Step 1. Anchor the two key levers

Preload = venous return → how much blood fills the ventricle.
Afterload = resistance the ventricle pumps against.

👉 Most maneuvers change preload, but a few importantly affect afterload.

Step 2. Maneuvers → preload/afterload

• Standing: ↓ preload
• Squatting: ↑ preload and ↑ afterload
• Valsalva (strain): ↓ preload
• Valsalva (release): sudden ↑ preload
• Handgrip: ↑ afterload (venous return unchanged)
• Inspiration: ↑ right heart preload, ↓ left heart preload
  Mnemonic: “Inspiration Increases Right”

Step 3. Murmur logic

Louder murmur = more flow or more gradient.

• Most murmurs: louder with ↑ preload, softer with ↓ preload.
• HCM: louder with ↓ preload/afterload.
• MVP: earlier click + louder murmur with ↓ preload.
• Handgrip: MR/AR/VSD louder; AS/HCM softer; MVP click moves later.

Step 4. Mnemonics

• Preload ↓ = “Empty ventricle” → MVP & HCM louder.
• Squatting = everything louder EXCEPT MVP & HCM.
• Handgrip = “Backward murmurs up, forward murmurs down.”
• Inspiration = Right-sided murmurs louder.

Step 5. MVP mechanics

Normal mitral valve closes snugly at systole. In MVP, floppy leaflets prolapse into LA → mid-systolic click + late systolic murmur.

• Small LV (↓ preload): early click, longer murmur.
• Large LV (↑ preload): late click, shorter murmur.

Step 6. Contrast with HCM

Both louder with ↓ preload:
• MVP: slack chordae → early prolapse.
• HCM: tighter chamber → worse LVOT obstruction.

Step 7. Exam picture

Think of a parachute in a box:
Small box (↓ preload) → parachute hits top sooner (early click).
Large box (↑ preload) → hits later (late click).