Cardiac: Basic Pathology and Clinical Aspects

In general the oxygen-rich blood travels from the lungs to the left atrium and then on to the left ventricle (LV), which pumps it to the rest of the body. Left ventricular failure involves the left ventricle. If the left ventricle contractility reduces, there is not enough force to push enough blood into circulation (systolic failure) and if the muscle has become stiff the ventricle loses its ability to relax normally and the heart cannot properly fill with blood during the resting period between each beat (diastolic failure). In both cases, blood coming into the left chamber from the lungs may back up or back flow causing fluid to leak into the lungs causing pulmonary oedema.

• Signs and symptoms of left-sided heart failure are:
• Dyspnea, orthopnea, paroxysmal nocturnal dyspnea (PND), nocturnal cough, confusion etc.
  
• Displaced apex beat, pathologic S3 Gallop, S4
  
• Crackles at the lung bases; dullness to percussion and tactile fremitus of lower lung fields
  
• Increased intensity of pulmonic component of 2nd heart sound
  

The right atrium receives the deoxygenated blood that returns to the heart and the right ventricle pumps it into the lungs. Right sided heart failure usually occurs as a result of left heart failure. During the left heart failure, the increased fluid pressure is transferred back through the lungs, ultimately damaging the right side.

When the right side of the heart loses its contractility or pumping ability, the blood backs in the body's veins causing swelling in the legs and ankles.

Signs and symptoms of right-sided heart failure are:

• Peripheral edema, ascites, nocturia, epitasis
  
• Jugular venous distention
  
• Hepatojugular reflux