Anesthesia and Analgesia in the Pregnant Cardiac Patient



Anesthesia and Analgesia in the Pregnant Cardiac Patient


Katherine W. Arendt

Key Points

The majority of maternal deaths from cardiovascular disease are from acquired heart disease

The pregnancy heart team is a multidisciplinary team consisting of obstetrician, maternal-fetal medicine, anesthesiologist, and cardiologist working together to optimize outcome of pregnant cardiac patient

Women with high-risk maternal cardiovascular disease should deliver at a Level 4 Regional Perinatal Health Center

Neuraxial labor analgesia is an important component of labor management in patients with moderate to severe cardiovascular disease

In certain circumstances general anesthesia is a safer option than a neuraxial technique for surgical anesthesia



Over the past 20 years, cardiovascular disease has gradually become the leading cause of maternal mortality in the United States [1]. Increased survival of congenital heart disease (CHD) patients has resulted in more women reaching childbearing age and presenting to labor and delivery units [24]. Factors such as increased maternal age and increased incidence of obesity, chronic hypertension, and diabetes has likely led to expansion of acquired heart disease seen among the childbearing population. Currently, acquired heart disease comprises the majority of maternal cardiac deaths [5,6].

Both the European Society of Cardiology and the American College of Obstetricians and Gynecologists (ACOG) guidelines for pregnancy and heart disease recommend that a pregnancy heart team care for pregnant patients with complex cardiovascular disease [7,8]. Such a team involves cardiologists, obstetricians, perinatologists, and anesthesiologists working together to achieve the best outcome for the pregnant patient with complex heart disease. The focus of this chapter is on the role of the anesthesiologist as a member of the pregnancy heart team. Specifically, this chapter will focus on anesthetic risk stratification, the physiologic changes of pregnancy, labor and delivery, hemodynamic goals for patients as they present for delivery, and appropriate anesthetic techniques to achieve those goals.


Anesthetic Risk Stratification

Stratification of the overall risk of pregnancy for women with cardiac disease is discussed elsewhere in this text (see Chapter 4). Tables 8.1 through 8.3 review tools used for risk-stratifying women with cardiac disease who are pregnant [911].

Table 8.1


Risk Factors


Prior cardiac event or arrhythmia 


NYHA class >II or cyanosis


Mechanical valve


Ventricular dysfunction


High-risk left-sided valve disease/LVOT obstruction


Pulmonary hypertension


Coronary artery disease


High-risk aortopathy


No prior cardiac intervention


Late pregnancy assessment


Total Score

Risk of Cardiac Complications

0–1 points


2 points


3 points


4 points


>4 points


Table 8.2

ZAHARA Risk Score

Risk Factors


Mechanical valve prosthesis


Left heart obstruction


History of arrhythmia


Cardiac medication prior to pregnancy


Cyanotic heart disease (corrected or uncorrected)


NYHA class II


Systemic atrioventricular valve regurgitation > Mild


Pulmonic atrioventricular valve regurgitation > Mild


Total Score

Risk of Cardiac Complications

0–0.5 points


0.51–1.5 points


1.51–2.5 points


2.51–3.5 points


>3.51 points


Table 8.3

WHO Classification for Pregnancy

Risk Classification

Cardiac Lesions

Class I

No detectable increased risk of maternal mortality and no or minimal increase in maternal morbidity

Uncomplicated mild pulmonary stenosis

Ventricular septal defect

Patent ductus arteriosus

Mitral valve prolapse with no more than trivial mitral regurgitation

Successfully repaired simple lesions (atrial or ventricular septal defect, patent ductus arteriosus, anomalous pulmonary venous drainage)

Isolated ventricular extrasystoles and atrial ectopic beats

Class II

Small increased risk of maternal mortality or moderate increase in morbidity

Unoperated atrial or ventricular septal defect

Repaired tetralogy of Fallot

Most arrhythmias

Class II–III

Depends on patient

Hypertrophic cardiomyopathy

Native or tissue valvular heart disease not considered WHO I or IV

Repaired coarctation

Marfan syndrome without aortic dilatation

Bicuspid valve with aorta <45 mm

Mild ventricular impairment

Heart transplantation

Class III

Significantly increased risk of maternal mortality or severe morbidity, and expert cardiac and obstetric pre-pregnancy, antenatal, and postnatal care are required

Mechanical valve

Systemic RV

Fontan circulation

Unrepaired cyanotic heart disease

Other complex congenital heart disease

Marfan syndrome with aorta 40–45 mm

Bicuspid aortic valve with aorta 45–50 mm

Class IV

Pregnancy is contraindicated

Pulmonary hypertension

Eisenmenger syndrome

Systemic ventricular EF <30%

Systemic ventricular dysfunction with NYHA class III–IV

Severe mitral stenosis

Severe symptomatic aortic stenosis

Marfan syndrome with aorta >45 mm

Bicuspid aortic valve with aorta >50 mm

Native severe coarctation

Prior peripartum cardiomyopathy with any residual impairment of ventricular function

Risk stratification is important to the anesthesiologist because anesthesiologists are an integral part of the multidisciplinary team who help identify pregnancies at high risk for maternal harm during childbirth and triage these women to deliver at appropriate hospitals. To do this, anesthesia teams should have the ability to see high-risk pregnant patients in advance of delivery in a clinical setting to obtain an anesthetic, obstetric, and cardiac history; perform a physical exam; and review cardiac testing. The most important aspects of this consultation are reviewed in Box 8.1.

Table 8.4

Normal Cardiovascular Changes during Pregnancy


Direction of Change

Average Change

Blood volume


Plasma volume


Red blood cell volume


Cardiac output


Stroke volume


Heart rate


Femoral venous pressure

+15 mmHg

Total peripheral resistance


Mean arterial blood pressure

15 mmHg

Systolic blood pressure

0 to 15 mmHg

Diastolic blood pressure

10 to 20 mmHg

Central venous pressure

No change

Anesthesiologists often prefer to think in physiologic systems when risk-stratifying patients for surgery or delivery. Understanding the hemodynamic changes of pregnancy and combining these changes with the physiologic vulnerabilities of various cardiac lesions allows the anesthesiologist to understand which lesions will perform poorly during pregnancy, under anesthesia, or under the physiologic stressors of labor, emergency surgery, or obstetric hemorrhage. The physiologic changes of pregnancy are reviewed in Table 8.4. How these changes affect the hemodynamics of a woman with specific cardiac lesions are reviewed in Table 8.5.

Table 8.5

The Hemodynamic Effects of Pregnancy in Specific Cardiovascular Diseases


Hemodynamic Effects of Pregnancy and Delivery

Coronary artery disease

() The decreased SVR of pregnancy can result in lesser coronary perfusion to the myocardium

() The increase in HR during pregnancy can result in decreased coronary filling time

() Cardiac work can increase significantly during labor, especially painful labor

Severe LV dysfunction (e.g., dilated or peripartum cardiomyopathy)

() The increase in cardiac output and blood volume during pregnancy can result in heart failure/pulmonary edema

() The decrease in oncotic pressure during pregnancy can result in greater risk for pulmonary edema

() Angiotensive converting enzyme inhibitors must be stopped during pregnancy secondary to teratogenicity

() Patients with a prior episode of peripartum cardiomyopathy are at risk for further deterioration in LV function with subsequent pregnancies

Pulmonary hypertension

() The increased cardiac output of pregnancy may not be accommodated by the fixed pulmonary vasculature resulting in right heart failure and death

() The decreased SVR of pregnancy can decrease coronary filling to a dilating and failing right ventricle

() The hypercoagulable state of pregnancy can result in pulmonary emboli which are especially lethal in patients with pulmonary hypertension

Unstable arrhythmia history

() Pregnancy, labor, and delivery can trigger tachyarrhythmias

Aortopathy (e.g., Marfan syndrome)

() Pregnancy, labor, and delivery may increase dilation of aortic root

() Pregnancy, labor, and delivery increase the risk of aortic rupture in women with Marfan syndrome

Valvular lesions

Mechanical prosthetic valve

() Hypercoagulable state of pregnancy increases risk of valve thrombosis

() Vitamin K antagonists (most effective way to prevent valvular clot formation) are teratogenic; often suboptimal anticoagulation regimens are used during pregnancy

Mitral stenosis

() Because of relatively fixed preload to the LV, the heart may not be able to generate increased cardiac output and pulmonary edema will develop

() Decreased oncotic pressure further increases risk of pulmonary edema

() The increase in blood volume and heart rate in pregnancy increases left atrial pressure and may lead to atrial fibrillation and pulmonary edema

Aortic stenosis

() The decreased SVR of pregnancy can result in lesser coronary perfusion pressure to the thickened LV myocardium

() Because of LV diastolic dysfunction, excess volume can lead to pulmonary edema

Mitral/aortic insufficiency

(+) The decreased SVR results in a lesser regurgitant volume

() Pregnancy can worsen ventricular dilation

Shunt lesions

R-to-L shunt (e.g., TOF, Eisenmenger’s)

() The decrease in SVR increases right-to-left shunting and possible cyanosis

(+) In unrepaired TOF and normal RV function, the increase in blood volume is beneficial because adequate RV preload is necessary to eject blood past the outflow obstruction and increase pulmonary blood flowa

L-to-R shunt (e.g., VSD or ASD)

(+) The decrease in SVR decreases the left-to-right shunting

() The increase in blood volume can precipitate failure because the patient is in a state of compensatory hypervolemia

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Jul 17, 2021 | Posted by in OBSTETRICS | Comments Off on Anesthesia and Analgesia in the Pregnant Cardiac Patient
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