Patient characteristics (ambulatory patch and historical unmatched comparator cohorts)
| Characteristic | Ambulatory patch cohort | n | Historical unmatched comparator cohort | n |
| Demographic data | ||||
| Age/years | 62.8±19.5 | 86 | 67.5±19.5 | 603 |
| Male sex | 46 (53) | 86 | 281 (47) | 603 |
| Examination findings | ||||
| Pulse/bpm | 73.7±14.9 | 86 | 74.9±15.8 | 601 |
| Blood sugar/mmol/L | 6.6±2.1 | 81 | 7.0±2.3 | 558 |
| Systolic BP/mm Hg | 138.6±27.1 | 86 | 133.4±24.5 | 597 |
| Diastolic BP/mm Hg | 75.9±17.5 | 86 | 68.6±13.3 | 596 |
| Postural drop (>20 mm Hg on standing) | 4 (7.0) | 57 | 41 (10.9) | 375 |
| Systolic difference if performed | 11.1±10.6 | 31 | 15.7±10.9 | 131 |
| Saturation ≤94% on admission on room air | 4 (4.7) | 86 | 40 (6.8) | 587 |
| Saturation ≤94% on admission on O2 | 21 (24.4) | 86 | ||
| Bradycardia ≤50 in ED or prehospital | 6 (7.0) | 86 | n/a | n/a |
| Examination | ||||
| Heart murmur heard | 6 (7.0) | 86 | 85 (14.5) | 586 |
| Clinical signs of heart failure present | 3 (3.5) | 86 | 48 (8.1) | 593 |
| New neurological signs on examination | 0 (0) | 86 | 10 (1.7) | 600 |
| FOB/Melena on PR | 0 (0) | 10 | 6 (7.1) | 87 |
| History of syncopal episode | ||||
| Subjective SOB | 6 (7.0) | 86 | 65 (10.8) | 603 |
| Prodromal/preceding symptoms | 41 (47.7) | 86 | 326 (54.1) | 603 |
| Palpitations prior to syncope | 3 (3.5) | 86 | 15 (2.5) | 603 |
| Associated chest pain | 5 (5.8) | 86 | 55 (9.1) | 603 |
| Associated headache | 4 (4.7) | 86 | 61 (10.1) | 603 |
| Situational symptoms, that is, micturition | 6 (7.0) | 86 | 40 (6.6) | 603 |
| Related to GTN use | 0 (0) | 86 | 12 (2.0) | 603 |
| Related to exertion | 5 (5.8) | 86 | 38 (6.3) | 603 |
| Witnessed seizure activity | 2 (2.3) | 86 | 13 (2.2) | 602 |
| Estimated length of loss of consciousness/min | 1.5 (1–3)* | 58 | n/a | n/a |
| Medical history | ||||
| Previous episodes of syncope | 36 (41.9) | 86 | 251 (41.8) | 600 |
| >1 episode in the last year | 17 (19.8) | 86 | 109 (18.2) | 600 |
| Previous hypertension | 35 (40.7) | 86 | 254 (42.2) | 602 |
| Known ischaemic heart disease | 11 (12.8) | 86 | 146 (24.2) | 603 |
| Previous myocardial infarct | 4 (4.7) | 86 | 75 (12.5) | 602 |
| Known history of valvular heart disease | 4 (4.7) | 86 | 40 (6.6) | 602 |
| Previous history of cardiac arrest | 1 (1.2) | 86 | 8 (1.3) | 602 |
| Known history of cardiac failure | 5 (5.8) | 86 | 34 (5.6) | 602 |
| Pacemaker | 0 (0) | 86 | 15 (2.5) | 603 |
| Implantable defibrillator | 0 (0) | 86 | 4 (0.7) | 603 |
| Management of index event | ||||
| Admitted | 39 (45.3) | 86 | 396 (65.7) | 603 |
| Discharged from ED with planned outpatient clinic appointment | 15 (17.4) | 86 | 47 (7.8) | 603 |
| Discharged from ED with GP follow-up only | 32 (37.3) | 86 | 160 (26.5) | 603 |
| Referred to hospital cardiac electrophysiology service (prior to patch report) | 0 (0) | 86 | n/a | n/a |
| Reason(s) for admission: | ||||
| High-risk syncope Comorbidity Syncope investigation Social reasons Other | 20 (51.3) 0 (0) 12 (30.8) 0 (0) 7 (17.9) | 39 | n/a | n/a |
| Treating clinician likelihood of underlying cardiac cause of syncope: | ||||
| 0 Least likely 1 2 3 4 5 6 7 8 9 10 Most likely | 2 (2.4) 7 (8.2) 13 (15.3) 12 (14.1) 11 (12.9) 10 (11.8) 10 (11.8) 9 (10.6) 5 (5.9) 5 (5.9) 1 (1.2) 4.5±2.5 | 85 | n/a | n/a |
| Admission ECG findings | ||||
| Rate | 73.2±22.1 | 86 | 73.7±16.7 | 545 |
| QRS axis | 42.0±38.8 | 75 | 16.8±47.0 | 333 |
| QTc int | 433.0±32.7 | 86 | 423.3±34.4 | 530 |
| Sinus rhythm | 81 (94.2) | 86 | 498 (91.4) | 545 |
| PR >200 ms (first degree heart block) | 14 (16.3) | 86 | 74 (13.6) | 545 |
| Mobitz type II/Wenkebach heart block | 0 (0) | 86 | 0 (0) | 545 |
| Bifascicular block/trifascicular block | 0 (0) | 86 | 7 (1.3) | 545 |
| Complete heart block | 0 (0) | 86 | 2 (0.4) | 545 |
| Sinus bradycardia <50 | 4 (4.7) | 86 | 11 (2.0) | 545 |
| Sinus pause >3 s | 0 (0) | 86 | 0 (0) | 545 |
| ST elevation >1 mm | 3 (3.5) | 86 | 26 (4.8) | 545 |
| T wave inversion | 14 (16.3) | 86 | 138 (25.3) | 545 |
| ST segment depression >1 mm | 0 (0) | 86 | 37 (6.8) | 545 |
| Q wave (not in lead III) | 4 (4.7) | 86 | 112 (20.6) | 544 |
| QRS duration ≥120 ms | 4 (4.7) | 86 | 47 (8.6) | 544 |
| Number of ventricular ectopics >0 | 6 (7.0) | 86 | 41 (7.6) | 543 |
| Atrial tachycardia (including AF) >100 | 0 (0) | 86 | 9 (1.7) | 545 |
| Narrow complex tachycardia >100 | 4 (4.7) | 86 | 29 (5.3) | 545 |
| Broad complex tachycardia >100 | 1 (1.2) | 86 | 2 (0.4) | 545 |
| Admission lab findings | ||||
| Hb/g/L | 136.1 (16.6) | 85 | 132.0 (17.3) | 595 |
| eGFR >60 | 65 (76.5) | 85 | 390 (66.2) | 592 |
Values are presented as mean±SD or n (%) unless stated * median (IQR). AF, atrial fibrillation; eGFR, estimated glomerular filtration rate; FOB, faecal occult blood; GTN, glyceryl trinitrate; Hb, haemoglobin; PR, per rectum; QRS, QRD wave complex; QTc int, QT interval corrected; SOB, shortness of breath.