Aortic Regurgitation

Aortic Regurgitation • Chronic: rheumatic disease, hypertensive and atherosclerotic diseases, cystic medial necrosis with or without other features of Marfan's syndrome, connective tissue diseases including Reiter's syndrome and ankylosing spondylitis, luetic (syphilitic) aortitis, • Acute: infective endocarditis, nonpenetrating trauma, ascending aortic aneurysm dissection Pathogenesis • Chronic: LV volume overload →LV dilation→LVH→ eccentric hypertrophy • ↑LVEDV but LVEDP still normal→ over time ↑ LVEDP • Acute: severe AR →LV volume overload, but without time for LV dilation,↑HR is the only comp mechanism to maintain forward CO, LVEDP and LAP ↑ rapidly, with pul congestion. History: chronic AR usually remain asymptomatic for years. Early symptoms include a sensation pounding in the chest, palpitations, or head pounding. Exertional dyspnea may be the first manifestation of LV decompensation, with later development of orthopnea and PND. • Symptoms of more advanced disease include angina pectoris, which may be nocturnal, and eventually symptoms of right-sided CHF with ascites and peripheral edema. • Prognosis worsens with the onset of symptoms; mortality rate is estimated to be more than 10% per year among patients with severe AR and angina pectoris and more than 20% per year among patients with symptoms of CHF. • Acute severe AR →Patients typically exhibit symptoms referable to the underlying disease, including fever with infective endocarditis, and chest or back pain with aortic dissection.

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Acute severe AR is poorly tolerated and patients frequently present with pulmonary edema or cardiogenic shock. P/E. widened pulse pressure, with ↓ DBP , patients can exhibit a bobbing motion of the torso or the head (de Musset's sign) synchronous with the heartbeat, Systolic pulsation of the uvula may be visible (Müller's sign), Arterial pulses are unusually prominent, with exaggerated systolic distention and exaggerated diastolic collapse on palpation (water-hammer or Corrigan's pulse). • The murmur of AR is a high-pitched, blowing decrescendo diastolic murmur, loudest at the left or right upper sternal border. Lab ECG: LVH and LBBB, CXR: cardiomegaly, dilation of the aortic root, or evidence of pulmonary venous congestion. Anesthesia Management Preload: maintain or ↑, Contractility: maintain, avoid myocardial depressant drugs, R&R: maintain NSR, avoid bradycardia maintain a higher HR about 90, Afterload: ↓ SVR • In a choice of neuroaxial anesthesia the epidural is better than spinal, because it cause less ↓ in SVR by titrating the LA. • Consider antibiotics prophylactic coverage in a Pt with AS. • Monitors: consider TEE, PAC.