Valvular Heart Disease (Clinical)

Aortic valve disease

Aortic stenosis (AS). A harsh crescendo-decrescendo systolic murmur at the right upper sternal border radiating to the carotids, with pulsus parvus et tardus (a weak, delayed carotid upstroke). Symptoms follow the SAD triad: Syncope (classically exertional), Angina, and Dyspnea. Causes are calcific degeneration in the elderly and a bicuspid valve in younger patients; bicuspid valves are associated with coarctation and Turner syndrome. Once symptoms begin, untreated severe AS carries about 50% mortality at 2 years.

Treating AS. Replace the valve for symptomatic severe AS, for asymptomatic severe AS with LVEF below 50%, or when the patient is having other cardiac surgery. TAVR (transcatheter) is used for intermediate-to-high surgical risk and now for selected low-risk elderly patients; SAVR (surgical) suits younger, low-risk patients. Medical therapy does not prolong survival, balloon aortic valvuloplasty is at most a bridge, and aggressive preload reduction (nitrates) can precipitate hypotension because cardiac output depends on filling.

Aortic regurgitation (AR). An early diastolic decrescendo murmur at the left sternal border, loudest with the patient sitting forward in expiration. Chronic AR causes a wide pulse pressure with a water-hammer (Corrigan) pulse, head bobbing (de Musset sign), nail-bed pulsations (Quincke sign), and an apical mid-diastolic Austin Flint rumble. Chronic causes are aortic root dilation, a bicuspid valve, and rheumatic disease; acute severe AR comes from endocarditis or aortic dissection.

Treating AR. Operate for symptomatic severe AR, or for asymptomatic severe AR once the LV starts to fail: LVEF ≤55% or LV end-systolic dimension >50 mm. Chronic AR benefits from afterload reduction with vasodilators.

Acute severe AR (dissection, endocarditis) has no time for LV dilation: pulse pressure is normal, there are no bounding pulses, and the patient is in pulmonary edema or cardiogenic shock. It needs emergent surgery, and an intra-aortic balloon pump is contraindicated because it worsens regurgitation.

Mitral valve disease

Mitral stenosis (MS). Almost always rheumatic. Listen for a loud S1, an opening snap after S2, then a low-pitched mid-diastolic rumble at the apex, best heard in the left lateral decubitus position. The tighter the valve, the higher the left atrial pressure and the earlier the valve opens, so a shorter S2-to-opening-snap interval means more severe stenosis. Patients present with dyspnea, atrial fibrillation, hemoptysis, and left atrial enlargement that can compress the esophagus (dysphagia) or recurrent laryngeal nerve (hoarseness). Pregnancy and tachycardia shorten diastolic filling and often unmask it.

Treating MS. Percutaneous balloon mitral valvuloplasty is first choice for symptomatic severe MS with favorable (pliable) valve morphology and no left atrial thrombus or significant MR; otherwise, surgical repair or replacement. Rate-control the frequent AF (β-blockers also lengthen diastolic filling) and anticoagulate with warfarin, not a DOAC.

Mitral regurgitation (MR). A blowing holosystolic murmur at the apex radiating to the axilla. Chronic causes are mitral valve prolapse, ischemic heart disease, rheumatic disease, and a dilated LV. Acute MR from papillary muscle rupture (2–7 days after MI) or endocarditis causes flash pulmonary edema and shock and needs urgent surgery, with afterload reduction as a bridge.

Treating primary severe MR. Surgery if symptomatic, or if asymptomatic with LVEF 30–60% or LV end-systolic dimension ≥40 mm. Repair is preferred over replacement; transcatheter edge-to-edge repair (MitraClip) is for high surgical risk. Secondary MR from a dilated LV is treated first with heart-failure therapy.

Mitral valve prolapse (MVP). A mid-systolic click followed by a late systolic murmur, from myxomatous degeneration. It is the most common valve lesion in developed countries and is associated with Marfan and Ehlers-Danlos syndromes. It can progress to significant MR.

Bedside maneuvers

Maneuvers change preload or afterload; most murmurs follow the volume in the ventricle, but hypertrophic cardiomyopathy (HOCM) and MVP behave in the opposite way because a smaller LV worsens outflow obstruction and lets the mitral leaflets prolapse sooner.

Endocarditis prophylaxis and prosthetic valves

Prophylaxis only for the highest risk. Give antibiotics before dental procedures that manipulate the gingiva only to patients with:

• A prosthetic valve or prosthetic material used in valve repair
• Prior infective endocarditis
• Unrepaired cyanotic congenital heart disease
• A cardiac transplant with valvulopathy

The drug is amoxicillin (2 g orally 30–60 minutes before). With penicillin allergy, use azithromycin or clarithromycin, doxycycline, or cephalexin if there is no history of anaphylaxis, angioedema, or urticaria with penicillin; clindamycin, the traditional alternative, is no longer recommended because of C. difficile risk. Native valve disease, MVP, bicuspid valves, and fully repaired defects without residual shunt no longer qualify.