Structural Heart Disease Flashcards by Anouk Wijeratne

What are the determinants of cardiac stroke volume?

Starling’ law of the heart (length tension)
Cardiac contractility
Arterial pressure

How well did you know this?

Not at all

Perfectly

What influences cardiac contractility?

Synthetic tone

Adrenaline

How well did you know this?

Not at all

Perfectly

What is the after load?

Pressure in the aorta

Force per unit area

How well did you know this?

Not at all

Perfectly

What is preload?

Stretching of the myocardium allowing the generation of forces

How well did you know this?

Not at all

Perfectly

What is the law of laplace?

P + 2T/r

Internal pressures generated inside a chamber is directly proportional to the tensions and inversely proportional to the radius

How well did you know this?

Not at all

Perfectly

Why is the law of laplace significant?

when radius of chamber increases pathologically

cannot generate sufficient pressure

How well did you know this?

Not at all

Perfectly

What are the two classification of valvular disease?

Stenotics

Dilatations

How well did you know this?

Not at all

Perfectly

What are two types of stenotic lesions?

Aortic stenosis

Mitral stenosis

How well did you know this?

Not at all

Perfectly

What is aortic stenosis?

Aortic valve becomes significantly narrowed

Severe is area is less than 1cm^2 or if speed of blod flow is greater that 4 metres per second

How well did you know this?

Not at all

Perfectly

What are the causes of aortic stenosis?

Bicuspid aortic valve - Congenital
Degeneration of valve with age
Rheumatic heart disease
Infective endocarditis

How well did you know this?

Not at all

Perfectly

What cause mitral stenosis?

Rheumatic fever
Congential
Rheumatoid arthritis
Lupus
Whipples disease

How well did you know this?

Not at all

Perfectly

What is the consequence of aortic stenosis?

Increased afterload on the left ventricle

Causing hypertrophy

How well did you know this?

Not at all

Perfectly

What is the consequence of mitral stenosis?

Increased pressure on the left atrium
Increased strain causes atrial dilation
Can lead to AF

How well did you know this?

Not at all

Perfectly

What causes mitral regurgitation?

Rheumatic fever
Infective endocarditis
Mitral valve prolapse

How well did you know this?

Not at all

Perfectly

What is the consequence of mitral regurgitation?

Less cardiac output to aorta

Reduces organ perfusion

How well did you know this?

Not at all

Perfectly

What causes aortic regurgitation?

Biscuspid aortic valve
Marfaans syndrome
hypertension
Infective endocarditis

How well did you know this?

Not at all

Perfectly

What is the consequence of aortic regurgitation?

Volume overload to left ventricle as blood goes back

Causing dilation

How well did you know this?

Not at all

Perfectly

How does mitral regurgitation present?

systolic murmur

How does aortic regurgitation present?

diastolic murmur

What are the three main types of cardiomyopathy?

Hypertrophic
Dilated
Arrhythmogenic right ventricular

What is the result of dilated cardiomyopathy?

Chambers have poor contractility

Wall tension does not generate effective pressure

What can cause dilated cardiomyopathy?

Stress
Post partum
Sarcodosis
Auto-immune diseases

What happens in arrhthmogenic right ventricular cardiomyopathy?

Abnormal right ventricle radius
Cannot work effectively
Also effect left ventricle

How can you treat valve issues?

Valve replacement
But must treat consequences of valve failure
Aim to replace before the issues has other effects

What are the pros and cons of different valves?

Metallic valves - last longer - need to be on warfarin Prosthetic valves -only last 20 years

Why is the mitral valve not often replaced?

The arrangement of the mitral valve means that it isn't easy to replace increased emphasis on repairing the existing valves This avoids open heart surgery

Define cardiogenic shock?

Impairment of cardiac systolic function resulting in reduced cardiac output causing end organ dysfunction

Why is it so important to identify cardiogenic shocl?

Treatment is very different to other types of shock e.g. dangerous to give more fluid reduces contractile function

How is cardiogenic shock treated?

Early coronary angiography PCI or CABG Reassess haemodynamic/tissue perfusion

What are inotropes?

Dopamine etc. Increase height and leftward shift of pressure volume loop Augmentation of end diastollic volume Increase in stroke work and stroke volume

What are the features of mechanical support devices?

Used when ionotropic drugs are ineffective IABP Impella recover TandemHeart VA-ECMO

How do you calculate cardiac output?

Stroke volume x Heart rate

How do you calculate ejection fraction?

Stroke volume divided by end diastolic volume

How do you calculate mean arterial pressure?

MAP = Cardiac output x total peripheral resistance MAP = Diastolic blood pressure + 1/3 Pulse Pressure MAP = 2/3 Diastolic blood pressure + 1/3 Systolic Pressure

What is infective endocarditis?

Infection of the endocardium (inner lining of the heart). Commonly caused by bacteria.

How do you diagnose infective endocarditis?

Dukes criteria Major: positive blood cultures/evidence of endocardium involvement Minor: predisposing factors, pyrexia, vascular phenomena, immunological phenomena, microbioloigcal evidence Blood cultures ECG ECHO

Which part of the heart does infective endocarditis affect particularly?

Heart valves, normally left aortic and mitral valves | Right sided occurs less frequently

What are some features of decompensation?

Weight loss Difficulty breathing Leg/Foot Swelling Fatigue

What is the relationship between IV drug use and infective endocarditis?

Higher risk of developing infective endocarditis | Can be right sided involving the tricuspid

Define dilated cardiomyopathy

Ventricle stretches and thins and is no longer able to pump efficiently

What are some common causes of dilated cardiomyopathy?

``` Heart disease Poorly controlled hypertension Infection Genetics Peri-partum Toxins Auto-immune Endocrine Metabolic disorders ```

What genes have been implicated in the diagnosis of dilated cardiomyopathy?

MYH7, MYBPC3, TNNT2, and TNNI3 | ACBC1, ACBC 2

How is dilated cardiomyopathy managed?

Medication: Diuretics, ACEi, Beta Blockers, Anti-coagulants, ARBs Pacemaker Surgical: LVAD (Left ventricular assist device) or Heart transplant

What are the implications of dilated cardiomyopathy?

High risk of heart failure Needs to manage BP Lower alcohol intake, stop smoking, minimise salt and caffeine