Favorable effect of catheter ablation on nocturnal hypertension in patients with paroxysmal atrial fibrillation.

OBJECTIVES

The current study was performed to determine whether pulmonary vein isolation (PVI) improves nocturnal hypertension in patients with paroxysmal atrial fibrillation (PAF).

BACKGROUND

Abnormal night-time blood pressure (BP) fluctuation is a risk factor for atrial fibrillation. Imbalance of autonomic nervous function is a risk factor common to both of these abnormalities. PVI can reportedly modify the autonomic nervous function balance in patients with atrial fibrillation.

METHODS

The study population comprised 50 consecutive patients (mean age, 69.8 ± 7.5 years; 35.0% male) with PAF scheduled for PVI. Both 24-h ambulatory BP monitoring and heart rate variability analysis were performed before and at 3 months after PVI.

RESULTS

Patients were classified into two groups according to the presence of nocturnal BP dipping before PVI: the normal dipping group (n = 27) and the nondipping group (n = 23). The low-frequency spectrum power and the ratio of low-frequency spectrum power to high-frequency spectrum power (low-frequency spectrum/high-frequency spectrum) were higher in the nondipping than the normal dipping group (low-frequency spectrum: 219.9 ± 210.2 vs. 92.7 ± 50.5 ms, respectively, P = 0.03; low-frequency spectrum/high-frequency spectrum: 1.8 ± 1.9 vs. 0.9 ± 0.8, respectively, P = 0.05). In the nondipping group, the elevated night-time BP disappeared in eight (35%) patients at 3 months after PVI, which was associated with an increase in high-frequency spectrum power. These patients did not develop atrial fibrillation recurrence during follow-up (mean, 568 ± 218 days).

CONCLUSION

Among patients with PAF, the nondipping group showed greater sympathetic activity (higher low-frequency spectrum power and low-frequency spectrum/high-frequency spectrum) than the dipping group. Restoration of BP dipping after PVI is associated with increased parasympathetic activity (higher high-frequency spectrum power) and reduced recurrence of arrhythmic events.