Cardio Conditions Flashcards
(33 cards)
What are some signs and symptoms of left sided heart failure?
Fatigue Exertional breathlessness Orthopnea Paroxysmal nocturnal dyspnoea Basal pulmonary crackles Displaced apex beat (cardiomegaly)
What are some signs and symptoms of right sided heart failure?
Fatigue Breathlessness Peripheral oedema - pitting Raised JVP Hepatomegaly - tender, smooth
What is heart failure?
Inability of the heart to meet the demands of the body
Syndrome consisting of:
Reduced CO
Tissue hypoperfusion
Pulmonary and tissue congestion => peripheral and pulmonary oedema
What are some causes of heart failure?
Most commonly IHD - fibrosis => myocardial dysfunction
HTN - inc afterload, accelerates atherosclerosis
Aortic stenosis - inc afterload on ventricle
What factors affect stroke volume?
Pre-load; EDV
After load; TPR
Increased by HTN
Myocardial contractility
Describe the pathogenesis of heart failure
Damaged ventricular tissue => reduction in efficiency of contraction => reduced SV => reduced CO => neurohormonal activation
What is Heart Failure with Preserved Ejection Fraction?
Diastolic heart failure - problem w/ filling
Ventricles too stiff - hypertrophied
Reduced space for blood therefore lower EDV
However can still eject same fraction of blood
What is Heart Failure with Reduced Ejection Fraction?
Systolic HF
Ventricles not able to contract with enough force to eject blood
Thin/fibrosed walls => enlarged chambers => abnormal myocardial contraction
Can fill, but can’t eject enough blood
More common
Describe Frank Starling Law (physiological)
More ventricular filling in diastole => greater volume ejected in systole
Inc stretching of myocytes => greater force of contraction (inotropy)
Optimal point of overlap of actin and myosin
If stretched too much => decreased inotropy
Describe the Frank-Starling curve for HF
Lower CO for a given end diastolic pressure
Inc filling of LV => little increase in CO
Eventually leads to worsening CO
Higher pressures in the LV => pulmonary oedema
Describe the effect of the sympathetic nervous system in heart failure
Dec CO => Dec BP => activation of baroreceptors => inc sympathetic drive
Increases HR and TPR => inc afterload => inc cardiac work
Describe the stimulation of RAAS in HF
Dec CO => Dec BP => Dec renal perfusion => RAAS
Angiotensin II => aldosterone secretion, ADH secretion, vasoconstriction, enhanced sympathetic activity
Aldosterone => Na+ and water retention => inc circulating volume
Increases pre-load and after-load => increased cardiac work
Outline treatment for acute heart failure
Admit to hospital
Oxygen
IV loop diuretic - furosemide
Heparin
What is the role of furosemide in treating oedema in HF?
Inhibits NaKCC channel in loop of Henle => reduce reabsorption of Na and water => reduce body fluid
Decrease filling of ventricles by decreasing circulation volume
How is HFrEF treated?
ACE-I and β-blockers
Diuretics (furosemide, spironolactone)
What is the MOA of β-blockers in HF?
Antagonists of β2 receptors
Inhibit effects of catecholamines
Reduce myocardial demand of oxygen
Reduced HR
Reduce BP => reduction in CO
What is the MOA of ACE-I used for HF?
Inhibit ACE => inhibit conversion of Angiotensin I to Angiotensin II
Therefore don’t get aldosterone release, and other effects of Angiotensin II
What is the MOA of spironolactone?
Aldosterone antagonist
Inc loss of Na => inc loss of water => reduce circulating volume
K sparing therefore lower risk of hypokalaemia => lower risk of arrhythmias
What is ischaemic chest pain?
Chest pain secondary to pathology involving the heart - angina
Caused by atherosclerosis
What are some modifiable risk factors for atherosclerosis?
Smoking Hypertension Hyperlipidaemia Diabetes Obesity Sedentary lifestyle
What are some non-modifiable risk factors for atherosclerosis?
Family history
Age
Gender (male)
What is stable angina?
Stable atherosclerotic plaque partially occluding an artery
Ischaemia occurs when metabolic demand exceeds what can be delivered by coronary arteries
Relieved by rest and GTN spray
What conditions can result from complications of an atherosclerotic plaque?
Rupture => acute coronary syndrome
Unstable angina
NSTEMI
STEMI
What are some symptoms of an MI?
S - central chest pain, radiating to shoulder Q - dull, crushing I - v bad T - A - R - P - angina Sx S - nausea, vomiting, autonomic features eg sweating, breathlessness
