Table 1.
Electrophysiological Characteristics of 3° AVB Fetuses
| First fMCG
|
Last fMCG
|
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|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fetus # | GA (Weeks) | RX | FHR (beats/min) | FHR Pattern | QRS (ms) | VT/JET | % Ectopy | # fMCG | GA (Weeks) | RX | FHR (beats/min) | FHR Pattern | QRS (ms) | VT/JET | % Ectopy |
| SSA | |||||||||||||||
|
| |||||||||||||||
| 1 | 25 | D | 74 | R | — | — | 0 | 5 | 37 | D | 70 | R | — | — | 0 |
| 2 | 25 | — | 67 | R | 45 | — | 0.7 | 4 | 37 | D | 75 | R | 62 | — | 17 |
| 3* | 26 | D | 71 | — | 44 | VT, JET | 92 | 4 | 30 | D | 50 | NR | 59–71 | — | 0.1 |
| 4* | 28 | D | 63 | R | 50–78 | — | 6.7 | 2 | 34 | D | 50 | NR | 59 | VT | 3.1 |
| 5 | 25 | D | 58 | R | 44 | — | 0 | 3 | 34 | D | 65 | R | 56 | — | 0 |
| 6 | 23 | D | 77 | R | 57 | — | 0 | 2 | 32 | D | 80 | R | 52 | 0 | |
| 7 | 23 | — | 67 | R | 48 | — | 0 | 4 | 37 | — | 68 | R | 59 | — | 0.4 |
| 8 | 26 | — | 53 | NR | 57 | — | 0.8 | 1 | |||||||
| 9 | 27 | D | 62 | R | 57 | — | 0.1 | 2 | 32 | — | 62 | R | 67 | — | 0 |
| 10* | 25 | T | 58 | NR | 51 | — | 0.1 | 3 | 33 | D, T | 60 | NR | 56 | — | 0 |
| 11* | 24 | — | 56 | — | 46 | JET | 89.7 | 6 | 34 | D | 52 | R | 57 | — | <0.1 |
| 12* | 20 | — | 72 | R | 44 | JET | 7 | 6 | 32 | D, T | 54 | NR | 50–83 | JET | 0.2 |
| 13 | 32 | D, T | 65 | R | 46 | — | 0.2 | 1 | |||||||
| 14* | 19 | D | 71 | — | 44 | JET | 91 | 3 | 30 | D | 60 | NR | 48 | — | 1.6 |
| 15* | 27 | D, T | 78 | NR | 75 | — | 0.1 | 2 | 31 | D, T | 64 | NR | 80 | — | |
| Avg | 25 | 65 | 49 | 29% | 20.6 | 3.1 | 34 | 62 | 60 | 14% | 2.2 | ||||
|
| |||||||||||||||
| CSD | |||||||||||||||
|
| |||||||||||||||
| 16* | 25 | — | 53 | NR | 48 | — | 0 | 2 | 31 | T | 63 | NR | 55 | — | 0 |
| 17*† | 23 | — | 64 | NR | 46 | — | 0.1 | 3 | 34 | — | 54 | NR | 57 | — | 0.1 |
| 18*† | 25 | — | 61 | NR | 51 | — | 0.1 | 1 | |||||||
| 19*† | 29 | T | 68 | NR | 61 | JET | 8.4 | 1 | |||||||
| 20*† | 29 | — | 56 | NR | 48 | — | 0 | 2 | 31 | T | 66 | NR | 60 | — | <0.1 |
| 21* | 24 | — | 61 | NR | 54 | — | 0 | 2 | 37 | 62 | NR | 55 | — | 1.5 | |
| 22*† | 23 | — | 61 | R | 56 | — | 0 | 1 | |||||||
| 23* | 21 | T | 63 | NR | 54 | — | 0 | 3 | 36 | T | 60 | NR | 61 | JET | 84 |
| Avg | 25 | 61 | 52 | 13% | 1.1 | 1.8 | 33 | 61 | 58 | 25% | 28.0 | ||||
Fetuses #1 to #15 had third-degree (3°) atrioventricular block (AVB) in association with SSA antibodies. Fetuses #16 to #23 had 3° AVB in association with complex structural disease (CSD); fetuses #16 to #21 had left atrial isomerism, and fetuses #18 and #20 were also twin pregnancies in which the other twin was normal; fetuses #22 and #23 had complex corrected transposition of the great arteries, accompanied by tricuspid atresia in fetus #22.
Fetuses requiring neonatal pacing;
neonatal deaths. Fetus #8 was electively terminated.
D = dexamethasone; FHR = fetal heart rate; FHR pattern = R: reactive; NR: nonreactive; GA = gestational age; QRS = QRS duration; RX = medication; T = terbutaline; VT/JET = ventricular tachycardia or junctional ectopic tachycardia; % ectopy = percent ectopic beats;
fMCG = number of fetal magnetocardiography sessions.