Hypertrophy

The pearl to know about RAE is that after you diagnose it you should go on to look for either pulmonary disease, PE, or for congenital heart disease that will lead to Eisenmengers (ASD, PS/TOF, Ebsteins).

Why not VSD? Because, unlike in ASD where there is continuous flow across the ASD and therefore the left atrium is constantly being decompressed and the right atrium and ventricle constantly loaded, in VSD there is only flow in systole and so the left atrium is loaded all the time and the left ventricle loaded all of diastole, but the right ventricle is never loaded at all because the blood is shunted in systole and straight away ejected through the pulmonary valve...so, in VSD get a big left heart and normal right heart, and in ASD get a big right heart and normal left heart.


The pearl to know about LAE is that see a biphasic wave in V1 because the left atrium is a posterior structure and therefore the depolarization heads posteriorly, therefore see an inverted P wave/P wave heading away from the chest.

The pearl to know about RVH is that what you see is a rR wave in V1 instead of the usual rS wave where the S represents the electricity going to the bigger LV muscle mass. Because there is more muscle mass, depolarization takes longer so you get a partial RBBB too. Finally, repolarization also takes longer, so get TWI in V1 and FLAT (i.e. not necessarily downsloping) ST depression in leads V2-3.
 Therefore, the pearl is that if you see partial RBBB and RAD, think of RVH.

How do you tell if there is only mild RAD or severe RAD? The pearl is that it's all in lead III - if lead III has a taller R wave than lead II, then there is severe RAD.

For LVH, the initial criteria used to be that you had to have abnormal S waves in the right-sided lead (V1) and abnormal R waves in the left-sided leads (V5, V6) [ because V2-4 are on the FRONT of the chest, whereas V5-6 are on the side of the chest). However, people with thin chests kept on being diagnosed with LVH, so the people at the Cornell came up with criteria that were more specific by using the left arm lead.
They still used an S wave on the "relative right" (V3) and an R wave on the lead that was the most left they could get (AVL). The numbers that they came up with were >28mm for men and >20mm for women.

So, the way that you can be the most specific is by looking for:-
- widened QRS
- ST-T changes
- LAE
-LAD

Finally, in vertical hearts, if AVF R>20mm, then suspect LVH.