CVS Overview Flashcards
Dysfunction of cardiac contractile function:
Heart failure
Heart failure is
Dysfunction of cardiac contractile function
Dysfunction of coronary blood supply is
Ischaemic heart disease
Ischaemic heart disease is
Dysfunction of coronary blood supply
Dysregulation of vascular tone is
Hypertension
The main components of the heart:
Vasculature
Coronary arteries
Myocardium
The heart acts as a…
Muscular pump
Why is blood pumped
Upped around the body to meet metabolic demands
Blood pumped to the lungs for gas exchange
These 2 pumping circuits connected by the heart
Describe the phases of the cardiac cycle
- Diastole (relaxation/filling)
Isovolumic relaxation, early filling, diastasis, late filling (active) - Systole (contraction)
Isovolumic contraction, ventricular ejection
What is cardiac output
The volume of blood pumped around the body in 1 minute
CO = strove volume x heart rate
What is stroke volume determined by
Cardiac stretch and ionotropic status among other factors
What is the calculation of ejection fraction
LVEF = (end diastolic volume - end systolic volume) / end diastolic volume
Describe heart failure definitions
A complex syndrome that can result from any structural or functional cardiac disorder that impairs the ability of the heart to function as a pump to support a physiological circulation
Clinical syndrome caused by a reduction i the hearts ability to pump blood around the body
Clinical syndrome in which a cardiac abnormality impairs its pump function and ability to support a physiology
Heart failure comprises …
A demonstratable abnormality of cardiac function and a resultant set of clinical features
May in Volvo systole, diastole or both
Mainly L ventricular failure, may be R and frequently both occur
LV systolic impairment is the main abnormality discussed
Pathophysiology of heart failure
Cardiac contractile impairment
Activation of compensatory mechanisms in dysfunctional way
Imbalance between vasodilator and vasoconstrictor effects on circulation
Haemodynamic consequences on the circulation and fluid balance
Describe the detection of heart failure
Clinical assessment - symptoms and signs
Evidence of systolic dysfunction - echocardiogram, electrocardiograph, brain natriuretic peptide
What are the symptoms of heart failure
Pathophysiology dominated by ‘back pressure’ changes related to elevated cardiac pressures
Dyspnoea
Exercise intolerance
Orthopnoea
Paroxysmal nocturnal dyspnoea
Fatigue
Oedema/fluid accumulation
Describe the myocardial blood supply
Pump function requires energy and oxygen
These are deliverable by the coronary arteries
Oxygen extraction is high at rest
Coronary arteries are essentially end arteries
Heart is therefore relatively susceptible to ischaemia
Supply and demand of the blood flow of the heart
Demands:
-Cardiac work, HR, BP
-Cardiac mass
-ionotropic status
Supply:
-oxygen carrying capacity
-Driving pressure
-Coronary tone , vasodilators factors, vasoconstriction factors, metabolic factors
Describe Ischaemic heart disease overview
Nearly lays due to coronary atherosclerosis
Obstructive disease of pericardial arteries
Multiple risk factors: age gender, genetic ,hypertension, diabetes, mellitus, hyperlipidaemia, cigarette smoking
Describe overview of myocardial infarction
Coronary artery plaque rupture with thrombotic occlusion
Blood flow reduction is complete and sudden
Ischaemia develops into infarction if unrelieved
Permanent cardiac damage ensues. May lead to systolic dysfunction/heart failure
What is hypertension
Elevation in systemic blood pressure
Level at which treatment is effective at reducing events
May be systolic, diastolic or both
Why treat hypertension?
Reduction in vascular and cardiac events:
Ischaemic heart disease, hypertensive heart damage, stroke/haemorrhage, renal disease
Treatment of hypertension
Confirm diagnosis
Consider ABPM
Screen for cause
Assess overall vascular risk
Lifestyle changes
Salt avoidance
Pharmacological therapy
Stage 1 hypertension
Clinical 140/90 or higher AND subsequent ambulatory blood pressure is 135/85 or higher
Stage 2 hypertension
Clinical blood pressure : 160/100 mmHg or higher but less than 180/120 mmHg and subsequent HBPM average 150/95 mmHg or higher
Stage 3 or severe hypertension
Clinical systolic BP of 180 mmHg or higher or clinical diastolic BP of 120mmHg or higher
