Acute Decompensated Heart Failure by Dr. Elizabeth Profita.
Hi there, I'm Dr. Elizabeth Profita. Today's talk will start with an overview of heart failure,
including understanding the causes of heart failure and reviewing the symptoms and signs
of heart failure. We will then learn how to assess a patient with heart failure
by learning how to assess both their cardiac output and volume status.
We will review concerning findings and heart failure that constitute red flags.
And we'll finish with a few patient cases to review the things we've discussed today.
Heart Failure Overview.
Heart failure is caused either by myocardial dysfunction or normal myocardial function
with abnormal workload. With myocardial dysfunction the heart is structurally normal
but the muscle itself isn't able to do a normal amount of work.
This decreased ventricular function leads to decreased cardiac output and heart failure.
Causes of myocardial dysfunction include cardiomyopathies, myocarditis, arrhythmias,
drug exposure, such as anthracyclines and chemotherapy and metabolic disorders.
Heart failure can also result from increased volume or pressure with normal myocardial
function. Examples of volume overload include left to right shunting lesions such as a VSD,
PDA or complete AV canal defect or valve regurgitation lesions. Volume overload
increases the amount of work the heart has to do and leads to heart failure over time. Examples of
pressure overload lesions include both right sided lesions such as pulmonary stenosis or
pulmonary hypertension or left sided lesions such as aortic stenosis or coarctation. In both cases,
outflow tract obstruction limits outflow and thus cardiac output causing heart failure.
Symptoms of heart failure can vary significantly with age. Infants may present with increased work
of breathing, sweating with feeds, irritability or poor growth. Young children may present with
abdominal pain, nausea, vomiting, decreased appetite or chronic cough. And older children
may present with exercise intolerance, anorexia, dyspnea, palpitations, chest pain or syncope.
Findings to look for an exam include jugular venous distention, respiratory signs such as
respiratory distress, tachypnea or crackles. Cardiac signs such as tachycardia and S3 gallop,
decreased pulses and perfusion, hepatomegaly and peripheral edema.
Assessment.
We will now discuss how to assess a patient with heart failure. When initially evaluating a patient
with heart failure it is helpful to think of them in the context of these four hemodynamic profiles.
Along the left side we have cardiac output from hypoperfusion to adequate perfusion. And along the
top we have volume status from dry to congested or wet. Using these two axes this allows us to define
four hemodynamic profiles. In the northwest quadrant we have warm and dry, which is the
ideal status for our patients. They have good perfusion and no evidence of volume overload.
In the southwest quadrant we have cold and dry, which is the profile of patients with low cardiac
output. Patients have cold extremities, hypotension, renal dysfunction, altered mental
status or hyponatremia. In the northeast quadrant we have warm and wet, which is the profile of
patients with volume overload. Patients have an S3 gallop peripheral edema, pulmonary edema
and an elevated jugular venous pressure. In the southeast quadrant is cold and wet, which is a
less common patient profile and corresponds with decompensated heart failure and shock.
And thus will be uncommon for patients in clinical settings outside of a cardiac intensive care unit.
Every day it is important to review the following items to be able to appropriately assess the
patient and determine their hemodynamic profile. Vital signs and vital trends should be reviewed
along with central venous pressure measurements if available, ins and outs and daily weights.
Telemetry should be reviewed for patients with any concern for arrhythmia. When seeing the patient,
a complete physical exam should be done assessing for volume, status and cardiac output.
Labs and lab trends should be reviewed, including electrolytes, renal function,
mixed venous oxygen saturation and BNP. Pertinent recent testing should also be reviewed, including
chest x-rays, echos, and cardiac catheterizations. In patients with heart failure we often trend the
mixed venous oxygen saturation as a surrogate for assessing cardiac output. We measure the
mixed venous oxygen saturation in the SVC or right atrium typically using a PICC line.
The cardiac index is your cardiac output divided by your body surface area and
is the preferred unit for discussing cardiac output in pediatric patients.
We use the Fick Principle to estimate your cardiac index by using your mixed venous oxygen and
arterial oxygen saturations if we assume a VO2 max and we know your hemoglobin concentration.
Cardiac index is then proportional to your arterial to venous oxygen difference.
If you assume a normal arterial oxygen saturation of 100% and the mixed venous
oxygen saturation of 70%, this would give you a normal A-vO2 difference of around 30%.
In patients with a lower arterial oxygen saturation as in the case of single ventricle
anatomy, the mixed venous oxygen saturation will be lower but the A-vO2 difference should
be similar. If your cardiac output is decreased, mixed venous oxygen saturation will decrease and
your A-vO2 difference will increase. In patients who have decreased cardiac output or who are cold
they will present with symptoms of abdominal pain, nausea, fatigue, fussiness or pale or gray color.
Vital signs review may demonstrate increased heart rates or decreased blood pressures.
Exam may show tachycardia, decreased pulses, delayed capillary refill,
cool extremities and in severe cases altered mental status.
Labs may demonstrate a decrease in mixed venous oxygen level,
decreased sodium level, increased creatinine, elevated lactate and an elevated BNP.
Echo may demonstrate a decreased systolic function with the decreased ventricular ejection fraction.
In patients who have volume overload they will present with symptoms of increased work
of breathing and respiratory distress. Review of vital signs may show increased respiratory rate,
weight gain and a positive fluid balance. Exam may show an S3 gallop or an S4 gallop,
tachypnea, crackles, hepatomegaly, peripheral edema or jugular venous distension.
Labs may show an increased central venous pressure, elevated BNP
and the low or normal BUN to creatinine ratio. And a chest x-ray may demonstrate pulmonary edema.
Now we're going to talk about some red flags in heart failure. End stage heart failure
patients are at high risk for decompensation and cardiac arrest. Arrhythmia is also poorly
tolerated in patients who already have ventricular dysfunctions. Red flags for heart failure patients
include new symptoms such as nausea, vomiting, or fussiness. Significant changes in their vital
signs, including tachycardia, or tachypnea. Exam changes, including feeling cold or with decreased
perfusion or blue coloring. And any arrhythmia including unexplained sinus tachycardia.
The first step when you notice a red flag is to see and assess the patient. Cardiac
patients can rapidly deteriorate and it is very important to assess the patient at the bedside.
You may start by reviewing their vital signs trends and any recent labs,
including blood gases, lactates, chemistry or mixed venous oxygen saturations.
If they have respiratory symptoms a chest x-ray may be appropriate and if you have any concerns
it is always appropriate to alert the cardiology fellow and attending and consider discussing with
the cardiac intensive care unit if there's an anticipation of need for escalation of care.
Case Studies.
Now we'll discuss some patient cases to test what we've learned today.
Case one. You receive a page from a nurse. Your patient seems to be
having trouble breathing. Your patient is a 10-year-old female with dilated cardiomyopathy
who was admitted with a heart failure exacerbation. She's been NPO all day
for a PICC line placement and just returned to the floor from interventional radiology.
On the phone you ask the nurse to tell you more about the breathing.
When did it start? What does it seem like? You ask what the current fluid and diuretic plan is.
While you're waiting to see the patient you review the vital signs with the respiratory
rate trend, the heart rate trend and oxygen saturations. You review her ins and outs and
her medication list including diuretic, doses and times. When you see the patient,
you assess her respiratory exam, her cardiac exam and her volume status.
You order labs with a chemistry and you transduce a central venous pressure.
You obtain a chest X-ray to assess for pulmonary edema
and if she's desaturated you could consider using a nasal cannula of oxygen.
If you have concern that she appears volume overloaded you could consider a dose of diuretics.
In this case, the patient had been NPO for the procedure today and had been kept on full
maintenance IV fluids throughout the day. She missed her afternoon dose of diuretics while at
the procedure. She had increased tachypnea from her baseline after the procedure.
Her PICC line was transduced for a central venous pressure and was found to be elevated
at 13 millimeters of mercury. A chest X-ray was obtained with increased pulmonary edema.
She was given an IV dose of diuretics with improvement in her symptoms.
Case two. You receive a page from your nurse. Your patient doesn't look great,
he is pale and has been vomiting. Your patient is a 14-year-old male with dilated cardiomyopathy who
is currently listed for heart transplant. And he was admitted with worsening heart failure
symptoms for milrinone initiation. A PICC line was placed and milrinone was started five days ago.
On the phone you ask your nurse, when did he last appear well? Does he have other symptoms
such as nausea, vomiting, or belly pain? And remind me what he's currently on for support?
While you're waiting to see the patient you review his vital signs,
including his heart rate trend his blood pressure and his oxygen levels,
such as his oxygen saturation or mixed venous oxygen saturations. His ins and outs and his urine
output and his recent labs, including his mixed venous oxygen level, a lactate and a hematocrit.
In the room you assess his cardiac exam, including pulses, capillary refill,
extremity temperature and his neurologic status. You order labs with a chemistry, a blood gas,
a mixed venous and a lactate and in conversation with your cardiac fellow you consider an echo.
If he appears to have poor cardiac output you could consider increasing afterload reduction
or adding inotropes. Or if he's anemic consider transfusion of red blood cells.
If he appears to have low volume status you consider a slow fluid bolus and if you're
worried he may get sicker you might consider transfer to the cardiac intensive care unit.
In this case, his exam showed that his pulses were weaker and his perfusion was worse than
you remembered. His heart rate was up 10 to 20 beats from his baseline heart rate.
His milrinone dose had been weaned earlier in the morning from 0.75 to 0.5. His mix venous oxygen
saturation prior to the wean 70%. A repeat mixed venous was sent and it was now 55%.
The transplant attending was called, his milrinone dose was increased back to 0.75
and the CICU attending was alerted to the patient case.
Case three. You get a page from your nurse, your patient's heart rate seems irregular
and the telemetry keeps alarming. Your patient is a two-year-old female with hypoplastic left
heart syndrome, who is status post Glenn surgery and currently listed for heart transplant due to
ventricular dysfunction. She was admitted with a heart failure exacerbation for IV
diuresis. When you talk to the nurse on the phone you ask, how is the patient feeling or appearing?
Was there any change in her clinical status or is it just a change of telemetry that was noted?
Before you see the patient, you reviewed her telemetry and her vital signs trends including
her heart rate and blood pressures and any recent labs, such as chemistry for electrolytes.
In the room you assess her cardiac exam and her perfusion. You order labs with a chemistry
and obtain a 12 lead ECG. If her electrolytes are abnormal you could consider repleating her
potassium and magnesium with a goal of keeping her potassium level above four and magnesium
level above two. If she's having a significant arrhythmia medical therapy may be warranted
and if she's in an unstable rhythm she may require transfer to the cardiac intensive care unit.
In this case, the patient had been receiving high dose IV diuretics. Review of her telemetry
showed frequent PVC's with a few couplets. There was no runs of ventricular tachycardia.
The patient was well appearing otherwise with good perfusion. Her electrolytes were checked,
her potassium was found to be 2.9 and repletion was given with subsequent improvement in PVC's.
Summary.
In summary, heart failure can result from myocardial dysfunction or
normal myocardial function with increased work such as increased pressure or volume. Symptoms
of heart failure can vary significantly with age. Assessment of cardiac output, warm or cold, and
volume status wet or dry is essential to determine management of heart failure. Daily weights,
vital signs trends, ins and outs, clinical exam and lab testing can be helpful with management.
Heart failure patients can deteriorate quickly. Red flags include any significant
change in vital signs, heart rhythm or clinical exam. Review of vital signs,
ins and outs, medications and labs can be helpful in determining the etiology of the decompensation
and always remember to ask for help early. Thanks so much.