Followup
DHF was defined as heart failure requiring medical therapy during post-procedure hospitalization, or that required re-hospitalization < 90 days after the procedure. DHF was classified into early peri-procedural DHF and late peri-procedural DHF; namely, early peri-procedural DHF was defined as occurring within 2 days after the procedure and late peri-procedural DHF as occurring ≥ 3 days after the procedure.
Long-term rhythm outcomes after catheter ablation were followed for 2 years. late phase DHF requiring re-hospitalization in this 2-year period was also assessed.
A 12-lead ECG and blood tests were performed one day before the procedure. In accordance with Japanese guidelines, we set cutoff values for brain natriuretic peptide (BNP) and N-terminal pro-BNP of 100 ng/L and 400 ng/L, respectively.4 After the procedure, a 12-lead ECG was performed one day after the procedure, and Δheart rate, which was defined as heart rate after ablation minus heart rate before ablation, were calculated. ECG monitoring, peripheral oxyhemoglobin saturation monitoring, and observations by nurses were performed for at least 2 days after the procedure. In general, ECGs and chest X-rays were also performed when DHF occurred. If heart rate could not be measured, pulse rate was measured and substituted for heart rate.
Followup after discharge was performed as a part of routine visits, usually conducted at 1, 3, 6, 9, 12, 18, and 24 months after the procedure. Each routine visit included a 12-lead ECG. In addition, 24-hour Holter electrocardiography was performed 6 months after the procedure.
Early recurrence of AF was defined as atrial tachyarrhythmias detected by 12-lead ECG or atrial tachyarrhythmias lasting > 30 seconds detected by ECG monitoring or 24-hour Holter monitoring at < 90 days after the procedure. If early recurrence of AF occurred, antiarrhythmic drugs were generally used. Electrical cardioversion was performed according to the chief doctor’s judgment.
AF recurrence was defined as atrial tachyarrhythmias detected by 12-lead ECG or atrial tachyarrhythmias lasting > 30 seconds detected by 24-hour Holter electrocardiography ≥ 90 days after the procedure.