Pregnancy and Heart Disease: Difference between revisions
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[[Pregnancy and Heart Disease: | ==[[Pregnancy and Heart Disease: Epidemiology and Demographics|Epidemiology and Demographics]]== | ||
==[[Pregnancy and Heart Disease: Physiology|Physiology]]== | |||
Revision as of 01:14, 20 May 2010
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]
Please Take Over This Page and Apply to be Editor-In-Chief for this topic: There can be one or more than one Editor-In-Chief. You may also apply to be an Associate Editor-In-Chief of one of the subtopics below. Please mail us [3] to indicate your interest in serving either as an Editor-In-Chief of the entire topic or as an Associate Editor-In-Chief for a subtopic. Please be sure to attach your CV and or biographical sketch.
Epidemiology and Demographics
Physiology
History and Symptoms
Often accompanied by symptoms of fatigue, decreased exercise capacity, hyperventilation, dyspnea, palpitations, lightheadedness, and even syncope. Leg edema is often observed late in pregnancy and can lead to an erroneous diagnosis of heart failure. The arterial pulsese are full and collapsing and are similar to those palpated in patiends with aortic insufficiency or hyperthyroidism.
Physical Examination
- Increased first heart sound
- Persistent split S2
- Third heart sound is uncommon
- Pulmonic midsystolic murmur
- Continuous murmur (mammary soufflé, cervical hum)
- Varicosities and ankle edema
- In general there are often innocent murmurs of pregnancy. These are the result of a hyperkinetic circulation. These murmurs are usually midsystolic and soft and heard best at the left lower sternal border and over the pulmonic area.
Laboratory Findings
Electrocardiogram
- The QRS axis may shift either to the left or the right, but usually lies within normal limits.
Chest X Ray
- The pelvic area should be shielded if a chest x-ray is done. The heart may seem enlarged due to elevation of the diaphragm and this should be interpreted with caution.
MRI and CT
- MRI: There are no known safety hazards but the experience with the technique is limited. Currently the FDA recommends prudence in using MRI during pregnancy.
Echocardiography or Ultrasound
- Echo: There is a progressive increase in chamber dimension with approximately a 20% increase in the size of the right atrium and the right ventricle, a 12% increase in left atrial size, and a 6% increase in left ventricular size. Postpartum, the changes gradually returned to baseline. In addition, there is early and progressive dilation of the mitral, tricuspid, and pulmonary annuli which is associated with an increase in valvular regurgitation.
- Fetal Echo:
- Risk factors for structural heart disease (i.e. who to ECHO):
- women with a history of congenital heart disease themselves or in previous children
- women with a history of congenital heart disease themselves or in previous children
- diabetes and collagen vascular disease predispose to congenital heart disease
- diabetes and collagen vascular disease predispose to congenital heart disease
- a history of a fetal arrhythmia
- a history of a fetal arrhythmia
- consumption of teratogens
- consumption of teratogens
- Fetal ECHO
- one study found a sensitivity of 96% in detecting major structural malformations (72/74 abnormalities identified among 1,022 fetuses)
- one study found a sensitivity of 96% in detecting major structural malformations (72/74 abnormalities identified among 1,022 fetuses)
- useful for management during pregnancy, postpartum, and genetics counseling
- useful for management during pregnancy, postpartum, and genetics counseling
Other Diagnostic Studies
- Exercise stress testing: If this is done, there should be fetal monitoring.
- Radiation: If the patient receives less than five rads, then they can be reassured a very likelihood of risk. If they received more than 15 rads, termination of the pregnancy is recommended. Routine chest x-ray is associated with radiation of 20 millirads to the chest. Standard fluoroscopy delivers 1-2 rads per minute. Cineangiography delivers 5-10 rads per minute. Only 5% of the radiation delivered is absorbed by the fetus. A lead apron should be used over the mother's pelvis. With the use of nuclear medicine procedures the radiopharmaceuticals collect in the bladder when the placenta is directly across from the fetus. The expected radiation with thallium-201 or Tc imaging is less than one rad per examination.
- Pulmonary artery catheterization: Hemodynamic monitoring can be of great help in managing high-risk patients during pregnancy, labor, delivery, and the postpartum period. The pulmonary artery line should be placed without fluoroscopic guidance. Insertion is recommended throughout labor and delivery for any patient with symptomatic cardiac disease during pregnancy or with the potential for deterioration due to valvular, myocardial, or ischemic heart disease. Hemodynamic monitoring should be continued for at least several hours after delivery to ensure stability.
- Cardiac catheterization: May be indicated in rare instances of cardiac decompensation. To minimize radion to the pelvic and abdominal areas, the brachial, rather than the femoral approach is preferred.
Pharmacotherapy
Antibiotic prophylaxis:
The official American Heart Association (AHA) recommendation is that antibody prophylaxis is not necessary for an uncomplicated delivery except among patients with a prosthetic heart valve or surgically constructed systemic to pulmonary shunt. However, because of the difficulties in predicting complicated deliveries and the potential devastating consequences of endocarditis, antibiotic prophylaxis for vaginal delivery in all patients with congenital heart disease expect those with an isolated secundum type atrial septal defect and those six months or more after repair of septal defects or surgical ligation division of a patent duct is arteriosus, seems reasonable. At the time of delivery it is recommended that all women with valvular disease receive antibiotics, usually penicillin (PCN) and gentamycin. For those with a PCN allergy, vancomycin is used.
Specific Disease States
Aortic Stenosis
- Most commonly bicuspid valve
- Fixed cardiac output in response to stress
- Patients with mild to moderate severity do very well
- Severe cases have maternal mortality up to 17% and fetal mortality up to 32%
- Critical cases need surgery / valvuloplasty
- Any reduction in preload can lead to cardiac / cerebral ischemia and compromised uterine flow
Congenital Heart Disease in Pregnancy
Overview
- Rapidly becoming most common cardiac problem among pregnant patients
- Improved diagnostic techniques
- Availability of corrective surgery
- Children of affected mothers at increased risk of having similar lesions
- Outcomes clearly linked to functional status pre-pregnancy
Classification of disease
Can classify lesions into 3 classes:
Volume Overload (L-->R shunt)
- ASD, VSD, and PDA well tolerated if pulmonary hypertension not present
- PVR and SVR falls to same degree
- Degree of shunting does not change
- Maternal and fetal mortality ≥50%
- Consider termination if detected early
- Careful medical management
- -Supplemental O2 during pregnancy
- -Hospitalization at 20 weeks gestation
- -Prompt treatment of CHF
- -Avoid shifts in preload/afterload
- Atrial Septal Defect (ASD): Arrhythmias, thromboembolism may develop among pregnant women with an ASD. However, there is no available evidence to suggest that pregnant patients should be managed differently from nonpregnant patients with respect to the indications for ASD closure are no different in pregnant women compared to non-pregnant women.
Pressure Overload
- Pulmonic Stenosis
- Degree of obstruction determines outcome
- Gradient >80 mm Hg mandates correction
- Coarctation of the aorta
- Accounts for 9% of all congenital disease in adults
- Class I or II patients usually do well
- Overall 3.5% mortality in unoperated patients (aortic dissection/rupture, CVA, CHF, endocarditis)
- HTN needs careful management
- Early to mid pregnancy, C.O. and end-diastolic dimension ↓ outflow tract obstruction (counteracted by SVR)
- Avoid Valsalva
- Encourage left lateral decubitus position
- Maximum risk period during delivery when blood loss can result in increased gradient + systemic hypotension
- Keep well hydrated
- Avoid digoxin, simpathomimetics and excessive diuretics
Cyanotic Heart Disease (R-->L shunt)[1]
- Poor prognosticators:
- Hematocrit > 60%
- O2 sat<85%
- Livebirth 12% vs. 92% is sat >90%
- Systemic RV pressures
- h/o recurrent syncope
- Tetralogy of Fallot most common unrepaired defect
- Drop in SVR leads to increased shunting, deeper cyanosis and rising HCT
- Need to avoid Valsava during delivery
- Maternal mortality more than 4%
Marfan's Syndrome
- Autosomal dominant inheritance pattern (counseling is essential)
- Major risk is aortic dissection
- Most common in 3rd trimester or 1st stage of labor
- Increases with enlarging aortic root diameter
- Surgery recommended pre-conception if root diameter >40 mm
- Surgery recommend during gestation if > 55 mm
- Prophylactic Beta-blockers appear to be helpful
- Close follow-up with serial echo
Mitral Stenosis
Overview
- Most hemodynamically important valvular problem during pregnancy
- Physiologic changes result in increased pulse and C.O. with augmentation of diastolic gradient
- Atrial fibrillation can lead to rapid deterioration
- Volume shifts during delivery can result in pulmonary hypertension or pulmonary edema
Management of MS in Pregnancy
- Restriction of physical activity and salt intake. Avoid supine position
- Beta-blockade to lengthen disatolic filling period
- Diuretics if necessary (gentle)
- Consideration of invasive monitoring
- Replace blood losses during delivery carefully
- Percutaneous Balloon Mitral Valvuloplasty can be performed during pregnancy if necessary (Class III,IV)
Myocardial Infarction
Overview
- First reported case in 1922
- Incidence ~1/10000
- Ages range 16-45
- Most common in 3rd trimester women > 33 years of age
- Anterior wall most commonly involved
- Maternal mortality 21% (most at time of MI or within 2 weeks- usually with labor and delivery)
- Outcomes better if MI early in pregnancy
- Fetal deaths usually associated with maternal deaths
- Risk factors:
- FH of CAD
- Low HDL
- High LDL
- Smoking
- Previous OCP use
Pathophysiology
- Caths in 54% of published cases:
- CAD with or without thrombus 43% (58% in prepartum period)
- Thrombus without CAD 21%
- Normal coronaries 29% (75% in peripartum period MIs)
- Coronary dissection 16% (33% in postpartum period)
Diagnosis
- EKG and enzymes are the gold standard
- 37% of patients undergoing elective C-section have EKG changes suggestive of MI or ischemia
- Echo to assess regional wall motion abnormalities can be useful
- Nuclear imaging and diagnostic cath exposure to conceptus <0.01 Gy (0.05 Gy considered to be threshold value)
Drugs
Check with pharmacist or Maternal Fetal Medicine Specialist before any drug administration
- ASA - low dose
- Nitrates – use low dose to prevent fetal distress
- Beta-1 selective Beta-blockers
- Morphine sulfate
- Avoid ACE inhibitors and warfarin due to teratogenicity
- Thrombolytics mostly untested
- Greatest experience in massive pulmonary embolism
- Streptokinase does not cross placental membrane in animals, but Ab found in neonatal spinal cord fluid
- Urokinase not teratogenic in mice/rats
- Risk for maternal hemorrhage (1 case of placental abruption reported); increased risk when given at time of delivery
- Delivery best delayed at least 2-3 weeks
Peripartum Cardiomyopathy
Diagnostic criteria (Demakis et al, 1971)
- Development of CHF/LV dysfunction in last month of pregnancy to 5 months postpartum
- Absence of determinable cause
- Absence of demonstrable cardiac disease before last month of pregnancy
Common Mimickers
- Accelerated HTN
- Infection/sepsis
- Diastolic dysfunction
- High output state of pregnancy
Demographics
- Estimates of incidence 1/1300-15000
- Previous studies likely overestimated
- More common in women with:
- Multiple pregnancies
- African decent
- h/o toxemia
- Long-term tocolytic use
- Age>30
- Twin Pregnancy
- Etiology remains unknown
- Signs and sxs similar to those of nl pregnancy
Hemodynamic findings
| Chamber | Normal Pregnancy | Peripartum CMP |
|---|---|---|
| RA | 2 | 11 (2-34) |
| PA | 11 | 39 (18-62) |
| PCW | 6 | 18 (5-32) |
| CO (L/min) | 7 | 6 (5-9) |
| HR | 83 | 104 (76-142) |
Treatment of Peripartum CMP
- Digoxin and diuretics are Class C
- ACE inhibitors absolutely contraindicated prepartum (hydralazine drug of choice)
Outcome of Peripartum CMP
- Mortality 25-50% (half deaths in first 3 months)
- Remainder stable/recover within 6 months
- Can recur with subsequent pregnancies
- Favorable outcomes with cardiac transplantation
Managing Prosthetic Valves During Pregnancy[2]
- Pregnancy is a thrombogenic milieu
- Coumadin use during 1st trimester associated with warfarin embryopathy
- Coumadin use in other trimesters postulated to cause CNS abnormalities
- Keeping Coumadin dose ≤ 5.0 mg/day appears safe
- Recommendations based more on opinion than scientific evidence
- SBE Prophylaxis at Delivery
Use of antithrombotic agents during pregnancy: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy[3]
- In women with prosthetic heart valves, the guideline developers recommend:
- Adjusted-dose, twice-daily LMWH throughout pregnancy in doses adjusted either to keep a 4-hour postinjection anti-Xa heparin level at approximately 1.0 to 1.2 U/mL (preferable) or according to weight (Grade 1C), or
- Aggressive adjusted-dose UFH throughout pregnancy: i.e., administered SC every 12 hours in doses adjusted to keep the mid-interval aPTT at least twice control or to attain an anti-Xa heparin level of 0.35 to 0.70 U/mL (Grade 1C), or
- UFH or LMWH (as above) until the thirteenth week, change to warfarin until the middle of the third trimester, and then restart UFH or LMWH (Grade 1C).
- Remark: Long-term anticoagulants should be resumed postpartum with all regimens
- In women with prosthetic heart valves at high risk, the guideline developers suggest the addition of low-dose aspirin, 75 to 162 mg/day (Grade 2C).
Regurgitant Valvular Lesions During Pregnancy
- Usually tolerated very well during pregnancy
- Severity may decrease during pregnancy due to drop in SVR
- Vasodilators only if systemic HTN (avoid ACE-inhibitors)
- Antibiotic prophylaxis important if infection suspected
Rheumatic Cardiac Disease in Pregnancy
- Previously accounted for over 90% of CV disease during pregnancy
- Recent studies show congenital disease now more common
- Royal Infirmary at Edinburgh University: 94% (1928-47), 36% (68-77), 24% (73-77)
- Remains common in less developed nations
Pulmonary Hypertension in Pregnancy
- High maternal / perinatal mortality (~50%)
- Vaginal delivery with limited anesthetics are preferred.
Resuscitation in Late Pregnancy
Cardiac arrest occurs in approximately one in 30,000 women in late pregnancy.[4] Maternal mortality is caused by venous thromboembolism, severe preeclampsia or eclampsia, sepsis, amniotic fluid embolism, haemorrhage, trauma, iatrogenic causes including anaesthesia and drug errors or allergy, and congenital or acquired heart disease.[5]
Consideration of urgent hysterotomy or Caesarean section should be made for the pregnant woman who has a cardiac arrest. If early resuscitation fails, birth of the fetus may improve maternal and fetal chance of survival. Infants over 24-25 weeks gestation have the best chance of survival if birthed within 5 minutes of maternal cardiac arrest. It is recommended that hysterotomy or Caesarean section be commenced 4 minutes after a cardiac arrest unless there has been a successful resuscitation and maternal perfusion restored within that time.[6]
Obesity exaggerates the risks and physical changes in pregnant women.[4]
Position of the pregnant women
- Position the women on her back with the shoulders flat. Place padding/wedge under the right buttock to give an obvious pelvic tilt to the left.[7]
- The thighs of a rescuer may be used for resting the women on, and providing a lateral tilt.[4]
- An assistant may move the uterus further off the vena cava by lifting the uterus with two hands to the left and towards the woman’s head.[4]
Airway management
- The woman should be inclined laterally for suction, removing ill-fitting dentures or foreign bodies, and inserting airways.[4]
- Mouth to mouth or bag and mask ventilation is done with a pillow; the head and neck are fully extended.
- Apply cricoid pressure until the airway is protected by a cuffed tracheal tube if sufficient staff are available to do this – this decreases risk of gastric aspiration.[6]
- A soon as possible tracheal intubation should be inserted – ensures adequate ventilation with increased intra-abdominal pressure.[6]
- Consider using a smaller tracheal tube if the airway is narrowed due to oedema and swellling.[6]
- Positioning for intubation - using one pillow helps to flex the neck and extend the head.[4]
Circulation management
- Adhesive defibrillator pads attachment are used to assist contact which may be difficult due to the larger breasts in the pregnant woman.[6]
- Hand position higher than the normal position for chest compressions may be needed to adjust for the elevation of the diaphragm and abdominal contents due to the gravid uterus.[6]
- Raising the woman’s legs will assist venous return.[4]
Gastrointestinal management
Early intubation decreases the risk of gastric aspiration.[6]
Intiating caesarean section
Immediately a pregnant woman collapses and requires resuscitation a staff member should collect the Caesarean Section Perimortem pack.
References
- ↑ Presbitero P. et al. Circulation 1994;89:2673-6.
- ↑ Vitale N., et al. JACC 1999;33:1637-41.
- ↑ Bates S.M. et al. Chest 2004;126:627S-44S.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Morris S, Stacey M. Resuscitation in pregnancy. BJM 2003;327:1277-1279.
- ↑ Mallampalli A, Powner DJ, Gardner MO. Cardiopulmonary resuscitation and somatic support of the pregnant patient. Critical Care Clinics,. 2004;20:747-761.
- ↑ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Soar J, Deakin CD, Nolan JP, Abbas G, Alfonzo A, et al. European Resuscitation Council Guidelines for Resuscitation 2005. Section 7. Cardiac arrest in special circumstances. Resuscitation 2005;6751:S135-S170.
- ↑ Australian Resuscitation Council. Guideline 7 Cardiopulmonary resuscitation. In: Australian Resuscitation Council Guidelines; 2006.
Sources:
Acknowledgements
The content on this page was first contributed by C. Michael Gibson M.S., M.D.