Fragmented QRS - A quick-lit-review

Transcript

1. The clinical significance of a fragmented-QRS. B Y S I M O N M A R K D A L E Y ( 2 0 1 7 ) A 'quick-lit-review'.
2. I kept seeing RSR patterns on ECGs. I kept writing “RSR pattern” and sometimes “negative RSR pattern”.. But then I asked myself “What does this really mean?”. WHY?
3. WHAT? Google informed me that "RSR pattern" is a term that should be avoided as it is used variably/interchangeably and may be misunderstood.
4. OKAY.. So I performed a quick-lit-review for the term "clinical significance of fragmented QRS". This is what I learned..
5. FRAGMENTED QRS IS.. Widely defined as an additional/notched R wave in the absence of a bundle branch block (QRS<120ms).
6. APPEARS TO BE ESTABLISHED.. There is a large body of evidence across a significant variety of studies to indicate that fQRS is a predictor of future major adverse cardiac events (MACE) (including arrhythmic events)/mortality/poor prognosis in patients with known coronary artery disease (CAD)/ acute coronary syndromes, left ventricular dysfunction, cardiomyopathy, and Brugada syndrome. There is less evidence (but some) of this in suspected CAD, acquired QT prolongation, sarcoidosis, amyloidosis and arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D).
7. GOOD PIECE OF EVIDENCE.. fQRS present in ~20% of middle-aged patients, overwhelming majority of these in the inferior territory. fQRS was not associated with increased mortality in those without known cardiac disease. Terho et al (2014).
8. WORTH CONSIDERING.. Both the sensitivity and specificity of fQRS in NSTEMI were higher than that of ischaemic T waves at identifying culprit lesion territory. fQRS 48hrs post-PPCI was a significant predictor of MACE at 6months. Lack of expected mortality benefit of reperfusion therapy in STEMI patients who present with fQRS. Unfortunately all 3 of these were small-cohort/single-centre studies. Guo et al (2011). Ari et al (2011). Stavileci et al (2014).
9. TAKE HOME MESSAGES.. In all cardiac pathologies, fQRS represents badness and can (should?) be considered a factor in risk stratification. fQRS alone doesn’t tell us a great deal. We must still utilise good clinical judgement and the testing modalities already available to us. However if you see a fQRS, its reasonable to be suspicious! (THE IMPORTANT BIT)..
10. REFERENCES. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5414988/ https://www.ncbi.nlm.nih.gov/pubmed/21344317 https://www.ncbi.nlm.nih.gov/m/pubmed/24517503/ https://litfl.com/qrs-interval-ecg-library/ https://www.ncbi.nlm.nih.gov/pubmed/24819902