Intern Report 7.4

Case Presentation by Dr. Nile Chang, MD

A 29 year old African-American pregnant female, G3P2, 38 weeks pregnant per LMP, presents with 2 weeks of progressively worsening shortness of breath and dyspnea with exertion, orthopnea, and ankle edema. She also reports occasional cough worse when she lies down. She reports having gained 15 pounds over the last month. She saw her OBGYN about a month ago and “everything has been fine”.  Her previous pregnancies were notable for full-term vaginal births without complications. She denies fevers, chills, vomiting, headache, or rash.

PMH:
No significant medical history
No significant surgical history
Allergies: no known drug allergies

Physical exam:

General: In mild distress, tachypneic
Vitals: T – 97.6 Pulse- 80 RR- 28 BP- 170/85 O2Sat-88% on RA
HEENT: Normocephalic, Atraumatic, PERRLA, no JVD or distended neck veins
Respiratory: Breath sounds clear and equal bilaterally, no wheezes, rhonchi, or rales, no accessory muscle use
Cardiac: Regular rhythm and rate, no murmurs, rubs or gallops
Abdomen: Gravid, non-tender, soft, no rigidity, rebound, or guarding
Skin: Warm and dry without diaphoresis
Extremities: Palpable pulses in equal bilaterally in all extremities. 2+ pitting edema in both lower extremities
Neurologically: A&Ox3, normal speech, symmetrical strength, DTRs 2+ at the patella and symmetrical, no clonus

Labs:

WBC: 10.2
HGB: 11.3
Plt: 335

Na: 133
K: 4.0
Cl: 100
HCO3: 22
BUN: 13
Cr: 1.2

Alb: 3.2
TP: 8
T.Bili: 0.3
D Bili: 0.1
ALT: 35
AST: 50
Alk Phos: 165

pH: 7.43
pCO2: 27
PO2: 56
FiO2:21

Urinalysis: normal

Fetal Doppler: 132 bpm

7.4 1

7.4 2

7.4 3
Questions:

Q1. Which of the following findings is least likely to be found on echocardiogram for this patient?
a) Dilated Left Ventricle
b) Reduced diastolic filling
c) Reduced LV ejection fraction
d) Small pericardial effusion

Q2. Which of the following imaging study exposes the fetus to the most amount of ionizing radiation?
a) Chest X-ray
b) Pelvis X-ray
c) CT Pulmonary Angiogram with abdominal shielding
d) V/Q Scan

Q3. Which one of the following pharmacotherapy should not be used to manage this patient?
a) Beta-blocker
b) ACE inhibitor
c) Hydralazine
d) Furosemide

Answers & Discussion:

1) B
2) B
3) B

Dyspnea in pregnancy is a common complaint seen in the ED. Normal physiological changes includes a normal increase in minute ventilation, which often presents as a complaint. However, dyspnea can be a harbinger for several life-threatening emergencies that require prompt evaluation. These emergencies include asthma, pneumonia, pulmonary embolism, and pulmonary edema secondary to preeclampsia or dilated cardiomyopathy.

The patient in this case has a clear clinical picture of pulmonary edema secondary to peripartum dilated cardiomyopathy (PPCM). Her history and physical is notable for worsening shortness of breath, ankle edema, orthopnea, and paroxysmal nocturnal dyspnea, all signs of heart failure. PPCM generally occur in the last month of pregnancy or within the first five months of delivery.

Q1.  Answer: B

PPCM is a dilated, high output form of cardiac failure. Of the answer choices, findings of a dilated left ventricle (a) and reduced LV ejection fraction (c) on echocardiogram is a definitive diagnosis. A small pericardial effusion can also be seen (d). Reduced diastolic filling (b) is more associated with a restrictive cardiomyopathy, not generally seen in PPCM.

In this patient, additional evaluation such as a BNP may also help confirm the diagnosis.

Q2.  Answer: B

When considering radiological imaging in the pregnant patient, one must be cognizant of the potential exposure of ionizing radiation to the developing fetus, and weigh the risk of the exposure against the risk of misdiagnosis.

The ACOG technical bulletin suggest that significant risk is unlikely when the fetus is exposed to less than 100 rads of cumulative radiation during pregnancy. With exposure to 15 rads or greater, there is a 6% chance of severe mental retardation and 15% chance of microsomia. The following table lists the estimated radiation dose to the fetus by imaging modality.

C-spine (<1mrad)
Chest X-ray (1-3 mrad)
KUB (200-500 mrad)
Pelvis X-ray (200-500 mrad)
L-spine (600-1000mrad)
CT Head/Chest (with shielding) (<1000 mrad)
CT Abdomen (3000 mrad)
CT Pelvis (3000-9000 mrad)
V/Q scan (<55 mrad)
CT PE (with shielding) (<50 mrad)

Conventional wisdoms suggest that a V/Q scan was the test of choice to rule out PE, however, more recent studies have shown that CT with PE protocol may provide a similar level of exposure while providing a higher level of sensitivity and specificity. Therefore, pregnancy should not preclude the use of helical CT for the diagnosis or rule-out of PE.

Of the answer choices, a pelvis X-ray (b) have a highest level of exposure (200-500mrad).

Q3.  Answer: B

For the most part, the goals of medical therapy are similar to those in patients with heart failure due to other causes. However, ACE inhibitors (b) and ARBs are contraindicated at any time in pregnancy. However, they are safe to use in women who are breastfeeding.

Because ACE Inhibitors and ARBS are contraindicated in pregnancy, hydralazine (c) is a safe option for antepartum vasodilation and blood pressure reduction.

Beta-blockers (a) are generally safe during pregnancy, with agents that are beta-1 selective (metoprolol) are preferable, as ones that are not (atenolol) may interfere with beta-2 mediated uterine relaxation and peripheral vasodilation.

Diuretics such as furosemide (d) and hydrochlorothiazide should only be used if there are signs of pulmonary congestion, as it may decrease blood flow over the placenta.

References:
1. Rosen’s Emergency Medicine, Concepts and Practices, 7th edition

2. Trauma during pregnancy: ACOG technical bulletin. American College of Obstetricians and Gynecologists. November 1991.

3. ESC Guidelines on the management of cardiovascular diseases during pregnancy. European Heart Journal (2001) 32, 3147-3197

4. Peripartum Cardiomyopathy. UpToDate. Wolters Kluwer Health. 2013.

One Response

  1. This lady is pregnant and in subacute heart failure.

    Q1: I think all these are associated with failure except:

    1.

    Q2. Both CT scans and VQ scans have lots of radiation, but CT scans have LOTS more. The whole shielding things is nice, but I doubt it makes a significant difference.

    2.

    Q3. This patient sounds like fairly well compensted failure, with the exception of the low pulse oximetry. I would think beta blockers are ok. I know ACE inhibitors are absolutely contraindicated in pregnancy because of all the badness they cause in the fetus.

    3.

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