3. Normal ECG 1/2 Flashcards
(27 cards)
What occurs during QRS and what are the normal times?
Ventricular depolarization… Normal less than .12s, greater than .12s = bundle branch block/hypertrophy
5 small squares is equal to 5mm/0.2s. One small square is equal to?
1mm and 0.04s
What occurs during P wave and which leads can be found upright and inverted?
P wave during atrial depolarization
urpright in 1,2,V4-V6, AVF
Invert: AVR (variable in rest)
What occurs during PR interval and what is the normal time?
Beginning of P wave to beginning of QRS complex: ***time from SA node to ventricular muscle fiber
Normal time is 0.12-0.2seconds (3-5squares)
What occurs during QRS complex, what is their duration and common width?
Ventricular depolarization usually 0.05-0.10s in duration. Q waves usually not wider than 0.04s or 1 full square
In Q waves which are narrow and small, 1-2 mm is normal in? (5)
1, AVL, AVF, V5, V6
ST segment is after QRS complex and is normally isoelectric (relative to baseline), what is normal in standard and chest leads?
In standard leads (1,2,3 AVF/R/L) elevated no more than 1mm and 2mm in chest leads, usually are not depressed more than 1/2 mm
What does a depressed or elevated ST segment indicate?
Depressed: subendocardial
Elevated: subepicardial or transmural injury/ichemia
What occurs during T wave, what are the upright and inverted heights found in, what are the normal heights in mm and what is the normal shape?
Ventricular repolarization Upright: 1,2,V3-V6 Inverted AVR Shape: round and assymetrical Height: not greated than 5mm in standard or 10mm in chest (precordial) leads
QT duration is length of ventricular systole. If abnormal length can signal?
Myocardial ischemia/injury/infarction
When ST is elevated= injury, when T wave is inverted = ?
ischemic pattern
Q wave or QS complex abonormalities signal?
pattern of necrosis or infarction
When is an ECG considered a sinus rhthym?
When there is a P wave before the QRS
If someone exercises alot and is healthy, what can be expected of their T waves?
T waves can be taller and still be normal
When the P wave looks like an M, it is called P-mitrale. P pulmonale: flat in lead 1, pointed/tall in Lead 2/3. What is characteristic of AV junctional rhythm?
Inverted P wave in Leads 2 and 3 with short PR interval
A prolonged PR interval can indicate a AV block due to coronary disease. A shortened PR interval can be due to?
AV junctional
Wolff Parkinson White syndrome
Lown Ganong-Levine syndrome
Where can you find an elevated fire mans hat on an ECG and what would that signal?
elevated from baseline Firemans hat in the ST segment due to myocardial infarction or injury
What are artifacts on an ECG reading?
Artifacts are square/rectangular readings on ECG which signal that the machine/leads are not hooked up correctly
What are the numbers for estimating HR? What occurs if its past the lowest number?
One box from where you are measuring is 300, then 150, 100, 75, 60
Anything past 60 is bradycardia
OR 300/(how many boxes from point)
What is the rhythm where a P wave precedes QRS?
SINUS rhythm
What two abnormalities present as P wave following QRS?
- SVT (AV nodal re-entry tachycardia)
2. Junctional rhythm
Atrial fibrillation, atrial flutter, juntional/ventricular escape rhythms, junctional tachycardia and ventricular tachycardia all have absent?
P waves
Which 6 leads meet to form six interseting leads in a frontal plane on the chest?
L1,2,3 AVF,R,L
A normal axis is?
Positive deflection in Lead1 and AVF
