580 likes | 974 Views
Valvular Heart Disease. J.B. Handler, M.D. Physician Assistant Program University of New England. VHD- valvular heart disease RF- rheumatic fever MR- mitral regurgitation AR- aortic regurgitation HF- congestive heart failure MS- mitral stenosis LAP- left atrial pressure
E N D
Valvular Heart Disease J.B. Handler, M.D. Physician Assistant Program University of New England
VHD- valvular heart disease RF- rheumatic fever MR- mitral regurgitation AR- aortic regurgitation HF- congestive heart failure MS- mitral stenosis LAP- left atrial pressure PuVR- pulmonary vascular resistance RV- right ventricle CO- cardiac output TR- tricuspid regurgitation PI- pulmonic insufficiency NSST-T- non specific ST-T PAH- pulmonary artery hypertension SV- stroke volume RVH- right ventricular hypertrophy AoV- aortic valve MVA- mitral valve area PSVT- paroxysmal supraventricular tachycardia MVR- mitral valve replacement MVP- mitral valve prolapse AS- aortic stenosis SEM- systolic ejection murmur LVEDP- left ventricular end diastolic pressure PND- paroxysmal nocturnal dyspnea LSB- left sternal border ACE- angiotensin converting enzyme BE- bacterial endocarditis RF- rheumatic fever Abbreviations
Etiologies of VHD • Rheumatic valve disease • Congenital, including bicuspid aortic valve. • Coronary heart disease: MI, papillary muscles • Dilation of the aorta: Aortic root disease • Chronic “wear and tear”: aortic sclerosis/stenosis • Dilation of the LV- from any cause: MR • Endocarditis • MV prolapse • Others
Acute Rheumatic Fever: IO • 2/3 all cases - developing countries • Episodes of RF are quite uncommon in U.S., except in immigrants. • Epidemiology - Identical to that of Group A Streptococcus; children 5-15 • Pathogenesis- oropharyngeal infection; RF follows the sore throat; usually within 2-3 wks. • Mechanism - systemic immune process involving Group A strep. antigens; abnormal immune response. Preventable with adequate Rx of streptococcal pharyngitis. IO – Interest Only
Diagnosis - Jones Criterion • Carditis - Pancarditis involving valves, endocardium, myocardium and pericardium • Healing of Rheumatic valvulitis - fibrous thickening resulting in valvular stenosis or insufficiency • Migratory polyarthritis • Sydenham’s Chorea • Subcutaneous nodules • Erythema marginatum
Treatment • Antistreptoccal Rx until regimen finished; Penicillin IM or oral (10 day course)Erythromycin and others are alternatives • Arthritis/fever - Salicylates • Severe carditis- Glucocorticoids • HF, MR, AI - specific Rx. • Secondary prophylaxis to prevent recurrences- PCN or alternative until adult.
Cardiac Pressures 4-12 4-12 4-12 4-12 8-15 4-12 4-12 Images.google.com
Mitral Regurgitation-Etiology • Chronic Rheumatic heart disease- ing frequency • LV dilatation from any cause • Coronary Heart Disease: Papillary muscle dysfunction with ischemia/infarction • Mitral Valve Prolapse • Infective endocarditis
Mitral Regurgitation Images.google.com
Pathophysiology of MR • Blood regurgitates from LV into LA. • LV volume increases progressively as severity of MR increases. • Increased blood return to LA: pulmonary veins + regurgitant volume from previous beat. • LV function- well preserved initially; often deteriorates in later stages as does cardiac output (CO). LV compensates for volume overload via the Starling mechanism. • Left atrium (and LV) dilates over time - LAP and LVEDP gradually risepulmonary congestion • Afib. common.
Symptoms • Often asymptomatic for years • Fatigue, DOE, orthopnea- symptoms of left sided heart failure (detailed discussion later in CV system). • With chronic severe MR –Elevation of pulmonary venous pressure leads to PuVR PAH and subsequent Rt Heart failure: hepatic congestion, peripheral edema, etc.
Physical Exam • Palpation: Systolic thrill may be present at apex depending on turbulence. • Auscultation: S1 soft or absent; S3 gallop if significant MR; Systolic Murmur is hallmark - Gr. II-IV/VI holosystolic in most cases -radiates to axilla (exception is MVP); murmur is high pitched and blowing.
Additional Findings • ECG: LAE; Atrial arrhythmias (Afib). • Echo/Doppler: LA & LV size; LV function. Can estimate severity of MR; LV often dilates with progressive MR. • CxR: Late findings - Progressive LVE; HF; pulmonary edema. CxR- chest x-ray LVE- left ventricular enlargement
Treatment of MR • Medical - Treatment depends on severity.Once symptomatic: Decreased physical activity and Na restriction. Drug therapy often significantly improves symptoms and patients may do well for many years. • ACE inhibitors or other vasodilators: decrease afterload and preload. • Diuretics: decrease preload, Na and volume overload • Inotropic agents: digoxin- limited role
Treatment of MR • Surgical- Indications: • Severe MR with Sx • Dilating LV with progressive dysfunction EF (even with mild symptoms). • Timing of surgery is important; needs to be done before significant deterioration of LV function/EF. • Surgical result dependent on pre-existing LV function. Mitral valve repair is preferred to MV replacement.
Mitral Valve Prolapse • Very common (3-5% adults) - Excessive redundant MV tissue from abnormal connective tissue: • MVP - most common form involves MV without major connective tissue disease elsewhere in body. Familial form also exists- autosomal dominant. • MVP as part of major CT disease (Marfan’s, Ehler’s-Danlos) or variations; these disorders are uncommon. • Pathology- myxomatous degeneration of MV leaflet tissue. • Associated deformities: high arched palate; pectus excavatum.
Mitral Valve Prolapse Images.google.com
MVP: Pathology • Mitral regurgitation can develop due to redundant floppy valve leaflets and/or involvement of the MV supporting structures – chordae tendineae. • Stress on Papillary muscles or chordae is presumed reason for localized and atypical chest pain. • Abnormal valve structure and MR can predispose to infective endocarditisbut incidence is very low antibiotic prophylaxis no longer indicated.
Clinical Features • Female > male; Sx, when present, commonly occur at ages 15-30. • Most are asymptomatic; often detected on PE- characteristic murmur. • Most common symptoms when present: chest pain (*atypical) and palpitations. • Arrhythmias common: PAC’s, PVC’s, PSVT, non-sustained VTach. • Sudden death – exceedingly rare arrhythmias *Atypical – CP unlike the pain/discomfort that is present with coronary heart disease
Physical Findings • Auscultation: Mid to late systolic click (tensing of chordal structures). • High pitched late systolic murmur best heard at apex.- click and murmur occur earlier and get louder with maneuvers thatdecrease LV volume: standing after squatting, valsalva. Maneuvers that increase LV volume delay the click and soften the murmur: isometric hand grip, squatting.
Additional Findings/Treatment • ECG: NST-TW changes. Usually in leads II, III, aVF. • Echo/Doppler: Diagnostic; shows MVP and identifies MR when present. • Treatment: Reassurance; ß-Blockers for chest pain or arrhythmias; additional anti-arrhythmics usually not necessary. • Infrequently, severe MR develops requiring MV repair (more common in men than women).
Mitral Stenosis • 2/3 females, 1/3 males- only cause is RF. • About 40% of all cases of RF develop MS. • Valve leaflets thicken and calcify, commisures fuse; valve orifice narrows; subvalvular supporting apparatus involved. • Least common rheumatic valvular lesion.
Mitral Stenosis Images.google.com
Pathophysiology • Normal MVA - 4-6 cm2. Valve leaflets fuse, decreasing valve area. Severe MS < 1 cm2. • LA pressure rises in order to propel blood across the stenotic valve- pressure gradient compared to LVEDP. • LAP reflected backwards into the pulmonary circulation results in pulmonary venous congestionpulm capillary congestion interstitial fluid dyspnea. Pulmonary arterioles subsequently constrict.
LV function usually normal. LVEDP normal. • Chronic severe MS - Elevation of pulmonary vascular resistance (PVR) and subsequent development of Pulmonary Artery Hypertension (PAH). • Chronic PAH RVH RV dysfunction and failure. • CO at rest- usually normal but does not rise adequately with exercise. With severe MS and PAH, CO eventually falls.
Symptoms/Complications • DOE, orthopnea, PND pulmonary edema • Findings of Rt Ht failure - late • Atrial arrhythmias: PAC’s, Atrial Fibrillation and Flutter • Hemoptysis ruptured pulmonary capillaries • Atrial Thrombi and embolization - (AFib)
Physical Exam • Palpation: prominent RV impulse • Auscultation: S1 loud/accentuated; S2 loud if PAH present Opening Snap of MV-apex, follows S2.Diastolic Rumble- Follows OS; low pitched/apex; length correlates with severity; MR murmur often audible.
Additional Findings • ECG: LAE/LAA; RAD, RVH (over time) • Echo/Doppler: diagnostic-shows abnormal valve motion, estimates the gradient and MVA, defines LA size and LV function. • CxR: Pulmonary congestion; RVE. • Cardiac Cath: Documents gradient, MVA, presence or absence of MR and more.
MS - Treatment • Sodium restriction, diuretics. • Rate control of Afib or cardioversion. • Surgery -Mitral valvulotomy - marked symptomatic improvement. MVR only when repair cannot be done (mortality 3-5 %). • Percutaneous balloon valvuloplasty- alternative to surgery; if successful, avoids or delays need for surgery.
Aortic Stenosis-Etiologies • Common: 20% all valvular disease; 80% males • Bicuspid valve leaflets thicken, fuseRheumatic valvulitis leaflets thicken, fuseIdiopathic – Sclerocalcific: chronic wear and tear- develops in the elderly leaflets thicken, fuse • Note: Thickening/calcification (without fusing) of the AoV often occurs with aging (Aortic Sclerosis) without progressing to significant aortic stenosisGr II/IIImurmur. Important to differentiate using history (asymptomatic), PE and echocardiogram if needed.
Aortic Stenosis Images.google.com
Pathophysiology • Obstruction to LV outflow- pressure overload. • Systolic gradient between LV and Ao. • Obstruction gradual - initially well tolerated; LV hypertrophy is compensatory. • Cardiac Output often normal at rest - does not adequately rise with activity. • Late in course- LV failure, LVEDP rises, CO falls.
Myocardial oxygen consumption (MVO2) increases from LVH and high LV pressures. • Coronary blood flow is impaired from high LV pressures. • Myocardial ischemia can occur in the absence of *CHD severe LVH/ high pressures outstrips coronary blood flow • Associated CHD may be present. • Normal AoV area: 2.5-3.0 cm2Critical AS: valve area <0.75 cm2 *CHD- coronary heart disease
AS Hemodynamics Images.google.com
Symptoms of AS • Exertional dyspnea - elevation of LVEDP transmitted backward into pulmonary circuit. • Angina Pectoris-Increased MVO2 (pressure overload and hypertrophy) and decreased coronary reserve. *CHD may co-exist but does not have to be present for angina to develop. • Syncope - Peripheral vasodilation with inadequate forward CO with activity or from arrhythmia. • HF occurs late - very poor prognosis. CHD – coronary heart disease
Physical Exam • Carotid pulse rises slowly; sustained peak. • Apex displaced laterally; +/- systolic thrill; systolic ejection sound (click ) variable. • Aortic valve closure is delayed - fixed or paradoxical splitting of S2. • S4 gallop common. • Murmur - SEM (crescendo-decrescendo)- peaks in mid to late systole depending on severity; harsh, low pitched, best heard at base and radiates to carotids – Grade II-IV/VI.
Additional Findings • ECG: LVH common; LAA. • Echo/Doppler: Diagnostic- identifies LVH, valve calcification and restriction; estimates gradient and aortic valve area. • CxR: LV prominence, displaced apex. • Cardiac Cath: Usually necessary prior to surgery; identifies gradient, valve area, LV function and presence or absence of CAD.
Natural History: Untreated • Angina Pectoris -death within 3 years • Syncope - death within 3 years • Dyspnea - death within 2 years • CHF - death within 1.5 years
Treatment • Medical - Mild to moderate AS without symptoms: Careful F/U; serial echo/doppler studies. Limited role for meds once symptoms begin. • Surgical- severe or symptomatic AS. Valve replacement with tissue or mechanical valve - Op risk 4%; 60-70% 10 yr. survival; marked symptomatic improvement. • Ross procedure an option for young patients with AS. • Ballon valvuloplasty- palliative
Aortic Regurgitation- Etiology • 75% male • Rheumatic Heart Disease • Infective endocarditis on previously deformed valve • Aortic Root disease and dilatation • Bicuspic Aortic Valve (AS more common than AR)
AR: Pathophysiology • Increase in LVEDV (preload): blood returning from LA + regurgitant blood. • LV dilates- allows increased SV (stroke volume) and adequate effective forward SV (Starling’s law). • Over time (years) LV function gradually declines and EF (ejection fraction) deteriorates.
Pathophysiology • LV deterioration often precedes symptoms (reason for serial echo/doppler exams). • As AR progresses, CO fails to rise adequately with exercise, LV dysfunction worsens Increased LVEDP pulmonary congestion HF.
AR: History • Sometimes familial - Connective tissue disease. • History of RF or infective endocarditis. • Patient often asymptomatic for 10-15 yrs. with significant AI. • Symptoms: Palpitations, exertional dyspnea, orthopnea; PND and HF occur later. • Atypical chest pain common.
AR: Physical Exam • Arterial Pulse - Rapid rising “water-hammer pulse” and collapsing pulse.“Quinke’s pulse” - alternate flushing and palling of the skin at the nail root. • “Pistol shot” sound over femoral artery in systole. • Derosiez’ sign - to and fro murmur over femoral artery. • Arterial pulse pressure widened- elevated systolic pressure (often greater than 200mm) and lowered diastolic pressure.
Physical Exam • Palpation - apex displaced laterally/inferiorly. • Diastolic Thrill may be present along LSB. • Auscultation: S2 soft; S3 common;high pitched blowing diastolic decreshendo murmur (LSB). • Best heard with diaphragm – patient sitting upright/leaning forward. • Systolic ejection (increased flow across AoV) murmur.
Additional Findings • ECG - Increased voltage/LVH develops over time. • Echo/Doppler: early on LV contractility normal or increased - later, LV dysfunction; AI jet detectable and semi quantitated by Doppler. • Cardiac Cath: Identifies severity of AI, degree of LV dysfunction and intra-cardiac pressures. Needed to assess coronary arteries in older adults. Cath may not be needed in younger patients.
Treatment of AR • Medical - very close follow-up; serial Echo/Doppler studies. Same Rx as for CHF: Afterload reduction with vasodilators (ACEI, hydralazine). Preload reduction with diuretics; digoxin may be useful in selected individuals. • Surgical - Timing of surgery is difficult as pts. with AI do not develop symptoms until after the development of LV dysfunction.Surgery indicated for progressive LV dilatation and dysfunction +/- symptoms.
Surgery • Aortic Valve Replacement with bioprosthesis (tissue valve) or mechanical valve. Ross procedure an option if young. • Op mortality dependent on pre-op LV function (5% or greater mortality).