Cardio Flashcards
Which ECG leads monitor the inferior aspect of the heart?
II, III, aVF
Which ECG leads monitor the lateral aspect of the heart?
I, aVL, V5, V6
Which ECG leads monitor the anterior aspect of the heart?
V3, V4
Which ECG leads monitor the septal aspect of the heart?
V1, V2
What is the normal QRS axis?
-30 to +90
What is the range for Left axis deviation?
-30 to - 90
What is the range for right axis deviation?
+90 to +180
What is the usual cause of right axis deviation?
Right ventricular hypertrophy
What is the usual cause of left axis deviation?
Conduction defects
How do you work out the heart rate for regular rhythms?
300 / number of big boxes
1500 / number of small boxes
How do you work out the heart rate for irregular rhythms?
Count beats on rhythm strip and x6
What does the P wave represent?
Atrial depolarisation - combination of left and right
What does right atrial enlargement look like on an ECG?
Taller P wave >2.5mm
What does a P wave taller than >2.5mm suggest?
Right atrial enlargement
What does left atrial enlargement look like on an ECG?
Wider P wave >120ms (3 small squares)
May be M shaped - P. mitrale
What does a wide P wave >120ms suggest?
Left atrial enlargement
What is the PR interval?
Start of P wave until end of QRS
What does the PR interval represent?
Conduction through the AV node
What is the normal duration of a PR interval?
120-200ms
3-5 small squares
What does a PR interval >200ms suggest?
First degree heart block - delayed conduction through AV node
What do progressively increasing PR intervals suggest?
2nd degree heart block (Mobitz I) - not all atrial impulses reach vetricles
What does a PR interval <120ms suggest?
Wolff-Parkinson-White syndrome - accessory pathway allows early activation of the ventricle
What is the PR segment?
End of P wave until start of QRS
What does a normal PR segment look like?
Flat, isoelectric
What is PR segment depression suggestive of?
Pericarditis