Ekg Measurement and Interpretation at Rest and During Exercise

cardiogram Measurement and Interpretation at Rest and During maintain Jonathan Murdock March 5, 2013 March 19, 2013 (KIN 375) Purpose In the United States, people take on from heart problems both day. According to the Centers of Disease Control and Prevention (CDC), every year about 935,000 people in the United States suffer from a heart attack and about 600,000 go past from heart problems. Electrocardiograms (cardiogram or ECG) rear important information concerning the electrical activity of the heart as well as the quantity and quality of heart condensations.An electrocardiogram, along with rootage plow to prevention troponin levels, can definitively determine whether or not a mortal has suffered from a myocardial infarction. In order to obtain an electrocardiogram, electrodes atomic number 18 strategically placed on the offsets and torso of a subject to measure the electrical current that is generated in the heart and transferred to the skin. The electrical manoeu vre is first generated in the sinoatrial node (SA node). It wherefore travels to both the left and right atria to cause them to contract.Then, the signal goes to the atrioventricular node (AV node) where it is briefly delayed to allow all of the squanderer from the atria to move into the ventricles. It hence moves through the Bundle of His toward the apex of the heart and then through the Purkinje fibers. This causes contraction of the ventricles to pump blood throughout the body and lungs. The place of this lab was to compare EKG at rest with and exercising EKG. In doing so, the subjects heart health could be determined base on the results of being put under the stress of exercise versus when resting.Methods theatre The subject participating in this lab was a college aged (18-25 years) male person enrolled in KIN 375. The participant was healthy, exercised regularly, and did not report any report of heart problems. Equipment The equipment used in this lab included intoxican t planning wipes, 10 electrodes and wires, a computer to read the EKG with paper to fall guy EKG strips, a chair, a tread-wheel, and a timer. Procedures The first step was to pick out the subjects shirt.Next, all of the areas where electrodes were going to be placed were cleaned with an alcohol prep wipe. Once these areas were dry, electrodes were placed in their proper places one electrode per limb and six on the torso. The electrodes for the left (LA) and right (RA) upper limbs were placed alone under the clavicles near the shoulders. The electrodes for the left (LL) and right (RL) lower limbs were placed at the waist line just above each limb. For the torso, electrode 1(V1) was placed in the fourth intercostal muscle space to the right of the subjects sternum.Electrode 2 (V2) was also placed in the fourth intercostal space further to the left of the subjects sternum. Next, electrode 4 (V4) was placed in the one-fifth intercostal space on the midclavicular line. Then, elect rode 3 (V3) was placed halfway in the midst of V2 and V4. Next, the sixth electrode (V6) was placed in the fifth intercostal space on the midaxillary line. Lastly, the fifth electrode (V5) was placed halfway between V4 and V6 in the fifth intercostal space. The subject sit down on the chair without moving for three proceeding to generate a resting EKG.Then, the subject walked 2 mph on the treadmill with a 7. 0% incline for five minutes. This generated an exercising EKG. Lastly, the subject sat on the chair without moving for three minutes to generate a recovery EKG. Results The subject successfully completed all three EKG recordings. The resting and recovery EKG readings were very easy to read whereas, the exercising EKG had a lot of artefact that made it difficult to read. Artifact is something that is not heart made and usually comes from movement.The exercising EKG also had the most(prenominal) QRS complexes due to the fact that the subjects heart rate was the highest speckle exercising. Discussion As previously stated, an EKG measures the electrical currents of the heart. There are different swans shown on an EKG. Each wave is makeed by a letter. The first small wave is cognise as the P wave. The P wave represents atrial depolarization and contraction. The next wave is slightly disallow and it is cognise as the Q wave. The Q wave initiates depolarization of the ventricles.The next wave, which is the large positive spike in the wave, is known as the R wave. The R wave represents ventricular depolarization and contraction. The next wave is slightly prohibit and it is known as the S wave. The S wave represents the negative wave of ventricular depolarization. The last wave is slightly larger than the P wave and it is known as the T wave. It represents ventricular repolarization and relaxation. Since there are three waves that represent ventricular depolarization, they are combined into what is known as the QRS complex.The section of the EKG from the beginning of the P wave to the beginning of the QRS complex represents the ventricular conduct time and is known as the PR interval. Ventricular systole, or contraction, is shown by the start of the Q wave to the start of the T wave and is known as the QT interval. Lastly, from the end of the S wave to the start of the T wave, ventricular repolarization is normally isoelectric (on the baseline) and is represented by the ST segment. Any slight dislodges from normal sinus verse in any of these waves could indicate a heart problem.Electrodes were used to measure the electrical current in the heart. The grades from each electrode to another created a lead. draw out I was the path between RA and LA. Lead II was the path between RA and LL. Lead III was the path between LA and LL. The ground electrode was RL. An EKG wave read positive when the current locomote toward a positive electrode and it read negative when the current moved toward the negative electrode. At rest, the EKG was often cleaner (less artifact) and the P waves, QRS complexes, and T waves were much easier to identify.During exercise, however, these waveforms were much more difficult to identify because of the large amount of artifact. Compared to at rest, the waveforms were much steeper and quicker which indicated the heart rate was speeding up, contraction and filling times decreased, and the contractions were much more forceful to pump the blood to the necessary tissue. There were a couple factors that could have hindered a alone accurate EKG reading such as, cheap electrodes, movement of wires, and the office of electrodes.All of these factors could have affected the EKG reading to cause extra artifact or inaccurate readings of the electrical current. Conclusion Every year, hundreds of thousands of people die from heart problems. Many of these heart problems could be detected if the individuals had received an EKG. An EKG measures the electrical currents of the heart and shows when there a re defects or blocks by the change in waveform. If more people were able to have an EKG when the problems arose, then maybe more lives would have been saved.