is due to arrhythmias, abnormal vasodepressor re \202 exes, and \200 is usually due to diastolic heart failure. Physical exam \200 Small-volume, slow rising pulse (pulsus parvus et tardus) is best felt at the carotid. BP \200\224narrow pulse pressure; in advanced AS systolic BP is decreased. Prominent a-wave on JVP. Sustained apical impulse. Systolic thrill is felt in the aortic area (second intercos tal space on right) during full expiration. Auscultation \200\224S1 normal or soft. S2 norm al in mild AS. As severity of AS worsens, A2 is delayed by prolonged systolic ejection time and S2 may be paradoxically split (P2 before A2), although it is usually soft or absent in severe AS. An S4 (atria contracting into stiff ventricle) and systolic ejection click (if valve pliable, especially bicuspid valves) may also be heard. Systolic ejection murmur is h eard throughout precordium but is best heard in the aortic area in full expiration and usua lly radiates to carotids. The murmur intensity peaks later in systole as AS worsens. The following exam \201 ndings are most speci \201 c for severe AS: \200 \200 \200 Late-peaking systolic murmur Delayed carotid upstroke Soft or absent S2 CHAPTER 4 Valvular heart disease 190 Aortic stenosis: management Diagnostic testing \200 ECG One may see AF. CXR dilatation in the ascending aorta. TTE restricted opening (2D and M -mode); also evaluate for congenital abnormalities and aortic pathology. Assess for LVH and LV systolic and diastolic function. Color Doppler CW Doppler calculate valve area using th e continuity principle. Dobutamine stress ECHO aortic stenosis from pseudoaortic stenosis d ue to low cardiac output. Cardiac catheterization artery disease prior to aortic valve surg ery. There is no need to assess valve gradient (signi \201 cant risk of embolic events wit h this; CW Doppler accurately assesses gradient and LV function) unless there is a discrepa ncy between echocardiogram and clinical \201 ndings. TEE is used for calculation of the v alve area by planimetry if TTE is nondiagnostic and to assess for aortic pathology (especia lly in patients with bicuspid valves). shows LVH with strain; branch bundle block (BBB) (either R or L). shows calci \201 cation involving valve or aortic root, poststenotic is the diagnostic test of choice. It will show a calci \201 ed valve with \200 is used to look for concomitant AR and/or MR. is used to measure transvalvular pressure gradient and can distinguish low-gradient true severe is used to assess for concomitant coronary Severity Severity is classi \201 ed according to pressure gradient and valve area (Table 4 .2). Echocardiography with Doppler is the preferred modality to acquire these measurements. Prognosis AS is a progressive condition that gradually worsens over time. Symptoms are usua lly not present until stenosis is severe. Once symptoms occur, prognosis without surgery is poor: of patients who present with symptoms of angina, 50% will die within 5 years; if pat ients present with syncope, 50% will die in 3 years; if patients present with congestive he art failure, 50% will die within 2 years. Treatment Surgery Aortic valve replacement (AVR) is the mainstay of therapy for sympto- mat ic patients and can be performed with a very low (1%) operative mor- tality (see Box 4.4). Medical therapy Medical therapy offers very little to symptomatic patients in terms of impr oved outcomes. These patients should be referred promptly for sur- gery. Medical therapy (i .e., diuretics) may provide temporary and palliative symptomatic relief to patients who are not surgical candidates, but must be administered with caution to avoid hypovolemia and hy potension. AORTIC STENOSIS: MANAGEMENT 191 Table 4.2 ACC/AHA classi \201 cation* of AS severity Gradient (mmHg) Velocity (m/sec) Valve area (cm2) Severity Mild <25 <3.0 >1.5 Moderate 25 \200\22340 3.0 \200\2234.0 1.0 \200\2231.5 Severe >40 >4.0 <1.0 Bonow, RO, et al. (2006) ACC/AHA 2006 guidelines for the management of patients with valvul ar heart disease. J Am Coll Cardiol 48:598 \200\223675. Box 4.4 2006 ACC/AHA guidelines* for AVR in AS Class I \200 \200 Symptomatic patients with severe AS Patients with severe AS undergoing CABG or aortic or ot her valvular surgery Patients with severe AS and LVEF <50% Class IIa \200 Patients with moderate AS undergoing CABG or aortic or other valvular surgery Class IIb \200 Severe AS in asymptomatic patients who have an abnormal response to exercise such as the de velopment of symptoms or hypotension Severe AS in asymptomatic patients with a high likelih ood of rapid progression Severe AS in asymptomatic patients in whom surgery might be delaye d at the time of symptom onset Mild AS in patients undergoing CABG surgery in whom there is evidence, such as moderate to severe valve calci \201 cation, that progression may be rap id 2, mean gradient Extremely severe AS (aortic valve area <0.6 cm >60 mmHg, and aortic jet velocity >5.0 m/sec) in asymptomatic patients in whom the expected operative mortality is (cid:100)1% Class III \200 For the prevention of sudden cardiac death in asymptomatic patients who have none of the cl ass IIa or IIb \201 ndings Bonow, RO, et al. (2006). ACC/AHA 2006 guidelines for the management of patients with valvu lar heart disease. J Am Coll Cardiol 48:598 \200\223675. CHAPTER 4 Valvular heart disease 192 Use of medications (particularly HMG-CoA reductase inhibitors) to delay AS progression in a symptomatic patients has been studied and the results thus far are inconclusive. Transcatheter techniques Balloon aortic valvuloplasty was introduced as a nonsurgical alter native treatment for AS and is integral to the management of congenital AS in the pediatric population. Results in the adult population are not as good as anticipated because of proc edural complications and high restenosis rates. Aortic valvuloplasty is currently not an acceptable alternative to surgi- cal AVR and its u se should be restricted to palliative therapy in patients deemed nonoperable and as a bridg e to AVR in hemodynamically unstable patients. Percutaneous aortic valve replacement is currently being performed at experienced centers a nd may be a valuable treatment approach in the future. Current use is restricted to patient s who are not surgical candidates. AORTIC REGURGITATION 193 Aortic regurgitation Causes Valvular \200 Rheumatic fever that they cannot appose properly. Infective endocarditis leads to \201 brosis, fusion, and retraction of cusps such causes destruction of valve lea \202 ets. Aortic root disease Dilatation, aneurysm, and dissection cause failure of coaptation of cus ps. One may see diastolic cusp prolapse in dissection. Causes \200 \200 \200 \200 \200 \200 \200 Hypertension Marfan \200\231s syndrome Osteogenesis imperfecta Syphilis Spondyloarthritides (ankylosing spondylitis, Reiter \200\231s, etc.) Trauma Bicuspid aortic valve Incidence Aortic regurgitation (AR) is less common than AS. Valvular causes are becoming le ss frequent and aortic root causes now account for >50% of cases. Pathophysiology As the aortic valve becomes incompetent, more stroke volume regurgi- tates into LV during diastole, causing LV volume overload. Cardiac output is maintained by increa sing stroke volume at the expense of increased LV end-diastolic volume. Eventually, with fu rther LV dilatation, myocyte func- tion deteriorates and LV failure occurs. Symptoms Symptoms include dyspnea/CHF, angina, and symptoms of an underlying cause (i.e., c hest pain in aortic dissection, fever in infective endocarditis). Physical examination There is very wide pulse pressure with associated signs: collapsing (w ater- hammer) pulse, Corrigan \200\231s sign (visible carotid pulsation), De Musset \200 \231s sign (head nodding with each pulse), M ller \200\231s sign (visible pulsation of uvu la), Traube sign (also called \200\234pistol shot femorals \200\235 \200\224loud noises he ard with the stethoscope over the femoral artery), Quincke sign (visible capillary pulsatio n in the nailbed), and Duroziez sign (heard over the femoral artery when the artery is digi tally compressed). Apex beat is displaced inferolaterally and is diffuse/hyperdynamic. Auscultation A2 may be normal (or louder) if AR is due to aortic root pathology; it may be soft or absent if AR is due to aortic valve pathology. S3 may be heard with dilated LV. A s ystolic ejection murmur similar to AS may be CHAPTER 4 Valvular heart disease 194 audible (due to either mixed AR/AS or turbulent \202 ow from increased stroke volume). Murmur of AR is a high-pitched early diastolic murmur immediately fol- lowing A2, heard bes t along the left sterna border with the patient sitting up and leaning forward in expiratio n. Duration of the murmur in diastole correlates with severity of AR. Austin Flint murmur is a mid-diastolic murmur heard at the apex due to antegrade \202 ow across a mitral valve ori \201 ce that has been narrowed by a combination of rising LV pre ssure and jet of AR directed at the anterior MV lea \202 et. Diagnostic testing \200 \200 ECG CXR: also be dilated ascending aorta with aortic root pathology. TTE: used to assess th e severity of regurgitation. 2D/M-mode measures aortic root and LV dimensions. Cardiac cath eterization artery disease prior to aortic valve/root surgery. An aortogram in left anterio r oblique (LAO) projection shows aortic root size and severity of AR. shows LVH with strain; left axis deviation. In chronic AR, an enlarged cardiac shadow is ev ident. There may Color Doppler and CW Doppler con \201 rm the diagnosis and are is used to assess for concomitant coronary Prognosis Chronic AR can be well tolerated for many years and is associated with a good pro gnosis: 5-year survival is 75%, 10-year survival is 50%. Prognosis worsens as symptoms de velop (see Table 4.3). Acute severe AR, however, is associated with a high mortality from LV failure, and early surgical intervention is indicated. Table 4.3 Natural history of aortic regurgitation Asymptomatic patients with normal LV function Progression to symptoms/signs of CHF <6%/year Progression to asymptomatic LV dysfunction <3.5%/year Sudden death <0.2%/year Asymptomatic patients with LV systolic dysfunction Progression to cardiac symptoms >25%/year Symptomatic patients Mortality rate >10%/year Reprinted with permission from Bonow RO, et al. (1998). ACC/AHA guidelines for the manageme nt of patients with valvular heart disease. J Am Coll Cardiol 32:1486 \200\2231582. 1998, American Heart Association, Inc. AORTIC REGURGITATION 195 Treatment Medical \200 Asymptomatic mild to moderate AR with normal LV: routine follow-up (every 1 \200\2232 years ) with ECHO Asymptomatic severe AR with normal LV: frequent (6-month) follow-up, or sooner if symptoms intervene. Symptoms of CHF may respond to medical therapy (i.e., loop diuretics) while arrangements ar e made for surgery. Vasodilators (ACE inhibitor, calcium channel blockers) offer symptomati c relief and may improve hemodynamics. Anginal chest pain can be treated with nitrates but use B-blockers with caution. Concomitant hypertension can worsen AR and should be treated with standard therapies. Antibiotic prophylaxis is not indicated in AR. Surgical Because of the relatively benign nature of asymptomatic chronic AR with normal LV function, these patients should be managed conservatively with close follow-up. Once sympto ms have developed or evidence of signi \201 - cant LV dysfunction appears, referral for AV R/root replacement should be considered (see Box 4.5). In borderline cases frequent (2- to 4-month) follow-up is indicated. CHAPTER 4 Valvular heart disease 196 Box 4.5 2006 ACC/AHA guidelines* for AVR in AR Class I \200 \200 Symptomatic patients with severe chronic AR Asymptomatic patients with severe chronic AR an d an LVEF at rest Patients with severe chronic AR who undergo CABG or surgery on the aorta or other heart valves (cid:100)50% Class IIa \200 Asymptomatic patients with severe chronic AR and an LVEF >50% who have severe left ventricu lar dilatation (EDD >75 mm or ESD >55 mm) Class IIb \200 Patients with moderate chronic AR who undergo CABG or surgery on the ascending aorta Asympt omatic patients with severe chronic AR, an LVEF >50%, and an EDD >70 mm or ESD >50 mm, and there is evidence of progressive left ventricular dilatation, declining exercise tolerance, or an abnormal hemodynamic response to exercise Class III \200 Asymptomatic patients with mild, moderate, or severe chronic AR and an LVEF >50% at rest an d an EDD <70 mm or ESD <50 mm. Bonow, RO, et al. ACC/AHA 2006 guidelines for the management of patients with valvular hear t disease. J Am Coll Cardiol 2006; 48: 598 \200\223675. RIGHT HEART VALVE LESIONS 197 Right heart valve lesions Tricuspid stenosis (TS) Causes include rheumatic fever (almost al ways associated with MS), con- genital, carcinoid, and pacemaker lead. Symptoms are fatigue , anorexia, and peripheral edema. Examination Look for wasting, edema, hepatomegaly, and elevated JVP with prominent a-waves. Rumbling mid-diastolic murmur is heard best at lower left sternal border (LLSB) in inspira tion. Investigation \200 ECG: coincides with signs of LA enlargement because of MS) but no RVH. enlarged RA but normal PA size. CXR: TTE: 2D image can show thickened restricted lea \202 ets. CW Doppler is diagnostic of increased transvalvular gradient. If diagnosis of TS is m ade, always look for coexistent MS. sinus rhythm, RA enlargement (tall peaked p-waves in II, V1 often \200 Treatment Salt restriction and diuretics may markedly improve symptoms. If coexist- ent MS is being operated on, then surgical valvuloplasty may help. Tricuspid valve (TV) replacement is occasionally performed. Bioprosthetic valves give better results than mechanical valves. TV balloon valvuloplasty is an alternative to surgery. Tricuspid regurgitation (TR) Causes These include any cause of RV dilatation (MV disease, c ongenital heart dis- ease, RV infarction, pulmonary embolism, pulmonary hypertension), infe c- tive endocarditis (particularly IV drug abuse), Marfan \200\231s syndrome, Ebstein anoma ly, rheumatic fever, and carcinoid causes. Symptoms Symptoms are usually mild. As right heart failure develops, patients com- plain of edema, ascites, nausea, anorexia, and abdominal pain (tender, congested liver). Examination Look for cachexia/wasting, jaundice, and edema. AF is common, along with elevat ed JVP with systolic V waves and tender pulsatile hepatomegaly. On auscultation RV S3 is of ten heard, and systolic murmur is audible at LSB (increases with inspiration). Murmur is lo udest in TR secondary to pulmonary hypertension. CHAPTER 4 Valvular heart disease 198 Investigation \200 ECG RA enlargement. CXR occasional distended azygos vein, pleural effusion. TTE : color Dop pler con \201 rms diagnosis. CW Doppler of TR jet can assess RV systolic pressure. Flow re versal in hepatic vein suggests severe TR. 2D images may reveal etiology of TR (RV infarcti on, ASD/VSD, Ebstein \200\231s, etc.). : nonspeci \201 c may show evidence of underlying condition, : cardiomegaly in patients with functional TR, RA/RV enlargement, Treatment In the absence of pulmonary hypertension, TR is well tolerated and may not requir e speci \201 c treatment (in infective endocarditis of TV, valve exci- sion is sometimes p erformed with good recovery). Symptoms of RV fail- ure respond to diuretics and \202 uid/ salt restriction. If coexistent MV disease is being operated on and TR is mild (with mini- mally elevated PA pressure), TR usually improves following surgery as PA pressure falls. In patients with sev ere TR due to annular dilatation, TV annuplasty may be indicated. TR secondary to valve pathology (Ebstein \200\231s, carcinoid) may require valve replacemen t, preferably with a large bioprosthesis to minimize risk of thrombosis. Pulmonic stenosis Causes include congenital, carcinoid, and rheumatic causes and extrinsic compression. Stenosis may be valvular or supravalvular. Symptoms Usually there are none. With severe stenosis there is exertional dyspnea and light -headedness. Eventually symptoms of RV failure may develop. Examination Look for prominent a-wave in JVP, RV heave, and occasional thrill in sec- ond l eft intercostal space. On auscultation there is a widely split S2 (as pul- monary valve [PV ] closure becomes delayed), P2 becomes softer (unless stenosis is supravalvular), and systo lic ejection murmur at left upper ster- nal border (LUSB), heard best in inspiration. Investigation \200 \200 ECG CXR if severe then oligemic lung \201 elds. TTE supravalvular, or RV out \202 ow tra ct) and measures pressure gradient. It can also demonstrate associated conditions (ASD, PDA , TOF, etc.). Cardiac catheterization hemodynamic effects. : RVH and RA abnormality. : dilated pulmonary arteries, occasionally with calci \201 catio n of valve; con \201 rms the diagnosis and level of obstruction (valvular, is used to assess the severity of obstruction and RIGHT HEART VALVE LESIONS 199 Treatment In general, invasive intervention is recommended when the gradient across the val ve is >50 mmHg at rest or when symptoms occur. \200 Medical therapy failure (diuretics, salt and \202 uid restriction). Balloon valvuloplasty valvular level. It is highly effective and safe with good long-term results. Surgical valv otomy signi \201 cant pulmonary regurgitation may occur. Pulmonary valve replacement is in dicated if the patient is not suitable for above treatments or develops severe PR following intervention. includes supportive/symptomatic treatment of RV is the treatment of choice for stenosis at the is very effective with minimal recurrence, though Pulmonary regurgitation Causes These include pulmonary hypertension (causes dilatation of v alve ring), infective endocarditis (rarely involves pulmonic valve), connective tissue dise ase (e.g. Marfan \200\231s), and iatrogenic (following valvotomy, valvuloplasty or PA cathe ter placement) carcinoid causes. Symptoms Patients are often asymptomatic. Symptoms develop when pulmonary hypertension or R V failure occurs and include dyspnea on exertion, leth- argy, peripheral edema, and abdomin al pain. Examination Look for RV heave, occasionally a thrill in pulmonary area. On auscultation P2 may be delayed (large stroke volume), loud (if pulmonary hyperten- sion), or soft (if PV st enosis). Murmur of pulmonary regurgitation (PR) is heard best in the third to fourth interc ostal space along the LSB and increases with inspiration. Investigation \200 \200 \200 ECG CXR TTE abnormal septal motion with RV volume overload. PR is seen on color Doppler and quanti \201 ed with pulsed Doppler. : RVH (if pulmonary hypertension), RBBB/rsR pattern in V1 : enlarged PA and RV : 2D images may show RV dilatation/hypertrophy. There is Treatment Usually, supportive treatment suf \201 ces. Treat RV failure in the usual way (d iuretics, etc.). If PR is due to PV ring dilatation secondary to pulmonary hypertension, tr eating the cause of pulmonary hypertension can relieve this and decrease the severity of PR (e.g., mitral valve surgery). If there is severe right heart failure then PV replacement can be considered. CHAPTER 4 Valvular heart disease 200 Prosthetic heart valves Types \200 Mechanical: lea \202 et \200\224Medtronic Hall, Bjork \200\223Shiley; bilea \202 et \200 \224St. Jude Medical, Carbomedics) (see Fig. 4.5) Bioprosthetic: Homograft: ball and cage (Starr \200\223Edwards) or tilting disc (single \200 porcine or bovine (Carpentier \200\223Edwards) preserved human cadaveric valve Mechanical valves These valves are very durable (often last >20 years). They are thrombo- g enic, therefore require lifelong warfarin therapy ( aspirin if high risk). Ball and cage valves are earlier models that are very durable but also highly thrombogenic and require more intensive anticoagulation. More recent tilting disc valves are less thromb ogenic (bilea \202 et valves are less thrombogenic than single-lea \202 et valves). The most commonly used prosthesis in practice today is the bilea \202 et valve. Tissue valves Tissue valves (bioprosthetic or homograft) have the advantage of not requirin g long-term anticoagulation but are not as durable as mechanical valves (15-year failure ra te of 10% \200\22320% for homografts and 20% \200\22330% for bioprostheses, and higher rate s for patients <40 years of age). Consequently, mechanical valves tend to be placed in younger patients (<65 years) or those with another reason for warfarin (AF, hypercoagula- ble state). Bioprostheses are generally implanted in older patients or those who refuse warfarin (see Table 4.4). Valve hemodynamics Different prosthetic valves have unique pro \201 les and valve areas. F or any given valve dimension, bioprosthetic valves and ball and cage valves have the smalle st effective valve ori \201 ce area, and homografts have the largest valve area (comparabl e to native valve area). Assessment of prosthetic valve function Clinically Each prosthetic valve produces a distinc tive sound. Dysfunction may be indicated by new sounds, a change in sound or volume of soun d, or a new (or changing) murmur. Imaging modality Fluoroscopy can be used to assess mechanical valve lea \202 et movement. Diminished lea \202 et motion is seen in valve thrombosis whereas excessive movement of th e base ring may indicate prosthetic valve dehiscence. TTE is of limited use because of shadowing caused by metallic leaf- lets in mechanical valv es. It can be used to look at valve ring motion (in mechanical valves), lea \202 et motion (in tissue valves), and regurgitation (with Doppler).