PATHOPHYSIOLOGY OF
HYPERTENSION
HYPERTENSION
• chronically elevated systemic BP
• Guidelines from British hypertension society
◦ ◦ Systolic 140/ Diastolic 90 mmHg
◦ ◦ Monitored: 135-139/ 85-89 *
• classification
◦ ◦ Essential hypertension (95% of cases)
◦ ◦ Secondary hypertension (eg. renal disease; Pre-eclamptic toxaemia)
▪ when you have a disease with added hypertension
• essential hypertension
◦ ◦ Benign essential hypertension: usually symptom-less; predisposing factors:
▪ obesity; excessive alcohol consumption; high dietary salt intake; stress; lack
of exercise
◦ ◦ Malignant hypertension: Rapid increase in BP
WHY DOES ARTERIAL BP RISE
• Pathophysiological alterations in the walls of blood vessels - could be cause or
effect of high BP
, • small resistance size arteries
◦ Small arterial narrowing raises peripheral resistance and mean arterial blood
pressure [MAP]
▪ ◦ This is the primary pathology
◦ ◦ Rarefaction: reduction in the number of vessels per unit tissue volume
▪ ◦ Seen in skin, retina and intestines
• MAP = CO x peripheral resistance
◦ peripheral resitiance is a function of the health of the small resistance size
arteries
• large elastic arteries - less of an effect than small arterial arteries
◦ ◦ Large arterial stiffening exacerbates systolic hypertension
◦ ◦ Increased wall stiffness; increased pulse wave velocity
FEATURES OF HYPERTENSION
• Increased vascular tone/ reactivity
• vessel wall remodelling - usually associated with increased media thickening
• eutrophic
◦ Change in vessel wall WITHOUT change in amount of material
◦ ◦ Ratio of wall thickness to internal radium is increased by ~30%
▪ smaller diameter
• hypertrophic
◦ change in vessel wall with increased amount
• endothelial dysfunction
• increased vascular tone
ENDOTHELIAL DYSFUNCTION
• endothelial dysfunction is a pathological condition of the vascular endothelium
HYPERTENSION
HYPERTENSION
• chronically elevated systemic BP
• Guidelines from British hypertension society
◦ ◦ Systolic 140/ Diastolic 90 mmHg
◦ ◦ Monitored: 135-139/ 85-89 *
• classification
◦ ◦ Essential hypertension (95% of cases)
◦ ◦ Secondary hypertension (eg. renal disease; Pre-eclamptic toxaemia)
▪ when you have a disease with added hypertension
• essential hypertension
◦ ◦ Benign essential hypertension: usually symptom-less; predisposing factors:
▪ obesity; excessive alcohol consumption; high dietary salt intake; stress; lack
of exercise
◦ ◦ Malignant hypertension: Rapid increase in BP
WHY DOES ARTERIAL BP RISE
• Pathophysiological alterations in the walls of blood vessels - could be cause or
effect of high BP
, • small resistance size arteries
◦ Small arterial narrowing raises peripheral resistance and mean arterial blood
pressure [MAP]
▪ ◦ This is the primary pathology
◦ ◦ Rarefaction: reduction in the number of vessels per unit tissue volume
▪ ◦ Seen in skin, retina and intestines
• MAP = CO x peripheral resistance
◦ peripheral resitiance is a function of the health of the small resistance size
arteries
• large elastic arteries - less of an effect than small arterial arteries
◦ ◦ Large arterial stiffening exacerbates systolic hypertension
◦ ◦ Increased wall stiffness; increased pulse wave velocity
FEATURES OF HYPERTENSION
• Increased vascular tone/ reactivity
• vessel wall remodelling - usually associated with increased media thickening
• eutrophic
◦ Change in vessel wall WITHOUT change in amount of material
◦ ◦ Ratio of wall thickness to internal radium is increased by ~30%
▪ smaller diameter
• hypertrophic
◦ change in vessel wall with increased amount
• endothelial dysfunction
• increased vascular tone
ENDOTHELIAL DYSFUNCTION
• endothelial dysfunction is a pathological condition of the vascular endothelium
