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Approximately 2% of pregnancies involve maternal cardiovascular disease Cardiac disease may sometimes be manifested for the first time in pregnancy Conversely, the symptoms and signs of a normal pregnancy may mimic the presence of cardiac disease Pre-pregnancy counseling is important to give prospective mothers appropriate information

In general, patients who cannot achieve more than 70% of their predicted functional aerobic capacity are unlikely to tolerate a pregnancy safely Four predictors of maternal cardiac events are as follows: (1) prior cardiac event (e.g., heart failure, transient ischemic attack, or stroke before pregnancy) or arrhythmia (2) baseline New York Heart Association (NYHA) class higher than Class II or cyanosis (3) left-sided heart obstruction (mitral valve area smaller than 2 cm 2, aortic valve area less than 1.5 cm 2, or peak left ventricular outflow tract gradient more than 30 mm Hg by echocardiography) (4) reduced systemic ventricular systolic function (ejection fraction less than 40%).

Hemodynamic Changes During Pregnancy The plasma volume begins to increase in the sixth week of pregnancy and by the second trimester approaches 50% above baseline.The plasma volume then tends to plateau until delivery This increased plasma volume is followed by a slightly lesser rise in red cell mass, which results in the relative anemia of pregnancy. The heart rate begins to increase to about 20% above baseline to facilitate the increase in cardiac output.

Uterine blood flow increases with placental growth, and there is a fall in peripheral resistance. This decreased peripheral resistance may result in a slight fall in blood pressure, which also begins in the first trimester. The venous pressure in the lower extremities rises, which is why approximately 80% of healthy pregnant women develop pedal edema. The adaptive changes of a normal pregnancy result in an increase in cardiac output, which also begins in the first trimester and by the end of the second trimester approaches 30% to 50% above baseline. These hemodynamic changes may cause problems for the mother with cardiac disease

During Labor and Delivery The hemodynamic changes during labor and delivery are abrupt. With each uterine contraction, up to 500 mL of blood is released into the circulation, prompting a rapid increase in cardiac output and blood pressure. The cardiac output is often 50% above baseline during the second stage of labor and may be even higher at the time of delivery. During a normal vaginal delivery, approximately 400 mL of blood is lost. In contrast, with a cesarean section, about 800 mL of blood is often lost and may pose a more significant hemodynamic burden to the parturient. After delivery of the baby, there is an abrupt increase in venous return, in part because of autotransfusion from the uterus but also because the baby no longer compresses the inferior vena cava. In addition, there continues to be autotransfusion of blood in the 24 to 72 hours after delivery, and this is when pulmonary edema may occur.

For most patients with cardiac disease, a vaginal delivery is feasible and preferable Cesarean section may be considered in patients who is anticoagulated with warfarin because the baby is also anticoagulated, and vaginal delivery carries an increased risk to the fetus of intracranial hemorrhage. patients who have a dilated unstable aorta (e.g., Marfan syndrome), severe pulmonary hypertension, severe obstructive lesion such as aortic stenosis. If vaginal delivery is elected, fetal and maternal electrocardiographic monitoring should be performed. Delivery can be accomplished with the mother in the left lateral position so that the fetus does not compress the inferior vena cava, thereby maintaining venous return. The second stage should be assisted, if necessary (e.g., forceps or vacuum extraction), to avoid a long labor. Blood and volume loss should be replaced promptly. For those patients with tenuous hemodynamics, Swan-Ganz catheterization before active labor facilitates optimization of the hemodynamics and should be continued for at least 24 hours after delivery, when pulmonary edema commonly occurs.

Physical Examination The heart rate increases pulse volume is often bounding. the jugular venous pressure may be elevated with brisk descents, because of the volume overload and reduced peripheral resistance. The apical impulse is more prominent the first sound may appear loud. Commonly, there is an ejection systolic murmur at the left sternal edge, never more than grade 3/6 in intensity. A third sound is very common. There should be no diastolic murmur..

The second sound may also appear accentuated, and these combined auscultatory features may suggest an atrial septal defect or pulmonary hypertension. Continuous murmurs may also be heard, from either a cervical venous hum or a mammary souffle. Peripheral edema is common as pregnancy advances.

Management During Pregnancy Patients who are NYHA Class I or II may need to limit strenuous exercise and to have adequate rest supplementation of iron and vitamins to minimize the anemia of pregnancy, low-salt diet if there is concern about ventricular dysfunction Patients who are NYHA Class III or IV may need hospital admission for bed rest and close monitoring and may require early delivery if there is maternal hemodynamic compromise.

Surgical Management Cardiac surgery is a higher risk of fetal malformation and loss if cardiopulmonary bypass is performed in the first trimester; if it is performed in the last trimester, there is a higher likelihood of precipitating premature labor. The “optimal time” appears to be between 20 and 28 weeks of gestation and the fetal outcome may be improved by use of normothermic circulation, higher pump flows, higher pressures (mean blood pressure of 60 mm Hg), and as short a bypass time as possible. Maternal functional class is an important predictive factor for maternal death.

High-Risk Pregnancies pulmonary hypertension, systolic pulmonary artery pressures higher than 60% to 70% of the systemic pressure. left ventricular ejection fraction less than 40% patients with significant stenotic cardiac lesions are likely to deteriorate during a pregnancy(AS,MS,PS,COA. Patients with a dilated aortic root more than 40 mm particularly those patients with Marfan syndrome. Cyanotic lesions Mechanical prosthetic valves

Congenital Heart Disease Atrial Septal Defect Patients with even a large secundum atrial septal defect usually tolerate pregnancy without complication unless there is coexistent pulmonary hypertension or atrial fibrillation. Meticulous attention should be paid to the maternal leg veins, particularly during peridelivery, because deep venous thrombosis could precipitate a paradoxical embolus and stroke. Elective closure of an atrial septal defect by device or operative repair is preferable before pregnancy is contemplated.

Ventricular Septal Defect Patients with small defects usually tolerate pregnancy without difficulty. In the setting of a large ventricular septal defect and pulmonary hypertension, patients should be counseled not to proceed with a pregnancy Patent Ductus Arteriosus Small ducts with normal or near-normal pressures usually cause no hemodynamic perturbations during pregnancy. In the setting of a large shunt, the added volume load of pregnancy might precipitate left ventricular failure. Those with pulmonary hypertension should be counseled not to have a pregnancy.

congenital Aortic Stenosis Aortic stenosis in women of childbearing age usually occurs secondary to a bicuspid aortic valve. there should be a careful examination of the entire thoracic aorta because aortic dilation or ascending aortic aneurysm may be present. Pregnancy is usually considered to be contraindicated if the aortic dimension is larger than 4.5 cm

Mild aortic stenosis is usually well tolerated, provided the patient has a normal exercise capacity and no symptoms. Moderate stenosis is sometimes well tolerated, but the patient needs to be evaluated carefully before pregnancy. In the absence of symptoms, with a normal exercise test without ST-T wave changes Those with severe aortic stenosis (valve area smaller than 1 cm 2 ) or a mean gradient greater than 50 mm Hg should be counseled not to have a pregnancy. Epidural analgesia needs to be carefully and slowly administered, and spinal block should be avoided because of the potential for hypotension. Delivery may be facilitated by central venous pressure monitoring or the use of a Swan-Ganz catheter to maintain optimum hemodynamics. This should be continued for at least 24 hours after delivery. Several small reports have reviewed percutaneous aortic balloon valvuloplasty during pregnancy; this can be accomplished, provided the valve anatomy is favorable and the procedure is performed by an experienced interventionalist

Coarctation of the Aorta Women with coarctation may present for the first time during pregnancy because of systemic hypertension. Therapeutic options include antihypertensive therapies, percutaneous balloon or stenting of the coarctation, or surgical intervention Pulmonary Stenosis Pulmonary stenosis is usually well tolerated during pregnancy, particularly if the right ventricular pressure is less than 70% of systemic pressure and sinus rhythm is maintained. If necessary, balloon pulmonary valvuloplasty can be performed, with shielding of the fetus from radiation.

Cyanotic Heart Disease Cyanosis poses risks for both mother and fetus. The decrease in peripheral resistance that accompanies pregnancy augments the right-to-left shunt and may exaggerate the maternal cyanosis. Because of the erythrocytosis that accompanies cyanosis and the propensity to thrombosis, women who develop venous thrombosis are at risk of paradoxical embolus and stroke. When the maternal oxygen saturation is less than 85%, the fetal outcome is poor, with only 2 of 17 pregnancies (12%) resulting in live-born infants Conversely, when the maternal oxygen saturation is 90% or higher, 92% of the pregnancies result in a live birth.

Pulmonary Hypertension Pulmonary hypertension, regardless of the cause, carries a high mortality when it is associated with pregnancy. When the pulmonary hypertension exceeds approximately 60% of systemic levels, pregnancy is more likely to be associated with complications. In the setting of severe pulmonary vascular disease (Eisenmenger syndrome) maternal mortality may approach 50%.

The time around labor and delivery is particularly dangerous, and the highest incidence of maternal death is during parturition and the puerperium. Vagal responses to pain may also be life-threatening. Death may also occur from pulmonary embolism or in situ pulmonary infarction. Only 25.6% of pregnancies reached term. Current recommendations are still that termination of pregnancy is the safer option Low-dose subcutaneous heparin may be administered during bed rest, but there is no evidence that it improves maternal survival.

If the vaginal route is selected, it should be performed in an intensive care unit. Epidural analgesia must be cautiously administered to minimize peripheral vasodilation. A prolonged second stage should be avoided. Meticulous attention should be paid to the peripheral venous system, and a thromboguard or compression pump may help prevent peripheral venous thrombosis. Cesarean section delivery is probably preferable with cardiac anesthesia. In summary, the mortality for patients with severe pulmonary hypertension and pregnancy is prohibitively high. Estrogen-containing contraceptives are contraindicated in this setting.

Valvular Heart Disease The most common problems encountered are bicuspid aortic stenosis (discussed previously) and mitral stenosis, which tends to worsen during pregnancy The cornerstone of therapy for the symptomatic patient is beta blockade. Bed rest may also be helpful to slow the heart rate and to minimize cardiac demands. The judicious use of diuretics is appropriate if there is pulmonary edema. Anticoagulants should probably be given if the patient is on bed rest and should certainly be administered in the setting of atrial fibrillation. when the mother is refractory to medical therapy, balloon valvuloplasty may be performed if the valve anatomy is favorable and there is no concomitant mitral regurgitation. Rarer still, surgical valvotomy may be performed Mitral and aortic regurgitation are fairly well tolerated in pregnancy, provided the regurgitation is no more than moderate, the mother is symptom free before pregnancy, and ventricular function is well preserved. Closer monitoring during pregnancy is usually warranted, however, particularly for those with mitral regurgitation, because the left ventricle tends to dilate as pregnancy progresses, and this may exacerbate the degree of mitral regurgitation. Early delivery may be necessary if there is maternal hemodynamic compromise. Prosthetic Valves

Mitral and aortic regurgitation are fairly well tolerated in pregnancy provided the regurgitation is no more than moderate the mother is symptom free before pregnancy, and ventricular function is well preserved. Closer monitoring during pregnancy is usually warranted, however, particularly for those with mitral regurgitation, because the left ventricle tends to dilate as pregnancy progresses, and this may exacerbate the degree of mitral regurgitation. Early delivery may be necessary if there is maternal hemodynamic compromise.

Prosthetic Valves Pregnancy for the woman with a prosthetic valve poses risks for mother and baby and has been called a “double jeopardy” situation. Tissue valves are less thrombogenic than mechanical valves and therefore are less problematic in pregnancy because they do not routinely involve the use of warfarin. The disadvantage is their tendency to degenerate after an average of 10 years Mechanical prostheses, in contrast, have a greater longevity but require anticoagulation, and whichever anticoagulant strategy is chosen during pregnancy there is a higher chance of fetal loss, placental hemorrhage, and prosthetic valve thrombosis.

Mechanical Prostheses and Anticoagulant Treatment The management of pregnancy when the mother has a mechanical valve prosthesis is controversial, and no universal consensus exists. During pregnancy, maternal blood is highly thrombogenic the risk of valve thrombosis and thromboembolism significant

ACC/AHA Recommendations for Anticoagulation Regimens in Pregnant Patients with Mechanical Prosthetic Valves Continuous therapeutic anticoagulation with frequent monitoring If warfarin is discontinued between weeks 6 and 12 of gestation, replace with continuous intravenous UFH, dose-adjusted UFH, or dose-adjusted subcutaneous LMWH Up to 36 weeks of gestation, the therapeutic choice of continuous intravenous or dose-adjusted subcutaneous UFH, dose-adjusted LMWH, or warfarin should be discussed fully. If dose-adjusted LMWH is used, the LMWH should be administered twice daily subcutaneously to maintain the anti-Xa level between 0.7 and 1.2 unit/mL 4 hours after administration If dose-adjusted UFH is used, the aPTT should be at least twice control.

If warfarin is used, the INR goal should be 3.0 (range, 2.5 to 3.5). Warfarin should be discontinued starting 2 to 3 weeks before planned delivery and continuous intravenous UFH given instead. LMWH should not be administered unless anti-Xa levels are monitored 4 to 6 hours after administration. Dipyridamole should not be used instead of aspirin as an alternative antiplatelet agent because of its harmful effects on the fetus.

Dilated Cardiomyopathy Patients with idiopathic dilated cardiomyopathy are usually counseled not to have a pregnancy if the ejection fraction is lower than 40%. Because angiotensin-converting enzyme (ACE) inhibitors are contraindicated in pregnancy, ventricular function must be assessed without this drug. Careful echocardiographic evaluation should be performed before pregnancy. Exercise testing may also be helpful because women with ejection fractions of 40% to 50% may not tolerate pregnancy well if they have a poor functional aerobic capacity. Symptomatic patients who proceed with a pregnancy may need hydralazine for afterload reduction, bed rest, and low-dose diuretics for heart failure. Early delivery may also be necessary.

Peripartum Cardiomyopathy Peripartum cardiomyopathy (PPCM) is a dilated cardiomyopathy documented with echocardiographic left ventricular dysfunction occurring in the last month of pregnancy or within 5 months of delivery. Patients with a prior history of myocardial disease are excluded from this definition. Risk factors include multiparity, being black, older maternal age, and preeclampsia. In a retrospective study of 123 women with PPCM, [33] a history of hypertension was obtained in 43% of patients, and twin pregnancies were reported in 13%. ]

The treatment of PPCM is the same as for other forms of congestive heart failure, except that ACE inhibitors and angiotensin receptor blocking agents are contraindicated in pregnancy. Hydralazine, beta blockers, and digoxin have been used and are safe, and diuretics may decrease preload and improve symptoms. Intracardiac thrombus and embolism are common, and consideration should be given to anticoagulation with unfractionated heparin in those with an ejection fraction lower than 35%. Early fetal delivery may be necessary in women needing hospitalization for heart failure Normalization of ventricular function occurs in about 50% of patients and appears more likely if the ejection fraction is more than 30% at the time of diagnosis. Most physicians counsel against a second pregnancy because PPCM will recur in approximately 30% of cases.

Hypertension Hypertension in pregnancy is an important cause of maternal morbidity and mortality. Chronic hypertension: (blood pressure ≥140 mm Hg systolic or ≥90 mm Hg diastolic) present before pregnancy or that is diagnosed before the 20th week of gestation Gestational hypertension: New hypertension with a blood pressure of 140/90 mm Hg on two separate occasions, without proteinuria, arising de novo after the 20th week of pregnancy. Blood pressure normalizes by 12 weeks post partum.

Preeclampsia superimposed on chronic hypertension: Increased blood pressure above the patient's baseline, a change in proteinuria, or evidence of end-organ dysfunction Preeclampsia-eclampsia: Proteinuria (>0.3 g during 24 hours or ++ in two urine samples) in addition to new hypertension. Edema is no longer included in the diagnosis because of poor specificity. When proteinuria is absent, suspect the disease when increased blood pressure is associated with headache, blurred vision, abdominal pain, low platelets, or abnormal liver enzymes.

About 50% of patients with Gestational hypertension will develop preeclampsia, however, so close monitoring is warranted. It develops in approximately 25% of patients with chronic hypertension.

Arrhythmias Because of the physiologic changes of pregnancy, the heart may be more vulnerable to arrhythmias during this tim Worsening of arrhythmias is not a consistent feature In general, supraventricular and ventricular ectopic beats require no therapy The most common arrhythmia is atrial reentry tachycardia. Treatment of this type of arrhythmia is generally the same as for nonpregnant women Atrial fibrillation is usually an indication that there is underlying structural heart disease. If the arrhythmia is unresponsive to medical therapy, electrical cardioversion may be performed and is not usually harmful to the fetus. Some have recommended that during elective cardioversion, fetal monitoring should be performed in case transient fetal bradycardia is present.