Left and Right Sided Heart Failure Flashcards
What type of HF does the left side of the heart correlate with?
Systolic HF
Why do you often get left sided HF?
Damage to the myocardium - can’t contract as forcefully and pump blood as efficiently
Why does ischaemia cause L-sided systolic HF?
Damage caused by coronary artery atherosclerosis is most common cause
May end up with scarring of myocardium
Reduction in force during contraction
Blood not pumped efficiently
Why does long-standing hypertension causes L-sided systolic HF?
Arterial pressure increase
Harder to pump
To compensate left ventricle bulks up (muscular hypertrophy)
Ventricles contract with more force
Increase muscle mass leads to an increase in oxygen demand
Coronaries squeezed - reduce supply
Both increased muscle mass and coronaries squeezed lead to weaker contraction
Leads to systolic failure
Why does dilated cardiomyopathy cause L-sided systolic HF?
Chamber grows
Pre-load increases
Increased filling
Contraction strength increases (Frank-Starling)
Muscle wall gets thinner and weaker
Causes systolic-left sided HF
Why does long standing hypertension cause L-sided diastolic HF?
Concentric left ventricular hypertrophy
New sarcomere are generated parallel to existing one
Heart muscle wall enlarges and crowds into ventricular chamber space
Less space for blood
Why does aortic stenosis cause L-sided diastolic HF?
Narrowing of arteries
Can cause concentric hypertrophy
Why does hypertrophic cardiomyopathy cause L-sided diastolic HF?
Abnormal ventricular wall thickening
Often caused by genetics
Can lead to concentric hypertrophy
Why does restrictive cardiomyopathy cause L-sided diastolic HF?
Muscle stiffer and less compliant
Can’t stretch and fill
Leads to diastolic heart failure
What is the main cause of right sided HF?
Often caused by left side
Fluid build-up increases pressure in pulmonary artery - this makes the right side have to pump harder
HF would be biventricular
How does left to right sided cardiac shunt cause isolated R-sided HF?
Left to right sided cardiac shunt
EG. atrial septal defect / ventricular septal defect
Fluid volume increase
Concentric hypertrophy
More prone to ischaemia - systolic dysfunction
Smaller volume - diastolic dysfunction
How does chronic lung disease cause isolated R-sided HF?
Hard to exchange oxygen
In response to the hypoxia, pulmonary arteriole constricts
Pulmonary blood pressure increases
Harder for right side to pump
Can lead to right sided hypertrophy
Known as Cor Pulmonale
