patho of cardiac diseases: valvular HD

preload

• ▪  Volume of blood filling the ventricle before contraction

• ▪  Stretch of heart muscle fibers at end-diastole

• ▪  Determines how much the heart muscle is stretched before pumping

increased preload?

• raises the work of the heart by increasing the volume it must eject

afterload

• ▪  Resistance the ventricle must overcome to push blood out during

  systole

• ▪  Depends on arterial blood pressure and vessel resistance

higher afterload?

• increases the work of the heart by making pumping more difficult

What event does the P wave represent on an ECG?

Atrial depolarization (leading to atrial contraction)

What happens during isovolumetric contraction?

All valves are closed; ventricles contract but no blood is ejected yet.
🫀 Pressure rises inside ventricles to open semilunar valves (aortic/pulmonary).
🔒 Mitral and aortic valves are both closed.

What ECG component corresponds to ventricular depolarization?

QRS complex
🫀 Triggers ventricular systole (contraction phase).
💡 Atrial repolarization is hidden within QRS.

During ventricular ejection, which valves are open and which are closed?

Semilunar (aortic/pulmonary) valves open; AV (mitral/tricuspid) valves closed
➡ Blood is pumped out of the ventricles into the aorta/pulmonary artery

What happens during isovolumetric relaxation?

All valves are closed; ventricles relax but no filling occurs yet.
🫀 Pressure drops rapidly in ventricles after blood is ejected.
🔒 Both mitral and aortic valves are shut.

What cardiac phase follows the T wave on an ECG?

Ventricular diastole (relaxation and filling)
💗 AV valves (mitral/tricuspid) open
🫀 Blood flows passively into ventricles from atria

What is the purpose of the isovolumetric phases (contraction and relaxation)?

To build or reduce pressure in the ventricles while all valves remain closed.
💡 These transitions allow controlled opening of valves and maintain forward flow.

1st heart sound (lub) occurs

at start of systole

1st sound caused by…

closure of the AV valves

right av valve

tricuspid valve

left av valve

mitral valve

what creates the lub sound?

Ventricular pressure rises → AV valves shut

▪ Valve closure causes surrounding tissue to vibrate

2nd heart sound (dub) occurs

at ehe end of systole

2nd heart sound caused by

• closure of the semilunar valves:

right semilunar valve

pulmonic valve

left semilunar valve

aortic valve

what creates the dub sound s2

• Ventricular pressure falls → semilunar valves shut

• ▪  Closure causes vibration → creates the “dub” sound

Physiologic Split

• ▪  Aortic valve closes slightly before the

  pulmonic valve

• ▪  Sometimes can hear two distinct sounds (especially during inspiration)

aortic valve

2nd intercostal space, right sternal border

pulmonic valve

2nd intercostal space, left sternal border

tricuspid valve

5th intercostal space, left sternal border

mitral valve

5th intercostal space, midclavicular line (apex)

heart murmurs

extra heart sounds caused by turbulent blood flow

▪ Usually heard with a stethoscope during the cardiac cycle

heart murmurs are most often due to?

valve problems

heart murmurs are classified by:

timing

systolic or diastolic

stenosis

Valve doesn’t open fully

▪ Blood flow is blocked or narrowed

▪ Heart has to work harder to push blood through

▪ Example: Aortic stenosis = narrowed aortic valve

regurgitation

• (also called insufficiency) = Valve doesn't close fully

• ▪  Blood leaks backward

• ▪  Leads to volume overload in the chamber behind the valve

• ▪  Example: Mitral regurgitation = blood leaks back into the left

  atrium

valve disorders are named after the?

affected valve and the actual problem

systolic murmors

(when the heart contracts)

systolic murmurs

1. aortic stenosis (left0

2. mitral regurgitation (left0

3. pulmonic stenosis (right)

4. tricuspid regurgitation (right)

aortic stenosis

• Narrowed aortic valve → blood struggles to exit the left ventricle

mitral regurgitation

• Leaky mitral valve → blood flows backward into the left atrium

pulmonic stenosis

• Narrowed pulmonic valve → blood has trouble leaving the right ventricle

tricuspid regurgitation

• Leaky tricuspid valve → blood flows backward into the right atrium

diastolic murmurs

when the heart relaxes and fills)

diastolic murmurs

1. aortic regurgitation (left)

2. mitral stenosis (left)

3. pulmonic regurgitation (right)

4. tricuspid stenosis (right)

aortic regurgitation

• Leaky aortic valve → blood leaks back into the left ventricle

mitral stenosis

• Narrow mitral valve → blood has trouble entering the left ventricle

pulmonic regurgitation

• Leaky pulmonic valve → blood leaks back into the right ventricle

tricuspid stenosis

• Narrow tricuspid valve → blood has trouble entering the right ventricle

causes of valve disease

1. calcific degeneration

2. myxomatous degeneration

3. CAD

4. congenital defects

calcific degeneration causing valve disease

•  Calcium builds up on the valve, making it stiff

• ▪  Most common cause of aortic stenosis in older adults

• ▪  Caused by aging, wear-and-tear, and chronic inflammation

• ▪  Valve cells may behave like bone cells and produce calcium

myxomatous degeneration causing valve disease

• ▪  Weakening of connective tissue in the valve

• ▪  Makes the valve floppy or stretched

• ▪  Common cause of mitral regurgitation

CAD causing valve disease

• ▪  Reduced blood flow can damage the structures that support valve closure

• ▪  Most often leads to secondary mitral regurgitation

congenital defects causing valve disease

• ▪  Valve is abnormally formed before birth

• ▪  May have the wrong number of cusps or improper shape

• ▪  Can cause stenosis or regurgitation, sometimes not noticed until adulthood

mitral valve stenosis (MVS)

•  Narrowed mitral valve slows blood flow from the left atrium to the left ventricle

  ▪ This increases afterload on the left atrium

Afib from MVS

• ▪  Caused by stretching of the left atrium

• ▪  Increases risk of clots and stroke (embolization)

pulmonary congestion from MVS

• Pulmonary congestion from pressure backing into the lungs:

  • ▪  Shortness of breath (dyspnea)

  • ▪  Trouble breathing when lying down (orthopnea)

  • ▪  Cough

  • ▪  Low oxygen levels (hypoxemia)

• Decreased stroke volume (SV) from MVS

• Decreased stroke volume (SV) due to reduced ventricular filling:

  • ▪  Fatigue

  • ▪  Weakness

  • ▪  Activity intolerance

mitral valve regurgitation

•  Left atrial volume overload due to backflow of blood

• ▪  Left atrial enlargement over time

afib and mitral valve regurgitation

• Atrial fibrillation caused by stretching of the left

  atrium
  ▪ Increases risk of clot formation and embolization

left ventricular volume overload with mitral valve regurgitation

• Left ventricular volume overload from increased preload

  • ▪  Leads to ventricular dilation and eventually heart failure

  • ▪  Chest pain from increased heart work

pulmonary congestion with mitral valve regurgitation

• Pulmonary congestion due to backward pressure:

  ▪ Dyspnea
  ▪ Orthopnea ▪ Cough

decreased CO mitral valve regurgitation

• Decreased forward flow (cardiac output):

  ▪ Fatigue

  ▪ Weakness
  ▪ Activity intolerance

mitral valve prolapse

• Mitral valve leaflets bulge backward into the left atrium during systole

• ▪  May cause the valve to open slightly → can lead to mitral regurgitation

mvp produces?

• systolic murmur (may include a mid-systolic click)

▪ caused by the sudden tensing of the mitral valve and chordae tendineae as the valve prolapses into the left atrium during ventricular contraction.

key manifestations of MVP

•  Often asymptomatic

• ▪  If regurgitation occurs, symptoms may resemble those of mitral regurgitation

aortic valve stenosis

▪ Narrowing of the aortic valve obstructs blood flow from the left ventricle to the aorta

▪ Increases left ventricular afterload

aortic valve stenosis leads to

a systolic murmur (heard when the heart contracts)

key manifestations of aortic valve stenosis

▪ Angina – heart muscle isn’t getting enough oxygen
▪ Syncope – especially with exertion, due to reduced cerebral perfusion

▪ Fatigue – from decreased cardiac output
▪ Hypotension – reduced forward flow into systemic circulation
▪ Weak peripheral pulses – due to poor stroke volume

aortic regurgitation

• ▪  Aortic valve doesn’t close fully, allowing blood to leak back into the left ventricle during diastole

aortic regurgitation causes a

diastolic murmur (heard when the heart relaxes)

key manifestations of aortic regurgitation

• ▪  Increased ventricular preload
  ▪ Blood returns from the left atrium and leaks back from the aorta

• ▪  Increased stroke volume → elevated systolic blood pressure (SBP)

• ▪  Backflow of blood → reduced diastolic blood pressure (DBP)

• ▪  Widened pulse pressure (↑ SBP, ↓ DBP)

• ▪  Bounding peripheral pulses (“water hammer” pulse)

  ▪ Pulses feel forceful and collapse quickly
  ▪ Caused by high SBP and rapid drop during DBP

cardiac auscultation diagnosis

• detects murmurs and abnormal heart sounds

chest xray diagnosis

• shows heart size and pulmonary congestion

echocardiography diagnosis

• visualizes valve structure and blood flow

electrocardiography (ECG) diagnosis

• identifies chamber enlargement or arrhythmias (e.g., A. fib)

doppler ultrasound diagnosis

• measures flow speed and direction across valves

cardiac MRI diagnosis

• detailed view of heart anatomy and function

coronary angiography diagnosis

• assesses coronary artery disease, especially before valve surgery

supportive care meds

o Medications manage symptoms and prevent complications but do not repair or

replace the damaged valve

diuretics meds

o Reduce pulmonary congestion and fluid overload in heart failure symptoms

o Used in mitral stenosis and regurgitation

beta blockers meds

o Slow heart rate to improve ventricular filling time and reduce oxygen demand

o Help with angina in aortic stenosis and control rate in atrial fibrillation

calcium channel blockers meds

o Control heart rate and manage angina when beta blockers aren’t suitable

o Useful in atrial fibrillation

anticoagulants meds

o Prevent blood clots in atrial fibrillation or enlarged atria
o Required for patients with mechanical valve replacements

valve repair surgery

• ▪  Fixes the patient’s own valve without removing it

• ▪  Corrects valve narrowing or leaking by repairing leaflets or opening fused parts

• ▪  Includes commissurotomy (surgical opening) and valvuloplasty (balloon widening)

valve replacement surgery

• ▪  Removes the damaged valve and implants a mechanical or tissue valve

• ▪  Used when repair is not feasible or has failed

• ▪  Mechanical valves last longer but require lifelong anticoagulation

• ▪  Tissue valves wear out over time but usually don’t require lifelong blood thinners