Table 2.
Differential Diagnosis of Foci Responsible for Focal Atrial Tachycardia
| I | II | III | aVR | aVL | aVF | V1 | V2 | V3 | V4 | |
|---|---|---|---|---|---|---|---|---|---|---|
| CT | + | + | − | +/− or + | ||||||
| TA | + or iso | + | − | − | ||||||
| RAA | low + | low + | low + | − or iso | ||||||
| CS mid‐body | deep − | deep − | + | deep − | + | iso | iso | |||
| CS ostium | deep − | deep − | + | deep − | iso | iso | ||||
| Perinodal/septal right | iso or − | |||||||||
| Left PVs | iso | broad, notched + | broad, notched + | − | − or iso | broad, notched + | broad, notched + | + | + | + |
| Right PVs | + | − | − or iso | + | + | + | + | |||
| Superior PVs | + | + | − | − or iso | + | + | + | + | + | |
| Inferior PVs | − | − or iso | + | + | + | + | ||||
| LAA | − | + | + | + | + | |||||
| AM continuity | iso | iso | iso or − | iso | −/+ | |||||
| Noncoronary cusp of aortic valve | + | low −/+ | low −/+ | + | low −/+ | − | − | |||
| Perinodal/septal left | + or −/+ |
CT = crista terminalis; TA = tricuspid annulus; RAA = right atrial appendage; CS = coronary sinus; PVs = pulmonary veins; LAA = left atrial appendage; AM = aortomitralic; iso = isodiphasic; + = positive; − = negative; iso = isodiphasic; +/− = positive/negative; −/+ = negative/positive.