“Management of Congestive Heart Failure” by Christina Vanderpluym, MD, for OPENPediatrics

“Management of Congestive Heart Failure” by Christina Vanderpluym, MD, for OPENPediatrics

Management of Congestive Heart Failure, by
Christina VanderPluym. My name is Christina VanderPluym. I’m the
Director of the Ventricular Assist Device Program at Boston Children’s Hospital. And
today I’m going to speak about heart failure in children, focusing on management strategies. In our first section, we discussed the pathophysiology
and diagnosis of heart failure. And in the subsequent session, we’re going to discuss
management of congestive heart failure. When thinking about the management of heart failure,
we first must consider what are the goals for therapeutic intervention? And following
this, we’ll then look into the components of therapy, be it either surgical or catheter
based therapies, pharmacological and non pharmacological therapies. And then we will focus on preventing
morbidity, or complications related to heart failure. Specifically, intracardiac thrombus,
arrhythmias, and nutritional and growth deficiencies. Let’s begin with the goals of therapeutic
intervention. The goals of therapy for heart failure include relieving symptoms of heart
failure, such as congestion and low cardiac output, decreasing morbidity, such as those
related to intracardiac thrombi and arrhythmia, and including the risk of hospitalization
itself. To slow, or even potentially reverse the progression of heart failure, to improve
patient survival, and importantly, improve patients’ quality of life. Next we move on to
the components of therapy. Management of heart failure depends firstly on the etiology and
pathophysiology of heart failure. This was further described in our first section, but
broadly consists of pump dysfunction, volume overload, or pressure overload. Many children
presenting in heart failure may have a combination of these types of dysfunction, be it either
pump dysfunction with volume or pressure overload, or one of these in isolation. We must also consider the severity of heart
failure. We can classify severity using a multitude of different classification systems
including New York Heart Association classification, which has been most widely described and used
in adults, the Ross classification, which is most commonly used in children, as well
as staging of heart failure from stage A to D, with stage A consisting of those patients
with no symptoms and otherwise normal cardiac function, but who may be at risk of cardiac
dysfunction, and stage D, those with end stage heart failure refractory to maximum medical
management. Another consideration of management therapies
in children is how do they present with their symptoms? For patients who present with symptomatic
heart failure, treatment must also be focused at what type of symptoms they present with,
be it either congestion or low profusion, or a combination of both. The ideal patient
is that person who presents well-profused with no evidence of congestion, and ultimately,
no treatment is warranted at that time. This is in converse to patients who may present
with good profusion, however with evidence of congestion– be it either pulmonary edema,
peripheral edema, or ascites– and these patients may benefit from non-pharmacological therapies,
such as fluid restriction, or pharmacological therapy, such as intravenous or oral diuretics. There are also those patients who present
with evidence of low profusion secondary to poor cardiac output. They may also present
with signs or symptoms of congestion or no congestion. And in the setting of a patient
being cold and dry, they may benefit from fluid resuscitation, plus or minus the addition
of inotropic intravenous medications. And then there are those patients who present
with evidence of poor profusion, as well as evidence of congestion, and these patients
may benefit from fluid restriction, diuretic therapy, as well as inotropic medication.
As you can see, the treatment strategies for heart failure it can be very varied, and one
must always consider not only the pathophysiology or the severity, but the symptoms that we
are trying to target. In addition to heart failure therapy, we must
also try to identify and correct all non-cardiac factors that may be contributing to cardiac
dysfunction or poor perfusion. These include sepsis, or active infection, metabolic derangements,
such as acidosis, anemia that may be impairing oxygen delivery to end organs and renal failure.
Renal failure and heart failure are two significant problems that sometimes require very different
treatment strategies. While heart failure requires low systemic arterial pressures and
lower volumes, renal failure, unfortunately, requires the opposite, with higher systemic
arterial pressures and more volume. As such, this can be a significant challenge to the
treating physician. Also we must consider any surgical or catheter
based therapies that may correct either volume loading or pressure loading anatomical defects.
Let’s move on to pharmacological heart failure therapies. These therapies are used in patients
with either pump dysfunction, otherwise known as systolic dysfunction, with a goal to improve
function and/or stabilize or relieve symptoms of poor output. It can also be used for patients
with poor ventricular relaxation, otherwise known as diastolic dysfunction with the goal
to improve pump compliance and relieve symptoms of congestion. And lastly, can be used in
patients with normal pump function in the setting of symptoms of congestion. Most add-on heart failure medication has
come from studies in adult patients, with only very small trials conducted in children.
This is due to the fact that we are unable to conduct large trials in children because
the prevalence of heart failure in children is relatively low as compared to our adults.
Additionally, there are many different causes of heart failure in children, resulting in
significant heterogeneity for large studies. Let’s begin with drugs for mild to moderate
heart failure, stages B and C. There’s a large armamentarium of medications that can be used
for symptomatic heart failure in the setting of poor ventricular function or congestion.
These include diuretics, with the goal to reduce filling pressures and reduce symptoms
of congestion, to digoxin to increase inotropy, or contraction of the ventricle. Angiotensin
converting enzyme inhibitors to reduce afterload and decrease the LV workload. Beta blockers
to reduce the maladaptive sympathetic activation of the heart to reduce heart rate and allow
for more diastolic filling time. And lastly, pulmonary vasodilators that decrease pulmonary
vascular resistance and decrease the workload of the right ventricle. Let’s begin with diuretics. Diuretics decrease
preload by promoting natriuresis and relieve symptoms of volume overload, be it other pulmonary
or peripheral edema. They are generally used in children with stage C and D heart failure.
This is symptomatic heart failure secondary to ventricular dysfunction, or end-stage heart
failure refractory to other medical managements. There are multiple different classes of diuretics.
And these include loop diuretics that inhibit sodium and chloride reabsorption in the thick
ascending loop of Henle. These include furosemide, bumetanide, and torsemide. Next are thiazide diuretics that inhibit reabsorption
of sodium and chloride in the convoluted tubules of the kidney. These include chlorothiazide,
hydrochlorothiazide, and metolazone. And lastly, aldosterone antagonists that decrease sodium
reabsorption and potassium excretion in the collecting ducts of the kidney, including
spironolactone and eplerenone. These medications are used in conjunction with loop and thiazide
diuretics, and they have been shown to reduce mortality and morbidity in patients with heart
failure, in addition to standard medications. Let’s move on to digoxin. Digoxin has a positive
inotropic effect, mediated by the sodium potassium ATPase pump and increases intracellular calcium.
Intracellular calcium is imperative to increase the squeeze or the contraction of the ventricle.
Additionally, it has a negative chronotropic effect that slows the atrial conduction and
vagotonic properties that counter the sympathetic upregulation, which is maladaptive for heart
failure. This ultimately decreases heart rate, and allows for more time for the ventricle
to fill. It’s generally used in infants and children with stage C heart failure for symptomatic
relief. Benefits of digoxin can be actually seen at much lower doses than traditionally
thought, with trough levels of only 0.5 to 1 nanogram per mL, resulting in lower risk
of adverse effects, such as arrhythmias. Next are renin-angiotensin-aldosterone inhibition.
The renin-angiotensin-aldosterone system is a very active system in heart failure. It
leads to increased sympathetic tone, which is a compensatory for low cardiac output in
the short term, but becomes maladaptive over time, resulting in tachycardia, fluid retention,
and hypertension. Inhibition of this system are target medications for heart failure.
And these include Angiotensin Converting Enzyme inhibitors, otherwise known as ACE inhibitors,
and Angiotensin Receptor Blockers, or ARBs. Angiotensin Converting Enzyme inhibitors inhibit
formulation of angiotensin II, which is a potent vasoconstrictor that promotes myocite
hypertrophy and fibrosis. ACE inhibitors improve survival in adults with symptomatic heart
failure in clinical trials, and reduce the rate of progression of heart failure. However,
there are a limited small studies in ACE use in children. Experts suggest that use of ACE inhibitors
in children with pump dysfunction, such as those with stage B or C heart failure, may
be of benefit. However, close monitoring of blood pressure and renal function is imperative,
as ACE inhibitors will decrease patients’ blood pressure. And this may adversely affect already
tenuous renal function. Enalopril, which has twice-daily dosing, is traditionally used
for larger children. And captopril, which is three times daily dosing, is used for smaller
infants and children. The next medication is Angiotensin Receptor
Blockers, otherwise known as ARBs. There is limited data on the effectiveness for use
in children. However, there are smaller case studies demonstrating its use as an alternative
to ACE inhibitors when there are significant side effects or intolerance of ACE inhibition
due to ACE-induced cough or angioedema. Beta blockers. Beta blockers counteract the
maladaptive effects of chronic sympathetic activation. In adults, they improve survival,
reverse LV remodeling, and decrease myocardial fibrosis. It should be noted that they should
only be added once stable on other heart failure medications, including ACE inhibitors and
diuretics. Carvedilol is generally the recommended beta blocker for use in children with LV dysfunction,
and dosing of carvedilol can be started very low, generally at 1/8 of the eventual target
dose, at 0.05 milligrams per kilo per dose twice daily, and increased cautiously every
two weeks to minimize side effects. Side effects of beta blockers include dizziness, fatigue,
hypotension, bradycardia, and hypoglycemia. Pulmonary vasodilators. Pulmonary vasodilators
are used in the setting of right-sided heart failure secondary to elevated pulmonary vascular
resistance. Pulmonary vascular resistance may be increased due to a multitude of different
reasons, including abnormalities of the pulmonary vasculature, such as idiopathic pulmonary
hypertension, or secondary to left heart failure with subsequent elevated left-sided pressures
resulting in secondary pulmonary hypertension. Phosphodiesterase-5 inhibitors, sildenafil,
is the most commonly used. And this has been associated with improved LV function, functional
capacity, and quality of life in adults. There are, to date, limited large studies in children.
However, there are a multitude of small studies demonstrating its usefulness in a multitude
of different congenital anatomies, including Fontan circulation. Let’s move on to drugs for advanced heart
failure– namely, heart failure stage D. These include inotropes, which are used for acute
exacerbations of heart failure with the goal to increase cardiac output by contraction
and heart rate response. Catecholamines are the most frequently used to improve myocardial
contractility. Generally we prefer the use of dopamine in combination with milrinone
for decompensated heart failure due to the fact that it not only improves myocardial
contractility and relaxation, but it also reduces peripheral vascular resistance, resulting
in a decreased workload for the left ventricle. Milrinone is a phosphodiesterase-3 inhibitor.
It increases contractility, reduces afterload, and has no significant increase in myocardial
oxygen consumption. All of these features make it very attractive for chronic use in
children who are awaiting transplantation. Infusions of milrinone can commence at 0.25
micrograms per kilo per minute, up to 1 microgram per kilo per minute. Additionally, this medication
has been shown to be effective and safe in an outpatient setting. Let’s move on to non-pharmacological therapies
for heart failure, which are as equally important as pharmacological therapies. Nutrition. Growth failure, feeding intolerance,
and anorexia is a common complication, as well as presenting symptom of children with
heart failure. Increasing caloric intake by fortification with diet is generally necessary
in all children with significant symptomatic heart failure. Additionally, the use of tube
feeds via nasogastric, nasojejunal, or direct surgical gastric tubes may be necessary. Another primary therapeutic intervention is
focused at fluid restriction. Fluid restriction should be one of the first steps in non-pharmacological
treatment of heart failure with symptoms of congestion. Heart failure may result in maladaptive
excessive thirst and water intake, leading to electrolyte derangements such as hyponatremia
and symptoms of congestion and edema. Simply by limiting fluid intake to high-caloric fluids
only and limiting total fluid intake may ameliorate symptoms of congestion dramatically. They
may also limit the use of diuretics that may have long-term negative effects on renal function. While there is currently no recommended total
fluid intakes for children, general guidelines suggest infants having around 100 cc’s per
kilo per day, children weights 10 to 30 kilos between 600 to 1 liter per day, and older
children and adolescents, between 1 to 2 liters per day. For more advanced forms of heart failure,
positive pressure ventilation may be necessary. This may be delivered by invasive methods,
such as intubation, or noninvasive, such as continuous positive pressure. Positive pressure
ventilation alleviates respiratory distress from cardiogenic pulmonary edema. It has also
been shown to improve alveolar recruitment, lung compliance, and decrease LV preload,
as well as afterload. And lastly, for patients with end-stage heart
failure, refractory to maximal medical management, mechanical circulatory support is an option.
There currently are many different forms of mechanical circulatory support that can provide
both short and long-term cardio and cardiopulmonary support. For short-term support, these include
Extracorporeal Membrane Oxygenation, otherwise known as ECMO. And for long-term support,
it includes ventricular assist devices. These can be used as a bridge to transplantation
or to stabilize patients with subsequent removal of the mechanical circulatory support with
ventricular myocardial recovery. Let’s
move on to preventing morbidity or complications related to heart failure. There are a multitude
of complications that can be related to heart failure. These include thrombi formation.
Intra-cardiac clots can form in the setting of severe RV or LV dysfunction, leading to
either pulmonary embolus, cerebral embolic strokes, or any other arterial embolic events. We suggest the use of anti-coagulation, be
it unfractionated or low-molecular heparin, or an oral vitamin K antagonist for severe
RV or LV dysfunction. And we suggest the use of an anti-platelet agent, such as aspirin,
in the setting of mild to moderate RV or LV dysfunction. There are currently no clear
guidelines on what ejection fraction should be used as the cutoff between the use of anti-coagulation
or anti-platelet therapy, however many adult studies demonstrate that an LV ejection fraction
less than 30% should be treated with anti-coagulation to prevent intra-cardiac thrombi formation. Next is arrhythmias. Decreased ventricular
function can lead to ventricular and atrial enlargement that predispose to sustain atrial
and ventricular arrhythmias. As can be expected, atrial and ventricular arrhythmias can result
in significant hemodynamic compromise and destabilize already marginal patients. As
such, medication, ablation, or even implantable cardioverter-defibrillators are all recommended
depending on the severity of the heart failure and the frequency of arrhythmias. In summary, there are a multitude of approaches
to heart failure, and ultimately they all depend on the pathophysiology of the underlying
cause of the heart failure as well as the severity of the presentation. In considering
patients with heart failure, we must first consider any surgical or based cath correction
of structural heart disease that may be resulting or contributing to heart failure. Next, we
must focus on therapies that are tailored to the severity of the heart failure. For stage A patients– those are those that
are at risk of heart failure but who currently have normal function– no therapy is recommended.
For stage B– these are patients who are asymptomatic with abnormal function– simply an ACE inhibitor
may cause regression or remodeling of the ventricle and normalization of function. For
stage C– patients with symptomatic heart failure in the setting of abnormal function–
there’s a large armamentarium of medications recommended, such as ACE inhibitors, aldosterone
antagonists, beta blockers, digoxin, and diuretics. Utilization of these therapies must be tailored
at what symptoms the patient presents with, be it congestion or low perfusion. And lastly,
for stage D– patients presenting with end stage heart failure refractory to oral medications–
the use of intravenous inotropes, diuretics, ventilation, mechanical circulatory support,
and lastly heart transplant are all warranted. Non-pharmacological therapy is also equally
important to pharmacological therapy, including nutritional support and exercise programs. And lastly, we must focus on prevention and
treating of complications related to heart failure, both thrombotic events and arrhythmias.
Thank you for watching this video on heart failure management in children. Please help us improve the content by providing
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7 Replies to ““Management of Congestive Heart Failure” by Christina Vanderpluym, MD, for OPENPediatrics”

  1. Very precisely and beautifully discussed all aspects of management of heart failure,, thank you so much

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