Electrophysiology Terms Q-S Flashcards
Q wave
in the qrs complex, the negative deflection
QRS complex
ventricular depolarization as seen on the ECG
QT interval
The length of time as measured on the ECG between ventricular depolarization and repolarization
Quadripolar
Four connections pr poles
R - on - T
dangerous condition induced when a PVC occurs during the T wave
R wave
intrinsic ventricular event
Radiofrequency Ablation
Destruction of tissue with radiofrequency energy delivered through an electrode catheter
Reentry
an abnormal conduction pathway, either anterograde or retrograde, though which an electrical impulse repeatedly enters and exits
Reentry Tachycardia
An abnormal condition in which a cardiac impulse may reexcite a region though which it has just traveled.
Refractory
inability of tissue to respond to a stiulus
Refractory Period
in the myocardium, the time period during which the muscle can be depolarized with a higher energy level than is normally required
Repolarization
the recovery process of excitable tissue following depolarization
Resistance
the opposition to the flow of electrical current in a conductor, usually stated in ohms. Relates only to electronic components, not to tissue or body fluids
Retrograde Conduction
Abnormal conduction marked by conveyance of the electrical impulse origination in the junction or ventricles backward to the atria, causing atrial depolarization
Sensing Threshold
the largest intrinsic atrial or ventricular signal, expressed in mV, which can be consistently sensed by the pulse generator’s sense amplifier
Sensitivity
Parameter which determines the amplitude of signals to which the device’s sense amplifiers will respond (mV)
The higher the mV the lower the sensitivity
Setscrew
A type if screw in the pulse generator’s epoxy connector used to tighten the lead’s terminal pin in the receptacles, pressing it securely against the connector block
SNRT
A test of sinus node automaticity. the length of time for the sinus node to recover after the discontinuation of sustained atrial pacing
Site of Earliest activation
During cardiac mapping, the portion of the myocardium activated first during tachycardia
Site of Origin
the exit point of an impulse from a tachycardia circuit, as determined by various cardiac mapping techniques
ST - segment
the portion of the ECG representing the end of ventricular depolarization and the beginning of ventricular repolarization
SVT
A tachycardia that originates outside the ventricle
