1-35 Flashcards
What does the P wave represent?
depolarization of the atrial myocardium
How does the autonomic nervous system influence the AV node?
vagal- slows it, sympathetic- accelerates it
What are the 3 components of the ventricular conducting system?
1- bundle of his, 2- bundle branches, 3- Purkinke fibbers
What are the 3 components of the left bundle branch?
septal fascicle, anterior fascicle, posterior fascicle
What does the QRS complex represent?
ventricular depolarization
What does the Q wave represent?
depolarization of the intraventricular septum
What does the T wave represent?
ventricular repolarization
What is a segment?
Straight line connecting two waves
What is an interval?
A part that includes at least one wave plus connecting straight line
PR is an ___
interval
What does the PR interval measure?
the time from the start of atrial depolarization to the start of ventricular depolarization
What does the PR segment measure?
the time from the end of atrial depolarization to the start of ventricular depolarization
What does the ST segment measure?
the time from the end of ventricular depolarization to the start of ventricular repolarization
What does the QT interval measure?
the time from the beginning of ventricular depolarization to the end of ventricular repolarization
What is the angle of lead I?
0 (left arm +, right arm-)
What is the angle of lead II?
60(legs+,right arm-)
What is the angle of lead III?
120(legs+,left arm-)
What is the angle of lead aVL?
.-30 (left arm +, other limbs -)
What is the angle of lead aVR?
.-150 (right arm +, other limbs -)
What is the angle of lead aVF?
90 (legs +, other limbs negative)
what are the inferior leads?
II, III, aVF,
what are the left lateral leads?
I, aVL, V5, V6
what are the right lateral leads?
aVR, V1
the limb leads are on the ___ plane
frontal
the precordial leads are on the ___ plane
horizontal
where V1 is placed?
fourth intercostal space to the right of the sternum
where V2 is placed?
fourth intercostal space to the left of the sternum
where V3 is placed?
between V2 and V4
where V4 is placed?
fifth intercostal space in the midclavicular line
where V5 is placed?
between V4 and V6
where V6 is placed?
fifth intercostal space in the midaxillary line
what are the anterior leads?
V2, V3, V4
P wave is usually positive in the __ lateral and ___ leads
left lateral leads (I, aVL, V5, V6) inferior leads (II, III, aVF)
P wave is most positive in lead ___, and most negative in lead ___
II, aVR
tall R waves can be seen in the __ lateral and __ leads.
left lateral leads (I, aVL, V5, V6), inferior leads (II, III, aVF)
