Background
Methods
Study population
Definitions of 12-lead surface ECG and transthoracic echocardiography parameters
Variables | Definitions |
---|---|
Epsilon wave (major depolarization criterion) | Distinct waves of small amplitude that occupy the ST segment in right precordial leads (V1-V3) and are distinct from the QRS complex |
Terminal activation duration (minor depolarization criterion) | Longest value in V1 through V3 from the nadir of the S wave to the end of all depolarization |
T wave inversion | Any T wave negativity |
Inferior leads T wave inversion | Inverted T waves in 2 out of 3 inferior leads (II, III, and aVF) |
Major repolarization criteria | Inverted T waves in right precordial leads (V1, V2, and V3) or beyond in individuals >14 years of age (in the absence of complete right bundle branch block) |
Minor repolarization criteria | - Inverted T waves in leads V1 and V2 in individuals >14 years of age (in the absence of complete right bundle branch block) or in V4, V5, or V6 |
- Inverted T waves in leads V1, V2, V3, and V4 in individuals >14 years of age in the presence of complete right bundle branch block | |
Complete right bundle branch block | QRSd ≥120 ms and: |
A1: R’ or r’ in V1 or V2 | |
A2: S duration > R duration in I and V6 | |
A3: S duration >40 ms in I and V6 | |
A4: R peak time >50 ms in V1 or V2 | |
a: A1 + A2 | |
b: A1+ A3 | |
c: A4+ (A2 or A3) | |
Incomplete right bundle branch block | QRS <120 ms and R peak time in V1 or V2 > 50 ms |
QRS notching | Additional deflections/notches at the beginning of the QRS, on top of the R-wave, or in the nadir of the S-wave in the absence of bundle branch block |
Left ventricular involvement | Echocardiographic documentation of LV wall motion abnormalities or a reduced ejection fraction (<50%) in the absence of other causes |
Right ventricular regional wall motion abnormalities | Echocardiographic documentation of regional right ventricular akinesia/dyskinesia |
ECG analysis
Transthoracic Echocardiography
Statistical analysis
Results
Baseline characteristics
Patient characteristic | All patients (n = 111) |
---|---|
Male, n (%) | 71 (64%) |
Age at baseline ECG (years) | 43 (30–56) |
Systolic blood pressure (mmHg) | 120 ± 19 |
Diastolic blood pressure (mmHg) | 76 ± 9 |
Heart rate (bpm) | 65 (57–74) |
Body mass index (kg/m2) | 24.3 ± 3.2 |
Medication | |
Amiodarone, n (%) | 17 (15%) |
Beta-blocker, n (%) | 47 (42%) |
Sotalol, n (%) | 13 (12%) |
12-lead surface ECG | |
Epsilon waves in V1, V2, or V3 | 21 (19%) |
Minor ECG depolarization criteria (2010 TFC) | 25 (23%) |
Terminal activation duration (ms) | 52 (43–64) |
Major ECG repolarization criteria (2010 TFC) | 37 (33%) |
Minor ECG repolarization criteria (2010 TFC) | 21 (19%) |
TWI in inferior leads | 38 (34%) |
TWI in V4, V5, or V6 | 43 (39%) |
Number of leads with TWI | 4.5 ± 2.5 |
Number of precordial leads with TWI | 2.6 ± 1.9 |
QRS duration (ms) | 111 (100–116) |
Corrected QT duration (ms) | 444 (426–480) |
Transthoracic echocardiography | |
Patients with RV regional wall motion abnormalities | 85 (77%) |
1 RV region involved | 25 (23%) |
≥2 RV regions involved | 56 (50%) |
Patients with LV involvement | 15 (14%) |
12-lead ECG changes during follow-up
ECG variable | Baseline ECG | Follow-up ECG | p-value |
---|---|---|---|
Epsilon waves in V1, V2, or V3 | 11 (14%) | 24 (31%) | 0.01 |
Late potentials in inferior leads | 6 (8%) | 9 (12%) | 0.45 |
Minor ECG depolarization criterion | 21 (27%) | 19 (25%) | 0.56 |
Terminal activation duration (ms) | 50 (44–64) | 50 (45–60) | 0.47 |
Major ECG repolarization criterion | 29 (38%) | 28 (36%) | 0.58 |
Minor ECG repolarization criterion | 14 (18%) | 18 (23%) | 0.55 |
T wave inversions in inferior leads | 28 (36%) | 31 (40%) | 0.65 |
T wave inversions in V4, V5, or V6 | 33 (43%) | 40 (52%) | 0.25 |
Number of leads with T wave inversions | 4 (2-6) | 5 (2–7) | 0.18 |
Number of precordial leads with T wave inversions | 2 (1–4) | 3 (1–5) | 0.1 |
QRS duration (ms) | 111 (100–125) | 114 (100–128) | 0.04 |
QT duration (ms) | 431 (399–435) | 420 (400–441) | 0.57 |