| Course | PA 518 Comp Clin Mod Cardiovascular |
|---|---|
| Week | 2 |
| Paper type | ECG interpretation drill |
| Length | About 800 words, 5 pages |
| Format | APA 7 student paper |
| School | Chamberlain University |
| Program | Master of Physician Assistant Studies (MPAS) |
| Updated | October 2026 |
Free sample paper for PA 518 Week 2
ECG Interpretation Drill: Two 12-Lead Strips Two Years Apart, the Same Left Bundle Branch Block Measured Field by Field, and No Concordant Change at a Faster Rate
Student Name
Chamberlain University
PA 518: Comp Clin Mod Cardiovascular
Instructor Name
Month Day, Year
ECG Interpretation Drill: Two 12-Lead Strips Two Years Apart, the Same Left Bundle Branch Block Measured Field by Field, and No Concordant Change at a Faster Rate
Calibration and Speed
Both strips were recorded at 25 mm per second and 10 mm per millivolt, with a calibration pulse of 10 mm visible at the left of each. A standard filter setting was used on both. Lead placement on Strip B was checked against the chest landmarks because a misplaced precordial lead can mimic a change between tracings (Kligfield et al., 2007). Strip A is from A.K.'s preoperative visit in 2024, before a knee arthroscopy; Strip B was recorded at the clinic appointment that followed A.K.'s phone call.
Strip A, Measured Before Named
Table 1
Strip A Measurements, 2024
| Field | Strip A value |
|---|---|
| Rate | 72 per minute, counted over 10 seconds (12 complexes) |
| Rhythm and P waves | Upright P before every QRS in II; one P per QRS; regular |
| PR interval | 176 ms |
| QRS duration | 148 ms |
| QT and QTc | QT 440 ms; QTc about 482 ms (Bazett), read with the wide QRS in mind |
| Axis | About minus 20 degrees |
| QRS shape by area | V1 and V2: QS pattern. I, aVL, V5, V6: broad, notched R with no Q wave and no S wave |
| ST and T by area | ST and T opposite in direction to the main QRS deflection in every lead; largest discordant ST elevation 3 mm in V2 |
Note. Note. Intervals measured in the lead showing them longest; QTc given for completeness, though the QT is lengthened by the wide QRS.
Strip B, Measured Before Named
Table 2
Strip B Measurements, Current Visit
| Field | Strip B value |
|---|---|
| Rate | 88 per minute, counted over 10 seconds (about 15 complexes) |
| Rhythm and P waves | Upright P before every QRS in II; one P per QRS; regular |
| PR interval | 170 ms |
| QRS duration | 150 ms |
| QT and QTc | QT 410 ms; QTc about 497 ms (Bazett) |
| Axis | About minus 20 degrees |
| QRS shape by area | Same as Strip A in all leads |
| ST and T by area | Discordant throughout; largest discordant ST elevation 3.5 mm in V2, with an S wave of 22 mm in that lead |
Note. Note. No lead shows ST elevation or depression in the same direction as its QRS complex.
Fields Left Blank
None. Fields with unremarkable values, such as the PR interval and the P wave relationship, are filled with numbers, because a blank field reads as a step skipped.
What a Strip Can Say
Strip A shows sinus rhythm at 72 with a left bundle branch block. The QRS is 148 ms, there is a QS pattern in V1, and the R waves in I, aVL, V5 and V6 are broad and notched, which meets the strict criteria proposed by Strauss et al. (2011) for a true left bundle branch block. Strip B shows the same rhythm and conduction pattern at a faster rate.
These lines describe the electrical pattern. They do not say whether A.K. has coronary disease. A left bundle branch block changes the ST segments and T waves on its own, so the usual ST criteria for ischemia cannot be applied to these strips.
The Second Strip Against the First
What moved: the rate rose from 72 to 88, and the QT shortened as expected with the faster rate. The QRS width, axis and shape did not change. The largest discordant ST elevation went from 3 to 3.5 mm in V2.
Because the block makes ST changes hard to read, the comparison was also checked against the criteria Sgarbossa et al. (1996) described for detecting infarction in the presence of a left bundle branch block: ST elevation of at least 1 mm in the same direction as the QRS, ST depression of at least 1 mm in V1 to V3, or discordant ST elevation of at least 5 mm. None is present on Strip B. The ratio of the V2 ST elevation to the depth of the S wave, 3.5 to 22, is well below the level at which a disproportionate discordant change is usually suspected.
What the Comparison Cannot Do
Two strips two years apart show that the block is old and that nothing new has appeared at rest. They cannot show whether A.K.'s arteries narrow with effort, because both were recorded at rest and without symptoms. They also cannot be used for exercise testing, since the block makes an exercise tracing uninterpretable for ischemia, which will matter when a stress test is chosen.
References
Kligfield, P., Gettes, L. S., Bailey, J. J., Childers, R., Deal, B. J., Hancock, E. W., van Herpen, G., Kors, J. A., Macfarlane, P., Mirvis, D. M., Pahlm, O., Rautaharju, P., & Wagner, G. S. (2007). Recommendations for the standardization and interpretation of the electrocardiogram: Part I: The electrocardiogram and its technology: A scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society. Endorsed by the International Society for Computerized Electrocardiology. Circulation, 115(10), 1306-1324. https://doi.org/10.1161/CIRCULATIONAHA.106.180200
Sgarbossa, E. B., Pinski, S. L., Barbagelata, A., Underwood, D. A., Gates, K. B., Topol, E. J., Califf, R. M., & Wagner, G. S. (1996). Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. New England Journal of Medicine, 334(8), 481-487. https://doi.org/10.1056/NEJM199602223340801
Strauss, D. G., Selvester, R. H., & Wagner, G. S. (2011). Defining left bundle branch block in the era of cardiac resynchronization therapy. The American Journal of Cardiology, 107(6), 927-934. https://doi.org/10.1016/j.amjcard.2010.11.010
PA 518 Week 2 instructions, in plain terms
Week two asks for a worksheet interpreting two or more ECG strips under the same set of headings. State the paper speed and calibration at the top, and note any check of lead placement. For each strip, record measured values first: rate as counted, rhythm and P wave relationship, PR, QRS and QT intervals with a corrected QT, axis in degrees, QRS shape by lead group and ST and T direction by lead group. Fill every field even where the value is normal. Close each block with an interpretation line describing the electrical pattern rather than a clinical diagnosis. Where an earlier strip is supplied, add a line naming what changed between them. If a conduction pattern alters how ischemia is judged, say which criteria you used instead. Cite the sources behind any criteria.
How this PA 518 Week 2 example is built
The worksheet opens with 25 mm per second, 10 mm per millivolt and a check of precordial lead placement on the new strip, citing the AHA standardization statement. Table 1 fills nine fields for the 2024 strip, from a rate of 72 counted over ten seconds to discordant ST elevation of 3 mm in V2. Table 2 repeats the fields for the current strip at 88. A short section explains why no field is left blank. The interpretation names sinus rhythm with a left bundle branch block meeting Strauss criteria and says the usual ST criteria cannot apply. The comparison lists what moved, rate and QT, and checks three Sgarbossa criteria plus the ST-to-S ratio in V2. The close explains that resting strips cannot show effort ischemia and that the block will rule out an exercise ECG later.
PA 518 Week 2 rubric: what full points look like
Marks in this drill follow measurement first. A strip named as a rhythm with no intervals, axis or rate beneath it loses the most, because graders cannot check the reading. Empty fields cost points even when the value would be normal, since a blank reads as a skipped step. The next share rewards interpretation lines that stay within what an ECG can say: calling a strip ischemic or naming a heart attack from a tracing alone is marked down. Faculty give credit for a comparison line that names what changed and what did not. Where a bundle branch block or paced rhythm is present, using the right modified criteria is expected and rewarded. Calibration and speed at the top earn a small share, and criteria sources should be cited in APA format.
Common PA 518 Week 2 mistakes, and how to avoid them
Many students lose points on this worksheet by naming the rhythm first and measuring afterward, or not at all. Send the strips from your assignment, or their described values, and the custom sample will lay out the same block of fields for each one with every value filled. Intervals, axis and the corrected QT are worked through so the numbers can be checked. If your strips include a bundle branch block, a paced rhythm or a prior tracing, the sample applies the appropriate criteria and adds a comparison line. Interpretation lines are kept to what the electrical pattern shows. If your instructor uses a particular worksheet layout, the sample follows it. Remeasure every value on your own strips before you rely on any reading.
Get a PA-518 Week 2 example written to your instructions
Send the strips your section issued, the headings its worksheet uses and any units it requires, and a custom example comes back worked to them inside 24 to 48 hours, the first one free. Where your assignment has you bring a tracing from your own clinical site, obtaining that page and removing its identifiers stays your work, and the example uses a constructed strip instead.
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PA 518 Week 2 questions, answered
How many strips does the drill usually carry?
Two to four is usual, and what matters more than the number is that every one of them gets identical treatment. Sections issue their own set, sometimes with a single strip repeated at a later time so that the comparison can be marked. Send the sheet your classroom published, with any strip images it includes, and the example works the same set in the same order.
Do measurements need to be in milliseconds?
Whatever your worksheet asks for. Small boxes, large boxes and milliseconds all appear in these templates, and a section publishing a unit marks against it. The safer habit is recording the count and the converted value together, so the working stays visible even where a conversion goes wrong. If your sheet names a convention, the example follows that one.
Ours wants a written interpretation paragraph as well.
It adds a short passage beneath the blocks rather than replacing them. That paragraph normally gathers the measured findings into one reading and states what the strip on its own leaves unresolved. The blocks still do the scoring work. Attach the assignment wording and the example arrives with both parts built to the weighting your section gives them.
Where can I find a free PA 518 Week 2 sample paper?
The full PA 518 Week 2 ECG drill is on this page, two strips measured field by field with a left bundle branch block checked against Sgarbossa criteria.
Why does the PA 518 Week 2 sample not read ischemia from the ST segments?
A left bundle branch block changes the ST segments by itself, so the ordinary criteria fail and the modified Sgarbossa criteria are used instead.