CARDIOVASCULAR DISEASES IN PREGNANCY

1. CARDIOVASCULAR DISEASES IN PREGNANCY BY: SAVITA AHLAWAT

2. INTRODUCTION • Ht Dis. & Mortality • In western countries maternal heart disease is now the major cause of maternal death during pregnancy [UK 2003-2005]. • In South India, 30% H’ge, 17% sepsis, 13% hypertensive disorders [2001-2003 Special Survey Of Deaths].

3. EFFECT OF CARDIOVASCULAR PHYSIOLOGY ON HEART LESION • Marked hemodynamic changes in pregnancy and cardiac output in particular, have profound effects on heart disease. A normal heart has got enough reserve power so that the extra load can well be tackled. While a damaged heart with good reserve can even withstand the strain but if the reserve is poor, cardiac failure occurs sooner or later. The cardiacfailure occurs during pregnancy around 30 weeks, during labor and mostly soon following delivery.

4. FACTORS RESPONSIBLE FOR CARDIAC FAILURE: • Advanced age • Cardiac arrhythmias or left ventricular hypertrophy • History of previous heart failure • Appearance of ‘risk factors’ in pregnancy are: infection, anemia, hypertension, excessive weight gain and multiple pregnancy • Inadequate supervision.

5. EFFECTS OF HEART LESION ON PREGNANCY: • There is a tendency of preterm delivery and prematurity. IUGR is quite common in cyanotic heart diseases.

6. PROGNOSIS • MATERNAL: • The prognosis depends on: • (1) Nature of lesion • (2) Functional capacity of the heart • (3) Quality of medical supervision provided during pregnancy, labor and puerperium • (4) Appearance of the risk factors mentioned earlier.

7. Maternal mortality is lowest in rheumatic heart lesions and acyanotic group of heart diseases—less than 1%. With elevation of pulmonary vascular resistance specially with cyanotic heart lesions, the mortality may be raised to even 50%. Most of the deaths occur due to cardiac failure and the maximum deaths occur following birth.

8. The other causes of death are— • Pulmonary edema • Pulmonary embolism • Active rheumatic carditis • Subacute bacterial endocarditis • Rupture of cerebral aneurysm in coarctation of aorta.

9. FETAL: • In rheumatic heart lesions, the fetal outcome is usually good and in no way different from the patients without any heart lesion. However, in cyanotic group of heart lesion, there is increased fetal loss (45%) due to abortion, IUGR and prematurity. Fetal congenital cardiac disease is increased by 3–10% if either of theparents have congenital lesions.

10. DIAGNOSIS: • Anatomical and physiological changes during pregnancy that mimic cardiac disease • Hyperdynamic circulation • Systolic ejection murmur at left sternal border (due to increased blood flow across the aortic and pulmonary valves) • Dyspnea, decreased exercise tolerance, fatigue, syncope • Tachycardia, shift of ventricular apex • Continuous murmur at 2nd to 4th intercostal space— mammary souffle • Loud first sound with splitting • Symptoms must be carefully assessed and investigations are to be done to confirm the diagnosis

11. DIAGNOSIS OF HEART DISEASE IN PREGNANCY • Symptoms: • Breathlessness, nocturnal cough, syncope, chest pain • Signs: • Chest murmurs—pansystolic, late systolic, louder ejection systolic or diastolic associated with athrill.

12. Cardiac enlargement, arrhythmia • Chest radiography (using lead shield): • Cardiomegaly, increased pulmonary vascular markings, enlargement of pulmonary veins. • Electrocardiography: T wave inversion, biatrial enlargement, dysrrhythmias • Echocardiography (color flow Doppler study): • Structural abnormalities (ASD, VSD), valve anatomy, valve area, function, left ventricular ejection fraction, pulmonary artery systolic pressure • Cardiac MRI can delineate complex (anatomy when it is not well-evaluated by echo cardiography)

13. NEW YORK HEART ASSOCIATION (NYHA) CLASSIFICATION OF HEART DISEASE (DEPENDING UPON THE CARDIAC RESPONSE TO PHYSICAL ACTIVITY) • Grade-I: Uncompromised and no limitation of physical activity • Grade-II: Slightly compromised with slight limitation of physical activity. The patients are comfortable at rest but ordinary physical activity causes discomfort

14. Grade-III: Markedly compromised with marked limitation of activity. The patients are comfortable • at rest but discomfort occurs with less than ordinary activity • Grade-IV: Severely compromised with discomfort even at rest • Limitation: This classification has considered the symptoms only but not the anatomical type and severity of pathology. It does not predict pregnancy outcome

15. RISKS OF MATERNAL MORTALITY WITH HEART DISEASE (NYHA, 1992)

16. PRINCIPLES • Early diagnosis and evaluation of anatomical type and functional grade of the case • To detect the high risk factors and to prevent cardiac failure • Combined (obstetrician and cardiologist) care and mandatory hospital delivery

17. ANTENATAL CARE • Injection penidure LA 12 (benzathine penicillin) is given at intervals of 4 weeks throughout pregnancy and puerperium to prevent recurrence ofrheumatic fever. Counseling is to be done regarding prognosis and risks. • Special care in each antenatal visit is to detect and to treat the risk factors that precipitate cardiac failure in pregnancy.

18. RISK FACTORS FOR CARDIAC FAILURE • Infections—Urinary tract, dental and respiratory tract. • Anemia • Obesity • Hypertension • Arrhythmias • Hyperthyroidism • Drugs—Betamimetics. • Excess intake of caffeine, alcohol, high calorie diet.

19. ROLE OF ANTICOAGULANTS: • Anticoagulants are necessary in cases of congenital heart disease who have pulmonary hypertension, artificial valve replacements or atrial fibrillation. The patient taking warfarin should discontinue it as soon as pregnancy is diagnosed and replace by heparin 5000 units twice daily subcutaneously up to 12th week. This is then replaced by warfarin tablet 3 mg. daily to be taken at the same time each day and continued up to 36 weeks. Thereafter it is replaced by heparin upto 7 days postpartum. Warfarin is then to be continued.

20. ADMISSION: ELECTIVE: • Grade–I : At least two weeks prior to the expected date of delivery • • Grade–II : At 28th week specially in case of unfavorable social surroundings • • Grade III and IV : As soon as pregnancy is diagnosed.

21. MANAGEMENT DURING LABOR • PLACE OF INDUCTION: Most patients with cardiac disease go into spontaneous labor and deliver without any difficulty. However, induction (vaginal PGE2) may be employed in very selected cases for obstetric indications. One should guard against infection and pulmonary edema due to fluid overload.

22. LABOUR • FIRST STAGE: • Position: The patient should be in lateral recumbant position to minimize aortocaval compression • Oxygen is to be administered (5–6L/min) if required • Analgesia in the majority, is best given by epidural • Fluids should not be infused more than 75 mL/hour to prevent pulmonary edema.

23. Careful watch of the pulse and respiration rate. If the pulse rate exceeds 110 per minute in between uterine contractions, rapid digitalization is done by intravenous digoxin 0.5 mg. • Cardiac monitoring and pulse oxymetry can detect arrhythmias and hypoxemia early. • Central venous pressure monitoring may be needed in selected cases.

24. Prophylactic antibiotics: Antibiotic prophylaxis during labor and 48 hours after delivery is considered appropriate. This is to prevent puerperal endocarditis. The recommended regimens include intravenous ampicillin 2 g and gentamicin 1.5 mg/kg (not to exceed 80 mg), at the onset or induction of labor followed by repeat doses 8 hours interval. All high risk patients with structural heart disease, complex cyanotic congenital heartdisease, prosthetic valves need endocarditis prophylaxis.

25. SECOND STAGE: • No maternal pushing and the tendency to delay in the second stage of labor is to be curtailed • by forceps or ventouse under pudendal and/or perineal block anesthesia. Ventouse is preferable to forceps as it can be applied without putting the patient in lithotomy position (raising the legs increases the cardiac load). Intravenous ergometrine with the delivery of the anterior shoulder should be withheld to prevent sudden overloading of the heart by the additional blood squeezed out from the uterus.

26. THIRD STAGE • Conventional management is to be followed. Slight blood loss is not detrimental but if it is in excess, oxytocin can be given by infusion. This may be accompanied by intravenous frusemide. It is better to administer oxytocin in preference to ergometrine in all cases of heart disease in third stage.

27. PLACE OF CESAREAN SECTION • CARDIAC INDICATIONS OF CESAREAN DELIVERY: • Coarctation of aorta • Aortic dissection or aneurysm • Aortopathy with aortic root > 4 cm • Warfarin treatment within 2 weeks • In coarctation of aorta, elective cesarean section is indicated to prevent rupture of the aorta or mycotic cerebral aneurysm. The anesthesia should be given by expert anesthetist using either epidural (preferred) or general anesthesia.

28. PUERPERIUM • The patient is to be observed closely for the first 24 hours. Oxygen is administered. Hourly pulse, BP and respiration are recorded. Diuretic may be used if there is volume overload. • Breastfeeding is not contraindicated unless there is failure. Anticoagulant therapy is not a contraindication of breastfeeding.

29. CONTRACEPTION • Steroidal contraception is contraindicated as it may precipitate thrombo-embolic phenomenon. • Intrauterine device is avoided for fear of infection. • Progestin only pills or parenteral progestins are safe and effective. They may cause irregular bleeding specially if the patient is anticoagulated. • Barrier method of contraceptives (condom) is the best.

30. Sterilization should be considered with the completion of thefamily at the end of first week in the puerperium under local anesthesia through abdominal route by minilaptechnique. If the heart is not well compensated, the husband is advised for vasectomy.

31. MANAGEMENT OF CARDIAC FAILURE IN PREGNANCY • Propped up position • O2 administration • Monitoring with ECG and pulse oxymetry • Diuretic: Frusemide (Loop) (40–80 mg) IV • Mechanical ventilation • Injection morphine 15 mg IM • Digoxin 0.5 mg IM followed by tab digoxin 0.25 mg P.O. (Digoxin crosses the placenta and is excreted in breast milk) • Dysrhythmias—quinidine or electrical cardioversion • Tachyarrhythmias—Adenosine (3–12 mg) IV or DC conversion

32. SPECIFIC HEART DISEASE DURING PREGNANCY AND THE MANAGEMENT

33. RHEUMATIC HEART DISEASE • MITRAL STENOSIS: Mitral stenosis is the commonest heart lesion met during pregnancy. Normal mitral valve area ranges between 4 and 6 cm2. Symptoms usually appear when stenosis narrows this to less than 2.5 cm2. In asymptomatic cases, the mortality is < 1% but once it is significantly symptomatic, mortality ranges between 5 and 15%. During labor continuous epidural analgesia is ideal and intravenous fluid overload is to be avoided.

34. PLACE OF VALVOTOMY: • It is better to withheld elective cardiac surgery during pregnancy. Surgery should be considered in cases of unresponsive failure with pregnancy beyond 12 weeks. Best time of surgery is between 14–18 weeks. Valve replacement, commissurotomy, balloon-valvotomy can be carried out in early second trimester.

35. AORTIC STENOSIS: • Normal aortic valve area is 3–4 cm. When it is reduced to < 1 cm, stenosis is significant. Maternal mortality of significant aortic stenosis is about 15–20% with perinatal loss of about 30%. Epidural anesthesia is contraindicated. During labor, fluid therapy (125-150 mL/h) should not be restricted. Left ventricular after load is high and the pregnant patient is sensitive to haemorrhage.

36. Common symptoms are angina, syncope and left ventricular failure. • Medical management is not helpful in a symptomatic patient. Valve replacement is the definitive treatment. Mechanical valves need anticoagulation. Open heart surgery is preferably avoided in pregnancy. Aortic balloon valvoplasty may be done as a palliative procedure.

37. CONGENITAL HEART DISEASE: • With increasing number of surgical correction of the congenital heart lesions from infancy to adulthood, more and more pregnancies with congenital lesions are met in day-to-day practice. These patients pose little problem in obstetrics. But when pregnancy occurs in uncorrected congenital lesions, problems are very much there specially in a cyanotic group. Risk to the offspring of congenital heart disease is high (3–13%).

38. Major maternal risks in pregnancyare: • Cyanosis • Left ventricular dysfunction and • Pulmonary hypertension. • The common maternal complicationsare: • Congestive cardiac failure • Pulmonary edema • Arrhythmia and • Hypertension. All women should have fetal echocardiography examination at mid pregnancy.

39. ACYANOTIC (L TO R SHUNT) • Atrial Septal Defect (ASD): • ASD (ostium secundum type) is the most common congenital heart lesion during pregnancy. • Even uncorrected ASD tolerates pregnancy and labor well. Congestive cardiac failure unresponsive to medical therapy requires surgical correction. Shunt reversal is the major risk which may develop in hypovolemia. Such cases may occur in hemorrhagic conditions and following injudicious administration of epidural anesthesia. In the absence of arrhythmias, and pulmonary hypertension, ASD does not usually complicate pregnancy.

40. Patent Ductus Arteriosus (PDA):

41. Presence of continuous murmur at the upper left sternal border is suggestive of diagnosis. Most patients with PDA tolerate pregnancy well. Pulmonary hypertension may cause maternal death. Surgical correction during pregnancy can be performed provided there is no pulmonary hypertension. Epidural analgesia is betteravoided to minimize shunt reversal due to systemic hypotension. Fetal loss may be up to 7% and there is 4% chance that the child of this parent will suffer from the same abnormality. Endocarditic prophylaxis should be given.

42. Ventricular Septal Defect (VSD): • In general, if the defect is less than 1.25 cm, pulmonary hypertension and heart failure do not develop. Pregnancy is well tolerated with small to moderate left to right shunt or with moderate pulmonary hypertension. The major risk is shunt reversal leading to circulatory collapse and cyanosis. Hypotension is to be avoided. Fetal loss may be up to 20%.

44. Mitral Valve Prolapse (MVP) • Is the commonest congenital valvular lesion. Most of them are asymptomatic. Women tolerate pregnancy and labor well. Endocarditis prophylaxis is given.

45. CYANOTIC (R TO L SHUNT) • Fallot’s tetralogy

46. It is the most common form of cyanotic heart lesion. It is a combination of ventricular septal defect, • pulmonary valve stenosis, right ventricular hypertrophy and an overriding aorta. After surgical correction, patients tolerate pregnancy well. Surgically uncorrected patients are at increased risk. Complications like bacterial endocarditis, brain abscess and cerebral embolism are more common. Maternal mortality is 5–10% and the perinatal mortality is 30–40%. IUGR is common. Epidural or spinal anesthesia is avoided. Pregnancy is discouraged in women with uncorrected tetralogy.

47. Eisenmenger’s syndrome:

48. Patients with Eisenmenger’s syndrome have pulmonary hypertension with shunt (right to left) through an open ductus, an atrial or ventricular septal defect. Maternal mortality is about 50% and so also the perinatal loss (50%). Termination of pregnancy should be seriously considered. Heparin should be used throughout pregnancy as there is risk of systemic and pulmonary thromboembolism. Epidural anesthesia is contraindicated. Inhaled nitric oxide or I.V. prostacyclin is used as a pulmonary vasodilator. Complications are: CCF, hemoptysis, arrhythmia, cerebrovascular accident and hypoxemia; hyperviscosity syndrome and sudden death.

49. OTHER CONGENITAL HEART LESIONS

50. COARCTATION OF AORTA: • The maternal risks are hypertension, aortic dissection, bacterial endocarditis and cerebral hemorrhage due to ruptured intracranial aneurysms. Maternal mortality is high 3–9%. Fetal loss is also increased to 25%. Surgical correction should be done prior to pregnancy. Termination of pregnancy should be seriously considered. Elective cesarean section is preferred to minimise dissection associated with labor.