Harrisons 234: Heart failure & cor pulmonale

Question 1

Heart failure: what is it?

Answer 1

Clinical syndrome of signs & symptoms arising from abnormality of heart structure & function.

Question 2

Heart failure: why is it bad?

Answer 2

Because you kinda need your heart, and if it fails, that will suck!

Or because of “frequent hospitalizations, poor quality of life, and shortened life expectancy,” which is really what I said anyway.

Question 3

Heart failure: some classic signs & symptoms

Answer 3

Signs: Edema, crackles
Symptoms: Dyspnea, fatigue

Question 4

The incidence of HF seems to be rising. How come?

Answer 4

Because we’re doing better at fixing OTHER cardiac disorders, like MI & valve disease.

“current therapies for cardiac disorders…are allowing patients to survive longer.”

Question 5

Heart failure patients are in 1 of 2 groups. What are those groups?

Answer 5

1) HF with depressed EF (systolic heart failure)

2) HF with preserved EF (diastolic heart failure)

Question 6

What is the “line” for preserved vs. depressed EF?

Answer 6

40% is the magic number!

< 40% = depressed EF
≥ 40% = preserved EF

Question 7

Some possible etiologies for depressed EF/systolic HF:

Answer 7

#CAD: myocardial infarct or ischemia
#Nonischemic dilated cardiomyopathy: familial/genetic disorder, infiltrative disorder
#Chronic pressure overload: HTN, obstructive valve disease, intracardiac (L-to-R shunting), extracardiac shunting
#Toxic/drug induced damage: metabolic disorder, viral
#Chagas disease
#Chronic arrhythmia: tachy or brady

Question 8

Some possible etiologies for preserved EF/diastolic HF:

Answer 8

#Pathologic hypertrophy: primary (hypertrophic cardiomyopathy) or secondary (hypertension)
#Restrictive cardiomyopathy: infiltrative disorders, storage diseases
#Aging
#Fibrosis
#Endomyocardial disorders
#Pulmonary heart disease: cor pulmonale, pulmonary vascular disorders

Question 9

HF patients are classified by objective assessment using what scale?

Answer 9

New York Heart Association (NYHA) Classes I-IV

Question 10

NYHA Class I

Answer 10

No limitation of physical activity. Ordinary activity does not cause undue fatigue, palpitations, dyspnea, or angina.

Question 11

NYHA Class II

Answer 11

Slight limitation of physical activity. Comfortable at rest. Ordinary activity results in fatigue, palpitation, dyspnea or angina.

Question 12

NYHA Class III

Answer 12

Marked limitation of physical activity. Comfortable at rest. Less than ordinary activity causes fatigue, palpitation, dyspnea, & angina.

Question 13

NYHA Class IV

Answer 13

Inability to carry on any physical activity without discomfort. Symptoms of HF or angina may be present at rest. Discomfort increases with any physical activity.

Question 14

What is an index event in the context of HF?

Answer 14

“An event that either damages the heart muscle…or disrupts the ability of the myocardium to generate force.”

It can be abrupt, gradual, or hereditary.

Question 15

Compensation mechanisms that keep HF patients asymptomatic:

Answer 15

1) Renin-angiotensin-aldosterone & adrenergic nervous systems
2) Increased myocardial contractility
3) Vasodilatory molecules (ANP, BNP, prostaglandins & nitric oxide)

Question 16

“I’ll take HF for $200, Alex”

“Left ventricular remodeling”

Answer 16

“What is a series of adaptive changes within the myocardium?”

(You win!)

Question 17

What causes LV remodeling?

Answer 17

1) Myocyte hypertrophy
2) Alterations of myocyte contractility
3) Loss of myocytes
4) beta-adrenergic desensitization
5) Abnormal myocardial metabolism & energetics
6) Reorganization of extracellular matrix so that it does not provide enough support to myocytes

Question 18

Cardinal Symptoms of HF

Answer 18

#Fatigue
#Shortness of breath

Question 19

What’s the origin of the classic dyspnea in HF?

Answer 19

Biggest contributor: Pulmonary congestion with accumulation of interstitial or intra-alveolar fluid

Runner ups: reduction in lung compliance, increased airway resistance, respiratory muscle fatigue, anemia

Question 20

Let’s talk about orthopnea! What IS it? Why is it a thing? How do we measure it?

Answer 20

What: dyspnea when patient lies down

Why: redistribution of fluid back into central circulation when the patient lies down, resulting in higher pulmonary capillary pressure

How measured: “How many pillows do you sleep on?”

Question 21

Paroxysmal nocturnal dyspnea (PND): What, when, & why?

Answer 21

What: acute episodes of SOB & coughing that wake ya up. Coughing & wheezing continue after assuming upright position.

When: At night, about 1-3 hours after HS

Why: Increased pressure in bronchial arteries, leading to airway compression. Probably also that fluid redistribution thing.

Question 22

Cheyne-Stokes respiration: What’s that?

Answer 22

Disordered breathing in which periods of apnea cycle with periods of hyperventilation.

Question 23

Cheyne-Stokes respiration: Why does it happen?

Answer 23

Diminished sensitivity to PCO2 in respiratory center.

Apneic phase results in higher arterial PCO2, which stimulates respiratory center, which triggers hyperventilation. Resulting hypocapnia triggers more apnea…and on and on.

Question 24

Other possible HF symptoms

Answer 24

#GI symptoms: anorexia, nausea, early satiety
#Right upper quadrant pain (re: liver congestion)
#Cerebral symptoms: confusion, disorientation & sleep/mood disturbances
#Nocturia

Question 25

HF: General appearance & vitals

Answer 25

#Mild/moderate HF: No distress at rest. Systolic BP may be high. 
#Severe HF: Orthopnea, labored breathing, SOB. Systolic BP probably low, possibly decreased pulse pressure. May be tachycardic.

Question 26

HF: Jugular vein exam

Answer 26

Estimation of right atrial pressure. With patient lying recumbent & head tilted at 45º, estimate height of the venous blood column above sternal angle in centimeters & add 5.

Question 27

HF: pulmonary exam

Answer 27

Crackles result from movement of fluid into alveoli from intravascular space. May not be present in chronic HF.

When present in patient without lung disease, CRACKLES ARE SPECIFIC FOR HEART FAILURE!

Question 28

HF: cardiac exam

Answer 28

Essential, but may not provide useful info re: HF severity!

#PMI displaced laterally below 5th intercostal space if cardiomegaly is present
#S3 most common in volume overload with tachycardia & tachypnea, often in hemodynamic instability
#S4 isn't specific, but often presents with diastolic dysfunction
#Possible mitral/tricuspid regurg murmurs

Question 29

HF: abdomen exam

Answer 29

Hepatomegaly is important sign in HF!

Question 30

Lifestyle measures to help control HF

Answer 30

1) Exercise: routine modest exercise may result in reduced HF symptoms
2) Diet: Restriction of Na recommended for ALL HF patients (2-3 grams/day)

Question 31

Vasodilators for the treatment of acute HF

Answer 31

Nitroglycerin
Nitroprusside
Nesiritide

Question 32

Inotropes for the treatment of acute HF

Answer 32

Dobutamine
Milirinone
Dopamine

Question 33

Vasoconstrictors for treatment of acute HF

Answer 33

Dopamine (for hypotension)
Epinephrine
Phenylephrine
Vasopressin

Question 34

These two diseases are responsible for 50% of the cor pulmonale in North America:

Answer 34

1) COPD

2) Chronic bronchitis

Question 35

What is the basic mechanism behind cor pulmonale?

Answer 35

Increased pressure in pulmonary capillary bed increases workload of right ventricle, which then dilates & fails.

Question 36

What is the most common cause of RIGHT heart failure? (Hint: not a lung disease…)

Answer 36

LEFT heart failure!

Question 37

Signs & symptoms of cor pulmonale

Answer 37

#Dyspnea: result of increased work of breaking bc of decreased lung elasticity, altered respiratory mechanics, or inefficient ventilation
# Elevated JVP, hepatomegaly, LE edema

Question 38

Treatment for cor pulmonale:

Answer 38

#Treat underlying pulmonary disease
#Decrease work of breathing
#Oxygenate
#Diuretics