6. Hypertensive Heart Disease

Front 1

Where IHD is a late manifestation of CAD, Hypertensive HD is a late manifestation of:

Back 1

Hypertension

Front 2

What do 15-20% of patients with HTN develop?

Back 2

Left ventricular hypertophy

Front 3

What is LVH and what is it stimulated by?

Back 3

An increase in left ventricle mass (myocyte hypertrophy) stimulated by elevated blood pressure

Front 4

Is systemic HTN the only cause of LVH?

Back 4

no

Front 5

What type of LVH develops from systemic HTN?

Back 5

Concentric

Front 6

What is considered Systemic HTN (bp measurement)?

Back 6

140/90

Front 7

What is the theory regarding what causes ventricular hypertrophy in hypertension?

Back 7

Systemic hypertension results in increased Afterload -> decreased CO.

Front 8

How does the myocardium respond to increased afterload?

Back 8

The left ventricle thickens as a compensatory mechanism to retain adequate cardiac output.

Front 9

What is the geometric arrangement of the thickening?

Back 9

Concentric

Front 10

What happens over time as concentric thickening continues?

Back 10

Contractile impairment of the myocardium - this may be bigger heart tissue, but it doesn't function the same or as well.

Front 11

What law describes the load theory?

Back 11

The law of laplace

Front 12

What is Laplace's Law?

Back 12

T = Pr/h

As myocardium thickens (h) the wall tension decreases

Front 13

What is the adverse effect of thickening the ventricle wall?

Back 13

Diastolic dysfunction - the thick wall impedes filling as the muscle takes up the lumen space.

Front 14

What is the adverse effect of impeded diastolic filling?

Back 14

The atrium thickens as it attempts to push more blood into the thick ventricle.

Front 15

What is the adverse effect of atrial enlargement?

Back 15

Atrial fibrillation

Front 16

So what do we normally see early in hypertensive heart disease?

Back 16

Diastolic dysfunction

Front 17

What is the clinical manifestation of early diastolic dysfunction?

Back 17

Pulmonary edema and SOB

Front 18

What is an early gene mediated process seen in early hypertrophy?

Back 18

Increased myocardial fibrosis

Front 19

What do you NOT see in early hypertrophy?

Back 19

Neurohormonal activation

Front 20

So early hypertrophy is mainly stimulated by _________

Back 20

increased AFTERLOAD

Front 21

And later hypertrophy is mainly stimulted by

Back 21

increased PRELOAD (aldosterone) and Afterload (vasoconstriction)

Front 22

What alterations in gene expression do we see in early hypertensive hypertrophy?

Back 22

Fetal protein synthesis expression

Front 23

If you see a biopsy of early hypertrophy what are 3 histologic changes you'll see?

Back 23

-Increased myocyte size
-Pleomorphism
-Fibrosis

Front 24

What may be a signal of transition from compensated hypertrophy to heart failure?

Back 24

Apoptosis

Front 25

What is myocardial apoptosis inhibited by?

Back 25

NO

Front 26

What is myocardial apoptosis stimulated by?

Back 26

Ang II-activated p53

Front 27

So what may be a clinical treatment to reduce apoptosis in hypertensive hypertrophy?

Back 27

ACE inhibitors

Front 28

What 2 EKG changes can be seen in hypertensive heart disease?

Back 28

-Prolonged P wave
-Elongated QRS complex

Front 29

What are EKG changes in hypertensive heart disease the strongest predictor of?

Back 29

A bad prognosis and likelihood of myocardial episode.

Front 30

What drug can reverse the deleterious effects of late hypertensive LV hypertrophy?

Back 30

Ang II inhibitors

Front 31

What are the 2 major effects seen when Ang II inhibitors are used to treat hypertension?

Back 31

-Reduced LV mass
-Improved coronary bloodflow

Front 32

What is that mechanisms, again, that allows Ang II inhibitors to improve bloodflow?

Back 32

-Ang II inhibits NO
-NO causes vasodilation

Front 33

So what are the 2 Theories regarding hypertensive heart disease?

Back 33

1. Load theory
2. Humoral theory

Front 34

What is the humoral theory?

Back 34

That loca vasoactive mediators initiate hypertrophic changes in hypertensive heart disease.

Front 35

Do dog studies indicate that there is any truth to the humoral theory that the RAS and Endothelin mediate early ventricular hypertrophy?

Back 35

No

Front 36

When do humoral factors play a role in HHD?

Back 36

In LATE hypertrophy

Front 37

What dietary factor has an impact on LV mass and hypertrophy of the myocardium in hypertension?

Back 37

Salt intake

Front 38

What happens in LATE hypertrophic heart disease?

Back 38

The cardiomyocytes begin to die

Front 39

When are symptoms of clinical heart failure seen in the course of HHD?

Back 39

When 40-50% of cardiomyocytes are dead

Front 40

Why are symptoms seen at 40-50% muscle cell death?

Back 40

Because that corresponds to <50% ejection fractions

Front 41

What are the 4 main clinical symptoms that will be seen in late HHD?

Back 41

-SOB via pulmonary edema
-Renal dysfunction
-Decreased exercise tolerance
-Jugulovenous distension

Front 42

What are 3 complications that commonly manifest in late hypertrophic heart disease?

Back 42

-Arrythmia
-Progressive heart failure
-Sudden cardiac death

Front 43

What is the main theory that rings true for the cause of HHD?

Back 43

The load theory - afterload increase drives heart disease.

Front 44

What are the other 2 theories and which is more likely true?

Back 44

-Humoral theory
-Salt theory (more likely true)

Front 45

What is the danger of HHD?

Back 45

It remains largely asymptomatic until cardiac failure has already occurred

Front 46

Is cardiac hypertrophy reversible?

Back 46

Yes, if it's caught early

Front 47

How is it reversible?

Back 47

With Ang II inhibitors

Front 48

What are the 2 main pathologic changes seen in the myocardium in HHD?

Back 48

-Hypertrophy
-Fibrosis