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CardioPath E: Valvular Heart Disease, Endocarditis

Terms in this set (186)

Group A streptococci
What is the causative agent behind acute rheumatic fever (ARF)?
Children & young adults
In which group of people does ARF mainly occur?
No; pathogenesis is unknown
Does the pathogenesis of ARF involve direct bacterial infection of the heart?
Carditis; polyarthritis; Syndenham's chorea (involuntary movements); erythema marginatum (skin rash with advancing edge and clearing center); subcutaneous nodules
What are the major Jones criteria for ARF?
Migratory arthalgias; fever; increased acute phase reactants (ESR, leukocytosis); prolonged PR interval
What are the minor Jones criteria for ARF?
ARF
What was once among the most common causes of valvular heart disease?
Penicillin & less over-crowding
Why has the incidence of ARF waned considerably in the past half-century in industrialized society?
Developing countries in the Middle East, Southeast Asia, & Indian subcontinent
Which regions are still commonly afflicted with ARF?
3%
During epidemics, what percentage of patients with acute streptococcal pharyngitis develop ARF 2-3 weeks after initial throat infection?
10-30 years later
When does valvular dysfunction related to ARF typically manifest from onset of infection?
High dose aspirin to reduce inflammation, penicillin to eliminate residual streptococcal infection, and therapy for complications such as CHF and pericarditis
What are the general treatment principles of ARF?
Low-dose penicillin until young adulthood (~ age 30)
What does the prophylaxis of ARF typically involve?
Regurgitation
What could possibly acutely result from the valve inflammation caused by ARF?
Rheumatic heart disease
10-30 years after an episode of ARF, the valves are scarred and can be stenotic, regurgitant, or both.
ARF
What is the most common etiology of mitral stenosis (MS)?
50%
Approximately what percentage of patients with symptomatic MS provide a history of ARF?
Congenital malformation, calcification, and obstructive vegetations in endocarditis
Aside from ARF, what are some other etiologies of MS?
Elevated LA pressure; LAE
What changes in chamber size and pressure are expected in MS?
LAE (broad notched P in II, deep negative deflection of P in V1), RVH (if pulmonary HTN has developed); atrial fibrillation possibly present
List the ECG abnormalities associated with MS.
LAE, pulmonary vascular redistribution, interstitial edema, and Kerley B lines
List the CXR abnormalities associated with MS.
Edema within the pulmonary septae
What is the cause behind the presence of Kerley B lines on CXR of MS patients?
Dyspnea & reduced exercise capacity
What are the symptoms associated with mild MS?
Fever, anemia, hyperthyroidism, pregnancy, rapid arrhythmias (like atrial fibrillation), exercise, emotional stress, and sexual intercourse
What are some conditions that might exacerbate the symptoms of mild MS?
Dyspnea at rest, increasing fatigue, orthopnea, & PND
What are the symptoms associated with severe MS?
Pulmonary congestion
What is the cause behind orthopnea & PND in severe MS?
RHF signs (jugular venous distention, hepatomegaly, ascites, peripheral edema, & hoarseness)
What are the symptoms associated with advanced MS (concurrent with pulmonary HTN)?
Compression of recurrent laryngeal nerve by an enlarged PA or LA
What is the cause behind the hoarseness associated with advanced MS?
RV "tap"
What is revealed upon palpation of chest wall landmarks in MS?
Loud S1 at LSB
What alteration in heart sounds occurs in MS?
High AV pressure gradient keeps MV leaflets widely separated
What causes the loud S1 auscultated in MS?
High-pitched OS following S2
What additional heart sounds are auscultated in MS?
Tensing of leaflets and chordae tendineae
What is the cause behind the high-pitched OS in MS?
Inversely related; shorter interval means more severe MS because LA pressure is higher, causing the valve to open earlier
What is the relationship between S2-OS interval and the severity of MS and why is this the case?
Low-frequency decrescendo diastolic murmur at mitral area
Which type of murmurs are found in MS and where are they heard?
Turbulent flow across stenotic MV
What causes the diastolic murmur associated with MS?
Prolonged
What happens to the duration of the diastolic murmur as the severity of MS progresses?
Intensity increases; no increase in intensity for atrial fibrillation
What change occurs in the diastolic murmur of MS at the end of diastole as the LA contracts? How is this different when there is concurrent atrial fibrillation?
Increases it
How does tachycardia affect the intensity of the murmur in MS?
Echocardiography, CXR, & ECG
Which tests are useful in diagnosing MS?
Doppler echocardiography
Which diagnostic modality is used to determine mitral valve area?
4-6; < 2; < 1
What is the normal mitral valve area (in cm^2)? In mild MS? Severe MS?
50-60%
What is the 10 year survival rate of untreated symptomatic MS patients?
> 80%
What is the 10 year survival rate of asymptomatic or minimally symptomatic MS patients?
< 3 years
What is the average survival rate of MS patients that also present with pulmonary HTN?
RHF, pulmonary congestion without ventricular failure, atrial fibrillation (AFib), intra-arterial thrombi and emboli, infective endocarditis (IE), & hemoptysis
What are the complications associated with MS?
Prevent recurrent ARF in young patients and IE in all patients
What is the purpose behind antibiotic prophylaxis in MS patients?
Diuretics
What is used to treat the vascular congestion in MS?
Only if accompanied by LV contractile dysfunction or to slow ventricular rate with AFib
When is digoxin used in MS treatment?
β blockers or CCBs (verapamil or diltiazem)
What is used to slow the heart rate of MS patients?
AFib, concurrent CHF, or previous embolic episodes
When is anticoagulant therapy indicated for MS patients?
Mechanical correction (percutaneous balloon mitral valvuloplasty)
What treatment option is available for MS if symptoms persist despite diuretic therapy and control of rapid heart rates?
Open mitral commissurotomy or MV replacement (MVR)
What surgical methods can be used to treat severe cases of MS?
Structural abnormalities of mitral annulus, valve leaflets, chordae tendineae, or papillary muscles
What is the general etiology behind mitral regurgitation (MR)?
Mitral valve prolapse, IE, & hypertrophic cardiomyopathy
Which etiologies of MR primarily affect the mitral leaflets?
Ischemic heart disease & marked LVE
Which etiologies of MR primarily affect the papillary muscles?
IE & ARF
Which etiologies of MR primarily affect the chordae tendineae?
Marked LVE & mitral annulus calcification
Which etiologies of MR primarily affect the mitral annulus?
Myxomatous degeneration of the MV (mitral valve prolapse)
Enlarged, redundant leaflets bow excessively into the LA during systole.
Leaflet perforation; rupture of infected chordae
How does IE affect the mitral leaflets & chordae tendineae in MR?
Abnormal systolic motion of anterior leaflet
How does hypertrophic cardiomyopathy affect the mitral leaflets in MR?
Papillary muscles stretched too far apart; annulus stretched too far
How does marked LVE affect the papillary muscles & mitral annulus in MR?
Shortens chordae
How does ARF affect the chordae tendineae in MR?
Elevated LA pressure
What changes in chamber size & pressure are expected in acute MR?
LAE with less elevated pressure & LVE
What changes in chamber size & pressure are expected in chronic MR?
LAE & LVE
List the ECG abnormalities associated with MR.
Pulmonary edema
List the CXR abnormalities associated with acute MR.
LAE, LVE (no pulmonary congestion), may see calcification of mitral annulus
List the CXR abnormalities associated with chronic MR.
Dyspnea; severe cases: orthopnea & PND
What are the symptoms associated with acute MR?
Pulmonary congestion & edema
What is the cause behind dyspnea in acute MR?
Weakness and fatigue; AFib; increased abdominal girth & peripheral edema
What are the symptoms associated with chronic MR?
Decreased forward CO
What is the cause behind weakness & fatigue in chronic MR?
LAE
What is the cause behind AFib in chronic MR?
RHF
What is the cause behind increased abdominal girth & peripheral edema in chronic MR?
Apical impulse often laterally displaced toward axilla due to LVE
What is revealed upon palpation of chest wall landmarks in MR?
Possible S3
What additional heart sounds occur in MR?
Increased volume return in early diastole
Why might an S3 be auscultated in MR?
Holosystolic murmur at mitral area
Which type of murmurs may be heard in MR and where are they heard?
Axilla
Where does the murmur associated with MR typically radiate to?
Have patient clench fist (increase SVR) which intensifies MR murmur but not AS murmur
How does one differentiate between the murmur of aortic stenosis (AS) & that of MR?
CXR, ECG, echocardiography, & catheterization
Which tests are useful in diagnosing MR?
Echocardiography
Which diagnostic measure is useful for MR because it can identify the structural cause and grade severity of regurgitation, along with assessing LV size?
Catheterization
Which diagnostic measure is useful for MR because it can identify the ischemic cause and grade severity of regurgitation?
Depends on underlying cause
What primarily determines the natural course of MR?
Increase CO while reducing regurgitation and relieving pulmonary congestion
What are the general treatment principles for MR?
IV diuretics (edema) and vasodilators (reduce resistance, ↑ CO)
What is the treatment plan for acute MR with heart failure?
Arteriolar vasodilators like ACE inhibitors or hydralazine
What is the treatment plan for chronic MR?
MV replacement or repair (preferred)
What are the surgical options for treating MR and which is preferred?
May be inherited as autosomal dominant trait but is commonly associated with CT diseases
What is the cause behind mitral valve prolapse (MVP)?
Characteristic murmur & Echo (CXR & ECG normal)
How is diagnosis of MVP typically made?
Midsystolic click with late systolic murmur; apex to axilla
What is the auscultatory finding associated with MVP and where does it radiate to?
Increased LV volume delays click & murmur
How does sudden squatting alter the murmur associated with MVP?
Decreased LV volume hastens click & murmur
How does sudden standing alter the murmur associated with MVP?
Age-related or congenital-related calcific changes of aortic valve; rheumatic AS is rare
What are the common etiologies of aortic stenosis (AS)?
LV concentric hypertrophy; LAH; dilation of proximal aorta
What changes in chamber size & pressure are expected in AS?
100
In advanced AS, pressure gradients > ____ mmHg between the LV and aorta are common.
LVH (advanced AS)
List the ECG abnormalities associated with AS.
Angina, exertional syncope, & CHF
What are the symptoms associated with AS? Note: patient may be asymptomatic for years
Increased myocardial O2 demand from hypertrophy and ↑ wall stress
What is the cause behind angina in AS?
CO cannot be increased to compensate exertion
What is the cause behind exertional syncope in AS?
LV develops contractile dysfunction, which elevates LA & eventually pulmonary pressure
What is the cause behind CHF in AS?
Onset of symptoms
At what point in the course of AS is there a significantly decreased survival unless it is surgically corrected?
None
What is revealed upon palpation of chest wall landmarks in AS?
Paradoxical splitting
What alteration in heart sounds occurs in AS?
S4 gallop (advanced AS)
What additional heart sounds may be heard in AS?
Crescendo-decrescendo systolic ejection murmur at aortic area
Which type of murmurs are associated with AS and where are they heard?
Echo, ECG, & catheterization
Which tests are useful for diagnosing AS?
57%
What is the 1-year survival rate of AS patients that did not have surgery?
20%
What percentage of mild, asymptomatic AS will progress over 20 years?
Aortic valve replacement, antibiotic prophylaxis (endocarditis), avoid hypotension
What are the general treatment principles of symptomatic (advanced) AS?
None
List the CXR abnormalities associated with AS.
Diseases of aortic leaflets & dilation of aortic root
What are the general etiologies of aortic regurgitation (AR)?
Rheumatic, endocarditis, congenital
Which etiologies of AR affect the aortic leaflets?
Aneurysm/dissection, annulo-aortic ectasia, Marfan, Syphilis
Which etiologies of AR cause dilation of the aortic root?
LV diastolic pressure rises substantially and transmits to LA & pulmonary circulation
What changes in chamber size & pressure are expected in acute AR?
LV volume & pressure increase (dilation & hypertrophy); drop in aortic diastolic pressure; increased systolic arterial pressure (increases SV)
What changes in chamber size & pressure are expected in chronic AR?
Angina, dyspnea & extensive rales
What are the symptoms associated with acute AR?
Pulmonary edema
What causes the extensive rales in acute AR?
Angina, fatigue, decreased exercise tolerance, forceful heart beat with high pulse pressure, exertional dyspnea
What are the symptoms associated with chronic AR?
Bounding pulses, enlarged and displaced apical impulse
What is revealed upon palpation of the chest wall landmarks in chronic AR?
Chronic >> acute
Compare the pulse pressure of acute & chronic AR.
Widened pulse pressure
What is the hallmark physical finding of AR?
Bisferiens pulse & systolic murmur at aortic area (even without AS)
What alteration in heart sounds occurs with an increased SV in chronic AR?
Ejection click
What additional heart sounds occur in AR?
Bicuspid aortic valve and/or aortic dilation
What causes the ejection click in AR?
Diastolic decrescendo murmur at LSB; systolic murmur at aortic area; severe AR: Austin-Flint murmur
Which type of murmurs are associated with AR and where are they heard?
AR has no OS nor presystolic increase in intensity
How do you differentiate a diastolic decrescendo murmur associated with AR from one caused by MS?
Patient leaning forward, after exhaling
In what position is the systolic murmur in AR best heard?
Austin-Flint murmur
Apical diastolic rumbling due to preclosure of anterior leaflet of mitral valve.
Pulmonary congestion
List the CXR abnormalities associated with acute AR.
LVE
List the CXR abnormalities associated with chronic AR.
CXR, Echo, & angiogram
Which tests are useful in diagnosing AR?
Echo
Which diagnostic modality helps identify and quantify AR along with its cause?
Angiogram
Which diagnostic modality helps evaluate LV function, quantify regurgitation, & assess possible CAD in AR?
60%
What percentage of asymptomatic cases of AR remain asymptomatic after 10 years?
4 years
What is the mean survival rate of AR patients who present with angina?
2 years
What is the mean survival rate of AR patients who present with CHF?
Periodic assessment of LV function, endocarditis prophylaxis
What is the treatment method for asymptomatic AR?
Diuretics & vasodilators; nifedipine
What is the treatment for symptomatic AR without LV dysfunction?
Surgery (valve replacement)
What is the treatment for severe chronic AR or persistent LV dysfunction (despite symptomatic treatment)?
Usually rheumatic heart disease
What is the etiology of tricuspid stenosis (TS)?
RAE & increased RA pressure
What changes in chamber size & pressure are expected in TS?
OS
What additional heart sounds are heard in TS?
Diastolic murmur at tricuspid area that intensifies with inspiration
Which type of murmurs are associated with TS and where are they heard?
Fatigue from a low SV
Patients with TS have MS, therefore, symptoms of TS are relative to both lesions. What is the major symptom that can be produced by both and what is it caused by?
Abdominal distention & hepatomegaly
What are the exclusive symptoms of TS (not caused by concurrent MS)?
RV enlargement
What is the etiology of functional tricuspid regurgitation (TR)?
Rheumatic, congenital, trauma, acquired causes (IE), carcinoid syndrome
What are the common etiologies of structural TR?
RAE & RVE
What are the chamber volume & pressure changes expected in TR?
Prominent v wave
List the ECG abnormalities associated with TR.
Pulsatile liver
What results from regurgitation of blood through systemic veins in TR?
Pansystolic murmur at tricuspid area (accentuated by inspiration)
Which type of murmurs are associated with TR and where are they heard?
Doppler Echo
Which diagnostic modality is used to detect and quantify TR?
Enlarged PA dilates the valve annulus
How does severe pulmonary HTN result in pulmonary regurgitation (PR)?
After pulmonary valvotomy in CHD; dilated PA; IE
What are the common etiologies of PR in cases of normal pulmonary artery pressure?
High-pitched decrescendo diastolic murmur that is indistinguishable from AR
Which type of murmur is associated with PR that results from pulmonary HTN?
Low-pitched decrescendo diastolic murmur that ends early in diastole
Which type of murmur is associated with PR in cases of normal PA pressure?
Infective Endocarditis (IE)
Infection of the endocardial surface of the heart, including the cardiac valves, by microbial organisms.
By clinical course (acute/subacute); host substrate (native/prosthetic valve, IV drug abuse); the specific infecting microorganism
What are the three ways by which IE is classified?
Endocardial surface injury; thrombus formation at the site of injury; bacterial entry into circulation; bacterial adherence to injured endocardial surface
What are the conditions required in the pathogenesis of endocarditis?
Fibrin-platelets provide a surface for adherence, then cover and protect adherent organisms
Why is thrombus formation at the site of injury necessary for the pathogenesis of IE?
They cause hemodynamic abnormalities such as turbulent blood flow & endothelial injury
Why are the predisposing lesions of IE more commonly affected?
Rheumatic valvular disease; acquired valvular lesions (calcific AS, AR, MR, MVP); hypertrophic obstructive cardiomyopathy; CHD (VSD, PDA, ToF, COARC, bicuspid AV, PS); surgically implanted intravascular hardware (prosthetic heart valves, P-S vascular shunts, ventriculo-atrial shunts for hydrocephalus); previous episode of endocarditis
What are the lesions that predispose patients to IE?
Streptococci, staphylococci, & other organisms (e.g. gram negatives)
What are the general groups of causative agents for IE?
In an environment favorable to infection (valvular dysfunction or prosthetic valves); bacteremia caused by dental procedures; IVDA (intravenous drug abuse)
In which circumstances is IE likely to occur?
Mechanical cardiac injury; thrombotic or septic emboli; immune injury mediated by Ag-Ab complex deposition
What complications may accompany IE?
100%
What is the fatality rate of IE that is not treated by antibiotics?
20-25%
What percentage of patients have a 6-month fatality in IE despite antibiotic treatment?
An explosive and rapidly progressive illness with high fever and shaking chills; Osler nodes, splinter hemorrhages, Janeway lesions, & Roth spots
What are the clinical manifestations of acute IE?
Predisposing or new murmur
What might cardiac exam reveal in the event of acute IE?
Low-grade fever often accompanied by nonspecific constitutional symptoms like fatigue, anorexia, weakness, myalgia, and night sweats; Osler nodes, splinter hemorrhages, Janeway lesions, Roth spots
What are the clinical manifestations of subacute IE?
Flu or URTI
What can a subacute IE be easily mistaken for?
Subacute
Are murmurs more common in acute or subacute IE?
Right-sided valvular lesions
What are the clinical manifestations of IVDA IE?
ECG
Which diagnostic modality helps identify extension of infection into the cardiac conduction system in IE (various degrees of heart block or new arrhythmias)?
Echo
Which diagnostic modality helps visualize vegetations, valvular dysfunction, & associated abscess formation in IE?
Transesophageal Echo (TEE)
Which type of Echo is useful for visualizing small vegetations?
TEE
Which type of Echo is more sensitive, TEE or transthoracic Echo (TTE)?
TEE
Which type of Echo is used to investigate IE in prosthetic valves?
TTE
Which type of Echo is useful for visualizing large & right-sided vegetations?
TTE
Which type of Echo is noninvasive and easy to obtain?
Specificity for vegetations high, but sensitivity < 60%
Briefly describe the specificity & sensitivity of TTE.
Helps identify offending microorganism
How does a blood culture help in the diagnosis of IE?
95%
How often is a microbe identified upon blood testing in IE?
Endocarditis prophylaxis
Administration of specific antibiotics before procedures to eliminate bacteremia in susceptible individuals (those with underlying structural heart disease).
Dental work, bronchoscopy or URT surgery, GU procedures, & GI surgery
Which type of people should be considered for endocarditis prophylaxis?
TEE
Which diagnostic modality is best for determining cardiac involvement in patients with unexplained persistent fever with or without positive blood cultures?
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