Baseline characteristics
| Atrial group | Ventricular group | ||||
|---|---|---|---|---|---|
| BTS− | BTS+ | BTS− | BTS+ | ||
| Number of patients | 67 | 43 | 64 | 51 | |
| Age (years) | 76 (9) | 76 (8) | 76 (9) | 75 (8) | |
| Sex (F/M) | 41/26 | 32/11 | 37/27 | 32/19 | |
| Blood pressure (mm Hg) | |||||
| Systolic | 145 (20) | 146 (26) | 145 (22) | 143 (29) | |
| Diastolic | 76 (10) | 79 (11) | 78 (11) | 79 (12) | |
| Symptoms indicating need for pacemaker | |||||
| Syncope | 31 | 23 | 32 | 32 | |
| Dizzy spells | 33 | 18 | 30 | 19 | |
| Heart failure | 3 | 2 | 2 | 0 | |
| Arrhythmia indicating need for pacemaker | |||||
| Sinus bradycardia | 18 | 18 | |||
| Sinoatrial block | 49 | 46 | |||
| Clinical events before randomisation | |||||
| Angina pectoris | 15 | 14 | 19 | 11 | |
| Myocardial infaction | 6 | 6 | 9 | 9 | |
| Stroke | 2 | 5 | 4 | 3 | |
| Arterial embolus | 2 | 0 | 0 | 2 | |
| Transient cerebral ischaemia | 6 | 2 | 0 | 2 | |
| Heart valve disease | 2 | 1 | 1 | 1 | |
| NYHA class I/II/III/IV | 51/12/4/0 | 28/12/3/0 | 50/12/2/ 0 | 42/8/1/0 | |
| M mode echocardiography1-150 | |||||
| Left atrial diameter (mm) | 34 (7) | 34 (5) | 34 (6) | 34 (7) | |
| Left ventricular fractional shortening | 0.36 (0.11) | 0.33 (0.16) | 0.37 (0.12) | 0.35 (0.12) | |
| Medical treatment | |||||
| Digoxin | 5 | 17 | 2 | 9 | |
| β Blocker | 3 | 4 | 1 | 0 | |
| Calcium blocker | 3 | 10 | 7 | 4 | |
| Antiarrhythmic drugs | 5 | 7 | 3 | 3 | |
| Frusemide (mg/day) | 23 (44) | 46 (60) | 18 (29) | 30 (47) | |
| Aspirin | 26 | 22 | 19 | 27 | |
| Warfarin | 4 | 2 | 0 | 1 | |
Values are numbers of patients. Continuous data are presented as means (SD).
↵1-150 Measurements represent data from 221 patients because of an inadequate echocardiographic window in four patients.
BTS, brady-tachy syndrome; NYHA, New York Heart Association heart failure classification.