1b Valvular Disease and Heart Failure Flashcards
What is the units of cardiac output?
Litres/minute
What is the mean arterial pressure?
the mean arterial pressure is an average arterial blood pressure throughout a single cardiac cycle of systole and diastole.
What MAP represents a pressure necessary to adequately perfuse the body organs?
MAP of >65 mmHg
What is infective endocarditis?
infective endocarditis is an infection of the endocardium or vascular endothelium of the heart
What does infective endocarditis typically affect?
Heart valves
What causes infective endocarditis?
It is usually the result of bacteria entering the blood stream and forming ”a vegetation” in the endocardium
What is a heart vegetation?
a bacterial infection surrounded by a layer of platelets and fibrin
What is the most common bacteria for infective endocarditis?
Streptococci (20-40 % of cases) are the most common infection.
What are the common symptoms of infective endocarditis?
Fever, malaise, sweats and unexplained weight loss are common symptoms
There may be a new heart murmur on examination
What might blood tests show in a patient with infective endocarditis?
Blood tests show anaemia and raised markers of infection
Blood cultures may isolate a microorganism
Which ECHO has the higher sensitivity, Transoesophageal or Transthoracic?
Transoesophageal
What might an ECHO show in a patient with infective endocarditis?
Echocardiogram can show a vegetation, abscess, valve perforation and/or new dehiscence of prosthetic valve. Often there is regurgitation of the affected valve
What is decompensation?
Inability of the heart to maintain adequate circulation
What are signs of cardiac decompensation you might look for?
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
What are some other complications of cardiac decompensation?
Vascular and embolic phenomena
(stroke, Janeway lesions, splinter/ conjunctival haemorrhages)
Immunological phenomena
(Osler’s nodes, Roth spots)
What are the minor criteria in Duke’s Criteria for infective endocarditis?
Predisposing heart condition or injection drug use
Fever >38
Vascular phenomena
Immunological phenomena
Positive cultures
What are the major criteria in Duke’s Criteria for infective endocarditis?
Persistently positive bacterial culture
ECHO = vegetation, abcess
New valvular regurgitation murmur
What part of the heart does infective endocarditis affect?
Infective endocarditis affects the endocardium, especially the valves of the heart
Aortic valve is affected most frequently (aortic > mitral > right-sided valves)
Why infective endocarditis occur more commonly at the Aortic valve?
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.
Why might drug users have an increased risk of infective endocarditis?
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.
What is the definition of dilated cardiomyopathy?
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
What are the commonest causes of dilated cardiomyopathy?
Idiopathic, genetic, toxins (alcohol, cardiotoxic chemotherapy), pregnancy (peripartum cardiomyopathy), viral infections (myocarditis), tachycardia-related cardiomyopathy, thyroid disease, muscular dystrophies
How is dilated cardiomyopathy managed?
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
What are the future implications of dilated cardiomyopathy?
Increased risk of heart failure, cardiac arrhythmia, sudden cardiac death due to ventricular arrhythmia and reduced survival
What does heart failure with preserved ejection fraction indicate?
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
What does heart failure with reduced ejection fraction indicate?
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
What medications are used to treat heart failure?
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.
