Stage
Aortic jet velocity (m/s)
Mean gradient (mmHg)
Valve area (cm2)
Mild
<3.0
<25
>1.5
Moderate
3.0–4.0
25–40
1.0–1.5
Severe
>4.0
>40
<1.0
3 months of surgery for asymptomatic with known severe disease
6–12 months for moderate disease
2 years for mild disease
2–3 years for aortic sclerosis
Perioperative Risk Stratification
Significant AS is associated with increased perioperative mortality; early studies demonstrated a mortality rate of 13% in patients with severe AS undergoing non-cardiac surgery [1, 2].
Patients with severe aortic stenosis may have impaired platelet function and decreased levels of von Willebrand factor, which can be associated with clinically significant bleeding (usually epistaxis or ecchymoses) [6].
Aortic sclerosis without stenosis is not considered an independent perioperative risk factor.
Perioperative Management
Preoperative Considerations
Evaluation for valve replacement is recommended in symptomatic patients prior to noncardiac surgery [6].
Consider cardiology consultation in asymptomatic patients with severe AS.
Balloon valvotomy is not recommended as a temporizing measure in patients with severe AS undergoing noncardiac surgery [6].
Postoperative Considerations
For asymptomatic patients with moderate to severe disease: Close postoperative hemodynamic monitoring (up to 48 h), maintenance of intravascular volume, avoidance of tachycardia, and maintenance of sinus rhythm [6, 7].
In the event of major bleeding or volume loss, maintenance of excellent IV access and rapid resuscitation are vital.
Avoid the use of nitrates in patients with severe or critical aortic stenosis, as nitrates reduce filling pressures and may precipitate cardiac arrest.
Patients with subaortic stenosis (i.e., idiopathic hypertrophic subaortic stenosis) should be managed similarly to patients with aortic stenosis.
Mitral Stenosis
Preoperative Evaluation
Patients with mitral stenosis are at increased risk for perioperative tachyarrhythmias and heart failure; thus, it is important to identify these patients preoperatively [1]. The most common cause of mitral stenosis is rheumatic fever, and common symptoms are dyspnea, decreased exercise tolerance, fatigue, and palpitations. Mitral stenosis causes a low-pitched, blowing diastolic murmur, which is best heard with the bell of the stethoscope [5]. Findings of increasingly severe mitral stenosis include:
Faint or inaudible murmur [5]
Diminished S1
Perioperative Management
Preoperative surgical correction of asymptomatic mitral valve disease is generally not indicated prior to noncardiac surgery [1, 6].
Percutaneous or surgical repair should be considered in patients with severe mitral stenosis who have symptoms and/or severe pulmonary hypertension [1, 6].
Perioperative heart rate control should be considered, as tachycardia can reduce diastolic filling and lead to pulmonary congestion; discussion with a cardiologist is warranted [1, 6].
Mitral stenosis leads to a fixed stroke volume, making it important to avoid hypotension and maintain normal systemic vascular resistance [1, 6, 7].
Perioperative management of atrial fibrillation is discussed in Chap. 9.
Aortic Regurgitation
Preoperative Evaluation
Limited data suggest that patients with moderate to severe aortic regurgitation (AR) have increased risk of perioperative cardiac and pulmonary morbidity and mortality, as compared to patients without significant AR [8]. Symptoms of chronic AR include palpitations, dyspnea, and chest pain. There are several physical exam findings associated with AR, the most important being the presence of an early, blowing, high-frequency diastolic murmur [5, 9]. Physical exam findings suggestive of moderate to severe AR include [5]:
Diastolic blood pressure ≤ 50 mmHg (+LR 19.3)
Pulse pressure ≥ 80 mmHg (+LR 10.9)
Murmur grade 3 or louder (+LR 8.2)
S3 gallop (+LR 5.9)
Perioperative Management
Symptomatic patients or asymptomatic patients with significantly reduced left ventricular (LV) function with AR should be considered for valve replacement [6].
Perioperative management should include attention to volume control and afterload reduction [1].
Bradycardia should be avoided, as low heart rates can acutely worsen regurgitation by increasing diastolic time [7].
Mitral Regurgitation
Preoperative Evaluation
Mitral regurgitation (MR) is considered the most common valvular disorder [3]. The most common etiologies are papillary muscle dysfunction from ischemic heart disease and mitral valve prolapse. Recent observational and retrospective studies have reported that patients with severe MR are at greatest risk for perioperative heart failure (20 %) and atrial fibrillation (14 %) [10, 11]—these risks are increased in patients with ischemic MR and decreased LV function [10, 11]. The murmur of MR is holosystolic, high-pitched, and is heard best at the apex. The characteristics of moderate to severe MR include [5]:
Murmur grade 3 or louder (+LR 4.4)
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
