26/09/2018
Now that we know the concepts behind the Autonomic Nervous System in regards to the Heart, we can take a step closer into EKG/ECG interpretation.
A proper ECG interpretation requires consideration of the 𝐑𝐚𝐭𝐞, 𝐑𝐡𝐲𝐭𝐡𝐦, 𝐀𝐱𝐢𝐬, 𝐇𝐲𝐩𝐞𝐫𝐭𝐡𝐫𝐨𝐩𝐡𝐲 𝐚𝐧𝐝 𝐈𝐧𝐟𝐚𝐫𝐜𝐭𝐢𝐨𝐧 (known as RRAHI); They are all equally relevant.
The Heart’s SA Node is the Heart’s pacemaker and dominant center ir automaticity, it generates a 𝐒𝐢𝐧𝐮𝐬 𝐑𝐡𝐲𝐭𝐡𝐦, pacing the heart at a rate range of 60 to 100 beats per min. Different foci from the AV junction and the Ventricles could also pace at their own inherent rate in different circumstances such as blocks or hyperthrophic hearts; however, my objective is to give two easy tools to calculate the Rate.
𝐓𝐡𝐞 𝐓𝐫𝐢𝐩𝐥𝐞𝐭𝐬, I personally use this one the most! You basically stand at the tip of the QRS and count the number of blocks between thick lines (5mm equivalent) until the next QRS. The triplets are 𝟑𝟎𝟎, 𝟏𝟓𝟎, 𝟏𝟎𝟎 and 𝟕𝟓, 𝟔𝟎, 𝟓𝟎; Every thick line after the first QRS follows this sequence.
The “3 second” marks, a technique mainly used for slow rates, bradycardia. On the top margin of every EKG strip, there are small marks that identify three second intervals. The number of cardiac cycles in a 6 second strip, which is of course a 3 second interval x2, multiplied by 10 will be the rate ( 6 X 10 = 60 sec or 1 min ); bradycardias have rates that do not fit the Triplets method.
Can you calculate the rate of these traces? I’ll edit the caption with them probably tomorrow.
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Rapid Interpretation of EKG’s, 6th ed. Chapter 4: Rate @ Panama City, Panama