Murmurs grading causes types n during inspiration n expiration etc
Reading File
Finding Sources
Finding Sources
Finding Sources
Finding Sources
Reading File
Reading File
Reading File
Reading File
Reading File
Reading File
I now have all the core content needed. Let me compile the full comprehensive answer.
Heart Murmurs: Complete Guide
1. What Is a Heart Murmur?
Murmurs are audible vibrations caused by:
- Increased turbulence from accelerated blood flow through normal or abnormal orifices
- Flow through a narrowed/irregular orifice into a dilated vessel or chamber
- Backward flow through an incompetent valve, VSD, or PDA
-Harrison's Principles of Internal Medicine 22E, p. 327
2. Grading (Levine Scale, Grade I-VI)
| Grade | Description |
|---|---|
| 1/6 | Very soft; heard only with great effort |
| 2/6 | Easily heard, but not particularly loud |
| 3/6 | Loud, but NO palpable thrill |
| 4/6 | Very loud + palpable thrill present |
| 5/6 | Heard with only the edge of the stethoscope on the chest |
| 6/6 | Heard with stethoscope slightly off the chest |
Murmurs of Grade 3 or greater usually signify important structural heart disease.
-Harrison's Principles of Internal Medicine 22E, p. 328
3. Types by Timing
A. Systolic Murmurs
| Type | Timing | Key Causes | Character |
|---|---|---|---|
| Holosystolic (pansystolic) | Entire systole, S1 to S2 | MR, TR, VSD | Plateau (constant intensity) |
| Midsystolic (ejection) | After S1, ends before S2 | AS, PS, HOCM, Innocent flow murmurs | Crescendo-decrescendo ("diamond-shaped") |
| Early systolic | S1 to mid-systole | Acute MR, small muscular VSD, early TR | Decrescendo |
| Late systolic | Mid to late systole | MVP (often with a click), mild MR | Crescendo |
B. Diastolic Murmurs (always pathological)
| Type | Timing | Key Causes | Character |
|---|---|---|---|
| Early diastolic | Begins at S2 | AR, PR (Graham Steell murmur) | Decrescendo, high-pitched, blowing |
| Mid-diastolic | After opening snap | MS, TS, Austin Flint (in AR) | Low-pitched rumble (use bell of stethoscope) |
| Presystolic | Late diastole, just before S1 | MS or TS in sinus rhythm | Crescendo |
C. Continuous Murmurs
Begin in systole, pass through S2, and continue into all or part of diastole:
- PDA (patent ductus arteriosus) - "machinery murmur"
- Coronary AV fistula
- Ruptured sinus of Valsalva aneurysm
- Cervical venous hum
4. Configuration (Shape)
| Shape | Example Murmur |
|---|---|
| Crescendo-decrescendo | AS (ejection systolic) |
| Plateau (uniform) | MR, TR, VSD (holosystolic) |
| Decrescendo | AR, PR (early diastolic) |
| Crescendo | MS presystolic component |
5. Inspiration vs. Expiration Effects
This is one of the most clinically important bedside tools:
The General Rule (Rivero-Carvallo Principle)
Right-sided murmurs increase with inspiration; left-sided murmurs increase with expiration.
This holds because inspiration increases venous return to the right heart, augmenting right-sided flow.
| Murmur | Inspiration | Expiration |
|---|---|---|
| Tricuspid regurgitation (TR) | Louder (Carvallo's sign) | Softer |
| Tricuspid stenosis (TS) | Louder | Softer (especially with Valsalva strain) |
| Pulmonary stenosis (PS) | Louder | Softer |
| Pulmonary regurgitation (PR) | Louder | Softer |
| Mitral regurgitation (MR) | Softer | Louder |
| Aortic stenosis (AS) | Softer | Louder |
| Aortic regurgitation (AR) | Softer | Louder |
| Mitral stenosis (MS) | Softer | Louder |
| HOCM | Softer (increased venous return fills LV) | Louder |
| MVP click | Moves later (less prolapse) | Moves earlier |
- Exception: The pulmonic ejection sound is the one right-sided event that decreases with inspiration (unique - valve is already partially open at end of deep inspiration).
-Harrison's 22E, p. 328; Schwartz's Principles of Surgery 11E, p. 842; Fuster & Hurst's The Heart 15E
6. Other Dynamic Auscultation Maneuvers
| Maneuver | Effect on Most Murmurs | Special Cases |
|---|---|---|
| Valsalva (strain phase) | Most murmurs decrease | HOCM and MVP - louder and longer |
| Standing | Most murmurs decrease | HOCM - louder; MVP - louder and longer |
| Squatting / leg raise | Most murmurs increase | HOCM and MVP - diminish |
| Exercise | Flow murmurs and stenotic murmurs louder; MR, VSD, AR also increase with isometric exercise | - |
| Amyl nitrate | Hypotensive phase: MR, VSD, AR decrease; AS increases | Later tachycardic phase: right-sided murmurs and MS increase |
| Transient arterial occlusion (BP cuff) | MR, VSD, AR increase | - |
| Post-PVC beat | Flow murmurs and semilunar stenosis murmurs increase | AV valve regurgitation murmurs do NOT change (useful to distinguish AS from MR) |
-Schwartz's Principles of Surgery 11E, p. 842
7. Innocent (Functional) Murmurs
These are benign, systolic (never diastolic), soft (Grade 1-2), and have no structural cause:
- Still's murmur - most common in children; vibratory, musical, best heard at LLSB
- Pulmonary flow murmur - at 2nd left ICS; common in children and young adults
- Physiologic murmurs - seen in pregnancy, fever, anemia, thyrotoxicosis (high-output states)
- Innocent murmurs get louder with exercise or fever (increased flow)
- They do NOT change in the post-PVC beat (unlike pathologic semilunar stenosis)
8. Location & Radiation at a Glance
| Murmur | Best Heard | Radiation |
|---|---|---|
| Aortic Stenosis | 2nd right ICS (aortic area) | Carotids; also apex (Gallavardin) |
| Aortic Regurgitation | 3rd left ICS (Erb's point) | Along left sternal border |
| Mitral Stenosis | Apex | Little radiation; use bell |
| Mitral Regurgitation | Apex | Axilla |
| Tricuspid Regurgitation | Lower left sternal border | - |
| Pulmonary Stenosis | 2nd left ICS | - |
| VSD | Left sternal border | Entire precordium |
| PDA | Left infraclavicular | - |
Quick Memory Aid
- "RILE" - Right-sided = Inspiration Louder; Left-sided = Expiration louder
- Thrill starts at Grade 4
- Diastolic murmur = always pathological (investigate with echo)
- HOCM and MVP behave oppositely to most murmurs with Valsalva and standing
This is a shared conversation. Sign in to Orris to start your own chat.