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

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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

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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

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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)

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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

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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

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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

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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

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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

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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.

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