Friday, January 20, 2012

Right-Sided Heart Failure


Reduction of right ventricular output for an increased atrial pressure is called right-sided heart failure.

MORPHOLOGY (Right-sided heart failure)
Organs affected: Liver, spleen, kidneys, subcutaneous tissues, brain, portal area of venous drainage.

Liver: Changes in the liver tissue are the following:

Chronic passive congestion:
It has two components as following:
  • Nutmeg pattern: The central region of hepatocytes become congested appearing red while the peripheral region is uncongested appearing yellow. This red and yellow mottling gives the liver a characteristic appearance called nutmeg pattern.
  • Ischemic atrophy: Congestion of the central vein causes diminished rate of blood flow through the lobule, leading to chronic oxygen  deficiency in the liver cells in the central region of the lobule which results in ischemic atrophy of the liver cells in the congested central region of the lobule.

Central hemorrhagic necrosis:
In severe congestive cardiac failure, hemorrhages into the hepatic cords occur producing necrosis of the liver cells, this is called central hemorrhagic necrosis.

Cardiac sclerosis:
It is a complication of severe cardiac failure and is characterized by fibrosis of the central areas of hepatic lobules and is termed as cardiac sclerosis or cardiac cirrhosis.

CLINICAL FEATURES

Acute right ventricular failure:

Acute right ventricular failure occurs in:
  • Massive pulmonary embolism: Acute right ventricular failure occurs when massive pulmonary embolus becomes impacted in and obstruct the outflow tract of the right ventricle and main pulmonary artery. This results in arrest of the circulation and sudden death.
  • Cardiac temponade: Acute right ventricular failure occurs when fluid accumulates in pericardial cavity that interferes the right ventricular diastolic filling, resulting in decreased right ventricular output; the condition called cardiac temponade.

Chronic right ventricular failure:
Most commonly occurs secondary to left ventricular failure and is manifested clinically by systemic venous congestion such as:
  • Liver is enlarged and tender: Enlargement due to congestion and tenderness due to stretching of liver capsule.
  • Peripheral edema: Occurring in dependent areas – the ankles in ambulatory patients and the sacrum in recumbent ones.
  • Pleural effusion, pericardial effusion or ascites.

INVESTIGATIONS

ECG: ECG may show:
  • Right or left ventricular hypertrophy
  • Myocardial ischemia or infarction
  • Arrhythmia

X-ray Chest:
  • Hilar congestion
  • Bat’s wings appearance in acute pulmonary edema (opacities tend to spread in a butterfly manner from the hilum, periphery is usually clear)
  • Cardiomegaly
  • Evidence of pulmonary hypertension
  • Pleural effusion
  • Pneumonia as a precipitating factor may be evident.

Echocardiography:
Echocardiography is a very important tool for the diagnosis and cause of heart failure. It may demonstrate:
  • Systolic or diastolic impairment of left or right ventricle.
  • Valve disease.
  • Regional wall motion abnormalities in ischemic heart disease.
  • Cardiomyopathy
  • Intracardiac thrombus
  • Ejection fraction

TREATMENT
  • Diuretics e.g. frusemide.
  • Vasodilators e.g. ACE inhibitors 
  • Digitalis

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