cardiovascular system ii. how do we measure blood pressure ?

CardiovascularCardiovascularSystem IISystem II

How do we measure blood pressure ?

Stroke volume (and hence, blood

pressure) are strongly influenced by the EDV

The regulation of blood pressure

The baroreceptor reflex

The regulation of blood pressure

Hypertension

Where to draw the limit of “normality” ?

12

48

16

32

64

128

256

Mort

alid

ad p

or

en

ferm

ed

ad c

oro

nari

a(x

1,0

00

paci

ente

s)

120 140 160 180

Usual BP (mmHg)

Age 80-89

Age 70-79

Age 60-69

Age 50-59

Age 40-49

Relationship between BP and CV riskMetaanalysis of more than 60 observational studies

Lancet 2002; 360: 1903–13

System/organ Impact of HTCNS Stroke, dementia

Myocardium Left ventricular hypertrophy

Hypertensive nephropathyKidney

Hypertensive retinopathyEye

Via heart failureAll body systems

Impact of chronic hypertension on body systems

Demographic

Cardiac

HTA

SexAge

Genetic

Angiotensinogen gene

Hyperaldosteronism

Cardiac output

Sodium retentio

nCaloric intake /

overweight

Renal

Gastrointestinal

Psychological

Stress

Central Nervous System

Sympathetic

hyperactivity

Vascular

Smooth muscle insulin sensitivity

Endothelial function

Why do some people develop hypertension while others don’t ?

Factors involved:

Atherosclerosis

Normal histology of the arterial wall

Infiltration of lipoproteins and

monocytes

Cell proliferation and differentiation in the

wall

Formation of “cap” and “shoulders”

Rupture and thrombosis

Atherosclerosis

World Deaths in millions

% of deaths

Coronary heart disease 7.20 12.2

Stroke and other cerebrovascular diseases

5.71 9.7

Lower respiratory infections 4.18 7.1

Chronic obstructive pulmonary disease

3.02 5.1

Diarrheal diseases 2.16 3.7

HIV/AIDS 2.04 3.5

Tuberculosis 1.46 2.5

Trachea, bronchus, lung cancers 1.32 2.3

Road traffic accidents 1.27 2.2

Prematurity and low birth weight 1.18 2.0

Top 10 world causes of death