Diagnostic Accuracy of a Smartphone-Operated Single-Lead ECG for Detection of Rhythm and Conduction Abnormalities in Primary Care
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* Divya Manda
* Michael E Johansen

The *Annals of Family Medicine* encourages readers to develop a diverse learning community to think critically about important issues affecting primary care, conduct journal clubs, and act on those discussions.1

## HOW IT WORKS

In each issue, the Annals selects an article and provides discussion tips and questions. Post a summary of your conversation in our online discussion. (Open the article and click on “TRACK Discussion/ Submit a comment.”) Discussion questions and information are online at: [http://www.AnnFamMed.org/site/AJC/](http://www.AnnFamMed.org/site/AJC/).

## CURRENT SELECTION

### Article for Discussion

 Himmelreich JC, Karregat EP, Lucassen WA, et al. Diagnostic accuracy of a smartphone-operated, single-lead ECG for detection of rhythm and conduction abnormalities in primary care. Ann Fam Med. 2019; 17( 5): 403- 411.[Abstract/FREE Full Text](http://www.annfammed.org/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6ODoiYW5uYWxzZm0iO3M6NToicmVzaWQiO3M6ODoiMTcvNS80MDMiO3M6NDoiYXRvbSI7czoyMzoiL2FubmFsc2ZtLzE3LzUvaWlpLmF0b20iO31zOjg6ImZyYWdtZW50IjtzOjA6IiI7fQ==)

### Discussion Tips

Many patients present to primary care physicians with symptoms that are suspicious for cardiac arrhythmias, but 12-lead ECGs to evaluate the symptoms are not always available or are cumbersome. This article describes a blinded case series to evaluate the utility of a smartphone-enabled 1-lead ECG.

### Discussion Questions

*   What does this study investigate and why does this matter?

*   How is this study different from previous studies about smartphone-enabled ECGs? What does this study add to the field?

*   How strong is the study design to answer the researchers’ questions?

*   Define sensitivity, specificity, likelihood ratios, positive/ negative predictive value. How are these calculated? 
    
    *   What are some criticisms about the use of these values?2,3

*   What were the primary and secondary findings of the study? How accurate was 1-lead ECG for detecting atrial fibrillation/atrial flutter vs other arrhythmias vs ectopic beats? Is there value in combining these end points? 
    
    *   Importantly, what does this study not investigate?

*   To what degree can the findings be accounted for by: 
    
    *   How patients were selected, excluded, or lost to follow-up; how the main variables were measured?; confounding variables; and how the findings were interpreted?

*   How applicable are the study results to your patient population? How applicable are the study results in a typical primary care office? What is the transportability of the findings?

*   How might spectrum bias be relevant to this study?

*   How might the study change your practice? Would you be more likely to use a smartphone-enabled 1-lead ECG in your office or at home visits?

*   What are the limitations of the study and how may this limit the applicability of the results?

*   How does this study relate to and differ from the discussion around using smartphone ECG as a screening tool?4

*   What are next steps in applying the findings to clinical practice and in primary care?

*   What research questions remain regarding the use of smartphone-enabled 1-lead ECGs in primary care?

*   © 2019 Annals of Family Medicine, Inc.

## References

1.  Stange KC, Miller WL, McLellan LA, et al. Annals Journal Club: It’s time to get RADICAL. Ann Fam Med. 2006;4(3):196-197. [http://annfammed.org/cgi/content/full/4/3/196](http://http://annfammed.org/cgi/content/full/4/3/196).
    
    [FREE Full Text](http://www.annfammed.org/lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiRlVMTCI7czoxMToiam91cm5hbENvZGUiO3M6ODoiYW5uYWxzZm0iO3M6NToicmVzaWQiO3M6NzoiNC8zLzE5NiI7czo0OiJhdG9tIjtzOjIzOiIvYW5uYWxzZm0vMTcvNS9paWkuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9) 

2.  Janssens AC, Deng Y, Borsboom GJ, Eijkemans MJ, Habbema JD, Steyerberg EW. A new logistic regression approach for the evaluation of diagnostic test results. Med Decis Making. 2005; 25(2): 168-177.
    
    [CrossRef](http://www.annfammed.org/lookup/external-ref?access_num=10.1177/0272989X05275154&link_type=DOI) 
    
    [PubMed](http://www.annfammed.org/lookup/external-ref?access_num=15800301&link_type=MED&atom=%2Fannalsfm%2F17%2F5%2Fiii.atom) 
    
    [Web of Science](http://www.annfammed.org/lookup/external-ref?access_num=000228014000005&link_type=ISI) 

3.  McNutt R, Hadler NM. Rethinking our thinking about diagnostic tests: there is nothing positive or negative about a test result. [https://thehealthcareblog.com/blog/2015/12/01/rethinking-about-diagnostic-tests-there-is-nothing-positive-or-negative-about-a-test-result/](http://https://thehealthcareblog.com/blog/2015/12/01/rethinking-about-diagnostic-tests-there-is-nothing-positive-or-negative-about-a-test-result/). Accessed Aug 9, 2019.
    
    

4.  Mandrola J, Foy A. Downsides of detecting atrial fibrillation in asymptomatic patients. Am Fam Physician. 2019; 99(6): 354-355.