Structural Heart Disease Flashcards
When there is heart failure, what stage of the cardiac cycle fails first?
Isovolumetric contraction
What are the 2 determinants of cardiac stroke volume?
Energy of contraction
Arterial pressure
What is Starling’s law?
Increased stretch of the heart increases calcium sensitivity and therefore energy of the contraction
Starting at the bottom left corner of a pressure volume loop, describe which valve opens and closes at each of the 4 points
Bottom left: mitral valve opens
Bottom right: mitral valve closes
Top right: aortic valve opens
Top left: aortic valve closes
What is stenosis of valves?
Their narrowing
What is the medical name for dilation of the heart valves?
Regurgitation lesion
One which side of the heart are valve problems more important?
Left
How is stenosis of heart valves assessed?
Transthoracic echocardiogram
How do transthoracic echocardiograms work? What result indicates severe stenosis?
They look at blood flow velocity, if blood flow is <4mm stenosis is severe
What are some causes of aortic stenosis?
Biscuspid aortic valve
Infective endocarditis
Hyper urethemia
What is a biscuspid aortic valve?
When the aortic valve has 2 flaps instead of 3
What are some causes of mitral stenosis?
Rheumatic fever Congenital SLE Whipples Rheumatoid arthritis
What affect does aortic valve stenosis have on the heart?
It causes increased pressure/higher after load in the left ventricle leading to left ventricular hypertrophy
What effect does mitral valve stenosis have on the heart?
It causes increased pressure in the left atrium which can cause left atrial dilation and further cause atrial arrhythmia
Name all the heart valves, what structures they separate and include alternate names for them if they have any
Mitral valve: also known as the left atrio-ventricular valve and separates the left atrium and ventricle
Aortic valve: separates the left ventricle and the aorta
Bicuspid valve: also known as the right atrio-ventricular valve, separates the right atrium and ventricle
Pulmonary valve: separates the right ventricle and the pulmonary artery
What side of the heart is the aorta associated with?
Left
What side of the heart is the pulmonary artery associated with?
Right
When can aortic stenosis be heard?
When the heart is contracting
When can mitral stenosis be heard?
When the heart is relaxing, but its harder to hear than aortic stenosis
What type of murmur does aortic stenosis cause?
Systolic heart murmur
What is regurgitation in terms of the heart?
Abnormal dilation
How does aortic regurgitation cause in terms of blood flow?
It causes back-flow of blood from the aorta to the left ventricle which causes dilation and makes the ventricle less effective
When must the aortic valve be replaced if theres stenosis?
If the patient presents with heart failure, fluid in the legs or fluid in the lungs
How is mitral regurgitation treated?
Replacing the valve if it gets serious
What complications can mitral regurgitation cause?
Heart failure or congestion
What is congested heart failure?
Heart failure due to fluid build up around the heart
How is mitral regurgitation treated?
Medication for heart failure and diuretics
What causes hypertrophic cardiomyopathy?
Genetic, screen first degree relatives for risk
What may be seen in someone with hypertrophic cardiomyopathy?
Abnormal ECG
Left ventricle thickening
Septum thickening
Systolic murmur
What is dilated cardiomyopathy?
Chambers are dilated and have poor contractility
What are some causes of dilated cardiomyopathy?
Stress induced
Infectious
Peri partum (last few months of pregnancy)
50% is genetic
How is dilated cardiomyopathy diagnosed?
Via angiogram
What is arrythmogenic right ventricular cardiomyopathy?
Dilation in the right ventricle that affects left ventricle function too
What type of cardiomyopathy is deadly? Why?
Arrythmogenic right ventricular cardiomyopathy as it can cause ventricular arrythmia which can lead to sudden death
When are metallic valve replacements used?
In children as they give longevity and durability
What medication must be given with metallic valves?
Warfarin
How many years of longevity do biological valve replacements give?
20 years
The replacement of which valve is complicated?
Mitral
Define cardiogenic shock?
Impairment of cardiac systolic function resulting in reduced cardiac output which will cause end organ dysfunction
Why does cardiogenic shock result in end organ failure?
As the reduced systolic output of the heart leads to the body not receiving enough glucose, oxygen or blood
How is cardiogenic shock different to other shocks?
Giving fluid will make things worse not better as the contractility of the heart is already reduced
How is cardiogenic shock recognised and confirmed?
Via bedside transthoracic echocardiogram
How is cardiogenic shock treated?
Percutaneous coronary intervention- stents are placed in arteries to open them up
Ionotrophs are given as the first line treatment, they alter the force of muscle contraction
How do ionotrophs work in cardiogenic shock?
They alter the force of muscle contraction
What effect will giving ionotrophs have on the pressure volume loop?
Increased height
Increased width
Leftward shift
Give an example of an ionotroph drug
Dopamine
What is used when ionotrophs dont work in cardiogenic shock?
Mechanical support devices
What must be given alongside mechanical support devices for the heart?
Anticoagulants
What will the pressure volume loop look like for someone in cardiogenic shock before treatment?
It will be small in terms of height and width, it will also be shifted more to the right than should be normal
