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What is the primary cause of left-sided heart failure?
Which condition is NOT a typical etiology of congestive heart failure?
Which of the following symptoms is most characteristic of congestive heart failure?
Which factor is a precipitating cause of congestive heart failure?
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What compensatory mechanism does the body use to combat congestive heart failure?
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Which of the following is NOT a known disease that can cause cardiomyopathy?
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Which of these factors is likely to lead to a decreased cardiac output in heart failure?
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What role does hypertension play in congestive heart failure?
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Which symptom indicates shortness of breath when lying down?
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What is the term for swelling in the legs, ankles, and feet due to excess fluid?
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What condition is characterized by a third heart sound (S3) and rales in the lungs during inspiration?
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Which class of medication primarily increases the force of contraction of the heart muscle?
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What is the primary purpose of using diuretics in heart failure treatment?
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Which one of the following medications is considered a direct vasodilator?
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What indicates the need for absolute rest in heart failure management?
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Which imaging technique is NOT typically used for diagnosing heart failure?
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What is the purpose of the loading dose in digitalization?
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What is the expected effect of a toxic dose of digitalis?
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Which of the following is NOT a side effect of digitalis toxicity?
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What clinical scenario would contraindicate the use of digitalis?
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What is the maintenance dose range for digitalis therapy?
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Which of the following conditions can increase digitalis toxicity?
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What is one primary action of digitalis on the cardiac cycle?
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What effect does digitalis have on AV conduction?
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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.
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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.
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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.
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Digitalis Medications:
-
Digoxin (Lanoxin):
- Improves myocardial contractility without increasing oxygen consumption.
- Controls heart rhythm abnormalities, especially atrial fibrillation and atrial flutter.
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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.
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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).
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Automaticity:
- Toxic doses increase automaticity, leading to ventricular extrasystole, ventricular tachycardia, and ventricular fibrillation.
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Contractility:
-
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.
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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.
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Gastrointestinal Tract (GIT):
- Nausea and vomiting due to local irritation and increased chemoreceptor trigger zone (CTZ) activity.
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Central Nervous System (CNS):
- Stimulates the vagal center, vomiting center (VMC), and CTZ.
- In toxic doses, can cause hallucinations, convulsions, and visual disturbances.
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Endocrine:
- Estrogen-like effects, can cause gynecomastia (enlarged breasts in males).
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Digoxin (Lanoxin):
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Diuretics:
- Chlorothiazide or hydrochlorothiazide: Thiazide diuretics.
- Frusemide and ethacrynic acid: Loop diuretics.
- Spironolactone: Potassium-sparing diuretic.
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Vasodilators:
- Nitrates:
- Hydralazine:
- Prazosin:
- Captopril: Ace inhibitor
- Sodium nitroprusside:
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Other Inotropics:
- Dopamine, Dobutamine, Prenalterol: Beta-adrenergic agonists.
- Amrinone and Milrinone: Phosphodiesterase inhibitors.
- Aminophylline and Sulmazole: Methylxanthines.
Digitalis Side Effects
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Early:
- Nausea
- Vomiting
- Bradycardia (<60 bpm)
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Late:
-
Cardiovascular (CVS):
- Bradycardia
- Heart block
- Increased ventricular automaticity (extrasystole, ventricular tachycardia, ventricular fibrillation).
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Extracardiac Effects:
- GIT: Nausea, vomiting.
- Eye: Yellow-green vision.
- Skin: Allergy.
- Gynecomastia: Enlarged breasts in males.
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Cardiovascular (CVS):
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.