Early repolarization syndrome: A cause of sudden cardiac death

Figure 1 Examples of the classic and new definitions of early repolarization. Examples of the original (classic) and emerging (new) definitions of early repolarization (ER). A and B show the classic form of STE-type ER, which is the form identified by ECG software algorithms. Notice the presence of a J wave in (B), followed by an ascending/upsloping ST segment. Both forms are considered benign; C and D show the malignant form of ER demonstrated as slurring at the end of QRS complex (C) or a discrete notch/J wave (D) followed by a horizontal/downslopping ST segment (no ST elevation). Reproduced from ref.[49], with permission from the publisher. STE: ST elevation type ER; ECG: Electrocardiographic.

Figure 2 Schematic representation of the possible mechanisms underlying J-wave occurrence. Action potentials from epicardium and endocardium from normal individuals (left) and early repolarization (ER) patients (right) as well as the respective electrocardiograms are shown. A prominent phase I-notch and the loss of epicardial dome in phase - 2 (thick arrow) results in transmural dispersion of repolarization (dashed arrows) and appearance of the J-wave and ST-segment elevation on the surface ECG. AP: Action potential; ECG: Electrocardiogram; ER: Early repolarization; RP: Resting potention. Reproduced with permission, from ref.[67].

Figure 3 Benign early repolarization: Electrocardiogram showing ST segment elevation by at least 0. 1 mV from the baseline. Reproduced with permission, from ref.[68].

Figure 4 Malignant early repolarization: J-wave elevation (arrows) as slurring (lead II) and notching in the inferior and lateral leads and ascending ST segment in most leads. Reproduced with permission, from ref.[69].

Figure 5 Brugada electrocardiogram-types. Type-1 is characterized by a complete or incomplete right bundle-branch block pattern with a coved morphology ST-segment elevation of ≥ 2 mm in the right precordial leads (V1-V3) followed by a negative T-wave. In type-2, ST-segment elevation has a saddleback appearance with a high takeoff ST-segment elevation of > 2 mm, a trough displaying > 1-mm ST-elevation followed by a positive or biphasic T-wave. Type-3 has an ST-segment morphology that is either saddleback or coved with an ST-segment elevation of < 1 mm. Reproduced with permission, from ref.[69].

Figure 6 Malignant early repolarization: Horizontal ST-segment after early repolarization.