RCM Versus Constriction

Question 1

What are the common features between RCM and constriction?

Answer 1

Impaired diastolic dysfunction (raised LVEDp and LAp), biatrial dilatation, IVC dilatation; and normal biventricular size/systolic function.

Question 2

How does the pathology of RCM and constriction differ?

Answer 2

RCM results from an intrinsically abnormal myocardium; whereas constriction results from an external constraint.

Question 3

How can echo differentiate RCM from constriction?

Answer 3

With respirophasic flow variation and TDI patterns (seen in constriction).

Question 4

True of false; with RCM there is respiratory flow variation.

Answer 4

False.

Question 5

True or false; with constriction there is respiratory flow variation.

Answer 5

True.

Question 6

In inspiration, will the E velocity increase on the mitral or tricuspid Doppler in constriction?

Answer 6

Tricuspid.

Question 7

In inspiration, will the E velocity decrease on the mitral or tricuspid Doppler in constriction?

Answer 7

Mitral.

Question 8

In constriction, what is the mechanism behind the common “septal bounce” finding?

Answer 8

Upon inspiration, there is increased flow into the RV and reduced flow into the LV meaning the septum is pushed into the LV (the RV free wall cannot expand outwards because of the external constraint). The exact opposite happens with expiration, whereby the septum is pushed into the RV because of increased flow into the LV.

Question 9

Hepatic vein flow will show flow reversal on inspiration or expiration (in constriction)?

Answer 9

Expiration.

Question 10

True or false; hepatic vein flow reversal is seen in RCM and constriction?

Answer 10

True.

Question 11

What is the mechanism behind hepatic vein flow reversal on inspiration in RCM?

Answer 11

With inspiration there is an increase in venous return to the RV. However, because of increased filling pressures blood is pushed back into the hepatic veins when the RA contracts (purely due to increased filling pressures).

Question 12

Hepatic vein flow reversal is seen in RCM and constriction; but in what part of the respiratory cycle?

Answer 12

Inspiration in RCM; Expiration in Constriction.

Question 13

With regards to TDI measurements, what are common findings in constriction?

Answer 13

Annulus Paradoxus and Annulus Reversus.

Question 14

What is annulus paradoxus/reversus?

Answer 14

Normal or increased mitral septal e’ velocities and reduced lateral e’ velocities (due to lateral tethering).

Question 15

With regards to TDI measurements, what are common findings in RCM?

Answer 15

Reduced e’ velocities (normal e’ velocities virtually exclude RCM).