Hypertension and Coronary Heart Disease Flashcards
Definition of Blood Pressure
force exerted by circulating blood on artery walls
BP =
cardiac output x peripheral vascular resistance
Cardiac Output =
volume of blood pumped out of the heart (stroke volume) x heart rate
Why do we check blood pressure?
hypertension damages blood vessels
What is systolic and diastolic?
systolic: contraction of left ventricle
diastolic: relaxation of ventricles
What increases vascular resistance?
increased blood viscosity, reduced blood vessel length, reduced vessel radius
What are the stages to measure BP?
- normal blood flow
- occlusion of blood
- release cuff - hear systolic pressure
- no pulse - diastolic pressure
Primary cause of hypertension?
essential/idiopathic
Secondary causes of hypertension?
- Renal or renovascular disease
- Endocrine disease
- Phaeochomocytoma
- Cushing’s syndrome
- Conn’s syndrome
- Acromegaly and hypothyroidism
- Coarctation of the aorta
- Pregnancy
- Medications
- Hormonal / oral contraceptive/ steroids
Stages of RAAS pathway
- low BP
- kidney releases renin
- angiotensinogen in liver activated
- angiotensinogen -> angiotensin 1
- ACE (angiotensin converting enzyme) angiotensin 1 -> angiotensin 2
- BP increased
What does Angiotensin 2 do?
vasoconstriction, increases blood volume
How does angiotensin 2 increase blood volume?
- adrenal cortex gland releases aldosterone
- kidneys retain water and salt and excrete potassium
- pituitary gland activated to release ADH (anti - diuretic hormone) causing kidneys to retain water
What is ABPM?
Ambulatory blood pressure monitoring - patient wears cuff for 24hrs and BP measured every 30 mins
Why do patients not tolerate ABPM and what is a suitable alternative?
ABPM interrupts sleep, home blood pressure measurement - first thing and before bed for 7 days and average (ignore day 1)
Stage 1 Hypertension
BP in clinic is ≥140/90 mm Hg and ambulatory blood pressure monitoring (ABPM) or home blood pressure monitoring (HBPM) is ≥135/85 mm Hg.
Stage 2 Hypertension
BP in clinic is ≥160/100 mm Hg and ABPM or HBPM is ≥150/95 mm Hg.
Severe Hypertension
BP in surgery/clinic is ≥180/110 mmHg or higher.
Systolic or Diastolic important for diagnosis?
systolic
difference between urgent and emergent?
Urgent: needs treatment but no end organ damage
Emergent: end organ damage likely, patient not behaving normally/ displaying symptoms
What lifestyle interventions can help manage hypertension?
- Healthy diet
- Stop smoking
- Encouraging exercise
- Encourage weight loss if overweight or obese
- Reduce alcohol intake
- Reduce salt intake
Treatment for under 55 (first line)?
ACE inhibitor or low cost angiotensin 2 receptor blocker
any age (black african/carribean) or over 55 (first line)?
calcium channel blocker (CCB)
Second line hypertension treatment?
ACE inhibitor + CCB
Third line hypertension treatment?
ACE inhibitor + CCB + thiazide like diuretic (normally referred to cardio clinic)
Treatment for resistant hypertension?
ACE inhibitor + CCB + thiazide like diuretic + further diuretic or alpha/beta blockers
expert advice advised
Why should Afro-Caribbean patients not be given ACE inhibitors?
They are at risk of angioedema
How do beta blockers reduce hypertension?
reduces heart rate so reduces cardiac output
How do alpha blockers reduce hypertension?
relaxes arteries, alpha blockers are not cardio selective so can reduce PVR