PHYSIOLOGICAL CHANGES IN PREGNANCY Dr. Sreejith V

Beginning of labor : > 7 L/min Uterine contraction : > 9 L/Min Anesthesia : < 8 L/min Post partum CO continues to increase upto 72 hours due to auto transfusion from uterus and reabsorption of edema fluid CO falls to non pregnant values in a few wks after delivery CO In labor

CCF In ventricular dysfunction The tachycardia reduces the time for diastolic filling in MS, with resultant increase in left atrial pressure. Mitral regurgitation, the afterload reduction helps offset the volume load on the left ventricle that gestation imposes. Effect of these changes in CVD

Tricuspid Pulmonic Pulmonary capillaries Mitral Aortic stenosis Resistance arterioles Aortic stenosis at rest  Cardiac output not sufficient to cause critically high LV intracavitary pressure / LV failure. LV dilation / hypertrophy

Tricuspid Pulmonic Pulmonary capillaries (edema) Mitral Aortic Stenosis Resistance arterioles– decreased SVR Aortic stenosis with increased cardiac output / arteriolar vasodilation: Decreased SVR  Fall in systemic BP and / or increase in LV intracavitary pressure  ischemia or LV failure. LV failure / ischemia

CO Variation with position

Clinical Findings in Normal Pregnancy Elevated JVP [↑plasma vol] Tachycardia low DBP PP ↑ [bounding pulses] Apex slightly left & up, prominent impulse ↓B.S. at lung bases Pedal oedema : ↑ plasma vol & venous pressures S1 Loud S2 wide split, accentuated [P2 delayed] S3 Flow aortic, pulm; ESM cervical venous hum, mammary souffle

Investiga tion Comments ECG Tachycardia LAD [ elev. Diaphragm] Increased ventricular voltage Increased Atrial & Ventricular ectopics Q wave and inverted T in lead III, an attenuated Q wave in lead AVF, and inverted T in leads V1, V2, and, occasionally,V3 CXR CE Horizontal shift of heart Fullness of Left cardiac border & pulmonary vasc Echo LV mass increased, LVED increased, RV & both Atrial enlarges Increased LVOT & RVOT velocities [gradients less reliable marker of stenotic severity, 2D valve area best] Pros. Valve- valve gradients, PHT serial changes to be measured Systolic function increases first but may decrease in the last trimester

Hypercoagulable state … Series of haemostatic changes, Increase in concentration of coagulation factors Platelet adhesivenes Diminished fibrinolysis Hypercoagulability and an increased risk of thrombo-embolic events. Obstruction to venous return by the enlarging uterus

Drug clearance Increased intravascular blood volume Higher dosages of drugs required to achieve therapeutic plasma concentrations, Increase drug clearance Raised renal perfusion Higher hepatic metabolism

CONGENITAL HEART DISEASES COMPLICATING PREGNANCY

PAH Sev. Ventricular dysfunction (LVEF <30%, NYHA III - IV) Sev. MS sev. symptomatic AS Marfan syndrome : Aorta >45 mm BAV : Aorta > 50 mm Severe coarctation WHO CLASS IV RISK

Statistics Hypertensive disorders : 6–8% Congenital heart disease –western world Rheumatic valvular disease in non-western Leading causes of maternal death are acquired disease, Myocardial infarction, Aortic dissection, Cardiomyopathy

Cardiac evaluation Measure the bp, in left lateral recumbency Proteinuria Oximetry BNP < 100 pg/mL - negative predictive value ECG ECHO Murmur and Dyspnoe Flow velocities increased TEE-safe TMT- Pre pregnancy Safe in pregnancy also To assess the functional class, and saturation <70% of predicted functional aerobic capacity Cycle

Radiological investigation There is no evidence of an increased fetal risk at doses of radiation of 50 mGy There may be a small increase in risk of childhood cancer. (1:2000 vs. 1:3000)

MRI Useful to image Ao Avoid gadolinium Should be used in all patient s suspected of ascending Ao Enlargement

Fetal Genetic Risk The recurrence risk varies between 3% and 50% Autosomal dominant Disoders - risk of 50%, Marfan syndrome, Hypertrophic cardiomyopathy long QT syndrome General Population 1%

Screening Genetic screening – chorionic villous biopsy can be offered in the 12th week Fetal echocardiography 19th to 22nd week Nuchal fold thickness 12th to 13 th week For women over 35 years of age. The sensitivity for the presence of a significant heart defect is 40%, The specificity of the method is 99%. The incidence of congenital heart disease with normal nuchal fold thickness is 1/1000

General Principles of Obstetric care

Antenatal Follow up Ranging from routine follow up to continuous hospital admission Preferably in Tertiary care centre with cardiac and cardiac surgical facilities Clinical examination and follow up echo Saturation

Induction of Labor Oxytocin and artificial rupture of the membranes are indicated when the Bishop score is favourable. A long induction time should be avoided if the cervix is unfavourable. Misoprostol or dinoprostone- there is a theoretical risk of coronary vasospasm and a low risk of arrhythmias. Dinoprostone also has more profound effects onBP than prostaglandin E1 and is therefore contraindicated in active CVD.

Vaginal or caesarean delivery The preferred mode of delivery is vaginal Caesarean delivery should be considered for obstetric indications Cardiac Indications- Dilatation of the ascending aorta >45 mm, Severe aortic stenosis, Pre-term labor while on oral anticoagulants Eisenmenger syndrome, Severe OR worsening heart failure Mechanical prosthesis

Labor Once in labor, the woman should be placed in a lateral decubitus position to attenuate the haemodynamic impact of uterine contractions. Avoid maternal pushing, to avoid the unwanted effects of the Valsalva Delivery may be assisted by low forceps or vacuum extraction. Continuous electronic fetal heart rate monitoring is recommended.

Anaesthesia Lumbar epidural analgesia is recommendable to reduce pain Regional anaesthesia can cause systemic hypotension and must be used with caution in patients with obstructive valve lesions.

IE prophylaxis Not recommended

Post-partum care Slow i.v. infusion of oxytocin Prostaglandin F analogues to treat post-partum haemorrhage Methylergonovine is contraindicated because of the risk of vasoconstriction and hypertension. Meticulous leg care, elastic support stockings, and early ambulation are important to reduce the risk of thrombo- embolism

Contraception Barrier methods (condom) The levonorgestrel releasing intrauterine device The safest and most effective 5% of patients experience vasovagal reactions at the time of implant Progesterone only pills or dermal implants Highly complex heart disease (e.g. Fontan, Eisenmenger) A copper intrauterine device is acceptable in non- cyanotic or mildly cyanotic women.

After 4 th month in 2 nd trimester By this time Organogenesis is complete The fetal thyroid is inactive Uterus size small Percutaneous therapy

b/w 20th & 28th wk 1 st trimester : high risk of fetal malformations 3 rd trimester : high incidence of preterm delivery & maternal complications Maternal complications are comparable to non-pregnant Cardiac surgery with cardiopulmonary bypass

Cardiac problems

Predictors of cardiac events Prior cardiac event Heart failure Transient ischemic attack Stroke Arrhythmia (NYHA) class higher than class II Cyanosis Left-sided heart obstruction MVA < 2 cm2 AVA < 1.5 cm2, EF < 40% Mechanical valve

NYHA class III / IV or cyanosis Previous cardiovascular event Left heart obstruction Ejection fraction ≤0.40 No. of points % Adverse Events > Predictors of Cardiovascular Events during Pregnancy

Specific lesions

Cyanosis Fetal and maternal hypoxia Increased thromboembolism Increased right to left shunt Worsening desaturation Paradoxical embolism

Cyanosis managment Restriction of physical activity Monitoring oxygen saturation Supplemental oxygen Prevention of venous stasis Use of compression stockings Avoiding the supine position For prolonged bed rest, prophylactic heparin administration

Pulmonary hypertension When the pulmonary hypertension exceeds approximately 60% of systemic levels, more likely to be associated with complications. Pulmonary hypertensive crises Pulmonary thrombosis Refractory right heart failure. Occurs even in patients with little or no disability before or during pregnancy. Maternal death –in the last trimester and in the first months after delivery

Pulmonary hypertension Maintain circulating volume, Avoid systemic hypotension, Avoid hypoxia, and acidosis which may precipitate refractory heart failure. Supplemental oxygen - if there is hypoxaemia. Prostacyclin or aerosolized iloprost, sildenafil, NO Continuation of existing therapy Teratogenic effects of bosentan.

Eisenmenger Pulmonary hypertension with cyanosis With a live birth unlikely if oxygen saturation is,85%. Maternal death as high as 50%

Eisenmenger The risks and benefits of anticoagulation considered on an individual patient basis. Diuretics The lowest effective dose Avoid haemoconcentration Intravascular volume depletion. Microcytosis and iron deficiency frequently seen Supplemental iron.

Common L to R shunt complicating pregnancy Prognosis Pulm hypertension Functional status Size of shunt Even large shunts are well tolerated if Pul. resistance < 3.0 WU Prior closure make pregnancy safer ASD

Ventricular septal defect Depends on the severity of PH Functional status LV dimentions Small VSD- CLASS I Pre-eclampsia may occur more often than in the normal population Vaginal delivery

Atrioventricular septal defect Arrhythmias Worsening of NYHA class Worsening of AV valve regurgitation PAH Cyanosis Paradoxical embolization Offspring mortality due to the occurrence of complex congenital heart disease Ostium primum ASD may be well tolerated

Pulmonary valve stenosis Relatively well tolerated if the right ventricular pressure is less than 70% of systemic pressure Right ventricular failure Arrhythmias. Balloon valvuloplasty if PG>64 CS- severe PS and in NYHA class III/IV despite OMT

Tetralogy of Fallot Pre repair Arrhythmias, heart failure, thrombo-embolism Progressive aortic root dilatation, Endocarditis Post repair Palliation – depends on the degree of cyanosis Dysfunction of the right ventricle Moderate to severe pulmonary regurgitation Screening for 22q11 deletion - %

Pulmonary regurgitation Severe pulmonary regurgitation An independent predictor of maternal complication Bad outcome in patients with impaired ventricular fn.. Pulmonary valve replacement Pre -pregnancy Preferably bioprosthesis TPVI – for refractory heart failure

Ebstein’s anomaly Outcome depend on The severity of the TR The functional capacity of the right ventricle Cyanosis Previous cardiac event Usually be managed medically during pregnancy. Echocardiographic surveillance of RV function Early caesarean delivery If RV function deteriorates

Transposition of the great arteries Post operative- WHO risk class III. Atrial repair Atrial arrhythmia Severe impairment of RV function Great arterial repair Obstruction Regurgitation Bradycardia or junctional rhythm - b-blockers cautious An irreversible decline in RV function in 10%

Congenitally corrected transposition of the great arteries WHO risk class III. Pre -disposed to developing AV block B-blockers must be used with extreme caution. An irreversible decline in RV function has been described in 10% Class 4 NYHA III or IV, EF < 40% severe TR

Fontan circulation Successful pregnancy is possible in selected patients with intensive monitoring - class III Class 4 Patients with oxygen saturation,85% at rest, Depressed ventricular function, and/or moderate to severe AV regurgitation Protein-losing enteropathy

Aortic Stenosis Severe AS – CI Bicuspid aortic valve - imaging of the ascending aorta before pregnancy, CS

Coarctation of the aorta Repaired Restenosis Site rupture Unrepaired Hypertension Risk of aortic rupture Rupture of a cerebral aneurysm PIH Associated bicuspid aortic valve- aortic dilation

Coarctation of the aorta Close surveillance of BP Avoid aggressive treatment to prevent placental hypoperfusion. PCI is associated with a higher risk of aortic dissection Should only be performed if severe hypertension persists despite maximal medical therapy and there is maternal or fetal compromise. The use of covered stents may lower the risk of dissection.

Aortic dilation Marfan syndrome Ehlers–Danlos syndrome Bicuspid aortic valve Turner syndrome Annuloaortic ectasia Tetralogy of Fallot Aortic coarctation Hyperrtension, Atherosclerosis

Aortic dilation Increased the susceptibility to dissection Haemodynamic changes Hormonal changes which lead to histological changes in the aorta Dissection timing Last trimester of pregnancy (50%) The early postpartum period (33%) The diagnosis of aortic dissection should be considered in all patients with chest pain during pregnancy as this diagnosis is often missed.

Marfan syndrome, Bicuspid aortic valve Factors for dissection Family history of dissection, Rapid growth Following elective aortic root replacement, patients remain at risk for dissection in the residual aorta. 50% of the patients with a bicuspid aortic valve and AS have dilatation of the ascending aorta Associated Mitral regurgitation

Ehlers–Danlos syndrome type 4 Increased bruising Hernias Varicosities Rupture of large vessels Rupture of the uterus. Contraindication for pregnancy

Management of aortic complicaltions Monitoring by echocardiography at 4–12 week intervals throughout the pregnancy and 6 months post-partum b-blockers in patients with Marfan syndrome Celiprolol - Ehlers–Danlos syndrome type IV Fetal growth should be monitored when the mother is taking b-blockers.

Surgery Marfan syndrome - pre-pregnancy surgery is recommended when the ascending aorta is ≥45 mm, Bicuspid AV - pre-pregnancy surgery should be considered when the ascending aorta is ≥50 mm. If progressive dilatation occurs during pregnancy, before the fetus is viable, aortic repair with the fetus in utero should be considered. When the fetus is viable, caesarean delivery followed directly by aortic surgery is recommended

Mode of delivery CS should be considered when the aortic diameter exceeds 45 mm If 40– 45 mm, vaginal delivery with expedited second stage and regional anaesthesia is advised to prevent BP peaks, which may induce dissection. Caesarean delivery may also be considered in patients with Ao 40-45, based on the individual situation.

Hypertrophic cardiomyopathy Frequently diagnosed for the first time in pregnancy by echocardiography. Intermittent high catecholamine state of pregnancy ↑ LVOT obstruction Epidural anaesthesia causes systemic vasodilation and hypotension in severe LVOTO Fluids must be given judiciously and volume overload must be avoided The implantation of an ICD should be considered in patients with high risk factors for sudden cardiac death All other management is the same, except for amiodarone for rhythm control Atenolol - class d

Take home message Hemodynamic of pregnancy Normal abnormal cardiac findings WHO class Risk prediction Basic principles of obstetric care Common congenital cardiac problems

QUESTIONS

Aortic diameter in Marfan syndrome above which pregnancy contraindicated

Normal increase in cardiac output

Risk of aotic rupture is maximum at which trimester

Safe limit of radiation exposure to foetus

Risk of fetus having congenital heart disease in general population

Only proven risk to fetus if exposed to low dose radiation is

Saturation below which pregnancy contraindicated

Beta blocker which is not class c

Thank you