B.1 Origin of Heart Murmurs. Diastolic Murmurs Flashcards
B.1 Origin of Heart Murmurs. Diastolic Murmurs
S1
Closure of AV valves (“LUB”); occurs at the beginning of systole; sounds loudest at the apex.
B.1 Origin of Heart Murmurs. Diastolic Murmurs
Functional heart murmur (physiological or innocent)
- An ejection murmur due to increased or turbulent blood flow across normal aortic and/or pulmonary valves, e.g., due to a hyperdynamic circulation
- Most commonly occurs in children and young adults
- Cardiac pathology must be ruled out
Timing: Most commonly midsystolic or continuou
Position-dependent; varies in intensity or disappear
B.1 Origin of Heart Murmurs. Diastolic Murmurs
Pathological murmur:
Caused by structural defects (valvular disease or heart defects
Timing: Systolic, diastolic, or continuou
Rarely disappears
B.1 Origin of Heart Murmurs. Diastolic Murmurs
S2
Closure of semilunar valves (“DUB”); marks the beginning of diastole; loudest at the left upper sternal border.
All diastolic murmurs are pathologic and require investigation.
B.1 Origin of Heart Murmurs. Diastolic Murmurs
Physiologic Splitting:
Occurs during inspiration due to increased intrathoracic pressure, which causes a delay in venous return (P1 > P2).
B.1 Origin of Heart Murmurs. Diastolic Murmurs
S3
Heard just after S2, in early diastole, during rapid ventricular filling; loudest at the apex in the left lateral position (ventricular gallop).
Physiological in children, athletes, and during pregnancy.
Pathological in dilated ventricles (e.g., MR, AR, HF, thyrotoxicosis).
B.1 Origin of Heart Murmurs. Diastolic Murmurs
S4
Left atrium must push against a stiff LV wall; occurs just before S1 in the left lateral position (atrial gallop).
Associated with ventricular noncompliance (e.g., hypertrophy); always considered pathological.
B.1 Origin of Heart Murmurs. Diastolic Murmurs
grading of intenstiry
Grade I refers to a murmur that is barely audible and requires careful listening for some time.
Grade II describes a faint murmur that becomes noticeable as soon as the stethoscope is placed on the chest.
Grade III indicates a readily audible murmur that does not produce a thrill.
Grade IV is characterized by a loud murmur accompanied by a thrill.
Grade V defines a very loud murmur that can be heard with the stethoscope just touching the chest,
Grade VI represents an extremely loud murmur that is audible even without the stethoscope in contact with the chest.
B.1 Origin of Heart Murmurs. Diastolic Murmurs
List all Diastolic Murmurs
Aortic Regurgitation
Mitral Stenosis
Pulmonic Regurgitation
Tricuspid Stenosis
B.1 Origin of Heart Murmurs. Diastolic Murmurs
Aortic Regurgitation defintion
Caused by aortic valve failure, leading to backflow of blood from the aorta into the left ventricle during diastole.
B.1 Origin of Heart Murmurs. Diastolic Murmurs
Aortic Regurgitation murmur type
- Murmur Type: High-pitched, “blowing” diastolic decrescendo murmur.
- Location: Best heard at the base or left sternal border.
B.1 Origin of Heart Murmurs. Diastolic Murmurs
Aortic Regurgitation characteristics
Characteristics: Long diastolic murmur, associated with a hyperdynamic pulse and head bobbing in severe and chronic cases.
Pulse: Wide pulse pressure; can lead to heart failure (HF).
Causes: Bicuspid aortic valve, endocarditis, aortic root dilation, rheumatic fever (BEAR).
B.1 Origin of Heart Murmurs. Diastolic Murmurs
Aortic Regurgitation Intensity Modulation:
↑ Intensity:
- Preload (passive leg raising and squatting)
- Afterload (hand grip)
↓ Intensity:
- Preload (Valsalva maneuver)
- Venous return (inspiration)
B.1 Origin of Heart Murmurs. Diastolic Murmurs
Mitral Stenosis
Occurs when the mitral valve does not open fully, obstructing blood flow from the left atrium to the left ventricle during diastole.
Characteristics: Follows an opening snap (OS) due to abrupt halt in leaflet motion during diastole, occurring after rapid opening due to fusion at the leaflet tips.
Murmur Type: Delayed rumbling mid-to-late diastolic murmur, with the interval between S2 and OS indicating severity.
Complications: Chronic mitral stenosis can lead to pulmonary congestion/hypertension and left atrial (LA) dilation.
Causes: Often a late consequence of rheumatic fever.
Intensity Modulation:
- ↑ Intensity - increase Preload (passive leg raise and squatting)
- ↓ Intensity decrease Valsalva maneuver (decreases preload)
increase Venous return (inspiration)
B.1 Origin of Heart Murmurs. Diastolic Murmurs
Pulmonic Regurgitation
Similar to aortic regurgitation but involves the pulmonic valve, allowing backflow from the pulmonary artery into the right ventricle during diastole.
Murmur Type: Rare, soft, high-pitched, early diastolic decrescendo murmur.
Location: Best heard at the left upper sternal border.
Causes: Pulmonary hypertension (HTN), dilated cardiomyopathy (DCM).
Intensity Modulation:
- ↑ Intensity — increasse Venous return (inspiration)
B.1 Origin of Heart Murmurs. Diastolic Murmurs
Tricuspid Stenosis
The narrowing of the tricuspid valve impedes blood flow from the right atrium to the right ventricle during diastole.
Characteristics: Rare, mild mid-diastolic murmur with a rumbling quality, best heard over the left sternal border during tricuspid opening snap (OS).
Causes: Often due to rheumatic fever or infective endocarditis (IE) in intravenous drug users.
Intensity Modulation:
- ↑ Intensity: Increased venous return (e.g., inspiration)
-Known as Carvallo’s sign.
