ECGS and rhythm recognition Flashcards
(30 cards)
SA Node?
Heart’s main pacemaker.
Controls the beat on information it receives from the nervous, circulatory and endocrine system.
Internodal pathways?
Anterior, middle and posterior.
Transmit the pacing impulse from the SA node to the AV node.
Small tract of specialised cells known as the Bachmann’s bundle that transmits the impulses through the inter atrial septum.
Bundle of HIS?
Only route of electrical communication between the atria and the ventricles.
Left bundle branch
Begins at the end of the bundle of his and travels through the interventricular septum.
Right bundle branch?
terminate purkinje fibres
Purkinje system
Cells that directly innervate the myocardial cells and initiate the depolarisation cycle.
Einthovens triangle?
represents leads 1 2 and 3 required for an ECG.
Lead 1?
Left arm electrode is the positive pole and the right arm electrode is the negative pole.
Lead 2?
In lead 2, the left foot is the positive pole and the right arm is the negative pole.
Lead 3?
The left food is positive pole and the left arm electrode is the negative pole.
AVL?
Right arm electrode and the left foot electrode comprise the mutual negative pole while the left arm electrode is the positive pole.
AVR?
The left arm electrode and the left food comprise the mutual negative pole while the right arm is the positive pole.
AVF?
The right arm electrode and the left arm electrode are combined to form the negative pole.
Waveform polarity?
When a depolarisation impulse flows towards an electrode, the ECG will record a positive or upward deflection.
When it flows away that is a downwards deflection.
What is the P wave?
Atrial depolarisation
Positive in 1,2 v4-v6
PR segment?
The time between the end of the P wave and beginning of the QRS complex.
Delta wave?
Due to early conduction through accessory pathway.
PR Interval?
Time period from the beginning of the P wave to the beginning of the QRS complex. Includes the P wave and the PR Segment.
Q wave?
First negative deflection of the QRS complex.
Represents ventricular depolarisation.
Pathological Q waves?
Pathological Q waves are greater than 0.04 seconds wide or greater than 02mV deep.
QRS complex?
Represents ventricular depolarisation
Summation of the vectors spreading across each ventricle.
Qrs complex
Q wave - first negatvie deflection
Q wave may be present or absent
R wave - first positive deflection after the P wave
The negative deflection after the R wave is called the S wave.
T wave?
T wave - ventricular repolarisation.
Deflection after the QRS complex and should begin in the same direction as the QRS.
ST Segment?
Section from the end of the QRS complex to the beginning of the T wave
J point - point where the QRS complex ends and the ST segment begins.
