Early Repolarisation - A quick-lit-review.

Transcript

1. Early Repolarisation. B Y S I M O N M A R K D A L E Y ( 2 0 1 8 ) A 'quick-lit-review.' (Not so benign)
2. EARLY REPOLARISATION.. (ER) Also historically referred to as ‘high take off’ - this term is outdated. Up to 15% of chest pain presentations to the ED will have ER. More common <50yrs, less common >70yrs. Physiological basis remains poorly understood. Historically thought to be benign. In the past 20 years multiple studies have shown a link to threatening arrhythmia and sudden cardiac death (SCD). Risk stratification remains challenging & controversial, although increasingly less so.
3. IS THERE AN ER DEFINITION? A 2015 consensus paper recommended that a new definition was urgently needed. It proposed the below criteria, which subsequently was reiterated by a further consensus meeting in 2016; ERP is present if the following criteria are met; There is end-QRS notch or slur on the downslope of a prominent R-wave. If there is a notch, it should lie entirely above the baseline. The onset of a slur must also be above the baseline. J-point is >0.1mV in 2 or more contiguous leads, excluding v1-v3. QRS duration is <120ms. ST elevation in the absence of a notched or slurred J-point should not be described as ER. a. b. c. Macfarlane et al (2015) Antzelevitch et al (2016)
4. ?ERP IN v1-v3 When ERP/non-specific ST- segment elevation is present in these leads, give careful consideration to differential diagnoses. Antzelevitch et al (2016)
5. TERMINOLOGY / CLASSIFICATIONS. The accuracy of categorisation is of importance, and should be standardised. If the ST-segment is upward sloping and followed by an upright T- wave, the pattern should be described as “early repolarization with an ascending ST segment.” If the ST-segment is horizontal or downward sloping, the pattern should be described as “early repolarisation with a horizontal or descending ST segment.” The leads in which the notching or slurring occurs should be used as part of the description, so that, for example, a complete report might state, “early repolarisation with descending ST-segment in leads II, III, and aVF.” Antzelevitch et al (2016) Macfarlane et al (2015)
6. ER PATTERN vs ER SYNDROME. Early repolarisation syndrome is diagnosed when there is ERP in the inferior/lateral leads presenting with aborted cardiac arrest, VF or polymorphic VT. Antzelevitch et al (2016) Macfarlane et al (2015) Antzelevitch et al (2016)
7. PATHOPHYSIOLOGY OF ERS (&BrS). Early repolarisation syndrome lies on a spectrum with BrS; Many clinical similarities – suggesting similar pathophysiology. Males predominate both syndromes (71% of BrS & 80% of ERS). Incidence of VF highest in third decade of life; ?linked to testosterone. ERP is prevalent in Africans/African-Americans, but apparently not associated with high risk.
8. RISK STRATIFICATION. Studies have shown that ER – especially in the inferior leads – predicts cardiac and arrhythmic death. The incidental discovery of a J-wave should not be interpreted as a marker of ‘high risk’ for SCD since the odds are extremely low. Presence of a J-wave on the ECG may increase the probability of VF from 3.4:100,000 to 11:100,000. Viskin et al (2014). Rosso et al (2011).
9. J WAVE MANIFESTATION. Antzelevitch et al (2016)
10. MANAGEMENT. ßeta-blockers can suppress electrical storms and associated J-wave manifestations. Long-term therapy using quinidine, bepridil, denopamine, & cilostazol is reported to suppress the development of VF/VT in both. Antzelevitch et al (2016)
11. TAKE HOME POINTS. ER can no longer assumed to be benign. ERS lies on a spectrum with BrS. ERP in the anterior leads appears more likely to be ‘benign’, with inferior/lateral ERP more likely to be high risk. Care must still be taken when labelling anterior ER/non-specific STE as "BER". Symptomatic ERS is an indication for ICD implantation. In the absence of syncope, or a strong family history of sudden cardiac death (SCD), the finding of the ERP does not merit further investigation. Asymptomatic ERS should receive ‘close’ follow up.
12. https://www.ncbi.nlm.nih.gov/pubmed/26205599 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4927622/ https://www.ahajournals.org/doi/full/10.1161/CIR.0000000000000388 https://www.ncbi.nlm.nih.gov/pubmed/21295159 REFERENCES.