Table 1.
Baseline characteristics
| All |
Excellent ECG quality sample† |
P value | |
|---|---|---|---|
| (n = 290) | (n = 189) | ||
| Age (years) | 67.0 (55.3–74.0) | 67.0 (56.0–75.0) | .925 |
| Female | 138 (47.6) | 85 (45.0) | .273 |
| Reason for ECG‡ | |||
| New symptoms | 173 (59.7) | 105 (55.6) | .069 |
| Cardiovascular risk management | 31 (10.7) | 23 (12.2) | .360 |
| Known diabetes mellitus | 47 (16.2) | 34 (18.0) | .337 |
| Known ischemic heart disease | 14 (4.8) | 13 (6.9) | .052 |
| Known heart rhythm disorder | 6 (2.1) | 4 (2.1) | 1.000 |
| Other | 19 (6.6) | 10 (5.3) | .348 |
| Symptoms§ | |||
| Palpitations | 74 (25.5) | 39 (20.6) | .014 |
| Chest pain | 64 (22.1) | 44 (23.3) | .595 |
| Dyspnea | 37 (12.8) | 24 (12.7) | 1.000 |
| Light-headedness | 23 (7.9) | 12 (6.3) | .256 |
| Fatigue | 26 (9.0) | 17 (9.0) | 1.000 |
| (Near) collapse | 12 (4.1) | 6 (3.2) | .414 |
| Other | 31 (10.7) | 18 (9.5) | .497 |
| Hypertension | 123 (42.4) | 79 (41.8) | .741 |
| Heart failure | 12 (4.1) | 7 (3.7) | .843 |
| Diabetes mellitus | 85 (29.3) | 60 (31.7) | .339 |
| Prior stroke/TIA | 18 (6.2) | 13 (6.9) | .694 |
| Atrial fibrillation | 30 (10.3) | 23 (12.2) | .233 |
| Other arrhythmia | 13 (4.5) | 9 (4.8) | .987 |
| Valvular disease | 13 (4.5) | 10 (5.3) | .540 |
| Hypercholesterolemia | 68 (23.4) | 44 (23.3) | 1.000 |
| Peripheral vascular disease | 22 (7.6) | 17 (9.0) | .314 |
| Coronary heart disease | 30 (10.3) | 20 (10.6) | 1.000 |
| COPD | 30 (10.3) | 16 (8.5) | .278 |
| Chronic kidney disease | 30 (10.3) | 18 (9.5) | .315 |
| Beta-blocker use | 57 (19.7) | 37 (19.6) | 1.000 |
| Sodium channel blocker use | 4 (1.4) | 2 (1.1) | .910 |
| Potassium channel blocker use | 2 (0.7) | 2 (1.1) | .770 |
| Calcium channel blocker use | 43 (14.8) | 28 (14.8) | 1.000 |
| Digoxin use | 2 (0.7) | 2 (1.1) | .770 |
Data are number (percentage) or median (interquartile range). P value is for difference between excellent (n = 189) and non-excellent (n = 101) ECG quality sample.
COPD = chronic obstructive pulmonary disease; ECG = electrocardiogram; IQR = interquartile range; TIA = transient ischemic attack.
†
Excellent ECG quality was defined as no or mild noise and/or up to 1 lead with baseline drift.
‡
Patients were assessed as having 1 (primary) reason for ECG.
§
Patients could report multiple symptoms at baseline, and symptoms were not mutually exclusive.