Congestive Heart Failure Overview

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Questions and Answers

What is the primary cause of left-sided heart failure?

Anemia

Pulmonary edema (correct)

Systemic edema

Cardiac arrhythmia

Which condition is NOT a typical etiology of congestive heart failure?

Neuromuscular diseases

Hypoxia

Chronic headaches (correct)

Valvular heart disease

Which of the following symptoms is most characteristic of congestive heart failure?

Persistent coughing

Shortness of breath (correct)

Dizziness

Nausea

Which factor is a precipitating cause of congestive heart failure?

Excessive intake of salt Signup and view all the answers

What compensatory mechanism does the body use to combat congestive heart failure?

Activation of the renin-angiotensin-aldosterone system Signup and view all the answers

Which of the following is NOT a known disease that can cause cardiomyopathy?

Diabetes mellitus Signup and view all the answers

Which of these factors is likely to lead to a decreased cardiac output in heart failure?

Cardiac arrhythmia Signup and view all the answers

What role does hypertension play in congestive heart failure?

It can be a pre-existing condition that exacerbates heart failure. Signup and view all the answers

Which symptom indicates shortness of breath when lying down?

Orthopnea Signup and view all the answers

What is the term for swelling in the legs, ankles, and feet due to excess fluid?

Pitting edema Signup and view all the answers

What condition is characterized by a third heart sound (S3) and rales in the lungs during inspiration?

Heart failure Signup and view all the answers

Which class of medication primarily increases the force of contraction of the heart muscle?

Digitalis Signup and view all the answers

What is the primary purpose of using diuretics in heart failure treatment?

Reduce fluid overload Signup and view all the answers

Which one of the following medications is considered a direct vasodilator?

Captopril Signup and view all the answers

What indicates the need for absolute rest in heart failure management?

Prevention of thrombosis Signup and view all the answers

Which imaging technique is NOT typically used for diagnosing heart failure?

Magnetic Resonance Imaging (MRI) Signup and view all the answers

What is the purpose of the loading dose in digitalization?

To initially establish therapeutic drug levels Signup and view all the answers

What is the expected effect of a toxic dose of digitalis?

Increased automaticity leading to arrhythmias Signup and view all the answers

Which of the following is NOT a side effect of digitalis toxicity?

Hypermagnesemia Signup and view all the answers

What clinical scenario would contraindicate the use of digitalis?

Ventricular tachycardia or extrasystole Signup and view all the answers

What is the maintenance dose range for digitalis therapy?

½ to 2 units Signup and view all the answers

Which of the following conditions can increase digitalis toxicity?

Hypokalemia Signup and view all the answers

What is one primary action of digitalis on the cardiac cycle?

Enhances the filling of the heart during diastole Signup and view all the answers

What effect does digitalis have on AV conduction?

Inhibits SA node and delays AV conduction at both low and high doses Signup and view all the answers

Study Notes

Congestive Heart Failure (CHF)

Definition: The inability of the heart to maintain adequate cardiac output (CO) leading to congestion in the pulmonary and/or systemic circulation.
Types:
- Left-sided heart failure: Causes pulmonary edema.
- Right-sided heart failure: Causes systemic edema.
Etiology:
- Hypertension
- Coronary artery disease
- Valvular heart disease
- Abnormal heart rhythms (arrhythmias)
- Hyperthyroidism
- Anemia
- Cardiomyopathy
Cardiomyopathy Causes:
- Infection (viral, bacterial, AIDS, rheumatic fever)
- Toxins (alcohol, cocaine, radiation, chemotherapy)
- Nutritional deficiencies (thiamine deficiency causing beriberi)
- Connective tissue disorders (lupus, rheumatoid arthritis)
- Neuromuscular diseases (muscular dystrophy)
- Infiltrative diseases (amyloidosis, sarcoidosis, cancer)
- Idiopathic (unknown)
- Familial
- Congenital heart disease
Precipitating Factors:
- Discontinuation of prescribed medications
- Excessive fluid or salt intake
- Uncontrolled hypertension
- Infection
- Heart attack
- Ischemia
- Cardiac arrhythmia
- Anemia
- Pulmonary embolus
- Hyperthyroidism
- Hypoxia
- New heart valve malfunction

Body's Compensatory Mechanisms

Sympathetic nerve stimulation: Increases heart rate and contractility.
Renin-angiotensin-aldosterone system activation: Increases blood volume and vasoconstriction.
Anti-diuretic hormone (ADH) activation: Increases water retention.
Hypertrophy: Increases heart muscle mass.

Symptoms of CHF

Dyspnea:
- Dyspnea on exertion: Shortness of breath with physical activity.
- Orthopnea: Shortness of breath when lying down.
- Paroxysmal nocturnal dyspnea: Intermittent shortness of breath at night.
Edema: Usually in legs, ankles, and feet.
Weight gain
Fatigue
Chest pain
Acute pulmonary edema

Diagnosis

Cardiomegaly: Enlarged heart.
S3 heart sound: Indicates fluid in the heart chambers.
Rales: Sound of fluid in the lungs during inspiration.
Jugular venous distention: Enlarged jugular vein in the neck.
Hepatomegaly: Enlarged liver.
Edema: In legs, ankles, and feet.
Pitting edema: Temporary pit after fingertip pressure.
Tachycardia: Rapid heart rate.
Tachypnea: Increased rate of breathing.
Hypertension: High blood pressure.
Hypotension: Low blood pressure.
Cardiogenic shock: Severe hypotension caused by heart failure.
Ascites: Fluid in the abdominal cavity.
Pleural effusion: Fluid in the space between the lungs and ribs.
Imaging:
- Chest X-ray (CXR)
- Electrocardiogram (EKG)
- Echocardiogram

Treatment of CHF

Diet and rest:
- Sodium restriction
- Absolute rest: Disadvantages include thrombosis, pneumonia, psychosis, and bed sores.
Digitalis Medications:
- Digoxin (Lanoxin):
  - Improves myocardial contractility without increasing oxygen consumption.
  - Controls heart rhythm abnormalities, especially atrial fibrillation and atrial flutter.
- Action:
  - Contractility:
    - Increases cardiac output without increasing oxygen demand.
    - Stronger and shorter systole, improves emptying.
    - Longer diastolic time, improves filling.
    - Reduces cardiac muscle stretch, facilitates contraction.
    - Reduces heart size.
    - Relieves venous congestion, reduces venous return.
  - Rhythmicity:
    - Decreases chronotropic effect (heart rate).
    - Small doses inhibit the sinoatrial node (SAN) and delay atrioventricular conduction (vagal effect).
    - Large doses inhibit SAN and delay AV conduction (direct effect).
  - Automaticity:
    - Toxic doses increase automaticity, leading to ventricular extrasystole, ventricular tachycardia, and ventricular fibrillation.
- ECG:
  - Prolonged P-R interval: Slow AV conduction.
  - Shortened Q-T interval: Short duration of systole.
  - ST segment depression:
  - Flattened or inverted T wave: Early digitalis toxicity.
  - Ventricular extrasystole or tachycardia: Digitalis toxicity.
- Kidney:
  - Acts as a diuretic in CHF.
  - Increases cardiac output, renal blood flow, and glomerular filtration rate (GFR).
  - Decreases renin secretion, reducing angiotensin II and aldosterone levels.
  - May compete with aldosterone.
- Gastrointestinal Tract (GIT):
  - Nausea and vomiting due to local irritation and increased chemoreceptor trigger zone (CTZ) activity.
- Central Nervous System (CNS):
  - Stimulates the vagal center, vomiting center (VMC), and CTZ.
  - In toxic doses, can cause hallucinations, convulsions, and visual disturbances.
- Endocrine:
  - Estrogen-like effects, can cause gynecomastia (enlarged breasts in males).
Diuretics:
- Chlorothiazide or hydrochlorothiazide: Thiazide diuretics.
- Frusemide and ethacrynic acid: Loop diuretics.
- Spironolactone: Potassium-sparing diuretic.
Vasodilators:
- Nitrates:
- Hydralazine:
- Prazosin:
- Captopril: Ace inhibitor
- Sodium nitroprusside:
Other Inotropics:
- Dopamine, Dobutamine, Prenalterol: Beta-adrenergic agonists.
- Amrinone and Milrinone: Phosphodiesterase inhibitors.
- Aminophylline and Sulmazole: Methylxanthines.

Digitalis Side Effects

Early:
- Nausea
- Vomiting
- Bradycardia (<60 bpm)
Late:
- Cardiovascular (CVS):
  - Bradycardia
  - Heart block
  - Increased ventricular automaticity (extrasystole, ventricular tachycardia, ventricular fibrillation).
- Extracardiac Effects:
  - GIT: Nausea, vomiting.
  - Eye: Yellow-green vision.
  - Skin: Allergy.
  - Gynecomastia: Enlarged breasts in males.

Treatment of Digitalis Arrhythmias

Discontinue digitalis.
Potassium chloride (KCl): To correct hypokalemia.
Atropine: To treat heart block.
Diphenhydramine, propranolol, lidocaine: To treat ventricular arrhythmias with heart block.
Digoxin Immune Fab (Digibind): To bind and remove digitalis from the body.

Factors Increasing Digitalis Toxicity

Hypokalemia
Hypomagnesemia
Hypothyroidism
Renal failure
Hepatic failure
Hypercalcemia
Hyperacidosis
Hyperthyroidism
Old age
Acute myocardial infarction (MI)

Digitalis Contraindications

Ventricular tachycardia or extrasystole.

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Description

This quiz covers the fundamentals of Congestive Heart Failure (CHF), including its definition, types, causes, and related conditions. Learn about left-sided and right-sided heart failures, their etiologies, and the role of cardiomyopathy in heart health. Test your understanding of this vital topic in cardiovascular medicine.