PH2113 - Cardiovascular 1 Flashcards
What is a cardiovascular disease?
Is a general term for conditions affecting the heart or blood vessels
Excludes diseases relating to formation of blood (haematological disease)
Includes disorders of blood coagulation (thrombotic disease)
Includes diseases of other organs resulting from abnormal blood supply esp. stroke, vascular dementia, renovascular disease
SCALE of CV diseases
-Is a general term for conditions affecting the heart or blood vessels.
-45% of CV deaths are due to coronary heart disease (same as ~ ischaemic heart disease)
-Nearly all deaths from CHD are due to acute
myocardial infarction (heart attack)
What does ischaemic mean?
Ischemia is a restriction in blood supply to tissues, causing a shortage of oxygen and glucose needed for cellular metabolism.
What does coronary mean?
relating to the arteries which surround and supply the heart
Define stenosis of blood vessels
Narrowing of blood vessels
What is Coronary heart disease (CHD) (also known as ischaemic heart disease)?
Is when your coronary arteries become narrowed by a gradual build-up of fatty material within their walls. These arteries supply your heart muscle with oxygen-rich blood. (see later for more info)
Why has CHD (coronary heart disease) mortality fallen steadily since 1970s
due mainly to better treatments and more of them.
what is happening to the SCALE OF CV DISEASE IN THE UK
CHD mortality is falling but morbidity is rising
I.E : less people dying from CV but more people are getting the disease.
-In over 65s, morbidity (including disability) due to CHD has increased by 20% since late 1980s.
what is happening to the GLOBAL SCALE OF CV DISEASE
- CV disease is the leading cause of death
worldwide: 17.3 million deaths in 2008
CV diseases can be CONGENITAL/INHERITED or Acquired
- Most cardiovascular diseases are acquired (gradually develop).
- Risk factors, environment and genetics influence it.
- mix of modifiable factors ± genetic (fixed) factors.
-Most CV disease develops as a result of life-style
(environmental, modifiable) factors
-Modifications of risk factors help to prevent CV- called primary prevention
What are modifiable CV risk factors?
- serum LDL-cholesterol
- smoking
- low physical activity
- diabetes
- hypertension
What are fixed CV risk factors?
- age
- male gender
- family history
APPROACHES TO PRIMARY PREVENTION (modifying the risk factors)
Primary prevention:
preventative measures in individuals with a high risk
of developing CV disease
- screening programmes
Identify populations at risk Investigate risk to individuals - intervention to reduce modifiable risk educate about risk life-style/behavioural alteration pharmacological intervention to reduce risk.
Approaches to SECONDARY PREVENTION
Secondary prevention :
comprehensive risk factor reducing interventions (including pharmacotherapies) and rehabilitation for patients who have had a heart attack or stroke
Target individuals with
established disease to reduce severity/mortality
- Early disease detection increases opportunities for
interventions to prevent progression and mortality
AIMS of secondary prevention:
extend survival
improve quality of life
decrease need for major interventions e.g PCI, CABG
reduce risk of subsequent major adverse CV event
What is SYSTEMIC ARTERIAL HYPERTENSION
- High blood pressure in the systemic arteries - the vessels that carry blood from the heart to the body’s tissues
Defining ‘normal’ and ‘abnormal’ blood pressure
Blood pressure determines tissue perfusion pressure
It is a physiologically regulated variable.
MAP ~ CO x TPR;
Cardiac Output = Heart Rate x Stroke Volume
Cardiac output
Is the volume of blood pumped by the heart per minute.
= Heart rate x Stroke volume (Volume of blood ejected by the left ventricle in one contraction to the body.)
Resting cardiac output: 4-7 l/min (depends on body size)
what is inotropy and chronotropy?
- Heart rate= chronotropy
2. Force of contraction = inotropy
how does resistance occur in the blood vessel?
Friction between walls and blood flow generate RESISTANCE.
how can friction in the blood vessels be measured ? (the equation)
Resistance to flow= (Viscosity of blood(Vf) X length(L))/ radius of vessel^4
-L - Longer the tube the greater the wall surface
R - Radius of vessel is inversely proportional to flow
-Noradrenaline angiotensin 2 and other circulating locally acting hormones also acting on smooth muscle tone (contraction of the muscle in the vessels)
What is hypertension?
- Abnormally high blood pressure.
- That level of blood pressure associated with increased risk of some adverse effect at some time.
- High bp associated WITH INCREASED CV RISK
What are guideline BP values?
Ideal < 120/80
STAGE 1: >140/90
STAGE 2: 160/100
severe: >180/110
For diabetic subjects and/or in cases of renal insufficiency, high BP is defined as 130/80 mmHg.
What are the Types of Hypertension ?
- Essential (primary, idiopathic) hypertension- no identifiable cause most common
- Secondary hypertension-
is high blood pressure that’s caused by another medical condition - borderline hypertension- blood pressures are above the upper boundary of “normal” (120/80 mm Hg) but have not yet crossed into hypertensive territory.
- The top/first number of a blood pressure measurement — greater than 140 mm Hg
- “white coat” (in US “office”) hypertension -raised blood pressure due to being stressed
- accelerated (“malignant”) hypertension- rapid and sudden increase in blood pressure over the baseline level
- uncomplicated/complicated hypertension
