Rapid Interpretation of EKGs - Chapter 8 highlights Flashcards
Hypertrophy
Hypertrophy usually pertains to an increase in size, but when relating to muscle as in myocardium, this term refers to what?
increase in muscle mass
Are you able to diagnose hypertrophy on an EKG?
yes. yes you can
Which wave is used to determine atrial enlargement on EKG?
the P wave
Which lead sits directly over the atria and is the best source of information about atrial enlargement?
lead V1
With atrial enlargement, the P wave in lead V1 is usually both positive and negative. Also known as what?
diphasic
Which component of the P wave in lead V1 indicates Right, rather than Left Atrial Enlargement? (the initial or terminal component)
the initial component
Which component of the P wave in lead V1 indicates Left, rather than Right, Atrial Enlargement? (the initial or terminal component)
the terminal component
If the height of the P wave in any of the limb leads exceeds ____ mm (even if it’s not diphasic), suspect Right Atrial Enlargement.
2.5 mm
Normally, in lead V1, the S wave is much larger than the R wave. (as shown here)
If the R wave is larger than the S wave in that same lead, what is this indicative of?
Right Ventricular Hypertrophy (the wall of the right ventricle is very thick, so there is much more (positive) depolarization (and more vectors) toward the positive V1 electrode)
After seeing the large R wave in lead V1, what pattern would you see in the size of the R waves from leads V1 - V6?
they would get progressively smaller
Would hypertrophy of the left ventricle cause dampened or exaggerated QRS complexes?
exaggerated QRS complexes (normally the S wave in V1 is deep, but with Left Ventricular Hypertrophy, even more depolarization is going downward to the patient’s left - away from the positive V1 electrode. therefore, the S wave is even deeper in V1)
What formula can be used to quickly tell if there is Left Ventricular Hypertrophy?
the depth (in mm) of S in V1 plus the height of R in V5
if it’s greater than 35 mm, there is LVH
What indicator of the T wave in the chest leads can point to LVH?
an inverted T wave with a gradual downslope and a very steep return to baseline
Which leads are used to determine Right and Left Atrial Enlargement, and which wave do you look at? Which leads are used to determine Right and Left Ventricular Hypertrophy and which wave(s) do you look at?
