Cardiac Anatomy and Physiology
Expert-defined terms from the Postgraduate Certificate in Electrocardiography course at Greenwich School of Business and Finance. Free to read, free to share, paired with a globally recognised certification pathway.
Cardiac Anatomy and Physiology #
Cardiac Anatomy and Physiology
Cardiac anatomy and physiology refer to the structure and function of the heart,… #
Understanding cardiac anatomy and physiology is crucial for interpreting electrocardiograms accurately and diagnosing various heart conditions. This glossary will cover key terms related to cardiac anatomy and physiology in the context of the Postgraduate Certificate in Electrocardiography.
Atria #
Atria
The atria are the two upper chambers of the heart responsible for receiving bloo… #
They contract to push blood into the ventricles.
Ventricles #
Ventricles
The ventricles are the two lower chambers of the heart that pump blood out to th… #
They have thicker walls than the atria to generate enough force to propel blood through the circulatory system.
Septum #
Septum
The septum is the wall of tissue that separates the right and left sides of the… #
It plays a crucial role in maintaining the efficiency of the circulatory system.
Valves #
Valves
Valves in the heart control the flow of blood between chambers and prevent backf… #
The four main heart valves are the tricuspid valve, pulmonary valve, mitral valve, and aortic valve.
Tricuspid Valve #
Tricuspid Valve
The tricuspid valve is located between the right atrium and right ventricle #
It opens to allow blood to flow from the atrium to the ventricle and closes to prevent backflow.
Pulmonary Valve #
Pulmonary Valve
The pulmonary valve is situated between the right ventricle and the pulmonary ar… #
It opens to allow blood to be pumped to the lungs for oxygenation and closes to prevent blood from flowing back into the heart.
Mitral Valve #
Mitral Valve
The mitral valve, also known as the bicuspid valve, is found between the left at… #
It opens to permit blood to pass from the atrium to the ventricle and closes to prevent regurgitation.
Aortic Valve #
Aortic Valve
The aortic valve is located between the left ventricle and the aorta, the body's… #
It opens to allow oxygenated blood to be pumped out to the body and closes to prevent blood from re-entering the heart.
Coronary Arteries #
Coronary Arteries
The coronary arteries supply the heart muscle with oxygen #
rich blood. They branch off from the aorta and encircle the heart, ensuring that the heart receives the nutrients it needs to function properly.
Cardiac Cycle #
Cardiac Cycle
The cardiac cycle refers to the sequence of events that occur during one heartbe… #
It includes atrial and ventricular contraction (systole) and relaxation (diastole), as well as the opening and closing of heart valves to facilitate blood flow.
Electrical Conduction System #
Electrical Conduction System
The electrical conduction system of the heart controls the heartbeat by generati… #
It includes the sinoatrial (SA) node, atrioventricular (AV) node, bundle of His, bundle branches, and Purkinje fibers.
Sinoatrial (SA) Node #
Sinoatrial (SA) Node
The SA node is the heart's natural pacemaker, located in the right atrium #
It initiates each heartbeat by generating an electrical signal that causes the atria to contract.
Atrioventricular (AV) Node #
Atrioventricular (AV) Node
The AV node is located between the atria and ventricles and serves as a relay st… #
It delays the signal to allow the atria to contract before the ventricles, ensuring efficient blood flow.
Bundle of His #
Bundle of His
The bundle of His is a collection of specialized muscle fibers that transmit the… #
The bundle of His is a collection of specialized muscle fibers that transmit the electrical impulse from the AV node to the ventricles, coordinating their contraction.
Bundle Branches #
Bundle Branches
The bundle branches are extensions of the bundle of His that deliver the electri… #
The bundle branches are extensions of the bundle of His that deliver the electrical signal to the right and left ventricles, ensuring synchronized contraction.
Purkinje Fibers #
Purkinje Fibers
Purkinje fibers are specialized conducting fibers that distribute the electrical… #
Purkinje fibers are specialized conducting fibers that distribute the electrical impulse throughout the ventricles, causing them to contract from the apex upward.
Electrocardiogram (ECG or EKG) #
Electrocardiogram (ECG or EKG)
An electrocardiogram is a test that records the electrical activity of the heart… #
It provides valuable information about the heart's rhythm, rate, and conduction system.
Normal Sinus Rhythm (NSR) #
Normal Sinus Rhythm (NSR)
Normal sinus rhythm refers to the typical pattern of electrical activity in the… #
It is characterized by a regular heart rate (60-100 beats per minute) and a coordinated sequence of atrial and ventricular contractions.
Arrhythmia #
Arrhythmia
An arrhythmia is an abnormal heart rhythm that can manifest as tachycardia (fast… #
It may result from disturbances in the heart's electrical conduction system.
Atrial Fibrillation (AFib) #
Atrial Fibrillation (AFib)
Atrial fibrillation is a common type of arrhythmia characterized by rapid and ir… #
It can lead to inefficient blood pumping and an increased risk of stroke.
Ventricular Fibrillation (VFib) #
Ventricular Fibrillation (VFib)
Ventricular fibrillation is a life #
threatening arrhythmia that causes the ventricles to quiver ineffectively, leading to cardiac arrest. Immediate treatment with defibrillation is necessary to restore normal heart rhythm.
Myocardial Infarction (MI) #
Myocardial Infarction (MI)
Myocardial infarction, commonly known as a heart attack, occurs when a coronary… #
This can result in tissue damage or death if not promptly treated.
Ischemia #
Ischemia
Ischemia refers to insufficient blood flow to a particular area of the heart, us… #
It can lead to chest pain (angina) and, if severe, myocardial infarction.
Cardiomyopathy #
Cardiomyopathy
Cardiomyopathy is a disease of the heart muscle that can lead to heart failure #
It may be caused by genetic factors, infections, toxins, or other underlying conditions.
Heart Failure #
Heart Failure
Heart failure occurs when the heart is unable to pump enough blood to meet the b… #
It can result from various heart conditions, leading to symptoms such as fatigue, shortness of breath, and fluid retention.
Valvular Heart Disease #
Valvular Heart Disease
Valvular heart disease refers to conditions that affect the heart valves, such a… #
These abnormalities can disrupt normal blood flow and cardiac function.
Hypertension #
Hypertension
Hypertension, or high blood pressure, is a common condition that can strain the… #
It is a significant risk factor for cardiovascular disease, including heart attacks and strokes.
Heart Murmur #
Heart Murmur
A heart murmur is an abnormal sound heard during auscultation of the heart, indi… #
Murmurs can be innocent (benign) or signify underlying heart problems.
Cardiac Output #
Cardiac Output
Cardiac output is the amount of blood the heart pumps out per minute, calculated… #
It reflects the heart's efficiency in delivering oxygen and nutrients to the body.
Stroke Volume #
Stroke Volume
Stroke volume is the volume of blood ejected from the left ventricle with each h… #
It is influenced by factors such as preload (volume of blood in the heart), afterload (resistance to blood flow), and contractility (heart muscle strength).
Preload #
Preload
Preload refers to the amount of blood in the ventricles at the end of diastole,… #
It determines the stretch of the heart muscle and influences stroke volume.
Afterload #
Afterload
Afterload is the resistance the heart must overcome to eject blood from the left… #
High afterload can impair cardiac function and lead to increased workload on the heart.
Contractility #
Contractility
Contractility refers to the strength and efficiency of the heart muscle's contra… #
It plays a crucial role in maintaining cardiac output and can be influenced by factors such as medications, hormones, and disease.
Frank #
Starling Law
The Frank #
Starling law of the heart states that the heart will pump more blood if it is filled with more blood before contraction. This relationship between preload and stroke volume helps the heart adapt to changing demands.
Cardiac Reserve #
Cardiac Reserve
Cardiac reserve refers to the heart's ability to increase cardiac output above r… #
It reflects the heart's capacity to meet the body's increased oxygen demand.
Baroreceptors #
Baroreceptors
Baroreceptors are specialized sensory receptors located in the walls of blood ve… #
They help regulate heart rate and blood vessel constriction to maintain blood pressure within a narrow range.
Autonomic Nervous System #
Autonomic Nervous System
The autonomic nervous system controls involuntary functions of the body, includi… #
It consists of the sympathetic (fight or flight) and parasympathetic (rest and digest) branches.
Sympathetic Nervous System #
Sympathetic Nervous System
The sympathetic nervous system prepares the body for action by increasing heart… #
It plays a crucial role in the body's response to stress and exercise.
Parasympathetic Nervous System #
Parasympathetic Nervous System
The parasympathetic nervous system helps the body rest and recover by slowing he… #
It counterbalances the effects of the sympathetic nervous system.
Cardiac Stress Test #
Cardiac Stress Test
A cardiac stress test is a diagnostic test that measures how the heart responds… #
It may involve exercise on a treadmill or medication-induced stress to evaluate heart function and detect coronary artery disease.
Echocardiogram #
Echocardiogram
An echocardiogram is a non #
invasive imaging test that uses sound waves to create a detailed picture of the heart's structure and function. It can assess heart size, valve function, and blood flow patterns.
Cardiac Catheterization #
Cardiac Catheterization
Cardiac catheterization is a procedure that involves inserting a thin tube (cath… #
It allows for the measurement of pressures, collection of blood samples, and visualization of the coronary arteries.
Heart Rate #
Heart Rate
Heart rate is the number of times the heart beats per minute, reflecting the bod… #
It can be influenced by factors such as age, fitness level, stress, and disease.
Heart Sounds #
Heart Sounds
Heart sounds are the noises produced by the heart during the cardiac cycle, hear… #
The two main heart sounds are "lub-dub," representing the closure of heart valves during contraction and relaxation.
Pacemaker #
Pacemaker
A pacemaker is a small device implanted in the chest to regulate heart rhythm by… #
It is used to treat bradycardia, tachycardia, and other arrhythmias.
Cardiac Rehabilitation #
Cardiac Rehabilitation
Cardiac rehabilitation is a structured program of exercise, education, and lifes… #
Cardiac rehabilitation is a structured program of exercise, education, and lifestyle modification designed to improve heart health and recovery after a heart attack, heart surgery, or other cardiac events.
Cardiovascular Disease (CVD) #
Cardiovascular Disease (CVD)
Cardiovascular disease refers to conditions that affect the heart and blood vess… #
It is a leading cause of death worldwide.
Electrophysiology #
Electrophysiology
Electrophysiology is the study of the heart's electrical system and its disorder… #
It involves the mapping of electrical signals in the heart to diagnose and treat arrhythmias.
Heart Block #
Heart Block
Heart block is a condition in which the electrical signals between the atria and… #
It can range from mild to severe, requiring treatment with medications or pacemakers.
Cardiac Arrest #
Cardiac Arrest
Cardiac arrest is a sudden loss of heart function, causing the heart to stop bea… #
It is a medical emergency that requires immediate intervention with cardiopulmonary resuscitation (CPR) and defibrillation.
Cardiopulmonary Resuscitation (CPR) #
Cardiopulmonary Resuscitation (CPR)
Cardiopulmonary resuscitation is a lifesaving technique used to revive individua… #
It involves chest compressions and rescue breaths to maintain blood flow and oxygenation until advanced medical care is available.
Defibrillation #
Defibrillation
Defibrillation is a treatment for life #
threatening arrhythmias, such as ventricular fibrillation, that involves delivering an electric shock to the heart to restore normal rhythm. Automated external defibrillators (AEDs) are used in public settings for rapid defibrillation.
Cardiac Enzymes #
Cardiac Enzymes
Cardiac enzymes are proteins released into the bloodstream following heart muscl… #
They can be measured through blood tests to diagnose myocardial infarction and assess the extent of cardiac injury.
Cardiac Troponins #
Cardiac Troponins
Cardiac troponins are specific proteins found in heart muscle cells that are rel… #
They are sensitive markers of heart injury and play a key role in diagnosing acute coronary syndromes.
Cardiac Biomarkers #
Cardiac Biomarkers
Cardiac biomarkers are substances in the blood that indicate heart damage or str… #
They include enzymes, proteins, and other molecules that can help diagnose heart conditions and monitor treatment response.
Cardiac Imaging #
Cardiac Imaging
Cardiac imaging encompasses various techniques used to visualize the heart's str… #
These tests provide valuable information for diagnosing and managing heart disease.
Cardiac Output #
Cardiac Output
Cardiac output is the volume of blood pumped by the heart per minute, calculated… #
It reflects the heart's ability to meet the body's metabolic demands.
Cardiac Pharmacology #
Cardiac Pharmacology
Cardiac pharmacology is the study of drugs used to treat heart conditions, such… #
It includes medications that regulate heart rate, blood pressure, and cardiac function.
Heart Valve Disease #
Heart Valve Disease
Heart valve disease refers to conditions that affect the valves of the heart, su… #
These abnormalities can impair blood flow and lead to symptoms such as chest pain, shortness of breath, and fatigue.
Cardiac Rehabilitation #
Cardiac Rehabilitation
Cardiac rehabilitation is a comprehensive program of exercise, education, and li… #
It helps patients regain strength, reduce risk factors, and enhance quality of life.
Cardiac Surgery #
Cardiac Surgery
Cardiac surgery involves procedures to treat heart conditions, such as coronary… #
It is performed by cardiothoracic surgeons in specialized cardiac centers.
Cardiac Risk Factors #
Cardiac Risk Factors
Cardiac risk factors are factors that increase the likelihood of developing hear… #
Identifying and managing these risk factors is essential for preventing cardiovascular events.
Cardiac Rehabilitation #
Cardiac Rehabilitation
Cardiac rehabilitation is a structured program of exercise, education, and suppo… #
It aims to improve cardiovascular fitness, reduce risk factors, and enhance overall well-being.
Cardiac Monitoring #
Cardiac Monitoring
Cardiac monitoring involves the continuous or intermittent recording of the hear… #
It may include ambulatory monitoring devices, telemetry, or event recorders.
Cardiac Assessment #
Cardiac Assessment
Cardiac assessment involves a comprehensive evaluation of the heart's structure,… #
It may include physical examination, imaging tests, blood tests, and electrocardiography.
Cardiac Rehabilitation #
Cardiac Rehabilitation
Cardiac rehabilitation is a supervised program of exercise, education, and couns… #
It aims to improve cardiovascular fitness, reduce risk factors, and enhance quality of life.
Cardiac Arrhythmia #
Cardiac Arrhythmia
Cardiac arrhythmia refers to abnormal heart rhythms that disrupt the heart's ele… #
It can manifest as tachycardia, bradycardia, or irregular heartbeats and may require treatment with medications, devices, or procedures.
Cardiac Assessment #
Cardiac Assessment
Cardiac assessment involves a systematic evaluation of the heart's structure, fu… #
It may include physical examination, imaging tests, blood tests, and electrocardiography.
Cardiac Catheterization #
Cardiac Catheterization
Cardiac catheterization is a procedure that involves inserting a thin tube (cath… #
It allows for the measurement of pressures, collection of blood samples, and visualization of the coronary arteries.
Cardiac Cycle #
Cardiac Cycle
The cardiac cycle is the sequence of events that occur during one heartbeat, inc… #
It is coordinated by the heart's electrical conduction system and the opening and closing of heart valves.
Cardiac Output #
Cardiac Output
Cardiac output is the volume of blood pumped by the heart per minute, calculated… #
It reflects the heart's efficiency in delivering oxygen and nutrients to the body.
Cardiac Rehabilitation #
Cardiac Rehabilitation
Cardiac rehabilitation is a structured program of exercise, education, and suppo… #
It aims to improve cardiovascular fitness, reduce risk factors, and enhance overall well-being.
Cardiac Stress Test #
Cardiac Stress Test
A cardiac stress test is a diagnostic test that measures how the heart responds… #
It may involve exercise on a treadmill or medication-induced stress to evaluate heart function and detect coronary artery disease.
Cardiac Troponins #
Cardiac Troponins
Cardiac troponins are proteins found in heart muscle cells that are released int… #
They are sensitive markers of myocardial infarction and play a key role in diagnosing acute coronary syndromes.
Cardiomyopathy #
Cardiomyopathy
Cardiomyopathy is a disease of the heart muscle that can lead to heart failure #
It may be caused by genetic factors, infections