A peek at AF myocardial substrate through the signal-averaged ECG?

Atrial tachycardia originating from the pulmonary vein: clinical, electrocardiographic, and differential electrophysiologic characteristics

INTRODUCTION AND OBJECTIVES

Although atrial tachycardia (AT) frequently originates in the pulmonary vein, pulmonary vein atrial tachycardia (PV-AT) can be difficult to recognize on an ECG. The aim of this study was to identify clinical and electrophysiologic characteristics specific to PV-AT, including sinus P-wave duration and notching.

METHODS

The study included 87 patients who underwent AT ablation, divided into four groups: those with PV-AT alone (Group 1, n=25), those with PV-AT associated with atrial fibrillation (Group 2, n=18), and those with other forms of left AT (Group 3, n=7) and right AT (Group 4, n=37).

RESULTS

The mean age of patients in Group 1, at 44 + or - 14 years, was less than in Groups 2, 3 and 4, at 57 + or - 9, 58 + or - 12 and 53 + or - 16 years, respectively (P< .05) and the left atrial diameter, at 38 + or - 4 mm, was less than in the other left AT groups: 48 + or - 7 mm in Group 2 and 49 + or - 5 mm in Group 3 (P< .05). Overall, PV-AT was most frequently due to abnormal automaticity or triggered activity (P< .05) and presented with a short cycle length: 289 + or - 45 ms and 280 + or - 48 ms in Groups 1 and 2, respectively, versus 392 + or - 106 ms and 407 + or - 87 ms in Groups 3 and 4, respectively (P< .05). In patients aged <50 years with AT and no underlying heart disease, PV-AT was significantly (P< .05) associated with a P-wave duration > or = 110 ms (sensitivity 68%, specificity 69%) and P-wave notching (sensitivity 79%, specificity 70%).

CONCLUSIONS

Sinus P-wave prolongation and notching in young patients with a rapid AT but without heart disease predicted an origin in the pulmonary vein.