Who Found Out Electrical Charges Can Get a Heart Beating Again

The electrocardiogram – looking at the eye of electricity

A milestone in heart diagnosis

The electrocardiogram or ECG (sometimes chosen EKG) is today used worldwide every bit a relatively unproblematic way of diagnosing heart conditions. An electrocardiogram is a recording of the small electric waves existence generated during middle activity.

The electrical currents in the heart take been measured for more than a hundred years, merely the central function of the ECG equally nosotros know it today was developed by the Dutch scientist Willem Einthoven in the beginning of the 20th century. In 1924 Einthoven was awarded the Nobel prize in Physiology or Medicine "... for his discovery of the mechanism of the electrocardiogram."

What makes the middle beat?

The electrical activity starts at the top of the eye and spreads downward.

A normal heart beat is initiated past a small pulse of electric electric current. This tiny electric "shock" spreads chop-chop in the heart and makes the heart muscle contract.

If the whole heart muscle contracted at the aforementioned time, there would exist no pumping issue. Therefore the electrical activity starts at the superlative of the heart and spreads down, and then upward again, causing the centre muscle to contract in an optimal way for pumping claret.

Where does the electricity come up from?

In the heart there are cells specialized in producing electricity. These are called pacemaker cells. They produce electricity past chop-chop irresolute their electric charge from positive to negative and back.

The showtime electric moving ridge in a heart trounce is initiated at the top of the heart. Considering of the heart muscle cell's ability to "spread" its electric charge to next heart muscle cells, this initial moving ridge will be enough to start a concatenation reaction.

The claiming of registering millivolts

Making the electrodes sensitive plenty was a challenge in the early days of the ECG. In the late 1800's early attempts to measure the electrical action in frog'southward hearts were successful simply when the hearts were exposed directly to the measuring equipment. The measuring conditions were indeed difficult; the scientists wanted to be able to measure the electrical signals without having to enter inside the trunk. The trouble was that the electric wave got weaker since information technology had to travel through bone and torso tissue before reaching an electrode applied on the skin. This trouble was solved a couple of decades later by Willem Einthoven. He managed to improve the sensitivity of the ECG past using a string galvanometer.

Willem Einthoven

A lot of Einthoven'south terminology is still being used and his original research remains fundamental to electrocardiography today.

From electrode to paper

The electrical waves in the heart are recorded in millivolts by the electrocardiograph. The waves are registered by electrodes placed on certain parts of the body. Each electrode controls an ink needle that writes on a grid newspaper. The higher the intensity of the electric wave, the higher upward the needle volition motion on the paper. The newspaper moves at a certain speed beneath the needle, resulting in an ink curve.

Sensitive electrodes are placed on certain parts of the torso.

The leads & Einthoven'due south triangle

The electrodes are typically twelve in number. The stretch between two limb (arm or leg) electrodes is called a atomic number 82. Einthoven named the leads between the three limb electrodes "standard lead I, Ii and Three" referring to the two arm electrodes and the left leg electrode. He studied the relationship between these electrodes, forming a triangle where the centre electrically constitutes the null betoken. The relationship betwixt the standard leads is called Einthoven'south triangle. Einthoven's triangle is used when determining the electrical axis of the heart.

The standard leads (height) and the augmented leads (lesser) reflect the limb electrodes (left arm, correct arm, left leg) used to record the heart'southward electrical axis in the frontal plane. Illustration by Urban Frank.

Mountains & valleys

An ECG bend has different characteristics depending on the location of the electrode recording it. When the curve falls beneath the base line it shows a negative deflection and when it rises higher up the base of operations line it is a result of positive deflection. A negative deflection indicates that the recorded wave has traveled away from the electrode and a positive deflection means it has traveled towards information technology.

An ECG curve reflects the perspective of the electrode recording information technology.

Aberrant heartbeats & conduction defects

If the electric or muscular part of the heart is disturbed for some reason, it will touch how the electric signals spread through the heart muscle. Ane instance is arrythmia, a status where the heart beats irregularly due to a defect in the electrical conduction arrangement.

A cardiac infarction is another condition which results in dead tissue in a function of the middle muscle, and therefore the electric signal cannot travel through that area.

A left or correct packet branch block delays the electric wave from spreading to the left or correct part of the eye. Sometimes these conditions touch the heart'southward ability to pump blood.

Cells directing the middle muscle

When the heart musculus is at rest, the pacemaker cells are negatively charged and when the heart contracts they are positively charged. When a positive moving ridge is recorded by a positive electrode, the ECG bend will exist pointing upwards and vice versa.

Repolarization and depolarization

The cells alter their electric charge by means of depolarization and repolarization. Depolarization occurs when negatively charged ions inside the cell travel out from the jail cell through the prison cell membrane and positively charged ions travel in (repolarization).

Assisting the heart

A pacemaker's job is to evangelize a steady and regular electric impulse to the heart.

Pacemaker is besides the proper noun of a device that tin can help stabilize the electric conduction organisation when the center'south electric part is not working properly. The pacemaker is surgically placed in the chest, and delivers a steady rhythm of "starting" waves where this function is defective.

Play the Electrocardiogram Game

More than almost the discovery of the electrocardiogram and Nobel Laureate Willem Einthoven

Outset published: Baronial 2002

To cite this page
MLA way: "The electrocardiogram, ECG". Nobelprize.org. Nobel Prize Outreach AB 2021. Spider web. ii Apr 2022. <http://educationalgames.nobelprize.org/educational/medicine/ecg/ecg-readmore.html>

maurysworsed.blogspot.com

Source: https://educationalgames.nobelprize.org/educational/medicine/ecg/ecg-readmore.html

Share this post