Cardiovascular Diseases 2: Heart Failure and Rheumatic Heart Disease

Heart Failure

Heart failure, unlike coronary artery disease which is a condition in which the blood does receive enough blood, is characterised by an inability to pump enough blood to the tissues. It is often referred to as congestive heart failure as fluid begins to accumulate in the tissues, i.e. oedema occurs. It is normally chronic, meaning it develops over a long period of time, and does not have a single cause:
  • Coronary disease
  • High blood pressure
  • Cardiomyopathy
  • Atrial fibrillation
  • Heart valvular problems
  1.   Left Heart Failure

Causes: mitral stenosis, aortic stenosis, pericarditis, myocardial infarction

Characteristics: output of left ventricle becomes less than the amount of blood received from the left side via pulmonary circuit → congested pulmonary circuit ('crackles' when listened to by doctors), systemic blood pressure falls

Symptoms: dyspnea, increased respiratory ate, cough, cyanosis (from lack of oxygen), blood tinged sputum from oedema in lungs and movement of RBCs into lungs, fatigue, increased blood fluid volume (due to increased aldosterone to increased blood pressure), salt and water retention to increase blood volume

  2.   Right Heart Failure

Causes: left heart failure, chronic obstructive lung disease, pulmonary valve stenosis, pulmonary embolus

Characteristics: output of right ventricle becomes less than the amount of blood received from the superior and inferior vena cavae → congested systemic circuit, increased peripheral venous pressure

Symptoms: fatigue, peripheral oedema, distention of jugular vein, liver engorgement, ascites (accumulation of fluid in the abdomen), loss of appetite, cyanosis, hepatosplenomegaly

Infective Endocarditis

Infective endocarditis describes the permanent damage to the heart following rheumatic fever. Rheumatic fever is an autoimmune disease involving the bacterium streptococcal pharyngitis (70%) or staphylococcus (30%). When strep A enters the body, plasma cells produces antibodies to bind to and destroy the strep A antigens, causing 'strep throat'. However, because myocardial antigens look similar to the bacterium's, the produced antibodies also attack the body's own heart tissue. The inflammation resulting from this reaction is known as rheumatic fever, and continuous damage to the heart causes damage to the valves, joints and even the central nervous system.

Ultimately rheumatic fever results in infective endocarditis. Depending on the location of the endocarditis, it then causes rheumatic heart disease.

Rheumatic Heart Disease

Risks: artificial heart valves, rheumatic fever, congenital heart defects, intravenous illegal drug use, inflamed gums

Consequences: chest pain, murmurs, exertion dyspnea, oedema, stroke, detached intravascular masses → block pulmonary circulation (if damage occurs in tricuspid valve) or brain circulation (if damage occurs in aortic and/or mitral valves) → liquefactive necrosis in the brain

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