1st lab homework

docx

School

Concordia University *

*We aren’t endorsed by this school

Course

259

Subject

Chemistry

Date

Feb 20, 2024

Type

docx

Pages

Uploaded by CountFlyPerson101

Serira Soltani (40124404) Group member: Elyse Benest (40093471) EXCI 259 Group 1, Tuesday Lab 1: Electrocardiography Analysis Lab 1 Homework Measuring the values on the ECG: This would often be done on second lead of the 6 lead ECG, because most of the times lead 2 has the largest upward (positive) deflections. Using the 5-step analysis for detecting arrhythmias: Step 1) Determining the R wave rhythm: In order to regulate the R wave, the distance between every two R wave is measured (in millimeters) in the designated 6 second duration. In my ECG, I got 7 R wave intervals in a 6 second duration. The average of all 7 values were calculated and converted in milliseconds unit. On my ECG, this value (the average of R-R intervals) is 762.86 milliseconds. In order to determine whether the values are within the normal range, each of the values should be between 642.86 milliseconds and 882.86 milliseconds. (the average-120= 642.86, and the average+120= 882.86). The majority of my values were within that range, except for one which was 900 milliseconds. However, this doesn’t necessarily indicate a cardiac malfunction, because

of a breathing artefact that is known to exist and affect the R wave rhythm, named “accordion effect”. This artefact is seen in 40 percent of population, and simply states that taking a deep breath in, will result in increase of R-R interval; and breathing out results in decrease of interval. Step 2) calculation the heart rate: Measuring the heart rate is basically measuring the sinus rhythms, which is the heart contractions driven by the SA node. The normal range of heart rate would be between 60 to 100 bpm (beats per minute). However, athletes (especially the ones that do a lot of endurance training) might have a lower rate. (about 55 bpm). any abnormality in the heart rate, would indicate SA node arrhythmia. If the heart rate of an individual (who is not an athlete) is lower than the normal range (less than 60 bpm), it would be considered bradycardia. While if that individual’s value is higher than the normal range (higher than 100 pm), it would be considered tachycardia. According to my average R-R interval form step one, my heart rate is about 76 bpm which falls into the normal range. Step 3) P wave consistency: For assessing the P wave, there are 4 main components that should be checked: the size, direction, position of the P wave through the ECG, and whether the P wave is followed by a QRS complex or not. (if there is not a QRS following each P wave, it indicates abnormality).

Also, on each lead, the P wave and the R wave must have the same direction in ordered to be considered normal. Abnormality in size and direction of the P waves is a sign of atrial arrhythmia, which could be cause by either an ectopic or a wandering pacemaker in the heart. In my ECG, P waves follow all the regulations to be classified as normal. Step 4) P-R interval: For assessing a P-R interval duration, the distance between the beginning of P wave up to the beginning of the Q wave right after should be measured and turned into milliseconds. If the Q wave isn’t present, the distance can be measured up to the beginning of the next R wave. The average of all P-R intervals measured in that 6 second time frame should be between 120 milliseconds and 200 milliseconds. Otherwise, it would be considered abnormal which could be due to AV node arrhythmia. My value for this is about 126, which shows that I fall into the normal range and I don’t have AV node arrhythmia. Step 5) QRS complex duration: The QRS duration is measured by the distance (millimeters) between the start point and end point of QRS complex (beginning of Q wave up to the end of the following S wave. The end point of S wave is also known as J point.) This distance should be converted into milliseconds, and averaged. The average value should not be greater than 120 milliseconds. If the value exceeds 120 milliseconds, the QRS complex duration is

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

considered abnormal and indicates ventricular arrhythmia. This value in my ECG is 120 milliseconds which is an indication of normal value. Signs of hypertrophy: Hypertrophy can be seen in atria, left ventricle or right ventricle. In order to diagnose the hypertrophy in each of these heart chambers, we should measure the amplitude of specific waves in certain leads. Hypertrophy in atria: if the amplitude of P wave is larger than 0.3 millivolts in the second, third and aVF lead, there is hypertrophy in the atria. This hypertrophy is likely to be due to sticky valves. (sticky valves is a condition where the valves aren’t functioning properly due to possible calcification. My values are all less than 0.4 millivolts (0.15 millivolts in lead 2, 0.1 millivolts in lead 3, and 0.2 millivolts in lead aVF) so they are considered normal and there is no signs of hypertrophy in the atria. Hypertrophy in left ventricle: if the amplitude of R wave is larger than 1.4 millivolts in the first lead, or if it is larger than 1.2 millivolts in the lead aVL, there is hypertrophy in left ventricle. This could be a result of systemic hypertension. My values are 0.2 millivolts in lea 1, and 0.25 millivolts in lead aVL; which are in within the normal range and show no sign of hypertrophy. Hypertrophy in right ventricle: if the amplitude of R wave is greater than 0.5 millivolts in the aVR lead, there is hypertension in the right ventricle. This could be because of pulmonary hypertension. My value for this is 0.4 millivolts which falls into the normal range because it is less than 0.5 mv and is not an indication for hypertrophy in the right ventricle.

Signs of myocardial damage: The analysis is done on the lead with largest positive deflections (in this case, the second lead) and only one complex is analyzed. This analysis has three components. The changes that the myocardial damage cause on the ECG graph can be either transient or persistent. Measurement of S-T segment elevation or depression (transient change): If the S-T segment (the 2 millimeters segment after the J point) is higher or lower than the baseline for more than 1 millimeters, this deviation from the baseline is considered abnormal. This abnormality is possible to be cause by some various factors such as ischemia, infarction, tachycardia, ventricular hypertrophy and early repolarization. In my case, the S-T segment is a little bit above the baseline but the deviation is less than I millimeter which is considered normal. T wave inversion (persistent change): Another indicator of myocardial infarction would be when on the second lead, the T wave and the R wave are not in the same direction. In case of my ECG, T wave actually is in the same direction as R wave, so it is classified as normal. Large Q waves (permanent change): When the Q wave amplitude is bigger than 25 percent of the R wave’s amplitude, it is considered as a large Q wave which is known to be abnormal. In my ECG, the Q wave amplitude (0.05 millivolts) is about 7 percent of R wave amplitude (0.65 millivolts). This is less than 0.16 millivolts (24% of Q wave amplitude) and is considered normal.

In order to assume that one has myocardial damage, at least 2 out of 3 changes should be seen on the individual’s ECG. On my ECG, there is no sign of any of these changes. So there isn’t any kind of myocardial damage present in my heart.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version