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A
40-year-old woman arrives at the emergency department with
a markedly panicked appearance, screaming, "I can't
breathe!" She is anxiously flailing her arms and
appears tachypneic and pale. Six nurses are needed to
obtain her vital signs and to place an intravenous (IV)
line. The patient's heart rate is 120 beats per minute (bpm)
with a blood pressure of 200/88 mm Hg, a respiratory rate
of 50 breaths per minute, and oxygen saturation of 79% with
the patient breathing room air. She is unable to cooperate
with history taking and physical examination, and she
repeatedly removes her oxygen mask and monitoring
equipment. She is intubated on an emergency basis by using
rapid-sequence induction.
After the patient is adequately sedated, physical
examination is possible. The ventilator is set on
assist-control mode at a rate of 16 bpm, tidal volume of
600 mL, positive end-expiratory pressure (PEEP) of 5 cm H2O,
and a fraction of inspired oxygen (FiO2) of
100%. Her vital signs include a rectal temperature of 37.1°C
with a heart rate of 110 bpm, ventilator-assisted
respiratory rate of 16 breaths per minute, blood pressure
of 183/100 mm Hg, and O2 saturation of 100%. Her
pupils are equal, round, and reactive to light. She has no
jugular venous distension or tracheal shift. Her heart rate
is a regular rhythm with no appreciable murmurs, rubs, or
gallops. She has coarse breath sounds with bibasilar rales.
Abdominal examination reveals linea nigra, and moderate
distension is noted, but palpation yields softness without
any masses. She has no lower-extremity edema or rashes.
The patient's husband arrives and provides additional
history. They had a baby by means of normal spontaneous
vaginal delivery 2 months ago with no complications. Three
days ago, the patient began having shortness of breath,
which was worst at night and when she was lying flat or
exerting herself. She has been using an over-the-counter
epinephrine inhaler (0.22 mg, Primatene Mist), with no
improvement. She has no notable medical history of asthma,
chronic obstructive pulmonary disease (COPD), or other
respiratory problems. He denies any knowledge of drug or
alcohol use.
An ECG shows sinus tachycardia with frequent premature
ventricular contractions (PVCs). The patient has no
ST-segment or T-wave changes and no S1Q3T3 pattern.
A portable postintubation chest radiograph is obtained (see
Image 1). Bedside abdominal and cardiac ultrasonographies
are performed in the emergency department. The sonogram of
her abdomen shows no free fluid and a nongravid uterus.
Images 2-4 are her cardiac sonograms.
What is the diagnosis and treatment?
Answer
Peripartum cardiomyopathy (PPCM): The radiographic
findings of acute congestive heart failure coupled
with the patient's history of recent pregnancy
suggest PPCM as the cause of her respiratory
distress. The echocardiographic images show a
dilated left ventricle (LV) with global hypokinesis
(Images 2-3, Video
1), no evidence of a significant or compromising
pericardial effusion (Image 3, Video
1), and lack of respiratory-associated changes
in the diameter of the IVC, suggesting fluid
overload and associated congestive heart failure
(Image 4, Video
2).
PPCM is a rare cause of heart failure with 4
diagnostic criteria: (1) echocardiographic evidence
of heart failure (ie, ejection fraction <45%),
(2) onset between the last month of pregnancy and 5
months after pregnancy, (3) no other identifiable
causes of heart failure, and (4) no preexisting
heart disease before the last month of pregnancy.
The incidence is 1 case per 299 live births in
Haiti, 1 case per 1,000 live births in South Africa,
and 1 case per 2289-4000 live births in the United
States (Sliwa, 2006). Reasons for these geographic
variations are not well understood.
The etiology of PPCM is currently unknown (Sliwa,
2006). Several possible causes have been
hypothesized, including increased inflammatory
cytokines, viral infection, myocarditis, a maternal
immunologic response to fetal cells in maternal
blood, and pregnancy-related hemodynamic changes.
Although no causal links have been identified to
date, the following factors have been associated
with an increased risk: age over 30 years;
multiparity; African descent; multiple-gestation
pregnancy; maternal cocaine abuse; and history of
preeclampsia, eclampsia, or postpartum hypertension.
Patients with PPCM may present with classic signs
and symptoms of heart failure. Their histories are
commonly notable for dyspnea on exertion, orthopnea,
paroxysmal nocturnal dyspnea, and cough. Physical
examination may reveal a displaced apical impulse,
an S3 heart sound, and heart murmurs. Patients
frequently present with severe heart failure, ie,
New York Heart Association (NYHA) functional class
III or IV, as did this patient.
Left ventricular (LV) stasis from severe heart
failure and current or recent pregnancy place
patients with PPCM at high risk for cardiac
thrombosis and subsequent peripheral embolization (Sliwa,
2006). Therefore, patients with PPCM may present
with lower-extremity arterial occlusion,
cerebrovascular accident, mesenteric ischemia or
infarct, and pulmonary embolism. Clinicians must
have a high index of suspicion for underlying PPCM
when they encounter patients with these embolic
diseases.
The differential diagnosis for PPCM is extensive.
Life-threatening differential diagnoses include
exacerbations of asthma or COPD, pneumonia, pleural
effusion, pneumothorax, pulmonary embolism, acute
congestive heart failure, acute myocardial
infarction, an incompetent cardiac valve,
endocarditis, anaphylaxis, and subarachnoid
hemorrhage (SAH) leading to flash pulmonary edema.
Minimal diagnostic evaluation should include ECG and
echocardiography. The ECG may show sinus tachycardia
or atrial fibrillation with nonspecific ST- and
T-wave changes. Additionally, as in this case, the
echocardiogram may show LV enlargement and a global
reduction in contractility without signs of LV
hypertrophy. Other studies, such as chest
radiography, chest CT, cardiac catheterization, and
myocardial biopsy should be performed on an
individual basis as needed to rule out other
conditions.
The treatment of PPCM is similar to that of other
causes of heart failure. In the setting of acute
pulmonary edema, urgent afterload and preload
reduction is required (Tintinalli, 2004). IV
nitroglycerin or nitroprusside infusions can be
uptitrated until BP is controlled. Diuretics, such
as IV furosemide, help lower BP and cardiac filling
pressures. Morphine is a potent venodilator and
helps reduce preload and alleviate respiratory
distress. Immunosuppressive agents, such as
azathioprine and steroids, as well as IV
immunoglobulin (IVIG) have shown mixed results in
small clinical trials and are not the standard of
care at this time (Sliwa, 2006). If these therapies
are not effective, intra-aortic balloon pump, LV
assist devices, and a heart transplant may be
necessary.
Maintenance therapy for PPCM is the same as for
heart failure of another etiology and may include
diuretics, digoxin, beta-blockers, and angiotensin-converting
enzyme (ACE) inhibitors. If the patient is pregnant,
ACE inhibitors should not be given because of the
risk of oligohydramnios, fetal renal damage, or
fetal death. Hydralazine with nitrates can be
substituted for ACE inhibitors.
Anticoagulation should be considered because
patients with PPCM are at high risk for
thromboembolism given their hypercoagulable state of
pregnancy and for LV stasis from severe LV
dysfunction. The decision to provide anticoagulants
should be made in conjunction with specialists and
after other life-threatening etiologies that may
deteriorate with anticoagulation (eg, SAH) are
appropriately ruled out (verbal communication, Eric
Savitsky, MD).
Many women with PPCM have spontaneous recovery of LV
function. This occurrence is distinct from outcomes
with other causes of dilated cardiomyopathy. A
retrospective study of 123 women in the United
States with PPCM showed that mean LV ejection
fractions increased from 29% to 48% over 1 year (Elkayam,
2005). This same series showed an overall
transplantation rate of 4% and a mortality rate of
9%.
Several studies have shown that patients with a
history of PPCM are at risk for severe LV
dysfunction if they become pregnant again. A recent
study showed that, of 9 patients with a history of
PPCM that became pregnant again, 5 (56%) died from
severe heart failure (Mishra, 2006). Patients must
be clearly advised of the risks of subsequent
pregnancy.
The patient in this case was extubated on hospital
day 3 and discharged home on day 7. As of this
report, the patient is doing well with a maintenance
regimen of isosorbide mononitrate, hydralazine,
carvedilol (Coreg), benazepril, and spironolactone (Aldactone).
She is awaiting a repeat echocardiogram to reassess
her cardiac function.
Image Legends
Image 1. Chest radiograph shows appropriate
placement of an endotracheal tube and a central line
in the left internal jugular vein. Image also shows
cardiomegaly, bilateral pulmonary congestion, and
cephalization of vessels.
Image 2. Apical 4-chamber cardiac sonogram shows a
dilated left ventricle (LV) with decreased wall
motion and an estimated ejection fraction of 10-15%.
The septum, inferior wall, and lateral wall are all
hypokinetic, a finding that suggests a global cause
rather than a local infarct. Likewise, the lack of
right ventricular (RV) dilatation suggests something
other than a massive pulmonary embolus. LA = left
atrium; RA = right atrium.
Image 3. Long-axis parasternal view shows a dilated
left ventricle (LV) with decreased wall motion,
normal right ventricular (RV) size, and lack of
clinically significant or compromising effusion. LA
= left atrium; RA = right atrium. For the
corresponding movie clip, see Video
1.
Image 4. Image shows the inferior vena cava (IVC) as
it inserts into the heart. Key findings are lack of
respiratory associated changes in the diameter of
the IVC. These results indicate fluid overload and
congestive heart failure. For the corresponding
movie clip, see Video
2.
References
- Elkayam
U, Akhter MW, Singh H, et al.
Pregnancy-associated cardiomyopathy: clinical
characteristics and a comparison between early
and late presentation. Circulation
2005;111:2050-5.
- Mishra
TK, Swain S, Routray SN. Peripartum
cardiomyopathy. Int J Gynecol Obstet
2006 Nov;95(2):104-9.
- Sliwa
K, Fett J, Elkayam U. Peripartum cardiomyopathy.
Lancet 2006;368:687-93.
- Tintinalli
J. Emergency Medicine: A Comprehensive Study
Guide. 6th ed. New York: McGraw-Hill;
2004:367-8.
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