CC4: Abnormal pressures Flashcards
What are the 7 phases of the cardiac cycle?
-Ventricular diastole
-Isovolumetric ventricular contraction
-Ventricular ejection
-Isovolumetric ventricular relaxation
-Atrial filling
-Passive/active ventricular filling
What 2 things can cause abnormal pressures?
-Disease of muscle
-Disease of valve
What 2 things are used to assess the presence/severity of valvular stenosis?
-Pressure gradient
-Valve area
What factors affect flow rate in Poiseuille’s equation?
-Pressure gradient
-Lumen
-Length
-Blood viscosity
How do you assess aortic/pulmonary stenosis?
-LV to Ao pullback
-RV and PA
How do you assess mitral/tricuspid stenosis?
-LV and PCW
-RV and RA
What is the Hakki formula for valve area?
What is the Systolic Ejection Period (SEP)?
-SEP starts with the opening of the aortic valve and finished at the dichrotic notch
SEP=amount of time the ventricles spend in systole per minute
What is a major cause of aortic stenosis?
Rheumatic heart disease
-scarring and fusion of valve leaflets
Symptoms of aortic stenosis
-Angina
-Syncope
-Heart failure (LV dysfunction)
What is the normal area of aortic valve?
2.5-5.0 cm^2
Mild, moderate and severe aortic stenosis
Mild: 1.5-2.5cm^2
Moderate: 1.0-1.5cm^2
Severe: <1.0cm^2
Aortic stenosis on echo
What is the peak pressure gradient?
LV systolic is higher than Ao
150-100=50
What is mean gradient?
-Difference between LV/AO the entire time Aortic valve is open
Where can aortic stenosis occur?
-Usually at valvular level
-Subvalvular stenosis caused by narrowing in the LVOT
-Supravalvular stenosis caused by constriction above the valve
What would pressure trace of subvalvular stenosis look like?
-Ventriclular
-Stenosis is in ventricle
-Drop in pressure in ventricle
-Then aortic
What are some causes of aortic regurgitation?
-Rheumatic heart disease
-Scarring and fusion of valve leaflets
-Infective endocarditis
Symptoms of aortic regurgitation
-SOB
-Chest pain
-Palpitations
What is pressure trace for aortic regurgitation?
-Aortic trace doesn’t reach zero
-In AR valve is open during diastole
-Normal systolic, lower diastolic in AR
What could wide pulse pressure indicate?
-Aortic regurgitation
What is the most common cause of mitral stenosis?
-Rheumatic heart fever
What is normal area of mitral valve?
4-6cm^2
How do you calculate gradient across mitral valve?
-LV trace and A/V wave
A wave = 20
EDP = 5
Gradient = 15mmHg
What is the diastolic filling period (DFP)?
-DFP starts with the closure of the aortic valve and finishes at the start of systole
-DFP = amount of time the ventricles spend in diastole per minute
Which pressure do we examine for mitral regurgitation?
-PCW and LV
Which part of the trace do we look at for mitral regurgitation?
-Valve is closed but blood is going back into atria
-Increased filling increases V wave
What are normal right heart pressures?
What pressure value indicates pulmonary hypertension?
-PA systolic pressure rises above 30mmHg
What does pressure trace for pulmonary stenosis look like?
During which part of cardiac cycle is tricuspid stenosis measured?
-Ventricular diastole - when Tricuspid valve is fully open
-Gradient measures difference in diastolic pressures across Tricuspid valve
During which part of cardiac cycle is aortic/pulmonary stenosis measured?
-Ventricular systole
-Elevated LV/RV pressure
During which part of cardiac cycle is aortic/pulmonary regurgitation measured?
-Ventricular diastole
-Decreased Ao/PA diastolic pressure
What is the pericardium?
-Encloses the heart and covers a portion of the great vessels
-Adheres to heart surface and lines fibrous pericardial sac
-Reduces friction due to heart movement
How many layers make up the pericardium?
3 layers
-Visceral - outer surface of heart/dense irregular connective tissue
-Serous - inner layer of mesothelium made up of 2 layers:
=>Parietal (lays under fibrous pericardium)
=>Visceral (epicardium, lays over heart)
What is constrictive pericarditis?
-Constriction of heart due to rim of fibrosed or calcified pericardium
-Results in inadequate filling of the heart
What causes changes in LV-RV pressure relationship?
-Ventricular septal interaction
Can occur in:
-Constrictive pericarditis
-BBB
-Pulmonary hypertension
-MI
-RV volume overload
What pressure trace is this?
-Constrictive pericarditis
-LV and RV have same diastolic pressure
What is meant by discordant ventricles?
-Occurs in constriction
-LV systolic pressure falls
-RV systolic pressure rises
What is meant by concordant ventricles?
-Occurs in restrictive cardiomyopathy
-LV systolic pressure falls
-RV systolic pressure falls
What pressure trace is this?
HOCM
What pressure trace is this?
-Same systolic value in LVOT and Ao indicates that aortic valve is normal
-It is something in the LV
During which part of cardiac cycle is mitral and tricuspid stenosis measured?
-Ventricular relaxation
