Heart Failure Concepts and Classifications

Heart Failure

• Heart failure is a pathophysiological process where the heart struggles to meet the metabolic needs of the tissues for oxygen and substrates, despite normal or increased venous return to the heart.

Preload and Afterload

• Preload: The volume of blood in the ventricles at the end of diastole. It depends on venous return and compliance.
• Afterload: The resistance the left ventricle must overcome to circulate blood. It depends on arterial blood pressure, pulmonary artery pressure, and valvular disease.

Heart Failure Key Concepts

• Cardiac output (CO) is calculated as Stroke Volume (SV) multiplied by Heart Rate (HR).
• Stroke volume (SV) is determined by preload, afterload, and myocardial contractility.
• Ejection Fraction (EF) is a measure of the heart's pumping efficiency.

Ventricular Remodeling

• Ventricular remodeling can lead to hypertrophy (growth) or dilation (enlargement) of the left ventricle.

Heart Failure Classifications

• Systolic failure: Contractile weakness.
• Diastolic failure: Impaired filling of the ventricles.
• Mixed failure: A combination of systolic and diastolic failure.

Left-Sided Heart Failure (Causes)

• Valvular disease: Aortic stenosis, aortic regurgitation, mitral stenosis, and mitral regurgitation.
• Hypertension
• Myocardial disease: Myocardial infarction, myocarditis, and cardiomyopathy.

Left-Sided Heart Failure (Symptoms)

• Pulmonary congestion: Dyspnea on exertion, dyspnea at rest, orthopnea, paroxysmal nocturnal dyspnea, acute pulmonary edema, and cough with frothy blood-tinged sputum.
• Decreased cardiac output: Fatigue, cold extremities, peripheral cyanosis, and oliguria.

Right-Sided Heart Failure (Causes)

• Secondary to left-sided heart failure.
• Chronic obstructive pulmonary disease (COPD) causing pulmonary hypertension.
• Pulmonary embolism.
• Pulmonary and tricuspid valve disease.
• Myocardial disease.

Right-Sided Heart Failure (Symptoms)

• Congestive symptoms: Congested neck veins, enlarged and tender liver, edema (ankles, sacrum, ascites), and lower limb edema.
• Visceral congestion: Mal-digestion related to visceral congestion.

Treatment of Heart Failure

• Underlying cause treatment: Surgical valve replacements.
• Rest: Bed rest is best in a semi-sitting position.
• Diet: Light diet in small, frequent meals and salt restriction.
• Diuretics: Decrease preload, Examples: frusemide and spironolactone.
• Vasodilators: Decrease preload and afterload. Examples include ACE inhibitors.
• Digitalis: Increase contractile force and decrease heart rate.
• Beta blockers: Used in chronic stable heart failure.

Shock (Acute Peripheral Circulatory Failure)

• Shock is a case of acute circulatory failure characterized by inadequate tissue perfusion leading to tissue hypoxia.

Types of Shock

• Hypovolemic shock: Reduced blood volume due to hemorrhage, burns, and severe vomiting or diarrhea.
• Septic shock: Extreme inflammatory response to an infection.
• Cardiogenic shock: Heart's inability to adequately pump blood.
• Anaphylactic shock: Allergic reaction that causes widespread vasodilation and capillary leakage.
• Obstructive shock: Obstruction of blood flow like cardiac tamponade or tension pneumothorax.
• Neurogenic shock: Sudden loss of sympathetic nervous system control resulting in massive vasodilation.

Hypovolemic Shock (Causes & Clinical Picture)

• Causes of hypovolemic shock stem from reduced blood volume due to hemorrhage, burns, severe vomiting, or diarrhea.
• Clinical manifestations include pallor, cold clammy sweat, irritability, confusion, rapid weak pulse, hypotension, oliguria, and anuria.

Septic Shock (Causes and Definitions)

• Sepsis: Overwhelming inflammatory response in the body triggered by infection.
• Severity: Severe sepsis, or sepsis leading to organ dysfunction.
• Septic Shock: Characterized by low blood pressure despite intensive fluid resuscitation (IV fluids), the final stage of sepsis.
• Causes: Bacterial infections, less commonly fungal or viral infections.

Septic Shock (Clinical Picture)

• Early signs can include: fast heart rate, fever or hypothermia, shaking or chills, and warm, sweaty skin; nausea, and vomiting.
• Signs of severe sepsis including low blood pressure, confusion, disorientation, oliguria or anuria (renal failure).
• Associated conditions: lactic acidosis, cool and pale limbs, skin rash.
• Septic shock: low blood pressure despite aggressive IV fluid therapy.

Risk Factors and Treatment of Septic Shock

• Risk factors: Age, immunocompromised status, diabetes, malignancy, artificial heart valves/artificial joints, and pregnancy.
• Treatment: Rapid administration of appropriate antibiotics guided by culture and sensitivity tests, maintaining vital parameters (e.g., oxygenation, blood pressure), using vasopressors for resistant hypotension, and administering anti-inflammatory agents like hydrocortisone.

Gastroesophageal Reflux Disease (GERD) and Peptic Ulcerations

• GERD: Reflux of gastric contents into the esophagus due to insufficient lower esophageal sphincter closure.
• Types: Physiological reflux (normal) and gastroesophageal reflux disease (pathological).
• Protective mechanisms: Intraabdominal esophagus, high esophageal pressure (lower part), esophageal mucosa.

Etiology of GERD

• Primary: improper relaxation of the lower esophageal sphincter.
• Secondary: impaired esophageal peristalsis, delayed gastric emptying, and hiatus hernia.

Symptoms of GERD

• Heartburn
• Pressure sensation
• Epigastric pain
• Burning sensation
• Vomiting
• Extraesophageal symptoms: reflux bronchitis, bronchial asthma, and posterior laryngitis.

Complications of GERD

• Chest pain (can resemble angina/infarction)
• Esophageal ulceration
• Barrett's esophagus (precancerous condition)
• Esophageal adenocarcinoma
• Aspiration of gastric contents

Peptic Ulcer Disease (Causes & Location)

• Causes: Infection with H. pylori, use of NSAIDs, and excessive alcohol consumption.
• Location: Commonly on the lesser curvature and antrum of the stomach or the duodenum.

Clinical Picture of Peptic Ulcer Disease

• Pain: Burning, stabbing, or dull ache.
• Location: Duodenal ulcers are often relieved by food.
• Location: Gastric ulcers are often worse after eating.

Diagnosis of Peptic Ulcer Disease

• History: Symptoms and risk factors.
• Investigations: Upper endoscopy with biopsy, H. pylori testing, and 24-hour pH monitoring.

Treatment of Peptic Ulcer Disease

• Treat H. pylori infection if present
• Eradication of H. pylori: PPI (e.g., omeprazole, lansoprazole), antibiotics (e.g., clarithromycin, amoxicillin).
• Reduce stomach acid secretion with PPIs
• Stopping NSAID use if possible
• Avoiding smoking, alcohol, and caffeine
• Follow-up endoscopic assessment.

Jaundice and Viral Hepatitis

• Jaundice: Yellowish discoloration of the skin and sclera due to elevated serum bilirubin.
• Hepatitis: Inflammation of the liver, mainly viral in origin.

Causes of Jaundice

• Hemolytic jaundice: Breakdown of red blood cells.
• Hepatocellular jaundice: Liver damage.
• Obstructive jaundice: Blockage of bile duct.
• Cholestatic jaundice: Impaired bile flow.

Cholestatic Jaundice (Etiology)

• Extrahepatic: stones in the common bile duct, worms, tumors, or pressure from outside the bile duct such as enlarged lymph nodes or pancreatic cancer.
• Intrahepatic: Primary biliary cholangitis, secondary sclerosing cholangitis, certain medications, pregnancy.

Cholestatic Jaundice (Symptoms)

• Age of onset: middle to old age
• Deep jaundice
• Dark urine, pale stools
• Pruritis and tendency to bleed.

Investigations in Jaundice

• Urine and stool examinations
• Bilirubin quantification
• Liver enzyme profile (e.g., AST, ALT)
• Abdominal ultrasound/MRCP
• Upper endoscopy
• Liver biopsy
• Viral markers