Myocarditis Quiz

Cardiac Failure

• Cardiac failure is the failure of the heart to pump sufficient blood to satisfy metabolic demands, resulting in under-perfusion, fluid retention, and increased blood volume.
• Types of cardiac failure:
  • Acute heart failure: rapid onset of symptoms, often with a definable cause (e.g., myocardial infarction)
  • Chronic heart failure: slow onset of symptoms, associated with conditions like ischaemic or valvular heart disease
  • Acute-on-chronic heart failure: chronic failure becomes decompensated by an acute event
• Systolic and diastolic cardiac failure:
  • Systolic failure: failure of the pump to move blood in systole, reduced ejection fraction, and reduced ventricular contraction
  • Diastolic failure: failure of the ventricular wall to relax, restrictive, stiff ventricle, reduced ventricular filling, and elevated end diastolic pressure
• Right and left ventricular failure:
  • Right ventricular failure: primary effects on the right side of the heart
  • Left ventricular failure: primary effects on the left side of the heart

Causes of Left and Right Ventricular Failure

• Coronary heart disease
• Hypertension
• Cardiomyopathies (familial/genetic or non-familial/non-genetic, including acquired, e.g., myocarditis)
• Hypertrophic, dilated, restrictive, and arrhythmogenic right ventricular cardiomyopathies
• Drugs (e.g., beta-blockers, calcium antagonists, antiarrhythmics, cytotoxic agents)
• Toxins (e.g., alcohol, medication, cocaine, trace elements)
• Endocrine disorders (e.g., diabetes mellitus, hypo/hyperthyroidism, Cushing syndrome, adrenal insufficiency, excessive growth hormone, phaeochromocytoma)
• Nutritional deficiencies (e.g., thiamine, selenium, carnitine, obesity, cachexia)
• Infiltrative diseases (e.g., sarcoidosis, amyloidosis, haemochromatosis, connective tissue disease)
• Others (e.g., Chagas' disease, HIV infection, peripartum cardiomyopathy, end-stage renal failure)

Clinical Effects of Left and Right Ventricular Failure

• Left ventricular failure: pulmonary oedema, pulmonary hypertension, and eventually, right ventricular failure
• Right ventricular failure: pitting oedema, congested "nutmeg" liver
• Combined left and right ventricular failure: often called "congestive" cardiac failure

Hypertension

• Systemic hypertension:
  • Definition: persistent raised blood pressure above 140/90 mmHg
  • Classification: primary vs secondary, essential vs accelerated
  • Epidemiology: 1.28 billion adults worldwide have hypertension, with most (two-thirds) living in low- and middle-income countries
• Pulmonary hypertension:
  • Definition: increased pulmonary vascular resistance
  • Causes: diffuse lung disease, elevated left atrial pressure, recurrent pulmonary emboli, primary pulmonary hypertension, left-right shunts
  • End-organ effects: pulmonary arteries, heart

An aneurysm is a bulging, swollen blood vessel

• Aortic and other arteries: atherosclerosis, hypertension
• Berry aneurysm: congenital
• Dissecting aneurysm: thoracic aorta, Marfan's
• Mycotic aneurysm: infective endocarditis

Neoplasia and the Heart

• Rare, most often metastatic (e.g., melanoma, small cell undifferentiated lung cancer)
• Primary benign: atrial myxoma
• Primary malignant: angiosarcoma, rhabdomyosarcoma, etc.