Blunted rate-dependent left atrial pressure response during isoproterenol infusion in atrial fibrillation patients with impaired left ventricular diastolic function: A comparison to pacing

Aims A heart rate (HR)-dependent haemodynamic linkage between peak left atrial (LA) pressure during sinus rhythm (LAP_peak) and estimated left ventricular (LV) filling pressure (E/Em) has not yet been explored. We hypothesized that rate-dependent LAP_peak response differs depending on E/Em in patients with atrial fibrillation (AF). Methods and results A total of 331 patients (68.0% male, 59.8 ± 10.8 years old) undergoing radiofrequency catheter ablation (RFCA) for AF were included, and their LAP_peak in sinus rhythm was recorded at the beginning of the procedure and at the HRs of 90, 100, 110, and 120 b.p.m. during right atrial pacing and isoproterenol (ISO-stress) infusion. We compared LAP_peak changes between patients with E/Em ≥ 15 (n = 58) and those with <15 (n = 273). (i) The patterns of pacing rate-dependent LAP_peak increase were similar in both the E/Em < 15 (P < 0.001) and E/Em ≥ 15 groups (P = 0.002). (ii) The ISO-stress reduced LAP_peak in patients with E/Em < 15 (P = 0.015), but not in those with E/Em ≥ 15 (P = 0.582). (iii) Paradoxical ISO-stress LAP elevation in patients with E/Em ≥ 15 was independently associated with 1-year follow-up E/Em reduction (B = -4.07, 95% CI -5.41 to -2.72, P < 0.001). Coexistence of E/Em ≥ 15 and ISO-stress LAP elevation increased specificity in predicting 1-year follow-up E/Em reduction after AF ablation than E/Em alone. Conclusion Isoproterenol LAP_peak reduction was blunted in patients with impaired LV diastolic function estimated by E/Em ≥ 15. The improvement of LV diastolic dysfunction 1 year after AF ablation was independently associated with both paradoxical ISO-stress LAP elevation and E/Em ≥ 15 at the time of procedure. Clinicaltrials.gov NCT02138695.