Table 3 Prevalence of cardiac electrical abnormalities

Bertrand et al., 2021[50]

• 12-lead ECG during a maximal exercise test: heart rate

N = 147 (68.1%) (49.7% males) did not achieve their predicted maximal heart rate

Maximal heart rate 97.3 ± 5.6% predicted

Brouwer et al., 2007 [51]

• 12-lead ECG: rhythm and conduction disturbances (Flattened T-waves, pathological Q-waves or a prolonged QTc. Ventricular arrhythmias were classified according to the Lown’s criteria. Lown 4 or higher was considered abnormal)

• 24-h ambulatory ECG: rhythm and conduction disturbances (Flattened T-waves, pathological Q-waves or a prolonged QTc. Ventricular arrhythmias were classified according to the Lown’s criteria. Lown 4 or higher was considered abnormal)

12-lead ECG:

- Flattened T-waves N = 7 (30%)

- Pathological Q-waves N = 0 (0%)

- Prolonged QTc N = 0 (0%)

24-h ambulatory ECG:

- Sinus rhythm N = 23 (100%)

- Normal atrioventricular conduction N = 23 (100%)

- Sporadic (less than 100/24 h) premature ventricular contractions (Lown 1) N = 1 (4.3%)

- Ventricular couplets (Lown 4) N = 2 (8.7%)

Halazun, 1974 [52]

• ECG

ECG abnormalities: N = 17 (9.9%) (males N = 10)

Age (years)

mean: 6.25

median (range): 5.00 (2.75–18.00)

Low voltage T N = 15

Low voltage QRS N = 14

Abnormal T axis N = 11

Left atrial enlargement N = 10

Abnormal QRS axis N = 9

Bi-atrial enlargement N = 7

Abnormal Q N = 2

ST changes N = 2

Hau Eva et al., 2019 [53]

• Questionnaire: arrhythmia

Arrhythmia:

- N = 27 (5.3%)

- Missing values 1.1%

Controls N = 21 3.0% (missing values 4.7%)

OR: 1.8

95% CI: 1.0–3.5

p-value: 0.065

Lipshultz et al., 1991 [3]

• 24-h ambulatory ECG Holter (N = 89): abnormalities of heart rate and rhythm

• 12-lead ECG during a maximal exercise test (N = 96): abnormalities of heart rate and rhythm

Holter:

- Ventricular tachycardia N = 4

Exercise Test:

- Excess tachycardia N = 8

- Atrial ectopy N = 3

- Ventricular ectopy N = 12 (Lown grade 1 through 4A) (10%)

- Abnormal ST-segment and T-wave changes N = 9

Pihkala et al., 1994 [49]

• 12-lead ECG: Total QRS voltage (pre/follow-up)

• Number of evaluations: 3 (pre diagnosis, 1–4 months after bone marrow transplantation and at follow-up)

- Change of QRS voltage from diagnosis to follow-up (%) significantly decrease (> 15%) N = 3

Cyclophosphamide + total body irradiation N = 2

Cytosine arabinoside + total body irradiation N = 1

- ST change (N = 0)

Velensek Prestor et al., 2000 [17]

• 12-lead ECG: rhythm and conduction disturbances

• 12-lead ECG during a submaximal exercise test (N = 44): rhythm and conduction disturbances

12-lead ECG at rest and/or exercise:

- Left ventricular hypertrophy: N = 2

12-lead ECG:

- ECG changes: N = 13

- Nonspecific ST-T changes: N = 3

- QTc prolongation ≥ 0.43 s: N = 7

- QTc prolongation ≥ 0.45 s: N = 2

- Right bundle branch block: N = 1

- Supraventricular tachycardia: N = 2

- Sinus bradycardia: N = 4

12-lead ECG during exercise:

- ECG changes: N = 13

- QTc prolongation: N = 2

- Ventricular premature complexes: N = 3

- Depression of ST interval: N = 10

Rammeloo et al., 2000 [54]

• 12-lead ECG: abnormalities (decreased QRS voltage, prolongation of the QTc interval Bazett, T wave inversion, ST-T abnormalities, and supraventricular and ventricular arrhythmias)

• 24-h ambulatory ECG: rate, basal rhythm, atrioventricular conduction, and supraventricular and ventricular arrhythmias

12-lead ECG:

- QTc interval > 0.44 s N = 0

- Group A: N = 1 prolonged QRS interval duration resulting from Wolff-Parkinson-White syndrome

- Group B: N = 1 flattened T-waves in the chest leads. N = 1 low QRS voltage

24-h ambulatory ECG (N = 89; Group A: N = 40 and Group B: N = 49):

- Second-degree AV block type I during sleep A: N = 0, B: N = 3

- Basal sinus rhythm A: N = 40, B: N = 46

- Premature atrial contractions > 100/24 h A: 2.5%, B: 6%

- Premature ventricular contractions > 50/24 h A: 6%, B: 2%

- Supraventricular or ventricular tachycardia N = 0

Shimomura et al., 2011 [55]

• ECG: abnormal ECG response was defined as a horizontal or downsloping ST segment depression of 0.10 mV (1 mm) for 80 ms

• Holter ambulatory ECG

• Number of evaluations: before, immediately following, and 1 min after exercise

ECG:

- ECG normal (rest) N = 61

- ST elevation (after exercise) N = 1 (1.6%)

Holter:

- Arrhythmia N = 2/59 (3.3%) (supra-ventricular premature contraction)

Steinherz et al., 1995 [48]

• Medical records

○ ECG

○ 24-h taped electrocardiography

Ventricular ectopy N = 1 (50%)

Ventricular dysrhythmia N = 2 (100%)

Tachycardia N = 1 (50%)

Ventricular premature contractions N = 1 (50%)

Turner-Gomes et al., 1996 [56]

Evaluation of heart rate during a maximal exercise test (no specification)

Maximal heart rate 97.4 ± 12.3% predicted

No difference heart rate responses to maximal exercise in the high risk/very high risk (96.5, 15.1% predicted) versus standard risk group (98.7 ± 8.2% predicted)

Normal limits of HRmax N = 19