Cardiac Cycle & Heart Sounds

Question 1

What is a Murmur?

Answer 1

Sound produced when the flow of blood through a valve is TURBULENT or DISRUPTED.

Occurs when valve is non-compliant, incompetent, stiff or damaged.

Concerning when associated with symptoms.

Evaluate with Echocardiogram.

Question 2

What are the 4 heart sounds and their associated events?

Answer 2

S1 “Lub” - Closure of AV Valves

S2 “Dub” - Closure of the Semilunar Valves

S3 “Ken-tuckee” - Vibratory sound that occurs from blood filling the relaxed and empty ventricle. NORMAL IN KIDS. PATHOLOGY IN ADULTS - CHF, Cardiomyopathy with stiff ventricular walls.

S4 “Tenness-ee” - Atrial filling from high pressure from SVC/IVC and pulm venous return - occurs BEFORE S1 heart sound.

Question 3

What is Regurgitation? Stenosis?

Answer 3

Regurgitation - Turbulent Flow Sound - Blood moving OPPOSITE direction.

Stenosis - Turbulent Flow - Blood moving through a stiff, damaged valve.

Question 4

How are murmurs identified in the Cardiac Cycle?

Answer 4

Timing in the Cardiac Cycle

• Systolic Murmur - ventricular systole
• Diastolic Murmur - ventricular diastole

Question 5

What are the 6 Heart Murmur Grades?

Answer 5

1 - Soft Murmur, Quiet Surrounding
2 - Soft Murmur, Noisy Surrounding

3 - Prominent heard murmur

4 - Loud Murmur PLUS THRILL
5 - Loud murmur heard with edge of steth tilted against chest PLUS THRILL
6 - Loud Murmur Heard 5-10 mm from chest PLUS THRILL

Question 6

In general, which portions of the respiratory cycle increase murmur sounds on the left and right of the heart?

How does Preload affect heart murmurs?

Answer 6

Inspiration - Increases murmur RIGHT
RINspiration (Tricuspid & Pulmonic)

Expiration - Increases murmur LEFT
LEXpiration (Mitral & Aortic)

Preload

• Increasing preload - louder murmur
• Decreasing preload - softer murmur

Question 7

Which 2 conditions IMPROVE with INCREASED PRELOAD?

Answer 7

1. HOCM (Hypertrophic Obstructive Cardiomyopathy)

2. MVP (Mitral Valve Prolapse)

Question 8

How do changes in afterload affect murmurs?

Answer 8

Increased afterload = louder murmur

Decreased afterload = softer murmur

Question 9

Which 2 conditions IMPROVE with INCREASED afterload?

Answer 9

1. HOCM (Hypertrophic Obstructive Cardiomyopathy)

2. MVP (Mitral Valve Prolapse)

Question 10

Most likely case presentation for:

1. Aortic Stenosis Murmur
2. Mitral Regurgitation
3. Tricuspid Regurgitation
4. Aortic Regurgitation
5. Mitral Stenosis

Answer 10

1. Calcified aortic valve and radiates UP to carotids
2. Rheum-mitral, radiates to axilla, holosystolic murmur, best heard at apex
3. Holosystolic and history of IVDA (Intravenous drug abuse)
4. Early blowing diastolic murmur; connective tissue disorders, Marfan’s, “Head-bobbing”, Water-Hammer pulse, Femoral Bruits.
5. History of rhemuatic fever. Opening Snap (OS) after S2 and prior to S1.

Question 11

What is the indication for HOCM (Hypertrophic Obstructive Cardiomyopathy)?

Answer 11

Family history of sudden cardiac death at a young age.

Question 12

What are the indications for a Mitral Valve Prolapse?

Answer 12

• Clinical presentation of a young woman with a psychiatric history
• Myxomatous Valvular disease