instruction: when was the last time on this month/31 patient 002-34744 was measured for a heartrate that was less than 76.0?
response: SELECT vitalperiodic.observationtime FROM vitalperiodic WHERE vitalperiodic.patientunitstayid IN (SELECT patient.patientunitstayid FROM patient WHERE patient.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.uniquepid = '002-34744')) AND vitalperiodic.heartrate < 76.0 AND NOT vitalperiodic.heartrate IS NULL AND DATETIME(vitalperiodic.observationtime, 'start of month') = DATETIME(CURRENT_TIME(), 'start of month', '-0 month') AND STRFTIME('%d', vitalperiodic.observationtime) = '31' ORDER BY vitalperiodic.observationtime DESC LIMIT 1