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What is the first heart sound (S1) associated with?
- Closure of the AV valves at the beginning of systole
- Mitral and tricuspid
- R-wave on EKG
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What is the second heart sound (S2) associated with?
- Closure of the semilunar valves at the end of systole
- Aortic and pulmonic
- End of QRS complex
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What is the third heart sound (S3) associated with?
- Blood entering and distending a relatively noncompliant LV
- Ventricular diastolic gallop indicates significant LV dysfunction and may be the first sign of CHF
- Weak rumble heard during the second 1/3 of diastole
- Corresponds to T-wave
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What is the 4th heart sound (S4) associated with?
- Late diastolic atrial contraction causes a rushing of blood into ventricles
- Almost never heard with stethascope except in hypertensive patients with a thick LV
- Corresponds to P-wave
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What anitomical location are S3 and S4 heard?
Apex of the heart
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What are the 4 main causes of murmurs?
- 1) Rheumatic fever
- 2) Bacterial endocarditis
- 3) Congenital defects
- 4) Degenerative defects
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What leads to the greatest number of valvular lesions?
Rheumatic fever
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What is the organism responsible for rheumatic fever?
Group A hemolytic streptococci
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What is the mechanism by which group A strep. causes valvular lesions?
Typically initiates an antibody response which can persist up to 1 year. This ultimately leads to autoimmune/immunologic damage
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What valves are most frequently affected by rheumatic fever?
- MV most frequently
- AV second most frequently
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What are typical causes of bacterial endocarditis?
- 1) IV drug abuse
- 2) Dental decay
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What are 2 congenital defects of valves that may cause murmurs?
- 1) Stenosis
- 2) Lack of 1 or more leaflets; congenital bicuspid AV
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What type of defect would calcific aortic stenosis be?
Degenerative defect
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What are pressure overload lesions caused by?
Stenotic valves
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What are volume overload lesions caused by?
Regurgitant valves
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What type of murmur is produced by AS?
- Systolic ejection murmur that may be transmitted into the neck
- "Woosh-dub"
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What is the normal area of the AV?
2.5-3.5cm2
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What are criteria for surgical repair of AS?
- 1) Pressure gradient >50mmHg or
- 2) Valve area <1cm2
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How high may LV pressure be in severe AS? What about aortic root pressure?
LV pressure may be as high as 300mmHg with normal aortic root pressure
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What type of LV changes may be caused by AS?
Concentric LV hypertrophy as sarcomeres are added in parallel
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Angina pectoris, DOE, and syncope are the classic triad of what valvular lesion?
Aortic stenosis
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What is the life expectancy without surgery of a patient presenting with aortic stenosis?
5 years
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What type of lesion is AS?
Pressure overload
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How do you manage hypotension in a patient with aortic stenosis?
Neosynepherine or vasopressin; increasing contractility will not increase BP due to stenotic, small orifice in AS
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What happens to SV in AS?
Net SV is reduced
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What type of murmur is AR?
- "Blowing" murmur of relatively HIGH PITCH with swishing quality
- Heard maximally over LV during diastole
- "lub-woosh"
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What is especially important regarding a short duration blowing murmur over the LV during diastole?
Severe aortic regurgitation - blood is flowing back rapidly into LV
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What happens with SV during AR?
Decreased net stroke volume as a large amount of blood immediately rushes back into the LV
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What type of LV changes may be caused by AR?
Eccentric hypertrophy (big floppy heart) as sarcomeres are added in series
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What type of LV change may lead to some signs and symptoms of IHD? Why?
- Eccentric hypertrophy, seen in AR.
- s/s of IHD because the thin LV wall allows compression of endocardium/subendocardial arteries during LV filling
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What type of lesion is AR?
Volume overload
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What type of murmur is MR?
- High-pitched blowing murmur heard throughout systole (holosystolic)
- Transmitted strongly to the LA, but LA is deep in the chest and difficult to hear the murmur
- "Woosh-lub" that is less harsh than AS
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Where is MR best heard?
Apex of the heart
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What valvular lesion allows blood from LV to be ejected back into the LA during systole?
MR
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What is the cause of atrial fibrillation and pulmonary edema due to heart valve problems?
Increased LA pressures
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What type of lesion is MR?
Volume overload
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What will happen with PA and PCWP during MR?
They will be elevated
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What are associated characteristics of acute MR?
- 1) Papillary muscle rupture/ischemia due to LAD infarction
- 2) High LA pressure
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What are associated characteristics of chronic MR?
- 1) Rheumatic fever
- 2) Bacterial endocarditis
- 3) Increased likelihood of A-fib
- 4) Dilated LA with normal pressure
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What type of murmur is MS?
- Described as a low rumbling "thrill" heard during last 1/3 of diastole over the apex of the heart
- "Kentucky" - "lub-dub-purr"
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What is the normal MV orifice area?
4-6cm2
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At what change of MV opening do patients typically become symptomatic in MS?
50% decreased orifice size
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MS causes what change in LVEDP? Why?
Decreased LVEDP because flow from LA to LV is decreased
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MS can result in what changes in the pulmonary system? How does this affect the RV?
May result in decreased pulmonary compliance causing increased RV pressures and subsequent RV failure
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What physiologic changes occur to the LV as the result of MS?
- None, the LV is normal
- CO and MAP do not decrease nearly as much as with AS
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What type of lesion is MS?
Pressure overload
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What valvular lesions cause a net reduced movement of blood from LA to LV?
MS and MR
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What congenital abnormalities are outflow obstructions?
- 1) Coarctition of the aorta
- 2) Pulmonic stenosis
- 3) Aortic stenosis
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What congenital abnormalities cause left-to-right shunting?
- 1) ASD
- 2) VSD
- 3) PDA
- TOF and hypoplastic left heart are congenital abnormalities causing what type of shunting?
- Right-to-left
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What are examples of "cyanotic" heart defects?
- Any abnormality causing a right-to-left shunt
- 1) TOF
- 2) Hypoplastic left heart
- 3) Tricuspid atresia
- 4) Transposition of the great vessels
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What are examples of "acyanotic" heart defects?
- 1) ASD
- 2) VSD
- 3) PDA
- 4) Coarctition of the aorta
- 5) Pulmonic stenosis
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What makes a PDA a left-to-right shunt?
- Blood flows from left side to right side of heart, bypassing systemic circulation
- Will see an increase in PA pressures
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What is the murmur of PDA?
Machinery murmur more intense during systole, less intense during diastole. Waxes and wanes with each heartbeat
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What congenital heart defect can lead to recirculating of blood through lungs? What can this cause?
- PDA; can cause decreased respiratory reserve and pulmonary edema
- Increased pulmonary flow can lead to RV hypertrophy
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What is the treatment for PDA?
For babies, indomethacin or surgical ligation
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What is the frequent cause of ASD?
Failure of the foramen ovale to close
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What is the prevalence of ASD?
About 1/3 of the population has ASD, but increased LA pressures force it close and many people are asymptomatic
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What is the murmur of ASD?
Systolic murmur over pulmonic valve that is very mild and often not detected
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What frequently undiagnosed congenital heart defect can lead to MI or CVA in the event of a venous air embolism (VAE)?
- ASD; air can shunt to arterial circulation
- What are the 3 variations of ASDs?
- 1) Ostium secundum
- a. About 75% of all ASDs
- 2) Ostium primum
- a. Endocardial cushion defect
- 3) Sinus venosus
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What EKG changes may be seen as the result of ASD?
Right axis deviation and RBBB
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What arrhythmias are associated with ASD?
a-fib and SVT
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What may be seen on a chest X-ray in a patient with ASD?
Prominent pulmonary arteries due to left-to-right shunting increasing pulmonary flow
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What is the most common congenital heart defect?
25-35% of congenital heart disease
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What congenital heart defect usually spontaneously closes by the age of 2?
VSD
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What is the murmur of VSD?
- Holosystolic murmur at the left sternal border is heard UNLESS the hole is closed during contraction
- Small VSDs may not produce a murmur
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How can a VSD go from left-to-right shunting to right-to-left shunting?
- Early pathophysiologic changes reflect increased pulmonary flow. With chronic increases of pulmonary flow, PVR may become > SVR reversing the shunt
- When a VSD is chronic, it becomes a cyanotic defect due to right-to-left shunting
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What is unique of CXR and EKG with small VSD?
They are normal
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What physiologic changes are seen with moderate to large VSD?
LA and LV enlargement
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What EKG changes are seen with VSD causing pulmonary hypertension?
- Right axis deviation
- Lead I - Lead aVF +
- this indicates RA and RV enlargement
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What congenital heart defect is the most common "cyanotic" defect?
TOF
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What 4 anatomical defects characterize TOF?
- 1) Aortia originates from RV instead of LV or overrides the septum
- 2) PA stenosis causes preferential flow from the RV through the path of least resistance which is the VSD to the aorta
- 3) VSD
- 4) RV hypertrophy secondary to increased afterload of both pulmonary stenosis and systemic afterload
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What is the usual treatment for TOF?
Surgical repair
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What diagnostic tools are available to identify murmurs?
- 1) Stethascope or phonocardiogram
- 2) EKG to identify hypertrophic axis deviation
- 3) Echocardiography
- 4) Chest radiography
- 5) Cardiac catheterization
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