Week 3 - Heart Failure Flashcards
Define Heart Failure
An acute or chronic condition in which the heart doesn’t pump blood as well as it should resulting in congestion (CHF) of blood backing up and unable to meet the demands of the body
- The heart’s inability to consistently pump enough blood to organs and tissues
- Cardiac output is insufficient to meet the metabolic demands of the body and accommodate venous return
- Occurs from either a structural or functional abnormality of the heart
- The resulting decreased blood supply to body impairs organs and tissue function
- The dominant feature is inadequate tissue perfusion
What is a structural abnormality of the heart?
Valve problem/dysfunction, ventricle thickness, rigidity
What is a Functional abnormality of the heart?
Following a MI, cardiomyopathy, CAD (coronary artery disease)
Define Cardiac Output (CO)
Stroke Volume x Heart Rate (3.5-5L/min)
Define Stroke Volume (SV)
Amount of blood pumped out per heartbeat
Define Preload
(Volume) amount of ventricular stretch at the end of diastole. The greater the stretch the stronger the contraction (Starling’s Law)
Define Afterload
(Pressure) resistance to the ejection of blood from the ventricle
Define Ejection Fraction, what the normal is and how it is measured
- The ejection fraction (EF) is the amount of blood that is pumped out of the left ventricle (LV) with each heartbeat
- A decreased EF = decreased amount of blood being pumped out = decreased perfusion
- It is measured in percentages
- Normal range is 55-70%
- An EF of 40% or less indicates HF
- Calculated from an echocardiogram
What is Systolic Heart Failure?
- Shortened to HFrEF which stands for Heart Failure reduced Ejection Fraction
- Pumping problem of the heart
- Inability of the Left ventricle to contract effectively
( Ventricles can’t pump hard enough during systole )
What is diastolic heart failure?
- Shortened to HFpEF which stands for Heart failure Preserved ejection fraction
- It is a relaxing problem
- Inability of the Left ventricle to relax and fill effectively
( Not enough blood fills into ventricles during diastole )
Define systole and diastolic
Systole = The ventricles eject blood (pump)
Diastolic = The ventricles fill with blood (relax)
What is Right-Sided Heart Failure?
- The right ventricle cannot eject sufficient amounts of blood - blood backs up in the venous system and may result in:
- Peripheral Oedema
- Weight gain but anorexia/nausea may be present
- Hepatomegaly/Splenomegaly
- Liver is the last place to send blood back to the heart
- Ascites
- Jugular vein distention
- The blood can back up to the rest of the body via the right atrium and manifest as oedema, legs/ankles/feet, sacrum/penis (dependent areas) around the eyes, organ oedema
(Could experience Anorexia, GI distress, Weight loss, signs related to liver function impairments)
What is Left-Sided Heart Failure?
- The left ventricle cannot pump blood effectively to the systemic circulation. The blood backs up in the pulmonary system so the pulmonary venous pressure increases in:
- Decrease EF
- Pulmonary congestion/oedema with dyspnoea
- Cough
- Crackles
- Impaired oxygen exchange
- LHF is the most common form (from left ventricular dysfunction). Blood cannot get out and around the body, so it backs up in the lungs via the left atrium and pulmonary vein
- It causes pulmonary congestion and oedema in the lungs
(cough with frothy sputum, Cyanosis and signs of hypoxia, orthopnea)
What is the patho for Heart Failure?
- MI or cardiac dysfunction/structural abnormality impairs ability of L) ventricle to fill with or eject blood
- Poor ventricular function/myocardial damage leads to decreased stroke volume and cardiac output
- Leads to a neurohormonal response
- Either sympathetic system is activated to increase cardiac workload, or RAAS pathway is activated
- Results in vasoconstriction and sodium + fluid retention
- Further stress on the ventricular wall and remodelling leads to heart failure
What are some signs and symptoms of heart failure?
Pale, grey, SOBOE, orthopnea (unable to lie flat and breathe), nocturia (increased urination overnight due to lying flat and kidneys being well perfused), oedema, confusion, tachycardia, hypotensive, dry cough, dyspnoea, weak pulse, tachypnoea, fatigue, anxiety, ECG abnormalities, palpitations, restlessness, hypoxaemia, moist cough, diaphoresis, cyanosis, dizzy, light-headed, nausea, weight-gain, SOB, crackles on auscultation, ascites, exercise intolerance