Outpatient follow-up tests
After SAVR, all 109 patients underwent TTE and laboratory investigations
at least once a year as a routine check. Signal averaged ECG (SAECG) and
Holter ECG were performed if patients had suspected clinical symptoms of
arrhythmias or they approved to undergo the tests to stratify the risk
of arrhythmia. SAECG was considered positive if at least two of the
following criteria were satisfied: filtered QRS duration >
114 ms; terminal (last 40 ms) QRS root means square (RMS) voltage
< 20 μV; and low amplitude (<40 μV) signal (LAS)
duration > 38 ms.