised 45 degrees.


Myocardial infarction

A condition in which the heart muscle necrotizes because the coronary arteries that nourish the heart have narrowed and completely closed up, blocking the passage of blood.


NT-proBNP concentration

If the heart is put under stress (especially the left ventricle) for any reason, this hormone is excreted. It has the effect of producing a type of urine. It is tested for the same purpose as BNP, but the NT-proBNP value will be 4-5 times higher than the BNP value.
NT-proBNP:N-terminal pro-Brain Natriuretic Peptide
BNP:B-type natriuretic peptide

NYHA classification

These functional classifications established by the New York Heart Association categorize heart failure severity in 4 classes based on subjective symptoms.



The national or global spread of a contagious disease. From the Greek "pan" (all) and "demi" (people).

Pleural effusion

Heart failure can cause blood to congest in the lungs, and in severe cases bodily fluids accumulate outside the lungs. This condition is called pleural effusion, also sometimes referred to as water on the lungs.



An abbreviation for "quality of life."



A term meaning something can be returned to its original state. (⇔Irreversibility)


Valvular heart disease

The heart contains valves that regulate blood flow. In this disease, the valves become narrow or fail to close properly.


These drugs dilate the peripheral arteries. They are normally used to treat angina and myocardial infarctions, but they are also used to reduce the burden on the heart in cases of heart failure.


6-minute walk test

The simplest and most widely used exercise tolerance test. It is used to evaluate heart and lung functions by having the subject walk on a flat surface as far as possible over a period of 6 minutes, and measuring the distance.