This will allow you to determine what area of the ECG represents one heart beat. From the length of a heart beat on the ECG trace, you will be able to calculate the heart rate. A normal heart beat contains a P wave, a QRS complex, and an ST segment. The one you will want to pay particular attention to is the QRS complex, as this is the easiest one to use to calculate heart rate.  The P wave is a small semi-circular shape located right before the tall QRS complex. It represents the electrical activity of the atria ("atrial depolarization"), which are the two small chambers located at the top of the heart. The QRS complex is the tallest most visible aspect of the ECG trace. It is usually pointy, like a tall, thin triangle and very easy to recognize. It represents the electrical activity of the ventricles ("ventricular depolarization"), which are the two large chambers located at the bottom of the heart that forcefully pump blood throughout the body. The ST segment directly follows the tall QRS complex. It is actually the flat area prior to the next semi-circular shape on the ECG (which is the T wave). The importance of this flat segment (the ST segment), located right after the QRS complex, is that it provides important information to physicians about things such as potential heart attacks. The QRS complex is normally the tallest part of the pattern that repeats on the ECG. It is a tall and skinny spike (for a person with normal heart function) that occurs repeatedly at the same rate across the ECG trace. Every time one QRS complex occurs, it is an indication that one heart beat has taken place. Therefore, you can use the space between QRS complexes on the ECG to calculate the heart rate. The next step is to determine the number of large squares on the ECG trace separating one QRS complex from the next QRS complex. The ECG normally has both small squares and large squares. Be sure you are using the large squares as your reference point. Go from the peak of one QRS complex to the peak of the following QRS complex. Note the number of large squares separating the two points.  Often, it will be a fractionated number as the complexes will not land exactly on the squares; for instance, 2.4 squares or 3.6 squares may separate adjacent QRS complexes. There are normally 5 little squares embedded in each large square, allowing you to approximate the distance between QRS complexes to the nearest 0.2 units (because 1 big square divided into 5 small squares gives you markings every 0.2 units). Once you have calculated the number of big squares separating QRS complexes (let's use 3.2 as an example), perform the following calculation to determine heart rate: 300/3.2 = 93.75. Round your answer to the nearest whole number. In this case, the heart rate would be 94 beats per minute.  Note that a normal heart rate is between 60 to 100 beats per minute. Knowing this can help to guide whether you are on course with your heart rate calculations. However, 60 to 100 beats per minute is only a loose guideline. Many athletes who are in excellent physical shape have lower resting heart rates. There are also disease states that can provoke unhealthy slower heart rates (called pathological bradycardias), and diseases that can lead to an unnaturally accelerated heart rate (called pathological tachycardias). Speak to a physician if the person you are calculating heart rate for appears to have an abnormal value.
كن على دراية "بشكل الموجة" الطبيعي عن طريق تتبعها على رسم القلب الكهربائي. تعرّف على مركب QRS. احسب عدد المساحة الثابتة بين مركبات QRS ابدأ بالخطوة الأولى وهي حساب عدد المربعات الكبيرة التي تفصل كل مركب QRS عن مركب QRS الذي يليه، كما توضح الصورة. اقسم الرقم 300 على إجابتك.