Ch.18 - Valvular Heart Disease

Overview of heart valve disorder

• Valves allow a one way flow through the heart, but injury or damage can affect this flow

• mild, asymptomatic to lethal

• turbulent flow heard with ascultation

• increased risk of clot formation due to blood pooling - anticoagulants needed

• site for infection - prophylactic antibiotics

Causes of valve disease

• Rheumatic fever

  • acute streptococcal infection leading to rheumatic heart disease

  • takes decades to develop and present symptoms

  • antibiotic usage to treat streptococcal infection reduces RHD incidence

• congenital defect

• MI

• arteriosclerosis

• aging

• Mitral valve prolapse - common, often asymptomatic

Types of valves in the heart

Atrioventricular valves

• tricuspid, between RA and RV

• bicuspid (mitral), between LA and LV

• has chordae tendinae and papillary muscles

Semilunar valves

• pulmonary = between RV and pulmonary trunk

• aortic = between LV and aorta

Toilet Paper My Ass

Heart sounds

• First: S1, “lub”

  • closure of AV valves

  • close at beginning of systole, open during diastole

• Second: S2, “dub”

  • closure of semilunar valves

  • close at beginning of diastole, open during systole

• Split of S2 sound - “A2 and P2”

  • aortic valve closes first, followed by pulmonary valve

• Third: S3

  • vibration of flow from atria to ventricles

  • normal in children, young adults

  • in older adults, may occur in heart failure “S3 gallop”

• Fourth: S4

  • usually not present in healthy individuals

  • occurs when LA contracts against stiff, noncompliant LV

Ascultation location of all 4 valves

• Mitral: apex of heart at 5th intercostal space, midclavicular line

• Tricuspid: left sternal border, 4th intercostal space

• Pulmonic: left sternal border, base of heart at 2nd intercostal space

• Aortic: right sternal border, 2nd intercostal space

Heart murmurs

• sound transmitted through chest wall d/t turbulent flow

• Physiologic: can be innocent or functional

  • heard during states of high blood flow in heart (anxiety, fear, pregnancy)

  • usually no symptoms

• Pathologic: caused by valve deformity/dysfunction

  • may result in hemodynamic consequences

  • medical intervention needed

Types of valve dysfunctions

Stenosis: stiff; narrowed valve opening

• high resistance to flow through narrowed opening

• inefficient movement of blood forward, results in excess blood being left behind

Regurgitant (insufficiency): leaky; loose valve that does not seal properly

• less forward ejection, blood going backwards

Pathological consequences of valve dysfunctions

• dysrhythmias: disruption of conduction system due to overstretching of heart chambers

• thrombus formation: turbulent and static blood flow that increases clot risk

• stroke: due to elevated risk of thrombus formation

• MI and heart failure: myocardium hypertrophy increase risk for ischemia and infarction

How to assess for valve dysfunction (Take history of…)

• Rheumatic fever in childhood that presents as RHD in adultfood

• MI of inferior wall

• myxomatous degeneration: weakening of connective tissue of mitral valve

• arteriosclerotic calcification of valve (aortic sclerosis)

Physical assessment of valve disorder invovles…

• inspect anterior chest: apical pulse

• palpation to detect cardiac thrills

• stethoscope

  • diaphragm for high pitched sounds

  • bell for low pitched sounds

• murmurs may echo and radiate

What is the GOLD standard for diagnosis of valve disorders?

Echocardiogram!!

• Transthoracic echocardiography (TTE): noninvasive, transducer placed on chest well

• Transesophageal echocardiography (TEE): transducer inserted into esophagus, more sensitive than TTE

• Doppler echocardiography: sound waves to measure velocity of blood flow across valves and chambers; can be colorized

Patients with valve disorders may need annual echocardiograms

Pharmacological treatments for valve disease

• nitrates for vasodilation, reducing ischemic chest pain

• beta adrenergic blockers: decrease HR, peripheral resistance

• anticoagulants: reduce clot risk

• diuretics: reduce blood volume overload

• antibiotics: prophylactic may be needed

Surgical treatments for valve disorders

• valvotomy - not practical

• valvuloplasty - Percutaneous balloon valvuloplasty: opening stenosed valve; think 360 degree stretch of T-shirt

• valve replacement

  • bioprosthetic: porcine, bovine, human cadaver

    • less durable, but anticoagulants not necessary

  • mechanical: lasts longer, but anticoagulants necessary

• can be open heart, or invasive percutaneous

What does Mitral Stenosis develop from?

• common after RF

  • RHD developed around age 30 - 40

• mitral annular calcification (MAC) associated with aging, atherosclerosis

  • few symptoms, often incidental discovery on chest X-ray

Pathophysiology of Mitral stenosis

• blood flow from LA to LV is reduced, resulting in overload of LA and decreased CO into LV

• murmur: heart apex, diastolic

  • low pitched rumble

  • left lateral decubitus position accentuates murmur

  • opening snap: rigid mitral valve opening

• fluid may back up from LA into lungs causing pulmonary edema

• causes increased risk of Afib and stroke d/t stretching and blood pooling

• CLINCIAL PRESENTATION: dyspnea with exertion, PND, orthopnea

Diagnosis and treatment for Mitral stenosis

Diagnosis: TTE, TEE, ECG, chest x-ray

• needed to stage severity

Treatment: anticoagulants, diuretics, beta blockers, prosthetic valve transplant, prophylactic antibiotics

Pathophysiology of mitral insufficiency (regurgitation)

1. mitral valve does not close properly

2. murmur: holosystolic murmur heard at apex that radiates into axilla because blood leaks through improperly closed MV throughout systole

3. portion of blood moves from LV into LA

4. decreased blood for coronary circulation

Can happen post-MI due to papillary muscle damage

• often asymptomatic, asses with echocardiography

Causes of mitral insufficiency

• mitral valve prolapse: mild, asymptomatic

• rheumatic heart disease

• infective endocarditis

• stimulant drugs

• myxomatous degeneration

• mitral annular calcifications

• Marfans and Ehlers-Danlos syndromes - connective tissue problems

Clinical presentations of mitral insufficiency

• may be asymptomatic

• severe chest pain due to ischemia

• exercise intolerance

• pulmonary symptoms due to fluid back up in lungs - hearing crackles, orthopnea, PND

• Afib

• diminished S1 sound as leaflets don’t close

Diagnosis and treatment for mitral insufficiency

Diagnosis: ECHOCARDIOGRAM, ECG, chest x-ray

• severity based on LV EF, volume regurgitated into LA, pulmonary artery pressure

Treatment:

• medications: ACE inhibitors, ARBs, beta blockers, diuretics

• surgical: repair rather than prosthetic

• mitral clip: implanted into heart to mechanically close mitral valve leaflets

Aortic Stenosis - characteristics and causes

Aortic valve doesn’t open all the way so it is difficult for LV to eject blood due to increased resistance, leading to LVH

• causes:

  • aortic sclerosis: calcification of aortic valve in the elderly most common cause

  • RHD

  • congenitcal valve defect

• symptoms occur when valve area is less than 1 cm

SXS of aortic stenosis

• exertional dyspnea

• pulmonary edema as blood backs up from LV to LA into pulmonary circulation

• angina pectoris d/t poor oxygenation

• heart palpitations, dysrhythmias

• fatigue, lightheadedness

• murmur: systolic, crescendo, low pitched

  • 2nd intercostal space

  • systolic thrill may be present

Diagnosis and treatment of aortic stenosis

Diagnosis: severity based on aortic transvalvular pressure and LVEF

Treatment: valve replacement, biophosphates can help decrease calcification of valves and transfer into bones

What is hypertrophic cardiomyopathy?

When interventricular septum of LV is enlarged, which inhibits ejection of LV blood

• genetic disorder, HTN where enlarged LV compromises functioning of aortic and mitral valves

• diamond shaped systolic murmur

Complications of hypertrophic cardiomyopathy

increased risk for both atrial and ventricular dysrhythmias

• Afib

  • PVCs - premature ventricular contractions

  • non sustained ventricular tachycardia - ventricles pump fast, sudden, then return to normal

• can cause sudden death, especially due to ventricular dysrhythmias

  • think football player that dies

Diagnosis and treatment of hypertrophic cardiomyopathy

Diagnosis: echocardiography

Treatment

• avoid strenuous exercise

• beta blockers

• calcium channel blockers

• surgical removal of excess tissue

• percutaneous transluminal septal myocardial ablation

• valve replacement and pacemaker (for dysrhythmias) may be needed

Aortic insufficiency characteristics, causes, diagnosis, treatments

• deformed aortic valve does not close properly, causing backflow of blood from aorta into LV (can affect mitral valve)

  • dilation and decreased contraction of LV

  • backup of blood into pulmonary circulation

• Caused by RHD, endocarditis, Marfan’s, ankylosing spondylitis

• high pitched murmur heard

  • Austin Flint murmur may be present in severe cases

• may be visible through chest wall if skinny skinny

Diagnosis: echocardiography

treatment: aortic valve replacement