Table 3.
Differential Diagnosis of SVTs with Identical P Waves and Regular PP Intervals
| Paroxy‐ | P‐Wave | PR and RP | Possible Variability | |||
|---|---|---|---|---|---|---|
| smal | Trigger | Morphology | P:R Ratio | Intervals | of PP and RR Intervals | |
| AT | Yes | Sudden | Any | Any | Any | Yes |
| Slow–fast AVNRT | Yes | PAC with PR prolongation | Retrograde and concentric | 1:1 | RP < 70 ms | No |
| Slow–slow AVNRT | Yes | PAC or PVC | Retrograde and concentric | 1:1 | RP < PR but > 70 ms | No |
| Fast–slow AVNRT | Yes | PVC | Retrograde and concentric | 1:1 | RP > PR | No |
| JT | Yes | Sudden | Retrograde and concentric | 1:1 or AV dissociation | P wave adjacent to QRS | Yes |
| Orthodromic AVRT | Yes | PAC or PVC | Any | 1:1 | RP > 70 ms | No |
| PFRJT | No | Rate‐dependent | Any | 1:1 | RP > PR | No |
| ST | No | Gradual | Sinus | 1:1 | Any | Yes |
AT = atrial tachycardia; AVNRT = atrioventricular nodal reentry tachycardia; JT = junctional tachycardia; AVRT = atrioventricular reciprocating tachycardia; PFRJT = permanent form of junctional reciprocating tachycardia; ST = sinus tachycardia; PAC = premature atrial contraction; PVC = premature ventricular contraction; AV = atrioventricular.