23. Diagnostic Features of the ECG Flashcards
____ is a lateral lead.
aVL
Hypokalemia causes ____ on the ECG.
a small, flat T wave that merges with a U wave
Right chest leads?
V1 and V2
Normally the QRS and T waves go in ____ direction.
the same
Normally in V1 and V2, the R wave is ____.
nearly absent
_______ causes a small, flat T wave that merges with a U wave on the ECG.
Hypokalemia
The light lines on the ECG paper = ____ sec.
0.04
How long is a normal QRS interval?
0.06-0.10 sec
Which are the bipolar leads?
limb leads I, II and III
A subendocardial infarct only involves the inner layer of the heart wall and causes ____ on the ECG.
persistent, flat ST depression
How long is a normal P wave?
0.08-0.10 sec
Ischemia due to _____ causes depression of the ST segment.
sudden high O2 demand in the presence of coronary obstruction
If LVH, there should be ____ on the ECG.
large, positive R waves in V5 and V6
ST elevation is a sign of transmural injury in _____.
an acute coronary syndrome or acute MI
What is the length to call a QT interval prolonged?
more than half of the RR interval
Hypokalemia predisposes to ____.
arrhythmia
How long is a normal P-R interval?
0.12-0.20 sec
Lateral leads?
I and aVL
What is the normal K+ concentration in the blood?
about 5 mmol
How long is a normal QT interval?
less than 0.44 sec
Which are the standard limb leads?
I, II, and III
____ is characteristic of demand induced ischemia.
ST depression
How is HR calculated on the ECG?
300 / # of heavy lines btw 2 QRSs
___ is an inferior lead.
aVF
The dark lines on the ECG paper = ____ sec.
0.2
What is a peaked T wave (hyperacute T wave)?
the very first, early sign of an MI
Inferior leads?
II, III, and aVF
Ischemia due to ______ causes T wave inversion.
acute coronary artery obstruction during low O2 demand
Left chest leads?
V5 and V6
______ causes a shortened QT on the ECG.
Hypercalcemia
What causes prolonged QT?
- hypo- Ca++, K+, or Mg++ 2. class 1A, 1C, or III anti-arrhythmic drugs 3. hypothermia 4. congenital long QT syndrome
Why is prolonged QT bad?
it makes you more susceptible to arrhythmias
Ischemia due to sudden high O2 demand in the presence of coronary obstruction causes _____.
depression of the ST segment
If RVH, there should be ____ on the ECG.
large, positive R waves in V1 and V2
Ischemia due to acute coronary artery obstruction during low O2 demand causes ____.
T wave inversion
The heart is more at risk for a _____ infarct.
subendocardial
____ is characteristic of acute coronary obstruction.
An inverted T wave
Hypercalcemia causes ____ on the ECG.
a shortened QT
In ventricular hypertrophy, the T wave is ____.
inverted (opposite the R wave)
Which are the unipolar leads?
aVR, aVL, aVF, V1-V6
A significant Q wave is how big?
25% or more the height of the R wave AND greater than one small box (0.04 sec) wide
The ____ is a is a measure of the AV node conduction time.
PR interval
_____ causes a prolonged QT interval on the ECG.
Hypocalcemia
Infarcted myocardium produces a _____ in leads over the affected area.
negative deflection Q wave
Hypocalcemia causes ____ on the ECG.
a prolonged QT interval
What is the treatment for long QT?
magnesium
The PR interval is a measure of the _____.
AV node conduction time
aVF is an ____ lead.
inferior
aVL is a ____ lead.
lateral
Serious hyperkalemia causes _____ on the ECG.
no P or R waves
Mild hyperkalemia causes ____ on the ECG.
a large, peaked T wave
Which are the augmented limb leads?
aVR, aVL, aVF
____ is a sign of transmural injury in an acute coronary syndrome or acute MI.
ST elevation
