OutlineOutline

The critical physiological changes of pregnancy.The critical physiological changes of pregnancy.

Predictors of cardiac events during pregnancyPredictors of cardiac events during pregnancy

Risk of cardiovascular complications during Risk of cardiovascular complications during pregnancypregnancy

Anesthetic management parturient with Anesthetic management parturient with valvular valvular diseases.diseases.

What are the critical physiological changes What are the critical physiological changes of pregnancy that affects a parturient with of pregnancy that affects a parturient with

cardiac disease ?cardiac disease ? 50% increase in the blood volume50% increase in the blood volume 40% increase in cardiac output40% increase in cardiac output 25% increase in heart rate to 25% increase in heart rate to

approximately 80-100 beats/min. approximately 80-100 beats/min. Reduced systemic vascular resistance Reduced systemic vascular resistance

and pulmonary vascular resistance.and pulmonary vascular resistance. Labor and delivery itself imposes Labor and delivery itself imposes

approximately 50% increase in CO and approximately 50% increase in CO and oxygen demand.oxygen demand.

The main predictors of cardiac The main predictors of cardiac events during pregnancy areevents during pregnancy are::

Prior cardiac events: (heart failure, transient Prior cardiac events: (heart failure, transient ischemic attack, stroke, or dysrrhythmias).ischemic attack, stroke, or dysrrhythmias).

Baseline New York Heart association Baseline New York Heart association functional class≥ II or the presence of functional class≥ II or the presence of cyanosis.cyanosis.

Left heart obstruction: (mitral valve area ≤ Left heart obstruction: (mitral valve area ≤ 2cm2cm22, aortic valve area ≤ 1.5 cm, aortic valve area ≤ 1.5 cm22, or left , or left ventricular outflow tract gradient ≥ 30mmHg by ventricular outflow tract gradient ≥ 30mmHg by echocardiography).echocardiography).

Reduced left ventricular function (ejection Reduced left ventricular function (ejection fraction ≤ 40%). fraction ≤ 40%).

Many of the signs and symptoms of normal Many of the signs and symptoms of normal pregnancy can mimic those of cardiac diseasepregnancy can mimic those of cardiac disease..

For example: Dyspnea due to LV failureFor example: Dyspnea due to LV failure

FromFrom Labored breathing typical Labored breathing typical

of normal pregnancyof normal pregnancy Leg edema due to CHFLeg edema due to CHF

FromFrom Venous stasis due to Venous stasis due to

aortocaval compressionaortocaval compression

heart murmurs due toheart murmurs due to

organic lesionsorganic lesions

fromfrom those due to increased those due to increased

blood flowblood flow

Rotation of the maternalRotation of the maternal

heart, because ofheart, because of

elevation of the diaphragmelevation of the diaphragm

fromfrom cardiac hypertrophy cardiac hypertrophy..

C.O: 30-50% during gestationC.O: 30-50% during gestation

30-45%30-45% during laborduring labor

After deliveryAfter delivery 50%50%of patients with symptoms of heart disease of patients with symptoms of heart disease

during minimal activity or at rest when not during minimal activity or at rest when not pregnant develop CHF during pregnancypregnant develop CHF during pregnancy..

Circulatory Changes and Co.ExistingCirculatory Changes and Co.Existing

HeartDiseaseHeartDisease

Risk of cardiovascular Risk of cardiovascular complications during pregnancycomplications during pregnancy

Risk of Risk of

cardiovascular

complications complications during pregnancyduring pregnancy

Low risk

of

complications (≤ 1%)

Intermediate risk risk

of of

complications (5-15%)complications (5-15%)

High risk risk

of of

complications complications

or death (≥25%)or death (≥25%)

Low risk of complications (≤ 1%):Low risk of complications (≤ 1%):Corrected tetralogy of fallotCorrected tetralogy of fallotAtrial septal defectAtrial septal defectVentricular septal defectVentricular septal defectPatent ductus arteriosusPatent ductus arteriosusMild pulmonic or tricuspid valve diseaseMild pulmonic or tricuspid valve diseaseMitral stenosis (NYHA class I, II)Mitral stenosis (NYHA class I, II)Mild regurgitant valve lesionMild regurgitant valve lesionBioprosthetic valveBioprosthetic valveCompensated heart failure (NYHA class I, II)Compensated heart failure (NYHA class I, II)

Intermediate risk of complications (5-Intermediate risk of complications (5-15%):15%):Mechanical valve prosthesisMechanical valve prosthesisAortic stenosis (mild to moderate)Aortic stenosis (mild to moderate)Mitral stenosis with atrial fibrillationMitral stenosis with atrial fibrillationMitral stenosis (NYHA class III, IV)Mitral stenosis (NYHA class III, IV)Uncorrected cyanotic congenital heart Uncorrected cyanotic congenital heart

disease (tetralogy of fallot)disease (tetralogy of fallot)Uncorrected coarctation of the aortaUncorrected coarctation of the aortaPrevious myocardial infarctionPrevious myocardial infarction

High risk of complications or death High risk of complications or death (≥25%):(≥25%):Pulmonary hypertension (severe)Pulmonary hypertension (severe)Eisenminger syndromeEisenminger syndromeMarfan disease with aortic root involvementMarfan disease with aortic root involvementPeripartum cardiomyopathyPeripartum cardiomyopathySevere aortic stenosisSevere aortic stenosisNYHA class IV heart failureNYHA class IV heart failure

One of the most common maternal heart diseases One of the most common maternal heart diseases areare::

Acquired valvular heart diseasesAcquired valvular heart diseases includedincluded:: MSMS (the most common type of cardiac(the most common type of cardiac

(( valvular defect in pregnantvalvular defect in pregnant MRMR (the second most common cardiac(the second most common cardiac

valvular defect seen in pregnancyvalvular defect seen in pregnancy(( ASAS ( rarely seen in pregnancy(( rarely seen in pregnancy(

AIAI ( is not common in pregnancy(( is not common in pregnancy(

Valvular Heart Disease:Valvular Heart Disease:

In general regurgitant valvular lesions In general regurgitant valvular lesions are well tolerated during pregnancy, are well tolerated during pregnancy, where as where as stenotic lesionsstenotic lesions have a have a greater potential for decompensationgreater potential for decompensation. .

Pregnant patients with valvular heart Pregnant patients with valvular heart disease can expect to have disease can expect to have worseningworsening of their New York Heart Association of their New York Heart Association (NYHA) functional class(NYHA) functional class, while others , while others may have adverse foetal outcome i.e. may have adverse foetal outcome i.e. preterm birth or still birth.preterm birth or still birth.

Mitral stenosis (MS):Mitral stenosis (MS):

Normal mitral valve orifice has a Normal mitral valve orifice has a surface area of4-6cms2, in mild surface area of4-6cms2, in mild stenosis the valve area stenosis the valve area (1.5 to 3 cm(1.5 to 3 cm22),), moderate mitral stenosis the valve moderate mitral stenosis the valve area area (1.1 to 1.5 cm(1.1 to 1.5 cm22),), while severe while severe mitral stenosis the valve area mitral stenosis the valve area (less (less than 1cmthan 1cm22).).

Mitral valve Mitral valve stenosis prevents stenosis prevents emptying of the left emptying of the left atrium (LA), with atrium (LA), with increased left atrial increased left atrial and pulmonary and pulmonary artery pressure, artery pressure, resulting in resulting in dyspnoeadyspnoea, , haemoptysishaemoptysis and and pulmonary pulmonary oedemaoedema..

Mitral stenosis (cont.):Mitral stenosis (cont.):

Peripartum considerations:Peripartum considerations:The hyperdynamic state of pregnancy is The hyperdynamic state of pregnancy is

poorly tolerated by women with poorly tolerated by women with severe mitral stenosis:severe mitral stenosis:

Increased plasma volume can cause Increased plasma volume can cause pulmonary edema and worsen the left pulmonary edema and worsen the left atrial enlargement.atrial enlargement.

Tachycardia decreases the left Tachycardia decreases the left ventricular diastolic filling through ventricular diastolic filling through the stenotic valve.the stenotic valve.

AF is common with MS, with loss of AF is common with MS, with loss of the atrial kick; which accounts for = the atrial kick; which accounts for = 30% of the left ventricular stroke 30% of the left ventricular stroke volume. Medical management of AF volume. Medical management of AF by a beta-adrenergic blocking agent.by a beta-adrenergic blocking agent.

Anesthetic considerations:Anesthetic considerations:

Should be based on the severity of the Should be based on the severity of the lesion,( according to the valve area, and the lesion,( according to the valve area, and the hemodynamic stability of the patient).hemodynamic stability of the patient).

Avoid increased heart rate.Avoid increased heart rate. Maintain venous return and SVR.Maintain venous return and SVR. Avoid aorto-caval compression.Avoid aorto-caval compression. Treat atrial fibrillation (AF) aggressively.Treat atrial fibrillation (AF) aggressively. Maintain sinus rhythm.Maintain sinus rhythm. Prevent pain, hypoxaemia, hypercarbia and Prevent pain, hypoxaemia, hypercarbia and

acidosis as these can increase PVR.acidosis as these can increase PVR.

There are increased incidence ofThere are increased incidence of:: Pulmonary edemaPulmonary edema

Atrial fibrilationAtrial fibrilation Paroxismal atrial tachycardiaParoxismal atrial tachycardia

Control of the heart rate is criticalControl of the heart rate is critical Excessive perioperative fluid administrationExcessive perioperative fluid administrationTrendelenburg positionTrendelenburg position

Autotransfusion (via uterine contraction( Autotransfusion (via uterine contraction( central central blood volume blood volume CHF CHF..

Pregnant patients with Mitral Pregnant patients with Mitral StenosisStenosis

Invasive monitoring is usually not necessary in the Invasive monitoring is usually not necessary in the absence of cardiac symptomsabsence of cardiac symptoms . .

Exceptions are parturients withExceptions are parturients with:: Pulmonary hypertensionPulmonary hypertension

Right-to-left intracardiac shuntsRight-to-left intracardiac shunts Coarctation of the aortaCoarctation of the aorta

invasive cardiac monitoring should be continued invasive cardiac monitoring should be continued for for 48 hours48 hours after delivery after delivery

MonitoringMonitoring

Spinal anesthesiaSpinal anesthesia

For most elective and urgent C/SFor most elective and urgent C/S

Epidural anesthesiaEpidural anesthesia

Decrease likelihood of hypotensionDecrease likelihood of hypotension

Combined Spinal-Epidural anesthesiaCombined Spinal-Epidural anesthesia

General anesthesiaGeneral anesthesia

Anesthetic techniqueAnesthetic technique

AdvantagesAdvantages: : --A decreased risk of failed intubation and aspirationA decreased risk of failed intubation and aspiration

of gastric contentsof gastric contents- - Avoidance of depressant agentsAvoidance of depressant agents

- - The ability of the mother to remain awakeThe ability of the mother to remain awake and enjoy the birthing experienceand enjoy the birthing experience

- - ReducedReduced blood lossblood lossDisadvantagesDisadvantages::

- - Dural punctureDural puncture - - Reduced SVR & BPReduced SVR & BP

- - Slower onsetSlower onset

Neuraxial anesthesia techniquesNeuraxial anesthesia techniques

AdvantagesAdvantages:: - -Speed of inductionSpeed of induction

- - Control of the airwayControl of the airway - - Superior homodynamicSuperior homodynamic

DisadvantagesDisadvantages:: - -Failed intubationFailed intubation

- - Pulmonary aspiration of gastric contentsPulmonary aspiration of gastric contents - - Neonatal depressionNeonatal depression - - Maternal awarenessMaternal awareness

General anesthesia techniqueGeneral anesthesia technique

Regurgitation of blood Regurgitation of blood through an incompetent mitral through an incompetent mitral valve valve chronic volume over chronic volume over load and dilatation of the LAload and dilatation of the LA

In the acute type, there is In the acute type, there is acute pulmonary congestion acute pulmonary congestion and pulmonary edema results.and pulmonary edema results.

If the patient survives this If the patient survives this episode of acute mitral episode of acute mitral regurgitation, pulmonary regurgitation, pulmonary artery pressure continues to artery pressure continues to increase and right heart increase and right heart failure occurs.failure occurs.

Mitral Regurgitation (MR):Mitral Regurgitation (MR):

Anesthetic consideration:Anesthetic consideration:

Primary considerations are:Primary considerations are:Maintain slightly increased heart rateMaintain slightly increased heart ratePrevent increase in SVR.Prevent increase in SVR.Prevent hypoxemia, hypercarbia, Prevent hypoxemia, hypercarbia,

acidosis which may increase PVR.acidosis which may increase PVR.Avoid aortocaval compression and Avoid aortocaval compression and

myocardial depression.myocardial depression.

Aortic stenosis (AS):Aortic stenosis (AS):

The pathophysiology of The pathophysiology of severe ASsevere AS entail a entail a narrowing of the valve to narrowing of the valve to less than 1 cmless than 1 cm22 associated with a trans-valvular gradient of associated with a trans-valvular gradient of 50mmHg with significant increase in after 50mmHg with significant increase in after load to the LV. load to the LV.

A valvular gradient which exceeds 100mmHg A valvular gradient which exceeds 100mmHg carries an increased risk of myocardial carries an increased risk of myocardial ischemia as the LV hypertrophies ischemia as the LV hypertrophies significantly.significantly.

In aortic stenosis In aortic stenosis transvalvular gradient transvalvular gradient increasesincreases progressively progressively throughout throughout pregnancypregnancy, due to increasing blood volume , due to increasing blood volume and decreasing SVRand decreasing SVR

Avoid tachycardia (decrease Avoid tachycardia (decrease time for coronary perfusion of time for coronary perfusion of the hypertrophied LV), and the hypertrophied LV), and bradycardia (slow heart rate bradycardia (slow heart rate decreases CO).decreases CO).

Maintain intravascular volume Maintain intravascular volume and venous return.and venous return.

Avoid aortocaval compression Avoid aortocaval compression and myocardial depression. and myocardial depression.

Arrhythmias are not well Arrhythmias are not well tolerated and should be tolerated and should be promptly treated.promptly treated.

Patients with Patients with trans-valvular trans-valvular gradient more than 50mmHggradient more than 50mmHg with symptomatic AS should with symptomatic AS should have have invasive monitoring i.e. invasive monitoring i.e. A-line and PA catheter in place.A-line and PA catheter in place.

Anaesthetic considerations:

Aortic regurge (AR):Aortic regurge (AR):

The pathophysiology is chronic The pathophysiology is chronic volume overload of the LV, with volume overload of the LV, with hypertrophy and dilatation and hypertrophy and dilatation and increase in LV End Diastolic increase in LV End Diastolic Volume (LVEDV), decrease in Volume (LVEDV), decrease in ejection fraction (EF) and signs and ejection fraction (EF) and signs and symptoms of pulmonary edema. symptoms of pulmonary edema.

Patients with aortic insufficiency Patients with aortic insufficiency tolerate pregnancy well as tolerate pregnancy well as pregnancy results in a modest pregnancy results in a modest increase in heart rate.increase in heart rate.

Anaesthetic considerations:Anaesthetic considerations:Prevent catecholamine – induced Prevent catecholamine – induced

increases in SVR due to pain, and increases in SVR due to pain, and avoid bradycardia, which may avoid bradycardia, which may increase regurgitant flow.increase regurgitant flow.