Heart rate and heart rhythm Flashcards
What is heart rate?
Heart rate is the number of heart beats per minute. It varies from person to person—normal resting heart rate for adults is between 60 and 100 beats/min. Heart rate is also called pulse rate.
Example sentence: The athlete’s heart rate increased during the intense workout.
What is heart rhythm?
Heart rhythm is the pattern or regularity of electrical impulses that causes the heart to contract. These electrical impulses can be seen as electrical activity in an electrocardiogram (ECG).
Additional information: Heart rate and heart rhythm are coordinated by a group of cells in the heart wall called the heart’s conduction system.
What is the SA node?
The SA node is in the superior surface of the right atrium and generates the nerve impulse that causes muscles in the atria to contract. It is also known as the pacemaker because it sets the pace of heart rate and heart rhythm.
Example sentence: The SA node is responsible for initiating the heartbeat.
What is a heart arrhythmia?
A heart arrhythmia is an irregular heartbeat that occurs when the heart’s conduction system does not function properly, causing the heart to beat too fast or too slowly.
Terms for abnormal heart rates are tachycardia (heartbeats ≥100 per minute) and bradycardia (heartbeats ≤60 per minute).
What is heart rate variability (HRV)?
Heart rate variability (HRV) is the variation in time intervals between heartbeats. It is controlled by the autonomic nervous system, which regulates the stress response (sympathetic division) and the relaxation response (parasympathetic division).
Additional information: Research has shown a relationship between low HRV and conditions such as cardiovascular disease.
What coordinates heart rate and heart rhythm in the heart wall?
The heart’s conduction system
Main parts of the system are the sinoatrial (SA) node, the AV node, the bundle of His, and Purkinje fibers.
Where is the AV node located?
In the posterior surface of the right atrium
Example sentence: The AV node is responsible for delaying the electrical impulse before it is conducted to the ventricles.
Where are the bundle of His and bundle branches located?
In the interventricular septum
Example sentence: The bundle of His is important for transmitting the electrical signals from the atria to the ventricles.
Where are the Purkinje fibers located?
In the walls of the right and left ventricles
Example sentence: Purkinje fibers are specialized cardiac muscle fibers that help to rapidly conduct the electrical impulses through the ventricles.
What generates the nerve impulse in the heart?
The SA node
The SA node generates the nerve impulse and causes muscles in the atria to contract.
Where does the nerve impulse travel to after the SA node?
The AV node through the bundle of His, down the bundle branches, and through the Purkinje fibers
The nerve impulse then travels to the AV node through the bundle of His, down the bundle branches, and through the Purkinje fibers, which causes muscles in the ventricles to contract.
What is fibrillation?
Fibrillation is a type of arrhythmia in which faulty electrical signals cause the heart to beat fast and in an uncoordinated manner—the heart quivers instead of contracting forcefully and efficiently.
Fibrillation is a type of arrhythmia.
What is atrial fibrillation (A-fib)?
Atrial fibrillation (A-fib) is irregular contractions of the atria.
Atrial fibrillation involves the atria.
What is ventricular fibrillation (V-fib)?
Ventricular fibrillation (V-fib) is irregular contractions of the ventricles.
Ventricular fibrillation involves the ventricles.
What do fibrillations require?
Fibrillations require medical treatment.
Fibrillations need medical intervention.
