Heartbeat
Eva Rudolf-Müller is a freelance writer in the medical team. She studied human medicine and newspaper sciences and has repeatedly worked in both areas - as a doctor in the clinic, as a reviewer, and as a medical journalist for various specialist journals. She is currently working in online journalism, where a wide range of medicine is offered to everyone.
More about the experts All content is checked by medical journalists.The heartbeat marks the rhythmic contraction of the heart muscle (systole). The heart relaxes (diastole) between heartbeats. By alternately contracting and relaxing, the heart pumps the blood through the circulation in order to supply all regions of the body with oxygen and nutrients. Read everything you need to know about the heartbeat!
What is the heartbeat
The heartbeat marks the rhythmic contraction of the heart muscle (systole), which is followed by a short relaxation phase (diastole). It is triggered by electrical impulses from the excitation conduction system that arise in the sinus node. The sinus node is a collection of specialized myocardial cells in the wall of the right atrium at the junction of the superior vena cava (vena cava superior) and is automatically active. From here, the impulses are transmitted to the heart chambers.
The heartbeat can be heard with the stethoscope. An electrocardiogram (EKG) can be used to record the electrical impulses that trigger it.
The normal resting heart rate for an adult is 60 to 80 beats per minute, and for newborns it is around 120 beats per minute. Well trained endurance athletes get by with 40 to 50 beats per minute. During exercise and physical work, the heartbeat frequency increases to 160 to 180 beats per minute.
What is the heartbeat doing?
With every heartbeat, the blood is pumped through the circulation. It supplies all body regions with oxygen and nutrients via the vascular network.
How does the heartbeat work?
The electrical impulses that arise in the sinus node are conducted to the AV node via the excitation conduction system. It is the secondary pacemaker of the heart and is also located in the right atrial wall, but on the border with the right ventricle. From the AV node, the impulses are transmitted via the bundle of His, the ventricular limbs and the Purkinje fibers into the heart muscle layer of the heart chamber (ventricular myocardium), where they are then passed on from cell to cell until the entire myocardium is excited. The process until the entire heart is excited from the sinus node to the entire myocardial fibers takes about 210 milliseconds - then the contraction (systole) of the heart muscle takes place and the blood is expelled from the heart chamber. This contraction manifests itself as a heartbeat.
Conduction system
You can read more detailed information about the electrical conduction of the heart in the article Conduction System.
Sinus node
You can read everything you need to know about the primary pacemaker of the heart in the article Sinus Nodes.
AV node
You can find out more about the secondary cardiac pacemaker in the article AV nodes.
What disorders are there with the heartbeat?
Cardiac arrhythmias are an expression of irritation or damage to the conduction system. The cause is often organic heart disease such as coronary artery disease (CHD), heart muscle disease (cardiomyopathy) or inflammation of the heart muscle (myocarditis). Psychogenic causes are also possible. In addition, poisoning (intoxication) and thyroid dysfunction can be the trigger for cardiac arrhythmias. Depending on the heart rate, the arrhythmias are divided into bradycardia and tachycardia: With bradycardia the heartbeat is slower than normal, with tachycardia faster.
.jpg)
