1b Valvular Disease and Heart Failure

Question 1

What is the units of cardiac output?

Answer 1

Litres/minute

Question 2

What is the mean arterial pressure?

Answer 2

the mean arterial pressure is an average arterial blood pressure throughout a single cardiac cycle of systole and diastole.

Question 3

What MAP represents a pressure necessary to adequately perfuse the body organs?

Answer 3

MAP of >65 mmHg

Question 4

What is infective endocarditis?

Answer 4

infective endocarditis is an infection of the endocardium or vascular endothelium of the heart

Question 5

What does infective endocarditis typically affect?

Answer 5

Heart valves

Question 6

What causes infective endocarditis?

Answer 6

It is usually the result of bacteria entering the blood stream and forming ”a vegetation” in the endocardium

Question 7

What is a heart vegetation?

Answer 7

a bacterial infection surrounded by a layer of platelets and fibrin

Question 8

What is the most common bacteria for infective endocarditis?

Answer 8

Streptococci (20-40 % of cases) are the most common infection.

Question 9

What are the common symptoms of infective endocarditis?

Answer 9

Fever, malaise, sweats and unexplained weight loss are common symptoms
There may be a new heart murmur on examination

Question 10

What might blood tests show in a patient with infective endocarditis?

Answer 10

Blood tests show anaemia and raised markers of infection
Blood cultures may isolate a microorganism

Question 11

Which ECHO has the higher sensitivity, Transoesophageal or Transthoracic?

Answer 11

Transoesophageal

Question 12

What might an ECHO show in a patient with infective endocarditis?

Answer 12

Echocardiogram can show a vegetation, abscess, valve perforation and/or new dehiscence of prosthetic valve. Often there is regurgitation of the affected valve

Question 13

What is decompensation?

Answer 13

Inability of the heart to maintain adequate circulation

Question 14

What are signs of cardiac decompensation you might look for?

Answer 14

Symptoms include shortness of breath, frequent coughing, swelling of the legs and abdomen, fatigue
Clinical signs include raised JVP (Jugular Venous Pressure), lung crackles and oedema

Question 15

What are some other complications of cardiac decompensation?

Answer 15

Vascular and embolic phenomena
(stroke, Janeway lesions, splinter/ conjunctival haemorrhages)
Immunological phenomena
(Osler’s nodes, Roth spots)

Question 16

What are the minor criteria in Duke’s Criteria for infective endocarditis?

Answer 16

Predisposing heart condition or injection drug use
Fever >38
Vascular phenomena
Immunological phenomena
Positive cultures

Question 17

What are the major criteria in Duke’s Criteria for infective endocarditis?

Answer 17

Persistently positive bacterial culture
ECHO = vegetation, abcess
New valvular regurgitation murmur

Question 18

What part of the heart does infective endocarditis affect?

Answer 18

Infective endocarditis affects the endocardium, especially the valves of the heart
Aortic valve is affected most frequently (aortic > mitral > right-sided valves)

Question 19

Why infective endocarditis occur more commonly at the Aortic valve?

Answer 19

It is more common for bacteria to attach to the endocardium if underlying damage is present, and this occurs more frequently at sites of turbulent blood flow such as the valves of the heart.

Question 20

Why might drug users have an increased risk of infective endocarditis?

Answer 20

increased risk of infective endocarditis due to repeated injection – potentially exposing their bloodstream to bacteria on the surface of the skin or use of non-sterile needles.

Question 21

What is the definition of dilated cardiomyopathy?

Answer 21

dilated cardiomyopathy is characterised by dilated and thin-walled cardiac chambers with reduced contractility.

typically there is reduced systolic function (ejection fraction) and global hypokinesis

Question 22

What are the commonest causes of dilated cardiomyopathy?

Answer 22

Idiopathic, genetic, toxins (alcohol, cardiotoxic chemotherapy), pregnancy (peripartum cardiomyopathy), viral infections (myocarditis), tachycardia-related cardiomyopathy, thyroid disease, muscular dystrophies

Question 23

How is dilated cardiomyopathy managed?

Answer 23

Medical heart failure therapy - ACE inhibitors, beta-blockers, mineralocorticoid receptor antagonists

Diuretics for fluid overload

Anticoagulation for atrial fibrillation

Cardiac devices – cardiac resynchronisation therapy and/or implantable cardioverter defibrillator

Transplant

Question 24

What are the future implications of dilated cardiomyopathy?

Answer 24

Increased risk of heart failure, cardiac arrhythmia, sudden cardiac death due to ventricular arrhythmia and reduced survival

Question 25

What does heart failure with preserved ejection fraction indicate?

Answer 25

HF with preserved ejection fraction: EF greater than 50%. Presence of diastolic or right heart dysfunction. Diastolic dysfunction leads to an increased reservoir of blood in the pulmonary veins, leading to increased pulmonary hypertension and pulmonary oedema.

Right heart failure – peripheral oedema e.g. leg swelling, raised jugular venous pressure

Question 26

What does heart failure with reduced ejection fraction indicate?

Answer 26

HF with reduced ejection fraction: EF less than 50%. Impaired left ventricular systolic function leading to pulmonary oedema secondary to impaired systolic function and flow of blood via the aorta. This leads to the backflow of blood into the pulmonary veins and lungs (leading to pulmonary oedema).

Left heart failure – pulmonary oedema

Question 27

What medications are used to treat heart failure?

Answer 27

Heart failure with preserved ejection fraction: Diuretics and SGLT2 inhibitors.

Heart failure with reduced ejection fraction: ACE inhibitors (ACEi) and angiotensin II receptor blockers (ARBs) – e.g. preformulated in Entresto. Beta blockers. Mineralcorticoid receptor antagonists, SGLT2 inihbitors, diuretics.