Hypertrophic Cardiomyopathy

Front 1

How does hypertrophic cardiomyopathy occur?

Back 1

This is and AD genetic disorder

Front 2

What is the pathophysiology of HCM?

Back 2

The genetic defect is within the sarcomere:
-there is a change in the beta-myocin protein (amongst many others) and the myocyte has a very disorganized architecture
-Pt. will develop thickening of the walls or septum within the heart

Front 3

Explain what occurs during outflow obstruction in HCM. What is the sequale of this event.

Back 3

The hypertrophy of the septum of the LV causes it to be displaced and during systole, the mitral valve is pulled toward the enlarged septum
-as a result, the cardiac output is decreased due to obstruction of flow.

Front 4

How is diastolic function affected if HCM?

Back 4

The increased hypertrophy of the heart causes the ventricle to become enlarged and decreases its compliance during ventricular filling

Front 5

Obstruction is cause by the interaction of these two structures in the heart.

Back 5

The hypertrophied septum and the ANTERIOR mitral valve leaflet (the obstruction is BELOW the aortic valve)

Front 6

How does the mutation in the sarcomere proteins affect the heart?

Back 6

The disorganization of the sarcomere causes the architecture of the heart to be disorganized and this leads to arrythmias

Front 7

Most common cause of sudden death in the young.

Back 7

HCM

Front 8

Physicians use this method to assess the presence of HCM.

Back 8

Use of different techniques to change preload and afterload to assess if there is a change in the murmur intensity

Front 9

This movements increase preload

Back 9

-Leg raise
-Stand, then squat

Front 10

How does an increase in preload to the heart in a pt. with HCM affect the intensity of the murmur? Why does this happen?

Back 10

Increased preload means, you increasing the volume of blood returning to the heart:
-the increased volume of the heart increases the stretch of the LV and the increased volume allows the outflow track to be opened more, so the intensity of the murmur decreases.

Front 11

This type of murmur is heard in pts. with HCM

Back 11

Systolic murmur (harsh)

Front 12

What manuevers decrease preload?

Back 12

Standing

Front 13

How does an decrease in preload affect the outflow obstruction in HCM?

Back 13

With less volume within the heart; the ventricle will shrink up and there is less force to open the obstruction due to the decreased volume; this therefore increases the intensity of the murmur

Front 14

What maneuvers increase afterload?

Back 14

hand-grip

Front 15

How does an increase in afterload affect the intensity of the murmur?

Back 15

-increased afterload means that there is greater resistance for the LV to overcome during systole; there will be a greater ESV, less CO, dilation of the ventricle due to increased volume and therefore less obstruction (now the mitral valve is further away from the ventricle wall during systole)

Front 16

How do contractility changes in the heart affect the intensity of the murmur? How will this affect drug therapy?

Back 16

Increased contractility = louder murmur (greater gradient across the obstruction)
-important to give the patient (-) inotropes to avoid increasing contractility and the outflow obstruction

Front 17

Why is important for patients with HCM to be well hydrated?

Back 17

Bc you want to avoid decreasing the preload! Decreasing the preload shrinks the ventricle and will bring it into closer contact with the mitral valve during systole

AVOID DIURETICS

Front 18

Why is important to avoid vasodilators with HCM patients?

Back 18

Vasodilation decreases the afterload and allows more EF and CO which prevents the expansion of the ventricle, which we want because it decreases the obstruction by pulling the wall further from the mitral valve.

Front 19

Why should pts. with HCM have a defibrillator? How is it helpful?

Back 19

-This detects the presence of arrythmias (which are common due to the disorganized structure of the myocardium) and decreases the rate of syncope and sudden death

Front 20

What are CV repair options in HCM?

Back 20

Alcohol septal ablation: catheter inserted to ablate the section of the septum causing obstruction

Septal myemectomy: open heart surgery; cut off the portion of the heart causing an obstruction

Heart transplant (when other treatments don't work)

Front 21

The mainstay of therapy in those with HCM. Why?

Back 21

-B-blockers because they help slow the heart rate which will help extend diastole and increase the preload (& avoid arrythmias)

-Decrease contractility

Front 22

Mumurs in HCM are heard at what point of the cardiac cycle?

Back 22

After S1, during systole

Front 23

Describe the apical pulse in HCM?

Back 23

Palpable, double apical pulse due to the hypertrophy

Front 24

Why are S3 & S4 present with HCM?

Back 24

S3: the rapid filling of a non-compliant ventricle
S4: occurs during the atrial kick (last filling of the ventricle with atrial blood) maximal stretching of the ventricle

Front 25

Why is there splitting of S1/S2?

Back 25

The aortic valve is opened longer than the pulmonic valve bc we delay the emptying of the ventricle

Front 26

Mitral valve prolapse is associated with these types of diseases? Or inherited how?

Back 26

CT disorders (i.e. Marfan's, Ehlers Danlos)

-AD inheritance

Front 27

Describe a prolapsed valve.

Back 27

A valve that is floppy and can open at inappropriate times in the cardiac cycle

Front 28

What other cardiac structure is damaged with mitral valve prolapse?

Back 28

Chordae tendinae are stretched out and thin

Front 29

As a result of mitral valve prolapse, this other pathophysiological process can occur.

Back 29

Mitral regurgitation

Front 30

These types of heart sounds are associated with mitral valve prolapse.

Back 30

Mid-systolic click (valve snaps open during systole)

If mitral valve regurgitation occurs you will also hear a murmur

Front 31

What manevers can be used to assess the presence of mitral valve prolapse? How will these maneuvers help you?

Back 31

Stand --> squat (increases preload)
Leg Raise (increases preload)
Standing (decreases preload

-If the person has mitral valve prolapse, the timing of the mid-systolic click will be different

Front 32

How does preload influence when you hear the mid-systolic click in MVR?

Back 32

Small preload = increased HR = decreased filling time decreased time for systole= click will be heard closer to S1

Increased filling time = decreased HR = increase ventricular filling = more volume in the blood increases the time it takes for systole to occur = click closer to S2

Mid-systolic murmur present with regurgitation

Front 33

When is it appropriate treat MVP? What are the clinical symptoms associated with severe mitral prolapse?

Back 33

When the regurgitation is severe or the patient is symptomatic

-Flailing leaflet (torn chordae tendinae)
-Pulmonary HTN

Front 34

What type of repair can you do to repair mitral prolapse?

Back 34

-Try and repair the valve before you replace

Front 35

What is the difference between what the interpretation of the maneuvers in HCM and MVP.

Back 35

With HCM, you are listening for INTENSITY and with MVP you are listening for TIMING

Front 36

With apical HCM, what is the difference in pathology?

Back 36

The apex of the heart is enlarged, but not really the walls which means that there is no outflow obstruction, therefore you will not have a change in the intensity of the murmur as you would with regular HCM