6000 Exam 1 HF Pathophysiology

What is heart failure (HF)?

a clinical syndrome involving structural and/or functional abnormalities of the heart that result in impaired cardiac function and associated signs and symptoms

What are the two major ways the heart can fail in HF?

• Decreased ability to contract and propel blood

• Decreased ability to stretch and accept blood

What happens to cardiac output in HF?

decreases because the heart cannot effectively pump blood forward and/or cannot adequately fill

What is the equation for cardiac output?

CO = HR × SV

What are the three major determinants of normal cardiac muscle function?

• Preload

• Contractility

• Afterload

What happens when preload, contractility, or afterload becomes abnormal?

Cardiac output can decrease and fluid can back up into the pulmonary or systemic circulation

What are major causes of heart failure?

• Hypertension

• Heart valve abnormalities

• Pericardial effusion/myocarditis

• Cardiomyopathy

• Myocardial ischemia/infarction

• Cardiac arrhythmias

• Pulmonary embolism

• Pulmonary hypertension

• Renal insufficiency

• Congenital heart disease

• Age-related changes

How can hypertension contribute to HF?

Hypertension is a major cause/association of HF and can contribute to abnormal cardiac workload and dysfunction.

How can myocardial infarction lead to HF?

Myocardial injury can impair myocardial contractility, contributing to systolic dysfunction/HFrEF

How can valvular disease contribute to HF?

Valve abnormalities alter pressure gradients and interfere with the normal movement of blood through the heart, potentially decreasing cardiac output

What is cardiomyopathy?

A disease of the heart muscle

What are the primary causes of cardiomyopathy?

Genetic or acquired causes.

• secondary are drug toxicity and environmental exposure

What are the three major types of cardiomyopathy?

• Hypertrophic

• Dilated

• Restrictive

What characterizes hypertrophic cardiomyopathy?

Thickened cardiac muscle.

What major complication is associated with hypertrophic cardiomyopathy?

Sudden cardiac death, particularly noted in athletes

What characterizes dilated cardiomyopathy?

Enlargement/dilation of a cardiac chamber

What characterizes restrictive cardiomyopathy?

Stiff cardiac muscle, resulting in impaired ability to stretch/fill

Which cardiomyopathy primarily involves a problem with the heart being too thick?

Hypertrophic cardiomyopathy

What happens to cardiomyocytes in HF?

Cardiomyocyte dysfunction causes decreased contractile properties and/or decreased compliance

What does decreased contractility mean?

The heart has difficulty squeezing/contracting and ejecting blood

What does decreased compliance mean?

The heart has difficulty stretching and accepting blood during filling

What happens when fluid accumulates in the heart chambers?

Pressure gradients across the valves change, interfering with normal circulation through the heart

What happens in left-sided HF?

Decreased LV output causes blood/fluid to back up into the pulmonary vasculature.

What are classic manifestations of left-sided HF?

• Pulmonary edema

• Shortness of breath

• Hypoxemia

• Crackles

• Orthopnea

• Paroxysmal nocturnal dyspnea

What happens in right-sided HF?

Decreased RV output causes fluid to back up into the systemic vasculature.

What are classic manifestations of right-sided HF?

• Peripheral edema

• JVD

• Hepatic congestion

• Ascites

What is the key distinction between left- and right-sided HF?

Left = lungs
Right = systemic circulation

A patient has pulmonary edema, crackles, and severe SOB. Which side of HF is most directly implicated?

Left-sided HF

A patient has peripheral edema, JVD, and ascites. Which side?

Right-sided HF

What is the most common cause of right-sided HF according to the lecture?

Advanced left-sided HF

How can left-sided HF eventually cause right-sided HF?

Pulmonary fluid backup increases pulmonary arterial pressure, increasing RV afterload. The RV eventually cannot sustain the increased workload, leading to RV dysfunction

What is biventricular HF?

HF involving both the left and right ventricles, commonly occurring in advanced HF

What is ejection fraction (EF)?

The percentage of blood pumped out of the heart during systole.

EF = Stroke Volume ÷ End-Diastolic Volume

What is a normal EF?

60–70%.

What is HFpEF?

Heart failure with preserved ejection fraction, with EF >50%.

What type of dysfunction characterizes HFpEF?

Diastolic dysfunction — the cardiac muscle cannot adequately stretch/fill.

What condition is identified as a cause of HFpEF?

Hypertension

What is HFrEF?

Heart failure with reduced ejection fraction, with EF <40%.

What type of dysfunction characterizes HFrEF?

Systolic dysfunction — the heart cannot contract/eject effectively.

What condition is identified as a cause of HFrEF?

Myocardial infarction

What is HFmrEF?

Heart failure with mildly reduced EF: 41–49%

A patient has an EF of 35%. How would you classify it?

HFrEF

A patient has an EF of 55%. How would you classify it?

HFpEF

A patient has an EF of 45%. How would you classify it?

HFmrEF

What are common signs/symptoms of decreased cardiac output in HF?

• Dyspnea

• PND

• Orthopnea

• Tachypnea

• Crackles

• S3

• Peripheral edema

• JVD

• Weight gain

• Sinus tachycardia

• Decreased exercise tolerance

• Decreased cognition

• Abnormal renal/liver labs

What is orthopnea?

Difficulty breathing when lying flat.

What is paroxysmal nocturnal dyspnea (PND)?

Episodes of shortness of breath that occur during sleep and may awaken the patient.

Why might a patient with HF sleep in a recliner?

Sitting upright can reduce symptoms associated with pulmonary congestion/orthopnea.

What does an S3 heart sound suggest in this context?

It is a clinical sign associated with HF/decreased cardiac output.

Why can HF cause peripheral edema?

Fluid backs up into the systemic circulation, particularly with right-sided HF.

Why might body weight increase rapidly in HF?

Fluid retention.

Why might cognition decrease in HF?

Decreased cardiac output can reduce blood flow/oxygen delivery to tissues, including the brain.

What is Stage A HF?

Patient is at risk for HF but has no current/prior structural changes, symptoms, or biomarkers of HF

What are examples of Stage A risk factors?

• Hypertension

• Ischemic cardiovascular disease

• Obesity

• Diabetes

What is Stage B HF?

Pre-HF — there is evidence of structural/functional cardiac abnormality or elevated natriuretic peptides, but no symptoms

What is Stage C HF?

HF with current or prior signs and symptoms.

What is Stage D HF?

Advanced HF with significant symptoms despite optimal medical management, often involving recurrent hospitalization and eligibility for advanced therapies

What is NYHA Class I?

No limitation in physical activity; ordinary activity does not cause fatigue, palpitations, or dyspnea

What is NYHA Class II?

Slight limitation; comfortable at rest, but ordinary activity causes symptoms.

What is NYHA Class III?

Marked limitation; comfortable at rest, but less-than-ordinary activity causes symptoms.

What is NYHA Class IV?

Symptoms are present at rest; unable to perform physical activity without symptoms.

Patient has symptoms at rest. What NYHA class?

Class IV.

Patient is comfortable at rest but becomes symptomatic with minimal activity. What NYHA class?

Class III

What is decompensated HF?

A period of instability in which symptoms deteriorate, structural/functional changes progress, and multisystem effects worsen

What can precipitate HF decompensation?

A precipitating event or progression of the underlying HF.

What are important signs of HF decompensation?

• Rapid/increasing weight gain

• Chest pain

• Worsening pulmonary edema

• Worsening peripheral edema

• Increasing fatigue

• Increasing dyspnea

A patient gained 3 lb in one week and now has crackles and an S3. What should you suspect?

HF decompensation/fluid overload.

What does a CardioMEMS sensor measure?

Pulmonary artery pressure.

What are broad categories of HF management?

• Dietary/nutritional management

• Exercise

• Pharmacologic treatment

• Devices

• Surgery

• Mechanical circulatory support

• Transplantation

What is an ICD?

An implanted device that monitors cardiac activity and treats dangerous arrhythmias with a shock; it can also function as a pacemaker

When can PT begin after ICD implantation?

When the patient is hemodynamically stable, while following physician-ordered precautions.

What common precaution may exist after ICD implantation?

Left upper-extremity lifting/ROM restrictions postoperatively; follow MD orders

What EF is an indication for CRT according to the lecture?

EF <35%

What is cardiac resynchronization therapy (CRT)?

Biventricular pacing that reduces ventricular dyssynchrony

What is an IABP?

An intra-aortic balloon pump that inflates during diastole to increase coronary perfusion and deflates during systole

What is an important PT precaution with a femorally inserted IABP?

No hip flexion >30°

What does a VAD do?

It assists/replaces ventricular pumping function. The LVAD is the most common type

When does PT begin with a VAD?

When the patient is hemodynamically stable at rest, and rehabilitation can continue through outpatient cardiac rehabilitation

What is pericarditis?

Inflammation of the pericardium

What can cause pericarditis?

• viral infection

• Bacterial infection

• Trauma

• Autoimmune disorders

• Complication of MI

• Renal failure

• Radiation therapy

What serious complication can pericarditis cause?

Pericardial effusion, which can progress to cardiac tamponade.

What is cardiac tamponade?

Compression of the cardiac muscle by accumulated pericardial fluid.

What procedure can be used to treat a significant pericardial effusion/tamponade?

Pericardiocentesis

What is myocarditis?

Inflammation of the myocardial wall

What can cause myocarditis?

• Viral infection

• Bacterial infection

• Fungal infection

• Rheumatic fever

• Parasites

• Allergic reactions

• Pharmacologic reactions

• Systemic disease

What serious cardiac condition can myocarditis progress to?

Dilated cardiomyopathy

When is PT contraindicated in myocarditis?

Until the patient is hemodynamically stable

What is an aneurysm?

An abnormal bulge/dilation in an arterial wall.

What are risk factors/causes of aneurysm?

• Atherosclerosis

• Hypertension

• Genetics

• Vessel injury

• Smoking

• Increasing age

What are two major consequences of an aneurysm?

• Blood clot formation

• Rupture

What symptoms may suggest an aneurysm?

sudden/unrelenting:

• Head pain

• Abdominal pain

• Back pain

• Chest pain

• Groin pain

What physical finding may occur with an aneurysm?

A pulsating mass, such as in the neck or abdomen.

What neurologic symptoms may occur with some aneurysms?

• Dizziness

• Vision changes

• Confusion

• Loss of consciousness

• Nausea/vomiting

How are small aneurysms generally managed?

Medications and monitoring.

What exercise maneuver should be avoided with an aneurysm?

Valsalva maneuver.

How are large aneurysms managed?

Surgical intervention.

When can PT see a patient following aneurysm surgery?

When the patient is hemodynamically stable.

Why is BP particularly important to monitor in a patient with an aneurysm?

monitor BP and stay below the physician-ordered BP limit to reduce risk during intervention

How does HF affect the kidneys?

It can contribute to increased creatinine and kidney failure.

How does HF activate the RAAS?

HF activates RAAS, increasing fluid and sodium retention.