Heart Failure Revision Flashcards
Define the cardiac output equation
Cardiac output = stroke volume x heart rate
(CO = SV x HR)
What is systolic
Maximum pressure the heart exerts while beating
What is diastolic
pressure in the arteries between beats
define heart failure in simple terms
Abnormal ventricular function causing the heart to not be able to pump sufficient blood to meet metabolic demand, characterised by inadequate tissue perfusion and volume overload
what are symptoms of heart failure
fatigue, SOB, exercise intolerance, venous distention (bulging neck veins), peripheral and pulmonary oedema (excess retained fluid in limbs/lungs)
Outline cardiac conditions that can disrupt myocyte activity
Myocardial infarction, Myocarditis, Dilated Cardiomyopathy, Hypertrophic Cardiomyopathy, Restrictive Cardiomyopathy, Recurrent myocardial ischaemia, Ventricular remodelling
define myocyte activity
heart contractility
What is a Myocardial infarction
aka heart attack, lack of sufficient blood flow to the heart
What is myocarditis
inflammation of the heart muscles
What is Dilated cardiomyopathy
heart muscle disease that causes ventricles to thin and stretch, growing larger
What is Hypertrophic cardiomyopathy
heart muscle disease that causes muscle thickening
What is restrictive cardiomyopathy
muscles of your heart’s ventricles stiffen and can’t fill with blood. The heart can fill and squeeze more poorly
What is recurrent myocardial ischaemia
repeat episodes of blood flow reduced blood flow to the heart, preventing the heart muscle from receiving enough oxygen
What is ventricular remodelling
(increased myocardial workload), changes in the size, shape, structure and function of the heart
what is the consequence of decreased cardiac contractility
a decline in stroke volume, and an increase in end-diastolic volume, causing heart chamber enlarging and increasing the heart’s workload
What does HFrEF stand for
Left Heart Failure- Reduced Ejection Fraction (Systolic)
Define HFrEF
Myocardium weakening results in a failure to pump enough blood to meet demand, resulting in bodily fluid building up in blood vessels and leaking into the interstitial spaces of the body and lungs, causing oedma and SOB
what is HFrEF characterised by
decreased contractility, ventricular remodeling, increased preload (increasing the size of the heart muscles) and increased after-load (resistance to ventricular emptying), this results in increased demand for oxygen which leads to increased hypertrophy
What are potential causes of HFrEF
Familial history, obesity, cigarettes, age, diabetes, toxins
What are symptoms of HFrEF
Dyspnoea (increased WOB), orthopnea (breathlessness while prone), fatigue, decreased urine output, oedema, elevated jugular venous pressure, cough with frothy sputum, pulmonary oedema (crepes on auscultation), HTN & Hypotension
What does HFpEF stand for
Left Heart Failure- Preserved Ejection Fraction (diastolic)
Define HFpEF
Can be an individual diagnosis or in conjunction with systolic heart failure (HFrEF), occurs when there is impaired filling of the left ventricle during the diastolic phase
What is HFpEF characterised by
Characterised by a low cardiac output from a ventricle that has thickened walls and therefore is less compliant (able to relax and fill with blood). Impaired diastolic relaxation and decreased compliance of the left ventricle results in end-diastole pressure that impacts pulmonary circulation
What are potential causes of HFpEF
HTN-induced myocardial hypertrophy, myocardial ischaemia w/ ventricular remodeling, familial history, age, diabetes, obesity
What are potential causes of HFpEF
HTN-induced myocardial hypertrophy, myocardial ischaemia w/ ventricular remodelling, familial history, age, diabetes, obesity
What are complications of HFpEF
angina/acute coronary syndrome (chest pain due to reduced blood to the heart), arrhythmias, kidney damage/renal impairment, oedema, dyspnoea
What are symptoms of HFpEF
Dyspnoea, fatigue, oedma, pulmonary oedema, nausea
Define Right-sided heart failure
Failure of the right ventricle to effectively fill and pump blood, leading to periphery fluid build-up
What is right-sided heart failure characterised by
Impaired contractility of the right ventricle (RV) causes by increased pressure, volume overload, intrinsic myocardial contractile dysfunction and/or cardiac rhythm
What are the physiological differences between the Left Ventricle and Right Ventricle
RV greater sensitivity to afterload (amount of pressure the heart needs to eject blood during a contraction) changes leading to increased risk of dilation to preserve stroke volume
Pressure in pulmonary circulation is lower than the systolic circulation, RV requires less muscle power than LV
RV is more compliant to accommodate larger variation in venous return without altering end-diastolic pressure
What are risk factors for Right-sided HF
Age, gender (Male), congenital heart defects, arrhythmias, Left-sided heart failure, left-to-right shunt (a “back-leak” of blood from the systemic to the pulmonary circulation), respiratory dysfunction, pericardial constriction, previous myocardial infarction, race (african-american men), infection
What are the causes of Right-sided HF
Left-sided heart failure (increased left ventricular filling pressure->increased pulmonary circulation->increase in resistance to right ventricular emptying->right ventricle dilates and fails
COPD, cystic fibrosis, cor pulmonale, ARDS, drug use, coronary artery disease, diabetes, alcohol, HTN, obesity. Pulmonary oedema/embolism/HTN
What are the complications of Right-sided HF
Liver failure, arrhythmia, impaired kidney function, heart valve issues, acute coronary syndromes. Angina
What are symptoms of Right-sided HF
Peripheral oedema, hepatosplenomegaly (enlarged liver and spleen), fatigue, increased urge to urinate, lack of appetite, nausea, weight gain
What is the primary goal for heart failure treatment
maximise cardiac output, decrease intravascular volume, decrease preload (blood volume that stretches the cardiac muscle prior to contraction), decrease afterload, improved gas exchange/oxygenation, improved cardiac function
Outline management of HFrEF
Aims to reverse the cycle of decreasing contractility & increasing preload+afterload, by increasing contractility and decreasing afterload+preload
Acute cause of HFrEF commonly due to acute myocardial ischemia (partial blockage of arteries to the heart)-> treated via nitrates (for vasodilation) , morphine (angina) & oxygen therapy to improve myocardial oxygenation
Outline management of HFpEF
Improving ventricular relaxation and prolonging diastolic filling times to reduce diastolic pressure
Outline management of Right-sided heart failure
Improving cardiac function, managing symptoms and reducing fluid acclimation
Outline management of HF related Oedema
Strict FBC, fluid restriction, daily weight, dietary restriction (i.e low sodium)
Diuretics: Thiazides (Hydrochlorothiazide), Loop diuretic (Frusemide), Potassium sparing (Spironolactone)
Outline the aim for pharmacological treatment of Heart failure
Aim to reduce fluid retention and intravascular volume, open narrowed blood vessels and improve blood flow, reduce blood pressure and heart rhythm, increase peripheral blood flow, prevent blood clots, lower cholesterol, maintain electrolytes
What common drugs are used for heart failure treatment
Angiotensin converting enzyme (ACE) inhibitors: enalopril, captopril
Angiotensin II receptor blockers: irbesartan
Vasodilator drugs: GTN
Beta Blockers: bisoprolol, carvedolol, metoprolol
Diuretic: furosemide
What surgical procedures can be used to treat heart failure
Ventricular assist device (VAD) surgery: implant to help the heart to pump
Intra-aortic balloon pump (IABP): augment arctic output
Heart transplant surgery
