Ventricular Timing Cycles

  1. Ventricular Refactory Period (V-Ref)
    • 250 ms
    • Primary Purpose to prevent sensing of T waves
    • Made up of Absolute and Relative
  2. Ventricular Blanking
    • about 15-30ms after a PACED atrial event
    • total period of blindness
    • purpose is to prevent seeing atrial activity
    • prevents crosstalk inhibition
  3. Crosstalk Detection Window
    setting in a st.jude pacemaker after VBP
  4. VSP
    • ventricular safety pacing
    • occurs if a single is deteted during CDW
    • paces at 100ms
  5. Medtronic & Biotonic
    • saftey period is 85ms after the VBP
    • no CDW
  6. Boston Scientific
    • No CDW, Saftey Period
    • But...longer VPB
  7. If you see the PAV go from programmed rate to 100ms you are looking at what?
    saftey pacing
  8. Why would you try and extend v-ref?
    is person has long QT syndrome
  9. Benefits of tracking
    • allows for atrial kick
    • improve cariac outpit
    • improves hemodynamics

    helps pacemaker respond to exercise and stress
  10. Drawacks of tracking
    • atrial tachyartrhthmias
    • ventricular pacing at rates the patient finds uncomfotable
Card Set
Ventricular Timing Cycles
Dual pacing part 2