The Parturient with Cardiac Disease
 
Epidemiology 
Mitral stenosis
Mitral regurgitation
Mitral valve prolapse
Aortic Stenosis
Aortic Insufficiency
Asymmetric Septal Hypertrophy
Coarctation of Aorta
Summary
References
Home-Amb-Card-Crit-Neuro-OB-Orth-Pain-Ped-Reg-Tran-Vasc-Misc

(from lecture by Kimberley R. Clemons, MD January 9, 2003)

Epidemiology of Cardiac Disease
0.2% to 3% of pregnancies complicated by maternal heart disease
Rheumatic heart disease accounts for majority of cases (~ 75%)
Female patients with congenital heart disease now living to childbearing age
Mortality based on NYHA classification of cardiovascular disease
Class I: Pts physical activity not limited by cardiac disease
Class II: Cardiac disease causes slight limitation in physical activity
Class III: Cardiac disease causes marked limitation in physical activity
Class IV: Cardiac disease causes inability to to carry on physical activity without discomfort
maternal mortality of Class I and II patients:<1% (asymptomatic patients)
maternal mortality of Class III and IV patients: 5-15% (e.g. severe MS)
perinatal mortality rates of Class III and Class IV patients range between 20-30%
Normal cardiovascular changes of pregnancy
plasma volume increases by 40-50%
cardiac output (CO) increases by 40-50% by term
increase in heart rate (20-30%) and stroke volume (11-32%)
decrease in SVR (20%)  and PVR (35%)
inc CO by 25% in late 1st stage
inc CO by 40% in 2nd stage
these changes reflect inc in sympathetic activity and autotransfusion from contractions
inc CO by 80% immediately post-partum
  tolerated well by normal parturients

Back to Top of Page
 

Mitral Stenosis
most common manifestation of rheumatic heart disease
incidence:  ~ 90%
symptoms develop ~ 30 years after rheumatic fever
Symptoms occur when mitral valve orifice <2cm² (normal: 4-6 cm²)
patients may present with fatigue, DOE, orthopnea, PND, and hemoptysis
auscultation may yield a diastolic murmur and an S4
CXR may reveal left atrial and right ventricular enlargement
ECG may demonstrate broadened p wave in V1 (LAE), right axis deviation, or afib (severe MS)
PCWP can be elevated to 25-30 mmHg (normal 0-12 mmHg)
Pregnancy can increase 1) pulmonary congestion (increased volume) and 2) dysrhythmias and tachycardia (decreased filling time)
Anesthetic considerations:
asymptomatic pts have only slightly increased risk; no additional monitors needed
pts with severe symptoms or evidence of advanced disease may require radial artery and pulmonary artery monitoring
Anesthetic goals:
1). Avoid tachycardia (diastolic filling time further decreased)
2). Avoid increases in blood volume (can result in pulmonary edema)
3). Avoid rapid and severe drops in SVR (compensatory increase in HR can lead to further decompensation)
Anesthetic Options
Vaginal delivery
epidurals or CSE decrease pain and tachycardia  from contractions (use dilute anesthetic concentrations)
left uterine displacement and fluids can prevent hypotension
delivery facilitated by vacuum extraction or forceps (prevent sudden inc central venous return after Valsalva)
phenylephrine- pressor of choice (no tachycardia)
C-section
if regional:  epidurals are preferred over spinals due to more predictability and control over hemodynamic changes.
if GA needed:
pts with mild MS can tolerate STP, intubation and light anesthesia
moderate-severe MS may require IV fentanyl or inhaled vapor induction
avoid drugs notorious for causing tachycardia

Back to Top of Page
 

Mitral Regurgitation
2nd most common valve disease in pregnancy
accounts for ~6.5% of cases of rheumatic heart disease
pts often asymptomatic for 30-40 years.  By 4th or 5th decade, they suffer from atrial fibrillation, systemic embolization, and bacterial endocarditis
patients may have a blowing pansystolic murmur at cardiac apex (radiating to axilla)
ECG may be normal if mild, but can show LVH or RVH if severe
CXR may be normal if mild, but LVH or RVH if severe
In pregnancy:
normally SVR is decreased, promoting forward flow and reducing regurgitant fraction
pregnancy can drive an already overloaded system into pulmonary congestion (secondary to increased blood volume)
pain, fear, and contractions during labor can increase SVR and decrease forward flow
Anesthetic goals:
1). Prevent inc in SVR:  afterload reduction with SNP or phentolamine
2). Treat new onset a-fib aggressively with cardioversion (can decrease LV function)
3). Avoid myocardial depressants
4). Avoid bradycardia; CO depends on HR, since stroke volume is limited
5). Prevent pain, hypoxemia, and hypercarbia which inc PVR
Anesthetic Options:
regional anesthesia (epidurals or CSE) may  be used for vaginal delivery or C-section: òSVR
left uterine displacement and fluid administration to maintain central venous return
if GA needed:
  pt with good heart function can tolerate a standard induction with halogenated volatile anesthetic for maintenance.
pt with poor heart function: N2O/narcotic/ SNP technique

Back to Top of Page
 

Mitral Valve Prolapse
most common congenital valvular lesion
incidence- 5-10% in women of childbearing age
85% of pts asymptomatic
pts with symptoms may experience palpitations, anxiety, and lighteheadedness
~15% of pts progress to MR
pts may have arrhythmias (i.e. PSVT 2° to alternative electrical tracts)
pregnancy does not have much influence on MVP
Anesthetic goals
1). maintain preload (decreases degree of prolapse)
2). continue antiarrhthymic therapy
3). avoid vasoconstriction (particuarly in pts with MR)
Anesthetic Options:
vaginal delivery- epidurals or CSE can be used (promote forward flow)
C-section:  regional can be used safely (maintain intravascular volume);
GA:
1) good heart function can tolerate volatile anesthetics;
2) poor heart function can benefit from N2O/narcotic (less myocardial depression)

Back to Top of Page
 

Aortic Stenosis
incidence 0.5- 3.0%
most pts symptomatic in 5th or 6th decade of life
symptoms, including exertional dyspnea, angina, and syncope, occur when aortic valve area < 0.75 cm² (normal 2.6-3.5 cm²)
valve area: better determinant of disease severity (pressure gradients can be increased 2° inc blood flow of pregnancy)
systolic ejection murmur in 2nd intercostal space (radiating to neck)
ECG may reveal LVH and/or LBBB
CXR demonstrates LVE, aortic valve calcification, and post-stenotic dilatation of ascending aorta
Anesthetic goals:
1). maintain SVR- these pts have relative fixed stroke volume, so they need to ñ heart rate to ñ CO
2). maintain normal HR (tachycardia â coronary filling; bradycardia â CO)
3). maintain good preload, as decreases in ventricular filling--> òstroke volume and cardiac output
Anesthetic options
regional anesthesia
epidurals, CSE, or spinal catheters
may be used for vaginal delivery or c-section (use dilute anesthetic concentrations and titrate anesthesia slowly)
avoid profound sympathectomy which can decrease central venous return
C-section under GA
etomidate and narcotic-based induction may result in less myocardial depression
Halogenated agents may be used unless the patient has severe LV dysfunction
N2O/ narcotic technique suitable alternative in pts with poor heart function

Back to Top of Page
 

Aortic Insufficiency
incidence ~2.5% of pts with rheumatic heart disease
signs and symptoms don't appear until 4th-5th decade
signs include: widened pulse pressure, low diastolic BP, bounding peripheral pulses, early blowing diastolic murmur at LSB (2nd-4th IC space)
symptoms relate to LV failure: DOE, orthopnea, PND; Late: RV failure
ECG may reveal inc QRS interval, depressed ST segments, inverted T waves, horizontal axis
In pregnancy:
Lesion well tolerated
reduced regurgitant flow 2° dec SVR and inc HR
Increased blood volume maintain filling pressures
In labor:
inc intravascular volume (autotransfusion) and inc SVR (pain, fear, etc) can dec LV function
Anesthetic goals:
1) prevent inc SVR with afterload redcution (i.e. SNP and/or epidural anesthesia)
2) avoid bradycardia==> inc regurgitant blood flow
3) avoid myocardial depressants
Anesthetic options:
regional anesthesia (i.e. epidurals) recommended  (if titrated slowly) for vaginal delivery or c-section  because of âSVR
if  c-section emergent and GA needed, avoid myocardial depressants

Back to Top of Page
 

Asymmetric Septal Hypertrophy
also known as hypertrophic obstructive cardiomyopathy (HOCM)
congenital lesion with autosomal dominant inheritance
incidence: 0.1% to 0.5% of parturients
characterized by hypertrophy of IV septum and outflow tract, resulting in obstruction to ejection during ventricular systole
signs and symptoms appear in 3rd or 4th decade
symptoms include: angina, syncope, and exertional dsypnea
ECG can demonstrate LVH, WPW syndrome, or abnormal Q waves in inferior and precordial leads
CXR reveals enlarged LV
In pregnancy:
inc volume  causes LV distention and â outflow obstruction
â SVR and inc HR and contractility can cause LV failure
symptomatic parturients should be monitored with radial artery and pulmonary artery catheters
Anesthetic goals:
maintain preload: â outflow obstruction
treat dysrhythmias (e.g. PSVT, a-fib, and atrial flutter) aggressively
maintain normal to elevated SVR: â outflow obstruction (phenylephrine)
avoid inc in contractility
Anesthetic options:
regional anesthesia relatively contraindicated because of vasodilation and â central blood volume
pts who deliver vaginally tolerate epidurals and CSEs or spinal catheters (using intrathecal opioids alone); maintain preload and SVR
pts requiring c-section
can likely tolerate slow titration of epidural (if euvolemia maintained), but not single-shot spinal 2° rapid sympathectomy
if GA required, pts can tolerate volatile agents, because they â contractility

Back to Top of Page
 

Coarctation of Aorta
represents 8% of all congenital heart disease in adults
males > females (3:1)
most patients are corrected early in childhood
corrected parturients have a normal risk of morbidity and mortality
occasionally seen uncorrected in obstetric population
uncorrected parturients have mortality of 3-9%
pts at risk for LV failure, aortic rupture, endocarditis, and COW aneurysms
fetal mortality may be as high as 20%      (2° â uterine perfusion)
pts have BP differences between upper and lower extremities or between right and left extremities
ECG reveals LVH (late finding)
CXR demonstrates LV enlargement or "3" sign in aortic knob
fixed stroke volume; inc HR==> inc CO
in pregnancy:
inc HR may not accommodate inc intravascular volume==>LV failure
inc HR and contractility==> aortic dissection
asymptomatic pts require no special monitoring
pts with LV enlargement or dysfunction may require radial artery and pulmonary artery monitoring
Anesthetic goals:
maintain SVR (use phenylephrine or 'light anesthesia')
maintain normal HR (CO dependent on HR)
maintain preload and LV filling
treat atrial dsyrhythmias aggressively
Anesthetic options:
systemic medication with pudendal nerve block is recommended for pts delivering vaginally
pts undergoing c-section can benefit from light GA with N2O-narcotic technique, which can keep HR, SVR, and contractility elevated

Back to Top of Page
 

Summary
Cardiac disease still occurs frequently in obstetric population
Rheumatic heart disease incidence decreasing, but pts with congenital heart disease are surviving longer and into childbearing years
Patients require significant thought and planning for their anesthetic management
Best approach for safe outcome: multidisciplinary treatment by obstetrician, cardiologist, and anesthesiologist

Back to Top of Page
 

References
1). Autore, C, Brauneis, S. et al.; "Epidural Anesthesia for Cesarean section in patients with hypertrophic cardiomyopathy:  a report of 3 cases; Anesthesiology90 (4): 1205-1207.
2). Brighouse, D; "Anesthesia for C-section in patients with aortic stenosis"; Anesthesia; 1998; Vol 53: p 107-112.
3). Camann, W. and Thornhill, M. "Cardiovascular disease in pregnancy" in Chesnut, DH Obstetric Anesthesia:  principles and practice (2nd edition); Mosby; St Louis.
4). Dessole, S., D'Antona, et al. "Pregnancy and delivery in young women affected by ishthmic coarctation of aorta"; Arch Gynecol Obstet; 2000; Vol 263: p 145-147.
5). Gei, AF and Hankins, G; "Medical Complications of pregnancy: cardiac disease and pregnancy"; Obstetric and Gyn Clinics; 2001; 28 (3): 465-512.
6). Jayasinghe, C and Blass, N; "Perspectives in Pain Management: pain management in Critically Ill Obstetric patient"; Critical Care Clinics; 1999; 15 (1): p. 201-228.
7). Mangano, D. " Anesthesia for pregnant cardiac patient" in Schnider and Levinson's Anesthesia for Obstetrics; Lippincott, Williams, & Wilkins; Philadelphia; 2001; p. 455-480.
8). Okutomi, T., Kikuchi, S. et al. "Continuous Spinal Analgesia for labor and delivery in a parturient with hypertrophic obstructive cardiomyopathy" Acta Anaesthesiol Scand; 2002; Vol 46: p 329-331.

Back to Top of Page

Home-Amb-Card-Crit-Neuro-OB-Orth-Pain-Ped-Reg-Tran-Vasc-Misc