00:00 / 00:00
of complete
of complete
2024
2023
2022
2021
heart failure p. 316
heart failure p. 316
heart failure p. 316
heart failure with p. 316
heart failure and p. 316
heart failure p. 316
heart failure p. 316
heart failure and p. 316
heart failure and p. 316
ACE inhibitors for p. 628
acromegaly p. 341
acute tubular necrosis with p. 620
amiodarone p. 327
angiotensin II receptor blockers p. 628
aortic regurgitation as precursor p. 296
associations p. 733
atrial septal defect p. 303
β -blockers for p. 245, 327
B-type natriuretic peptide in p. 299
calcium channel blockers p. 361
carcinoid syndrome p. 586
cardiac glycosides for p. NaN
chronic ischemic heart disease p. 308
contractility in p. 290
diabetic ketoacidosis p. 355
disopyramide p. 326
dobutamine for p. 241
dopamine for p. 241
Ebstein anomaly p. 302
ejection fraction in p. 290
ESR in p. 210
fludrocortisone and p. 360
hydralazine for p. 320
hypertension p. 304
hypertension treatment in p. 320
hypertensive emergency and p. 304
jugular venous pulse in p. 293
loop diuretics for p. 624
MI p. 309
Paget disease of bone p. 468
pleural effusion p. 699
potassium-sparing diuretics p. 627
pulmonary hypertension p. 697
pulse pressure in p. 290
readmissions with p. 276
renal failure causing p. 620
shock caused by p. 320
in sleep apnea p. 697
systolic vs diastolic p. 290
thiazides for p. 627
ventricular septal defect p. 303
heart failure p. 316
heart failure p. 320
for heart failure p. 316
heart failure caused by p. 316
heart failure p. 316
heart failure p. 316
for heart failure p. 316
heart failure p. 316
Heart failure’s used to describe a point at which the heart can’t supply enough blood to meet the body’s demands.
This can happen in two ways, either the heart’s ventricles can’t pump blood hard enough during systole, called systolic heart failure, or not enough blood fills into the ventricles during diastole, called diastolic heart failure.
In both cases, blood backs up into the lungs, causing congestion or fluid buildup, which is why it’s also often known as congestive heart failure, or just CHF.
Congestive heart failure affects millions of people around the world and since it means that the body’s needs are not being met, it can ultimately lead to death.
Part of the reason why so many people are affected by heart failure, is that there are a wide variety of heart diseases like ischemia and valvular disease that can impair the heart’s ability to pump out blood and—over time—can ultimately cause the heart to fail.
Alright, first up is systolic heart failure, kind of a mathematical way to think this one is that the heart needs to squeeze out a certain volume of blood each minute, called cardiac output, which can be rephrased as the heart rate (or the number of beats in a minute) multiplied by the stroke volume (the volume of blood squeezed out with each heart beat).
The heart rate is pretty intuitive, but the stroke volume’s a little tricky.
For example, in an adult the heart might beat 70 times per minute and the the left ventricle might squeeze out 70ml per beat, so 70 x 70 equals a cardiac output of 4900 ml per minute, which is almost 5 liters per minute.
So notice that not all the blood was pumped out right?
And the stroke volume is only a fraction of the total volume.
The total volume might be closer to 110 ml, and 70ml is the fraction that got ejected out with each beat, the other 40ml kind of lingers in the left ventricle until the next beat, right?
In this example, the ejection fraction would be 70ml divided by 110 ml or about 64%, a normal ejection fraction is around 50-70%, between 40-50% would be considered borderline, and anything about 40% or less would indicate systolic heart failure because the heart is only squeezing out a little blood each beat.
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