EKG diagnostics Flashcards
How much time in a big square on the EKG paper?
0.2 seconds
How’s the conduction system of the heart divided?
SA node, AV node, His bundle, RBB and LBB (septal fascicle, left anterior, left posterior).
What is the difference between in hypertrophy and enlargement?
Hypertrophy = increase in muscle mass
Enlargement = dilation of particular chanber
Changes when a chamber enlarges or hypertrophies
-Longer to depolarize;
-More current/larger voltage;
-Shifting of axis.
What is the normal QRS axis?
Between +90° and 0°
What is the axis when lead I is negative and lead aVF positive?
Right axis deviation
What is the normal P wave duration? Largest deflexion?
<120 ms
2.5 mm (2.5 mV)
Best lead to assess P waves
V1 (+ II for enlargement)
What is 2nd degree heart block? (Mobitz I)
PR interval gets longer and longer until a QRS is dropped
What is 1st degree AV block?
Long (>120ms) PR interval (no clinical significance)
Difference between atrial flutter and atrial fibrillation?
Flutter : Regular
Fibrillation : Irregular
How is right atrial enlargement diagnosed?
P waves > 2.5mm in II, III OR aVF
What is the main finding in ventricular hypertrophy?
Axis deviation
Findings in right ventricular hypertrophy.
-R wave in V1 larger than S wave;
-S wave in V6 larger than R wave.
Findings in left ventricular hypertrophy?
Increased R wave amplitude in leads overlying left ventricule and increased S wave amplitude in leads overlying right ventricule.
