The heart health library
Understand heart symptoms, conditions and tests, with clear explanations and trusted medical references.
20 topics
Conditions
Angina pectoris
Angina is chest discomfort caused by reduced blood flow to the heart muscle. It can feel like pressure, squeezing or heaviness. New or unexplained chest pain needs prompt medical attention; symptoms alone cannot reliably identify the cause.
Conditions
Heart rhythm disorders · Irregular heartbeat
An arrhythmia is a problem with the heart’s rate or rhythm caused by abnormal electrical signalling. The heartbeat may be too fast, too slow or irregular. Some arrhythmias are harmless, while others need treatment; the rhythm and its significance need clinical assessment.
Conditions
Artery plaque buildup
Atherosclerosis is the gradual buildup of plaque in artery walls. Plaque contains cholesterol, fats and other substances. It can narrow arteries and limit blood flow, often without early symptoms. The effects depend on which arteries are affected; coronary artery disease involves those supplying the heart.
Conditions
AF · AFib
Atrial fibrillation is an irregular heart rhythm involving the upper chambers of the heart. The heartbeat is often fast, but some people notice no symptoms. It can increase the risk of stroke, so care includes assessing stroke risk as well as managing the rhythm and symptoms.
Conditions
Slow heart rate · Slow pulse
Bradycardia means a slow heart rate. A slow resting pulse can be normal during sleep or in trained athletes. It can also be a problem if the heart does not supply enough oxygen-rich blood, causing symptoms such as dizziness, fatigue or breathlessness. The cause and symptoms matter when assessing it.
Symptoms
Shortness of breath · Dyspnea · Dyspnoea
Breathlessness is the feeling of not getting enough air or having to work harder to breathe. Heart and lung conditions are common causes, but other conditions can also contribute. Sudden or severe breathing difficulty needs urgent medical attention.
Conditions
Heart muscle disease
Cardiomyopathy affects the heart muscle and can make it harder for the heart to pump blood. There are several types, including dilated, hypertrophic and restrictive cardiomyopathy. Symptoms and treatment depend on the type and severity; some people have no symptoms.
Symptoms
Chest discomfort · Chest tightness
Chest pain has many possible causes, including problems involving the heart, lungs, digestive system or chest muscles. It may feel sharp, dull, tight or heavy. Because serious causes cannot be excluded from the feeling alone, new or unexplained chest pain needs medical attention.
Conditions
CAD · Coronary heart disease
Coronary artery disease affects the arteries supplying the heart muscle. Plaque buildup can narrow these arteries and reduce blood flow, sometimes causing angina or breathlessness. A complete blockage can cause a heart attack. Treatment depends on the individual assessment.
Tests
Echocardiogram · Echo · Heart ultrasound
An echocardiogram uses sound waves to create images of the heart. It helps assess heart structure, pumping and blood flow through the valves. It is different from an ECG, which records electrical activity. Preparation varies with the type of echocardiogram.
Tests
ECG · EKG
An electrocardiogram records the heart’s electrical activity using sensors placed on the skin. It helps assess heart rate and rhythm and can show signs of certain heart problems. A short recording may miss a rhythm disturbance that happens at another time.
Symptoms
Syncope · Passing out
Syncope is a brief loss of consciousness caused by a temporary reduction in blood flow to the brain. It has several possible causes, including changes in blood pressure or heart rhythm. Fainting needs medical assessment because some causes are serious; it should not automatically be attributed to a heart condition.
Conditions
Congestive heart failure · Cardiac failure
Heart failure means the heart is not pumping blood as well as it should. The heart may be too weak or stiff to fill and pump properly, and fluid can build up. Breathlessness, fatigue and swelling can occur. Treatment depends on the cause and type.
Symptoms
Pounding heart · Racing heart · Skipped beats
Palpitations are sensations of a racing, fluttering, pounding or skipping heartbeat. They can occur with stress, exercise, medicines or a heart rhythm problem. Palpitations with chest pain, fainting, severe breathlessness or severe dizziness need emergency medical attention.
Conditions
Valvular heart disease · Valve narrowing · Valve leakage
Heart valve disease occurs when one or more valves do not work properly. A valve may become narrowed or fail to close fully, changing blood flow through the heart. Some people have no symptoms for years. Care depends on the affected valve and disease severity.
Risk factors
Hypertension
High blood pressure means the pressure against artery walls stays too high. It usually causes no symptoms, so measurement is important. Over time, uncontrolled blood pressure increases the risk of heart disease and stroke. A healthcare professional should interpret readings and advise on management.
Risk factors
High blood cholesterol
Excess cholesterol can contribute to plaque buildup in arteries and increase the risk of heart disease and stroke. High cholesterol usually has no symptoms and is identified with a blood test. Management may include lifestyle changes and medicines.
Tests
Ambulatory ECG · Continuous heart rhythm recording
A Holter monitor is a wearable device that continuously records heart rhythm during daily activities. It may help detect irregular rhythms that a brief ECG does not capture. The recording period and instructions depend on the device and the reason for monitoring.
Conditions
PACs · PVCs · Extra heartbeats · Skipped beats
Premature beats are extra heartbeats that start earlier than expected. Premature atrial contractions (PACs) start in an upper chamber; premature ventricular contractions (PVCs) start in a lower chamber. They may feel like a skipped beat. Their significance depends on factors such as frequency and underlying heart disease.
Conditions
Fast heart rate · Fast pulse
Tachycardia means a fast heart rate. Exercise or stress can cause a normal rise in heart rate, while an abnormal rhythm can also cause it. The cause and type determine whether treatment is needed. Some people have no symptoms; other forms can be serious.
Understanding the differences
These tests provide different information. The choice depends on the clinical question; they are not interchangeable.
An ECG records electrical activity over a short period, helping assess heart rate and rhythm.
Source: Mayo Clinic, Electrocardiogram (ECG or EKG)An echocardiogram uses ultrasound to show heart structure, pumping and valve function.
Source: Mayo Clinic, EchocardiogramA Holter monitor records rhythm during daily life over a longer period, helping capture changes a brief ECG may miss.
Source: Mayo Clinic, Holter monitorA sensation and a heart rhythm diagnosis describe different things.
Palpitations describe feeling your heartbeat race, pound, flutter or skip. They can occur with or without an abnormal rhythm.
Source: Mayo Clinic, Heart palpitations: symptoms and causesAn arrhythmia is a problem with the heart’s electrical rhythm. Some cause palpitations; others cause no noticeable symptoms.
Source: Mayo Clinic, Heart arrhythmia: symptoms and causesThe terms overlap, but chest pain has a wider range of possible causes.
Angina is chest discomfort caused by reduced blood flow to the heart muscle.
Source: Mayo Clinic, Angina: symptoms and causesChest pain can have cardiac and non-cardiac causes. The sensation alone cannot establish the cause; new or unexplained pain needs medical attention.
Source: Mayo Clinic, Chest pain: symptoms and causesCardiology in Shanghai
Patient services can help coordinate an appointment with the cardiology team.
