2) ECG Flashcards
QT interval:
RR interval:
= any action in ventricles
= measuring HR
(ECG Horizontal Boxes) small box is how long
5 small boxes:
Each large box is how long
= 0.04 sec
= 1 large box
= 0.20 sec
(ECG Vertical Boxes) Each small box is & what:
5 small boxes equal:
Each large box is:
2 large boxes equal
= Each small box 1 mm & 0.1mV
= 1 large box
= 0.5 mV & 5mm
= 1mV & 10mm
PRI measured by:
PRI “PR/PRI” interval rep/s:
A normal PRI interval range:
prolonged PRI indicates:
= distance from beginning of P wave to beginning of QRS complex.
= time impulse takes from atria-ventricles “Gatekeeper Gandolf”
= 0.12-0.20 sec / 3-5 SB
= a delay in the AV node & possible HB
QRS interval measured:
QRS interval represents
QRS interval range:
QRS interval Q,R,&S:
= distance from 1st deflection of complex to last deflection
= time needed for ventricle depolarization (bundle of his > ventricles)
= 0.04-0.12secs / 1-3SB
= 1st -deflection not >1SB, 1st +deflection, -deflection after R
T wave represents:
T wave amplitude:
= Repolarization of ventricles
= <5mm in LL <10mm in precordial
Absolute refractory period:
Relative refractory period:
= Apex of T wave Q-T wave apex of wave: ventricle not ready to work
= T wave top to end of T wave: (commodo cordis) cells not repolarized (torsades de pointes more dead from repolarization not in sync)
who 1st noted skeletal M.s are excitable by shocking frogs:
who Pub/ed 1st ECG using a capillary metter w/ salt water:
= 1786 Dr. Luigi Galvani> “Muscle contract w/ elect”
= 1821, Augustus Waller > (couldn’t recreate same impinge)
1786 Dr. Luigi Galvani:
1821, Augustus Waller:
= 1st noted skeletal muscles were excitable by shocking frogs “Muscle contract w/ elect”
= Pub/ed 1st ECG using a capillary metter w/ salt water (couldn’t recreate same impinge)
Resting potential of the cardiac contractile cell occurs at:
Action potential of the cardiac contractile cell occurs at:
What ion causes the cardiac contractile cell to depolarize?
What ion causes the cardiac contractile cell to repolarize?
= -90mV
= -85mv
= Sodium
= Potassium
A normal QRS has a duration between:
A normal PRI has a duration between:
= 0.04-0.12 secs / 1-3SB
= 0.12 - 0.20 secs/ 3-5SB
On ECG paper, one small vertical box represents:
On ECG paper, one large vertical box represents:
= 0.1mV/ 1mm
= 0.5mV/ 5mm
Purkinje System has an inherent firing rate of:
AV Node has an inherent firing rate of:
SA Node has an inherent firing rate of:
= 15-40BPM
= 40-60BPM
= 60-100BPM
Natural pacemaker of the heart is:
If SA Node failed to initiate a impulse, what is 1st back-up firing site?
If both SA & AV fails what is last firing site:
= SA node
= AV node
= Purjunkie
impulse traveling towards a positive electrode will produce a:
Impulse traveling away from a positive electrode will produce a:
= positive deflection wave ECG
= negative deflection wave ECG
Action potential of autorhythmic cell occurs at:
Resting potential of autorhythmic cell occurs at:
ion causes autorhythmic cell to depolarize:
ion causes autorhythmic cell to repolarize:
= -40mV
= -60mV
= Calcium
= Potassium
The SA Node is found where in the heart?
The AV Node is found where in the heart?
Purjunkie System found where in the heart?
= Upper right of atrium
= In the lower right of atrium
= Septum to bottom of ventricles
Cardiac cell communication w/ ions
Phase 0 of the cardiac contractile cell:
Phase 1 of the cardiac contractile cell:
Phase 2 of the cardiac contractile cell:
Phase 3 of the cardiac contractile cell:
Phase 4 of the cardiac contractile cell:
= gab junction & intercalated disc 400x faster
= P0) Depolarization
= P1) slow K efflux
= P2) Plateau> Slow Ca in & K out “- for +”
= P3) Repolarization> rapid K efflux
= P4) Refractory Na/K pumps & Ca pumps out
What does the P wave represent on an ECG:
What does the T wave represent on an ECG:
What does the QRS wave represent on an ECG:
= Arterial depolarization
= Ventricular depolarization
= electrical activity in ventricles
Normal ECG paper speed is
On ECG paper, 1 Small horizontal box represents:
On ECG paper, 1 Large horizontal box represents
= 25mm/sec
= 0.04 secs
= 0.20 secs
A normal P wave in Precordial leads should be:
A normal P wave Limb leads should be:
= nice & round w/ amplitude <1.5mm
= nice & round w/ amplitude <2.5mm
Na> affect on heart:
Ca> affect on heart:
K> affect on heart:
= depolarizing myocardium
= M. contraction depolarization
= influences repolarization
IF RAAS freaks out:
= BP & afterload increases
ANP Atrial Natriuretic Peptide:
BNP “Brain” Natriuretic Peptide:
= released by + pressure/ atrial dilation & stress
= myocytes stretched out releases more BNP, Starlings law correlates w/ BNP “BNP + = CHF/Heart failure”
Cardiac artifacts:
Causes of artifacts:
= hard to decipher iso-electrical lines w/ 0 & skewed
= M. tremors/shivering, PT mnt(moves baseline), Loose electrodes, 60-hertz interference(ungrounded electricity near you (AC current alternating in house), Machine malfunction (Dotted flat line),& electrode bad connection/ off
Eintovhens triangle (bipolar) camera always at
L1 + & - leads:
L2 + & - leads:
L3 + & - leads:
= positive > Bipolar - to +
= -RA to +LA
= -LL to + LL
= -LL to + LL
Unipolar leads:
Unipolar lead camera:
aVR:
aVL:
aVF:
= 1 polarity(need 4 LL): AvR,LvR, (Wilson’s central terminal)
= Starts at middle point of lines look to center terminal
= augmented voltage right (right (looks at R-atrium)
= augmented voltage Left Positive Left arm +, L-wall
= augmented voltage Foot: Left Leg positive inferior
Precordial leads:
V1 location:
V2 location:
V3 location:
V4 location:
V5 location:
V6 location:
V ”5” 8 location:
V ”6” 9 location:
= “chest”
= V1: 4th ICS R of sternum
= V2: 4th ICS L of sternum
= V3: ½ in between
= V4: 5th ICS mid-clavicularly
= V5: 5th ICS anter auxillary
= V6: mid auxillary
= V ”5” 8: 5th ICS mid scapular
= V ”6” 9: ½ between spine & midscapular
(KEV interpretation APPROACH) step 1:
Step 2:
Step 3:
Step 4:
Step 5:
= 1st (what is rate per min)
= 2nd Rhythm: is it regular, regularly irregular, or totally irregular
= 3rd P waves> present? All same/location, P wave in front every QRS
= 4th: PR interval> w/in norm limits, Same w/ every beat
= 5th QRS> all present, same, QRS after each P wave, w/in norm limits
Wandering atrial pacemaker:
Double hump morphology:
Sharp P morph/:
= dif/ morph b/c coming from dif/ spots in atrium
= atrium ballooning & way dif
= Pulmonale from right atrium pulmonary
WNL :
Within Normal Limits
Wide QRS=
ventricular problem /slow
(Limb leads) placement:
positive to negative makes wave:
positive to negative makes wave:
= mid forearm on M. & inside of calf (if amputee/ go less distally)
= positive wave
= negative wave
U wave:
= “late bloomers” repolarization (hypothermic PTs)
(P wave) Limb leads amplitude:
Precordial “chest” leads amplitude:
= <2.5mm in limb leads Avl (2.5mV)
= <1.5mm in precordial (1.5mV)
(T wave) Limb leads Amplitude:
Precordial “chest” leads amplitude:
= <5mm in LL
= <10mm in precordial
(Dysfunctions) Wandering pacemaker:
no P wave bc
No QRS:
Premature ventricular contractions:
R prime:
= > no similarities in P waves
= pathways/AV node dysfunction, block, or death
= AV node pacing and/or heart block
= Ventricle fires premature after initial ventricle contraction
= 2 R waves “dub hump” b/c pathways not in sync
!!Starling’s Law of heart:
= states that the more the myocardium is stretched, up to a certain amount, the more forceful the subsequent contraction will be
(Einthoven’s triangle) Negitive & Positive lead 1 sites:
Negitive & Positive lead 2 sites:
Negitive & Positive lead 3 sites:
=negative @ RA & positive @ LA
= negative @ RA & positive @ LL
= negative @ LA & positive @ LL
!!!Einthoven’s triangle: green electrode:
Blue electrode:
Red electrode:
=neutral/ground “ground grass”
= Negative “feeling blue”
= Positive
The 3 types of ECG leads are:
bipolar, augmented “unipolar”, and precordial.
1957, Dr. J. Frank Pantridge & his colleague Dr. John Geddes made:
= modern concept of cardiopulmonary resuscitation (CPR) for the early treatment of cardiac arrest.
feeling a pulse is from what:
= ventricles/QRS contracting
(3 internodal pathways) 1:
2:
3:
= SA node to Bachmann’s bundles left atrium
= AV junction to AV node,
= Junction AV node, Sinus SA node
(only in heart) Intercalated discs:
Discs speed Vs standard cell membrane:
Syncytium:
= Special tissue bands inserted between myocardial cells that increase the rate(400x) in which AP is spread from cell-cell thus Syncytium
= 400x faster than standard cell membrane drom/Inotropy
= Group of cardiac cells physiologically function as a unit, “working together in sync” “top in syncytium to bottom”
OMI:
Occlusion Myocardial infarction (V2)
Precordial “Chest” leads help in viewing:
L-ventricle & septum.
prolonged QT interval related to:
= increased risk of certain ventricular arrhythmias & sudden death. Numerous meds, (particularly some antipsychotics)
(leads veiws) I and aVL:
II, III, and aVF:
aVR:
V1 and V2:
V3 and V4:
V5 and V6:
= Left side of the heart in a vertical plane
= Inferior (diaphragmatic) side of the heart
= Right side of the heart in a vertical plane
= Right ventricle
= Interventricular septum and the anterior wall of the left ventricle
= Anterior and lateral walls of the left ventricle
