As you know, as long as the battery has electricity, the pulse signal of the aircraft black box, will be issued constantly at a certain frequency. The human heart also has current activity, “life does not stop, current does not stop”, the normal heart current activity has the following characteristics. First, the “origin and route” of the current is fixed: it starts at the “sinus node” (station 1) and passes successively through the “atrium” (station 2), the “atrioventricular node” (station 3) and the “atrioventricular node” (station 4). “Atrioventricular node” (station 3) to the “ventricle” (station 4, which is also the terminal station). Second, when the current reaches the ventricles, that is, it causes one ventricular contraction, and the heart beats once. Therefore, the number of heartbeats per minute (heart rate) depends on how many times per minute the current is conducted to the ventricles (station 4). Third, although the atria (station 2) and ventricles (station 4) are structurally connected (connected by a “ring”), they are electrically insulated (the ring is like the rubber ring you see in everyday life, it does not conduct electricity). In a normal person, there is only one electrically conductive pathway between the atria and ventricles, the AV node (station 3). In fact, the name of the atrioventricular node, that is, reflects its role and function (electrical activity connecting the atria and ventricles). Other than that, there is no other way for the current to travel between the atria and ventricles. Fourth, the current is conducted in one direction. It originates in the “sinus node” (station 1) and is conducted one stop down to the “ventricle” (station 4, the end station), which causes a heartbeat, and then the current dissipates. The heart also takes a break and waits for the sinus node to send the next current to cause the next heartbeat. This is how the “smart” heart works in an orderly fashion. Under normal circumstances, the current can never return the way it came, or wind back up another way. In layman’s terms, a patient with pre-excited syndrome has a problem with the “circuit” of the heart. This is due to congenital development and has a probability of occurring in the general population of about 1 to 5 per 1,000. In the so-called pre-excitation syndrome, the atria (station 2) and ventricles (station 4) are connected not only by the “atrioventricular node” (station 3), but also by an additional conductive circuit (actually a thin fleshy wire), i.e., the aforementioned “annulus This means that the previously mentioned “flap ring” (which should be insulated and non-conductive) is no longer completely insulated, it has an extra conductive line, which is medically called “bypass” or “bypass”. Do not underestimate this tiny little extra “wire”. Because of its disturbance, the original rule of the heart current will have the possibility of derailment. Specifically, the following problems arise: First, when the current is conducted from the “atrium” (station 2) to the “ventricle” (station 4), not only is the “atrioventricular node” (station 3) the only In other words, there are actually two stations 3 (station 3A and station 3B), and the current can be conducted from station 2 to station 4 in two ways (via the AV node and the bypass, respectively). The current that comes down through the bypass is called “pre-excitation” (small short circuit). Second, originally, the current in the heart should be conducted in one direction, and after passing down, it cannot return in a circle. However, since there are now two 3rd stations between the atrium (2nd station) and the ventricle (4th station, terminal station), it is possible in some cases for the current to pass through one of the 3rd stations (3rd station A), travel down to the ventricle, then return to the atrium through the other 3rd station (3rd station B), then travel down the previous 3rd station A to the ventricle, and then return to the atrium along the 3rd station B. ………. As a result, the current is repeatedly and rapidly “circling” between “Station 2, Station 3 A, Station 4, Station 3 B”. As a result, the sinus node (station 1) loses absolute control over the heart’s current and the heart is controlled by the abnormal “circling” current, the frequency of which is usually 150-250 revolutions per minute, so that the number of heartbeats is The frequency of the current is usually 150-250 revolutions per minute, so the number of heartbeats is 150-250 per minute, which is the “big short circuit” caused by the pre-excitation, i.e. “paroxysmal supraventricular tachycardia”. Patients with preexcitation syndrome often have irregular episodes of supraventricular tachycardia, ranging from a few minutes to several hours or even days, which can cause panic, chest tightness and other discomforts, and in severe cases can lead to blackness, cold sweats, hypotension and fainting. As you know, as long as the battery has electricity, the pulse signal of the aircraft black box, will be constantly issued at a certain frequency. The human heart also has a current activity, “life does not stop, the current does not stop”, the normal heart current activity has the following characteristics. First, the “origin and route” of the current is fixed: it starts at the “sinus node” (station 1) and passes successively through the “atrium” (station 2), the “atrioventricular node” (station 3), and the “atrioventricular node” (station 4). “Atrioventricular node” (station 3) to the “ventricle” (station 4, which is also the terminal station). Second, when the current reaches the ventricles, that is, it causes one ventricular contraction, and the heart beats once. Therefore, the number of heartbeats per minute (heart rate) depends on how many times per minute the current is conducted to the ventricles (station 4). Third, although the atria (station 2) and ventricles (station 4) are structurally connected (connected by a “ring”), they are electrically insulated (the ring is like the rubber ring you see in everyday life, it does not conduct electricity). In a normal person, there is only one electrically conductive pathway between the atria and ventricles, the AV node (station 3). In fact, the name of the atrioventricular node, that is, reflects its role and function (electrical activity connecting the atria and ventricles). Other than that, there is no other way for the current to travel between the atria and ventricles. Fourth, the current is conducted in one direction. It originates in the “sinus node” (station 1) and is conducted one stop down to the “ventricle” (station 4, the end station), which causes a heartbeat, and then the current dissipates. The heart also takes a break and waits for the sinus node to send the next current to cause the next heartbeat. This is how the “smart” heart works in an orderly fashion. Under normal circumstances, the current can never return the way it came, or wind back up another way. In layman’s terms, a patient with pre-excited syndrome has a problem with the “circuit” of the heart. This is due to congenital development and has a probability of occurring in the general population of about 1 to 5 per 1,000. In the so-called pre-excitation syndrome, the atria (station 2) and ventricles (station 4) are connected not only by the “atrioventricular node” (station 3), but also by an additional conductive circuit (actually a thin fleshy wire), i.e., the aforementioned “annulus This means that the previously mentioned “flap ring” (which should be insulated and non-conductive) is no longer completely insulated, it has an extra conductive line, which is medically called “bypass” or “bypass”. Do not underestimate this tiny little extra “wire”. Because of its disturbance, the original rule of the heart current will have the possibility of derailment. Specifically, the following problems arise: First, when the current is conducted from the “atrium” (station 2) to the “ventricle” (station 4), not only is the “atrioventricular node” (station 3) the only In other words, there are actually two stations 3 (station 3A and station 3B), and the current can be conducted from station 2 to station 4 in two ways (via the AV node and the bypass, respectively). The current that comes down through the bypass is called “pre-excitation” (small short circuit). Second, originally, the current in the heart should be conducted in one direction, and after passing down, it cannot return in a circle. However, since there are now two 3rd stations between the atrium (2nd station) and the ventricle (4th station, terminal station), it is possible in some cases for the current to pass through one of the 3rd stations (3rd station A), travel down to the ventricle, then return to the atrium through the other 3rd station (3rd station B), then travel down the previous 3rd station A to the ventricle, and then return to the atrium along the 3rd station B. ………. As a result, the current is repeatedly and rapidly “circling” between “Station 2, Station 3 A, Station 4, Station 3 B”. As a result, the sinus node (station 1) loses absolute control over the heart’s current and the heart is controlled by the abnormal “circling” current, the frequency of which is usually 150-250 revolutions per minute, so that the number of heartbeats is The frequency of the current is usually 150-250 revolutions per minute, so the number of heartbeats is 150-250 per minute, which is the “big short circuit” caused by the pre-excitation, i.e. “paroxysmal supraventricular tachycardia”. Patients with preexcitation syndrome often have irregular episodes of supraventricular tachycardia, ranging from a few minutes to several hours or even days, which can cause panic, chest tightness and other discomforts, and in severe cases can lead to blackness, cold sweats, hypotension and fainting.