Table 2.
Comparison of Septal VT Localization
| Variables | Endocardial Myocardium (n = 20) |
Purkinje Related (n 8) |
Intramural Myocardium (n = 5) |
p Value |
|---|---|---|---|---|
| No. of VTs | 32 | 9 | 5 | — |
| Age, yrs | 65 ± 10 | 62 ± 7 | 64 ± 7 | NS |
| Women/men | 3/17 | 0/8 | 0/5 | NS |
| QRS width, ms | 204 ± 38* | 137 ± 15 | 155 ± 37† | <0.0001 |
| QRS: V1−/V2+ | 4/32 (13%) | 0/9 (0%) | 4/5 (80%) | 0.0003 |
| Morphology | 0.03 | |||
| LBBB | 16/32 | 1/9 | 4/5 | |
| RBBB | 16/32 | 8/9 | 1/5 | |
| Axis | NS | |||
| Superior | 21/32 | 9/9 | 3/5 | |
| Inferior | 11/32 | 0/9 | 2/5 | |
| VT cycle length, ms | 404 ± 97 | 415 ± 127 | 385 ± 78 | NS |
| Pace-map match score at effective site | 11.1 ± 0.9* | 12.0 ± 0.0‡ | 8.8 ± 0.5† | <0.0001 |
| CE | (10/10) | 9/9 | 0/5 | — |
| Ejection fraction, % | 26 ± 15 | 29 ± 11 | 43 ± 14† | <0.05 |
| Low-voltage area (<1.0 mV), cm2§ | Median = 109; IQR = 53 | Median = 55; IQR = 61‡ | Median = 22; IQR = 8† | 0.002 |
| Low-voltage area (<1.0 mV), cm2, within left ventricular septum§ | Median = 32; IQR = 32 | Median = 27; IQR = 15 | Median = 13; IQR = 16 | NS |
| Septal involvement to whole septal area, %§ | Median = 55; IQR = 30 | Median = 50; IQR = 47‡ | Median = 16; IQR = 26† | 0.04 |
| Infarct localization | 0.05 | |||
| Inferior | 11 | 6 | 0 | |
| Anterior | 11 | 3 | 5 | |
| Coronary artery | <0.05 | |||
| LAD | 11 | 3 | 5 | |
| RCA | 12 | 6 | 0 | |
| LCx | 0 | 0 | 0 | |
| Septal origin | ||||
| Basal/nonbasal | 8/24 | 4/5 | 5/0 | 0.005 |
| Anterior/posterior | 19/13 | 1/8 | 2/3 | 0.04 |
Values are n, mean ± SD, or n (%).
*
QRS: V1−/V2+ = QRS morphology with QS complex in V1 and a broad R-wave in V2. P values were adjusted for multiple comparisons. *Endocardial VTs versus Purkinje-related VTs: p < 0.05.
†
Intramural versus endocardial VTs: p < 0.05.
‡
Purkinje-related VTs versus intramural VTs: p < 0.05.
CE = concealed entrainment; IQR = interquartile range; other abbreviations as in Table 1