an electrocardiogram often abbreviated as ekg or ecg is a test that measures the electrical
activity of the heart this is an important diagnostic tool that can be used to detect
a number of heart conditions such as arrhythmias heart attacks and other cardiac abnormalities we
created this video to cover the medical definition of an electrocardiogram and provide a brief
overview of this topic so if you're ready let's get into it as previously mentioned an ekg is a
test that measures the electrical activity of the heart it's a non-invasive test which means that it
does not involve any needles or injections the electrical activity of the heart is produced by
the coordinated contraction of the heart's fourth chambers the two upper chambers known as the atria
contract first this is followed by the two lower chambers known as the ventricles the timing and
sequence of these contractions are important in ensuring that the heart pumps blood effectively
so how exactly is an ekg measured the electrical activity produced by the heart's contractions can
be detected by electrodes that are placed on the patient's skin these electrodes are connected to
an ekg machine which records the electrical activity and produces a graph that can be
interpreted by medical professionals now let's talk about the electrophysiology of the heart
the electrophysiology of the heart refers to how signals and electrical impulses
are conducted within the heart there are a number of different parts of the heart that are involved
in this process including the sinoatrial node atrioventricular node and the purkinje fibers
the sa node also known as the pacemaker is responsible for setting the heart's rhythm
the wave of depolarization that originates from the sa node is responsible for causing the atria
to contract this is known as a p wave on an ekg reading the impulse is then received by the av
node which causes a short delay this delay is interpreted as a pr interval on an ekg tracing
then the stimulus moves through the bundle of his through the left and right bundle branches and
into the purkinje fibers this produces ventricular depolarization and contraction occurs which can
be seen as the qrs complex then the heart enters into a short period of repolarization which is a
period that no electrical activity can be detected this is known as the st segment on an ekg tracing
finally the heart enters into a period of recovery where the sa node is recharged
and another cycle can begin there are two primary components of an electrocardiogram electrodes and
leaks electrodes are small metal discs that are placed on the patient's skin they are responsible
for detecting the electrical activity of the heart and transmitting it to the ekg machine
leads represent the electrical activity of the heart from a specific angle there are
six different leads in an ekg reading which are referred to by the letters 1 2 3 a vr avl and avl
but we'll talk more about those in another video but for now let's talk a bit more about the ekg
electrodes as previously mentioned there are six standard electrodes that must be attached
to a patient's chest during an ekg in order to obtain a reading this includes the following v1
which is placed on the fourth intercostal space on the right side of the sternum v2 which is at
the fourth intercostal space on the left side of the sternum now let's skip to v4 which is at the
fifth intercostal space on the left mid clavicular line and going back to v3 it is located between v2
and v4 on the left side now let's do the same thing and skip to v6 which is at the fifth
intercostal space on the mid axillary line and going back to v5 it is located between v4 and v6
on the left side each electrode has an adhesive backing that is placed on the patient's skin
and then connected to the ekg machine this allows the machine to detect the electrical activity
of the heart and produce a graph that can be interpreted by doctors and medical professionals
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i think you will enjoy and just a quick reminder we are not doctors this video is for informational
purposes only thank you so much for watching have a blessed day and as always real easy my friend