Electrocardiographic Differentiation of Early Repolarization From Subtle Anterior ST-Segment Elevation Myocardial Infarction
Annals of Emergency Medicine,

Smith SW et al. – R–wave amplitude is lower, ST–segment elevation greater, and corrected QT interval (QTc) longer for subtle anterior ST–segment elevation myocardial infarction (STEMI) versus early repolarization. In combination with other clinical data, this derived and validated ECG equation could be an important adjunct in the diagnosis of anterior STEMI.

Methods
  • This was a retrospective study of patients with anterior STEMI (2003 to 2009) and early repolarization (2003 to 2005) at 2 urban hospitals, one of which (Minneapolis Heart Institute) receives 500 STEMI patients per year.
  • The authors compared the ECGs of nonobvious (“subtle”) anterior STEMI with emergency department noncardiac chest pain patients with early repolarization.
  • ST-segment elevation at the J point and 60ms after the J point, T-wave amplitude, R-wave amplitude, QTc, upward concavity, J-wave notching, and T waves in V1 and V6 were measured.
  • Multivariate logistic regression modeling was used to identify ECG measurements independently predictive of STEMI versus early repolarization in a derivation group and was subsequently validated in a separate group.

Results
  • Of 355 anterior STEMIs identified, 143 were nonobvious, or subtle, compared with 171 early repolarization ECGs.
  • ST-segment elevation was greater, R-wave amplitude lower, and T-wave amplitudeavg/R-wave amplitudeavg higher in leads V2 to V4 with STEMI versus early repolarization.
  • Computerized QTc was also significantly longer with STEMI versus early repolarization.
  • T-wave amplitude did not differ significantly between the groups, such that the T-wave amplitudeavg/R-wave amplitudeavg difference was entirely due to the difference in R-wave amplitude.
  • An ECG criterion based on 3 measurements (R-wave amplitude in lead V4, ST-segment elevation 60ms after J-point in lead V3, and QTc) was derived and validated for differentiating STEMI versus early repolarization, such that if the value of the equation ([1.196 x ST-segment elevation 60ms after the J point in lead V3 in mm]+[0.059 x QTc in ms]-[0.326 x R-wave amplitude in lead V4 in mm]) is greater than 23.4 predicted STEMI and if less than or equal to 23.4, it predicted early repolarization in both groups, with overall sensitivity, specificity, and accuracy of 86% (95% confidence interval [CI] 79, 91), 91% (95% CI 85, 95), and 88% (95% CI 84, 92), respectively, with positive likelihood ratio 9.2 (95% CI 8.5 to 10) and negative likelihood ratio 0.1 (95% CI 0.08 to 0.3).
  • Upward concavity, upright T wave in V1 or T wave, in V1 greater than T wave in V6, and J-wave notching did not provide important information.

Please login or register to follow this author.
Are you sure you want to Unfollow this Author?
► Click here to access PubMed, Publisher and related articles...
<< Previous Article | Next Article >>

Your Unread Messages in Nursing

See All >> Messages include industry-sponsored communications and special communications from MDLinx

Most Popular Nursing Articles

1 Long-term associations of nut consumption with body weight and obesity American Journal of Clinical Nutrition, June 23, 2014    Clinical Article

2 Yogurt and weight management American Journal of Clinical Nutrition, April 3, 2014    Review Article

3 Chocolate intake and diabetes risk Clinical Nutrition, July 21, 2014    Clinical Article

4 Metformin in chronic kidney disease: Time for a rethink Peritoneal Dialysis International, July 9, 2014    Clinical Article

5 Blood pressure in relation to coffee and caffeine consumption Current Hypertension Reports, August 8, 2014    Review Article

6 Tea consumption and leukemia risk: A meta-analysis Tumor Biology, February 12, 2014    Evidence Based Medicine    Clinical Article

7 Vitamin D and sleep disorders Full Text Nature and Science of Sleep, August 13, 2014    Free full text    Clinical Article

8 Yogurt consumption, weight change and risk of overweight/obesity: The SUN cohort study Nutrition, Metabolism & Cardiovascular Diseases, July 28, 2014    Clinical Article

9 Nut consumption for vascular health and cognitive function Nutrition Research Reviews, July 14, 2014    Review Article

10 The associations between yogurt consumption, diet quality, and metabolic profiles in children in the USA European Journal of Nutrition, July 22, 2014    Clinical Article

11 Vitamin D and the risk of dementia and Alzheimer's disease Neurology®, August 27, 2014    Clinical Article

12 Long-term coffee consumption and risk of cardiovascular disease Circulation, February 11, 2014    Evidence Based Medicine    Review Article    Clinical Article

13 Soda consumption and risk of hip fractures in postmenopausal women in the Nurses’ Health Study American Journal of Clinical Nutrition, August 18, 2014    Clinical Article

14 Effect of omega-3 fatty acids on kidney function after myocardial infarction: The Alpha Omega Trial Clinical Journal of the American Society of Nephrology, August 12, 2014    Clinical Article
Exclusive Author Commentary

15 Coffee consumption and mortality from all causes, cardiovascular disease, and cancer: a dose-response meta-analysis American Journal of Epidemiology, August 26, 2014    Evidence Based Medicine    Review Article

16 Effect of a low-flatulogenic diet in patients with flatulence and functional digestive symptoms Neurogastroenterology & Motility, February 25, 2014    Clinical Article
Exclusive Author Commentary

17 NIDA review summarizes research on marijuana's negative health effects Full Text NIH News, June 6, 2014    Free full text

18 Egg consumption is associated with increased risk of ovarian cancer: Evidence from a meta-analysis of observational studies Clinical Nutrition, August 5, 2014    Evidence Based Medicine

19 The effect of chromium supplementation on polycystic ovary syndrome in adolescents Journal of Pediatric and Adolescent Gynecology , May 30, 2014    Clinical Article

20 Vitamin D and melanoma and non-melanoma skin cancer risk and prognosis: A comprehensive review and meta-analysis European Journal of Cancer, August 7, 2014    Review Article

Indexed Journals in Nursing: Journal of Advanced Nursing, Journal of Clinical Nursing, Nurse Education In Practicemore

Register now to view all the MDLinx contents (FREE)!

  • Stay current on the latest literature, research and clinical news
  • Get special communications and offers from MDLinx and our sponsors
  • Receive invitations to paid market research
View Samples and Register

Connect with us, stay current.

Receive the latest mecial news
updates for free via email

Sign up!

Subscribe to our free RSS feeds:

Get the latest news in your specialty automatically added to your newsreader or your personal My Yahoo!, Google, My MSN or My AOL page. Learn More

Close