Download HYPERTENSIVE HEART DISEASE (Hypertensive cardiomyopathy)

HYPERTENSIVE HEART
DISEASE (Hypertensive
cardiomyopathy)
H.A MWAKYOMA, MD
HHD
DEFINITION:
Is the disease of the heart resulting from
systemic hypertension of prolonged duration
and manifesting by left ventricular
hypertrophy
Or
Is the response of the left ventricle to
increased peripheral resistance due to
increased systemic arterial pressure
Systemic Hypertensive Heart Disease:
• Hypertensive heart disease is an important
and common form of heart disease.
• Features:
• - Patient has a history of hypertension.
• - Left ventricular hypertrophy, concentric
type.
• - Absence of other lesions that might induce
cardiac hypertrophy. Eg: Aortic valve
stenosis
HHD
• Hypertension predisposes to
atherosclerosis
• Most patients of HHD have advanced
coronary atherosclerosis and my develop
progressive IHD
Definition of HTN
CATEGORY SYSTOLIC BP DIASTOLIC
BP
normal
< 120 and
< 80
Pre-HTN
120-139
or
80-89
Hypertension
Stage 1
140-159 or
90-99
Stage 2
≥ 160 or
≥ 100
TYPES OF HYPERTENSION
SYSTOLIC AND DIASTOLIC
• Primary(Essential, Idiopathic)
• Secondary
•
•
•
•
•
•
•
Renal: Acute GN, Diabetic Nephropathy
Endocrine: TSH, cortisol, calcium
aortic coarctation
pregnancy-induced
neurologic: tumor, sleep apnea
stress: surgery, burns, EtOH withdrawal,S.cell
Drugs: decongestants, antidepressants, OCP
ESSENTIAL HYPERTENSION
• Most common HBP( > 90 %)--multifactorial
• increased peripheral resistance perpetuates the
process of high blood pressure and all of its
secondary effects
• structural hypertrophy giving rise to smooth
muscle hypercontractility
• pressure varies throughout the day
• major risk factor for coronary, renal, and
cerebrovascular disease
• carries prognostic value: 16X increased risk 40
years of smoke
HYPERTENSION WITH AGE
• Systolic BP rises continuously with age
• Diastolic rises up to age 50, then falls
• Pulse pressure then widens with age
Pathogenesis:
• There is myocytic hypertrophy in response to
the increased work. (pressure load in systemic
hypertension)
• The stress of pressure on the ventricular wall
causes increased production of: Myofilaments
 Myofibrils
 Other cell organelles and
 Nuclear enlargement
• Since the the adult myocardial fibres do not
divide, the fibres are hypertrophied
Pathogenesis:--cont--• Thickened myocardium reduces left ventricle
compliance, impairing diastolic filling.
• Individual myocyte hypertrophy increases
the distance for oxygen and nutrient
diffusion from adjacent capillaries.
• In a significant number of patients there is
associated coronary atherosclerosis
accompanying hypertension which may
further lead to ischemia
TARGET ORGAN DAMAGE
Left Ventricular Hypertrophy
•
•
•
•
End result of hypertensive heart disease
structural adaptation to pressure overload
initially adaptive and later pathologic
mass >100-130 g/m2
PATHOLOGIC CHANGES:
• Thickened left ventricle wall.
 The left ventricle wall thickness is usually more
than 2cm wall thickness. (NORMAL 1.3cm – 1.5cm)
• increased heart weight.
 The average heart weight is 500 to 600 gm. It may
be as much as 1100gm.
 The papillary muscle and trabeculae carneae are
rounded and prominent and
 cardiac chamber is small (concentric
hypertrophy).
PATHOLOGIC CHANGES:--cont-• When cardiac failure ensues, dilatation
of the chamber also may be prominent.
• Endocardial fibrous thickening may be
present in the left ventricle in instances
of long-standing hypertension.
• After the onset of left ventricular
failure, there may be dilatation and
hypertrophy of the right side of the
heart
Hypertensive Heart Diseases
Left Ventricular Hypertrophy:
HHD
• Microscopic features:
• Myocytes and nuclei are enlarged.
• In long-term cases diffuse interstitial fibrosis
and focal myocyte atrophy and degeneration
may develop, with left ventricle chamber
dilatation and wall thinning.
• Myocardial edema and foci of necrosis
characterized either by intense eosinophilia
or by complete dissolution of the muscle
fibers occur in malignant hypertension
HHD
• FATE:
• Patients die of congestive heart failure ;
• Complications of coronary artery disease, such
as myocardial infarction can occur ;
• There is increased risk of sudden death ;
• Some patients die of renal disease, stroke etc. ;
• Fibrinous pericarditis may be evident in
patients who die as a result of uraemia ;
• Therapeutic control of pressure may, lead to
regression of the enlarged myocytes and
reduction of heart size