Heart Failure and Cardiac Arrhythmias Flashcards
(72 cards)
What is heart failure?
The inability of the heart to deliver enough blood to meet the body’s needs/supply the body’s demands
What characterises the clinical syndrome of heart failure? (3 points)
Breathlessness
Oedema (usually ankles)
Fatigue
Which side do the pulmonary vein and aorta belong to in the heart?
Left
Which side do the pulmonary artery and superior/inferior vena cava belong to in the heart?
Right
Which atrioventricular valve is on the left?
Mitral valve
Which atrioventricular valve is on the right?
Tricuspid valve
What are the main indications of acute heart failure?
Pulmonary oedema with breathlessness at rest
Chronic heart failure has several underlying ______ causes. It is aggravated by ___________ _______-_________ regulation. It is associated with ______ mortality. Patients have a high risk of complications of procedures involving __________ __________.
Cardiac, dysfunctional neuro-hormonal, high, general anaesthesia
What happens in left-sided heart failure?
Raised pulmonary venous pressure
Pulmonary oedema
Pulmonary venous congestion
What happens in right-sided heart failure?
Peripheral oedema
Raised jugular venous pressure
Systemic venous congestion
What are the possible cardiac causes of heart failure? (4 points)
Heart muscle disease such as cardiomyopathy or ischaemic heart disease causing left ventricular systolic dysfunction where less than 40% of blood is pumped out of the left ventricle
Excessive volume load due to valvular regurgitation
Excessive pressure load due to hypertension, aortic stenosis, pulmonary hypertension
Sustained abnormal rhythm such as tachycardias, bradycardias
What are the 2 main non-cardiac causes of heart failure syndrome or what aggravates heart failure?
Excessive demand in high output caused by arteriovenous shunts (may be present in patients undergoing haemodialysis), anaemia, hyperthyroidism
Fluid overload from excessive IV therapy or renal failure (as kidney removes water from body)
What are the 4 most common causes of heart failure?
Ischaemic heart disease (which may lead to myocardial infarction resulting in left ventricular weakness)
Hypertension (excessive pressure load)
Valvular heart disease (valve stenosis and valve regurgitation causing excessive volume load)
Chronic obstructive pulmonary disease
What physical signs are examined in patients with suspected heart failure? (8 points)
Pulmonary oedema - breathless, cyanosis, basal lung crackles on auscultation
Peripheral oedema - pitting (leaves an indent and doesn’t spring back after pressing firmly for a few minutes)
Ascites
Pleural effusions
Raised jugular venous pressure
Irregular pulse
Heart murmur
Anaemia
What investigations can be done to assess cardiac causes of heart failure?
Chest X-ray (shows if the heart is enlarged or if lungs are congested with fluid)
ECG (shows signs of MI/previous MI and atrial fibrillation)
Echocardiogram (ultrasound; best test; shows how well the chambers are contracting in real-time)
What investigations can be done to assess non-cardiac causes of heart failure? (3 points)
Urea and electrolytes test (check kidney function)
Full blood count (check for anaemia)
Thyroid function test
One of the conflicting neuro-humoral compensatory mechanisms is how reduced cardiac output and blood pressure resemble dehydration or haemorrhage, therefore activating the ______-______-________ system to retain salt and water as well as the ________ nervous system to vasoconstrict (maintain blood pressure) and stimulate heart rate (maintain cardiac output). These are fine during the acute phase but will become harmful in the chronic phase as excess adrenaline can overdrive the heart and damage it, and the RAA system can lead to oedema which we wanted to avoid in the first place.
Renin-angiotensin-aldosterone, sympathetic
Another conflicting neuro-humoral compensatory mechanism: increased intracardiac pressures detected by ‘______ receptors’ in the heart resembles fluid overload causing atrial and ‘brain’ ________ peptides coming from ventricles to stimulate sodium excretion
Stretch, natriuretic
What does reduced renal blood flow stimulate?
Secretion of renin from the kidney
What does renin stimulate?
Angiotensin-Converting Enzyme (ACE)
What does ACE catalyse?
Production of angiotensin II from angiotensin I
How does angiotensin II work?
Acts as a vasoconstrictor through the AT1 receptor and stimulates aldosterone secretion from the adrenal cortex
What is aldosterone and what does it do?
A mineralocorticoid that increases sodium retention in the kidney
What does sodium retention indirectly do?
Stimulates water retention through vasopressin
(antidiuretic hormone) from the posterior pituitary
