Early repolarization: Difference between revisions
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== Natural History, Complications and Prognosis == | == Natural History, Complications and Prognosis == | ||
* Early repolarization pattern has been considered benign for a long time until some studies suggested an association between early repolarization and increased risk of [[arrhythmia]], particularly [[ventricular fibrillation]]. This association has shed light on the importance of evaluating early repolarization patterns and their prognostic implications. | |||
* Whereas early repolarization is a common finding, idiopathic [[ventricular fibrillation]] is a rare entity which incidence ranges from 3:100000 to 10:100000.. | |||
** The majority of early repolarization patterns, especially if incidentally found in otherwise asymptomatic people with a negative family history, have no or minimal increased risk of [[arrhythmia]]. | |||
** Early repolarization carries a higher risk of [[arrhythmia]] in patients with underlying cardiac pathology. | |||
** Early repolarization is rarely associated with a primary arrythmogenic disorder that manifests as idiopathic ventricular fibrillation. Genetic predisposition seems to play a role in this group of people. In addition, early repolarization seems to cause arrhythmia during sleep or at rest in the absence of any physical activity.<ref name="Obeyesekere-2013">{{Cite journal | last1 = Obeyesekere | first1 = MN. | last2 = Klein | first2 = GJ. | last3 = Nattel | first3 = S. | last4 = Leong-Sit | first4 = P. | last5 = Gula | first5 = LJ. | last6 = Skanes | first6 = AC. | last7 = Yee | first7 = R. | last8 = Krahn | first8 = AD. | title = A clinical approach to early repolarization. | journal = Circulation | volume = 127 | issue = 15 | pages = 1620-9 | month = Apr | year = 2013 | doi = 10.1161/CIRCULATIONAHA.112.143149 | PMID = 23588960 }}</ref> | |||
A case control study of 120 post MI patients with implantable cardioverter-cefibrillators (ICDs) demonstrated that early repolarization was more frequently observed among patients with documented episodes of VT/VF (32% vs. 8%, p=0.005). | *A case control study of 120 post [[MI]] patients with [[ICD|implantable cardioverter-cefibrillators]] (ICDs) demonstrated that early repolarization was more frequently observed among patients with documented episodes of VT/VF (32% vs. 8%, p=0.005). The leads demonstrating early repolarization were more often the inferior leads (23% vs. 8%, p=0.03). A trend was observed for the lateral leads (V4-V6) as well (12% vs. 3%, p=0.11). In contrast, leads I and aVL were not commonly involved (3% vs. 0%). The morphology of the ST segment was critical and a notch in the ST segment was observed more frequently among patients with VT/VF (28% vs. 7%, p=0.008). In contrast, J-point elevation and slurring of the ST segment surprisingly were not associated with ventricular arrhythmias.<ref>Patel RV et al; doi: 10.1161/CIRCEP.109.921130</ref> | ||
== Diagnosis == | == Diagnosis == | ||
Revision as of 18:00, 22 July 2013
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Synonyms and keywords: early repolarization pattern; early repol; early repol variant
Overview
Early repolarization is defined as notching or slurring of the morphology of the terminal QRS complex or J-point elevation >0.1 mV above baseline in at least 2 lateral or inferior leads.[1] Early repolarization is a normal ECG variant that is most commonly seen in young males. It can be confused with ST elevation MI and pericarditis.
Natural History, Complications and Prognosis
- Early repolarization pattern has been considered benign for a long time until some studies suggested an association between early repolarization and increased risk of arrhythmia, particularly ventricular fibrillation. This association has shed light on the importance of evaluating early repolarization patterns and their prognostic implications.
- Whereas early repolarization is a common finding, idiopathic ventricular fibrillation is a rare entity which incidence ranges from 3:100000 to 10:100000..
- The majority of early repolarization patterns, especially if incidentally found in otherwise asymptomatic people with a negative family history, have no or minimal increased risk of arrhythmia.
- Early repolarization carries a higher risk of arrhythmia in patients with underlying cardiac pathology.
- Early repolarization is rarely associated with a primary arrythmogenic disorder that manifests as idiopathic ventricular fibrillation. Genetic predisposition seems to play a role in this group of people. In addition, early repolarization seems to cause arrhythmia during sleep or at rest in the absence of any physical activity.[2]
- A case control study of 120 post MI patients with implantable cardioverter-cefibrillators (ICDs) demonstrated that early repolarization was more frequently observed among patients with documented episodes of VT/VF (32% vs. 8%, p=0.005). The leads demonstrating early repolarization were more often the inferior leads (23% vs. 8%, p=0.03). A trend was observed for the lateral leads (V4-V6) as well (12% vs. 3%, p=0.11). In contrast, leads I and aVL were not commonly involved (3% vs. 0%). The morphology of the ST segment was critical and a notch in the ST segment was observed more frequently among patients with VT/VF (28% vs. 7%, p=0.008). In contrast, J-point elevation and slurring of the ST segment surprisingly were not associated with ventricular arrhythmias.[3]
Diagnosis
Differentiating Early Repolarization From Other Disorders
Early repolariztion must be differentiated from other causes of ST elevation including ST elevation MI and pericarditis.
Vagal Maneuvers and Bradycardia Exacerbate Early Repolarization
- The ST segment elevation of early repolarization is exacerbated by bradycardia, and carotid sinus massage or vagal maneuvers may also exacerbate the variant. This is not true in ST elevation MI or pericarditis.
Early Repolarization is Characterized by a Notch at the J Point
- In the figure shown below, the red arrow points to a characteristic notch which is present at the J point in early repolarization but not in ST elevation MI or pericarditis.:
Height of the J Point
Only lead V6 is used to distinguish between early repolarization and pericarditis. As shown in the figure below, if A/B > 25%, suspect pericarditis. If A/B < 25%, suspect early repolarization.
Electrocardiographic Examples
Shown below is an example of benign early repolarization with J point elevation, concave shaped up-sloping ST segment, and prominent T waves in the inferior and lateral leads:
Shown below is an example of early repolarization with notching of the J point in the lateral leads:
Shown below are examples of early repolarization and other normal variants of ST Elevation:
References
- ↑ Patel RV et al; doi: 10.1161/CIRCEP.109.921130
- ↑ Obeyesekere, MN.; Klein, GJ.; Nattel, S.; Leong-Sit, P.; Gula, LJ.; Skanes, AC.; Yee, R.; Krahn, AD. (2013). "A clinical approach to early repolarization". Circulation. 127 (15): 1620–9. doi:10.1161/CIRCULATIONAHA.112.143149. PMID 23588960. Unknown parameter
|month=ignored (help) - ↑ Patel RV et al; doi: 10.1161/CIRCEP.109.921130