Acute Heart Failure


 Acute Heart failure is a clinical syndrome that occurs secondary to severe, overwhelming cardiac disease. It occurs because the heart is no longer able to maintain normal venous/capillary pressures, cardiac output, and/or systemic blood pressure. A chronic disease that results in a severe decrease in myocardial contractility, severe regurgitation or shunting or severe diastolic dysfunction most commonly causes it. However, it is common to have all three abnormalities present simultaneously (but with one predominating). By far, the most common clinical manifestations seen with heart failure are directly due to edema and effusion (congestive or backward heart failure).


The causes of acute heart failure may be grouped into the followings:

  1. Severe disorders of cardiac filling and is mostly seen when there is a traumatic rupture of either atria, ventricle, pericardium, aorta, pulmonary, or coronary arteries.
  2. Failure of the heart to act as a pump may be seen
    1. Ventricular fibrillation and severe tachycardia (associated with bacterial myocarditis, nutritional myopathy with selenium or copper deficiency, plant poisoning, electrocution, and lightening stroke)
    1. Severe bradycardia associated with an overdose of any sedatives/anesthetic e.g. Xylazine, barbiturates, injection of concentrated potassium salt.
  3. Sudden increases in workload are usually associated with acute anaphylaxis or rupture of the aortic valve.


Under the influence of any etiological factors mentioned above the cardiac output will be seriously reduced to the point where there is the development of a severe degree of tissue anoxia. The brain is the most sensitive organ to be first affected. As indicated by nervous signs (unconsciousness and clonic convulsions). It has been observed that complete anoxia for 15 seconds may lead to irreparable damage to brain tissues. An acute reduction in arterial blood flow will lead to the development of severe pallor of mucosae and the absence of a pulse. In less severe cases, the signs of acute congestive heart failure such as pulmonary congestion and edema may be noted.

Clinical Findings:

  • Sudden development of dyspnea
  • Staggering
  • Unconsciousness followed by death
  • Asphyxia gasps
  • Clonic convulsions
  • Pallor of mucosa
  • Absence of palpable pulse

In Severe Cases:-

  • Tachycardia
  • Bradycardia
  • Distress
  • Fast Breathing
  • Pulmonary edema


In the necropsy of an animal whose death occurred with acute heart failure, we usually find the following observable sign and symptoms:-

  • Engorgement of pulmonary vessels
  • Lung edema

Differential Diagnosis:-

  • Diseases of the nervous system have the same clinical manifestation as off
  • Epilepsy is characterized by repetitive attacks of unconsciousness

Below mentioned signs are indicative of AHF:-

  • Sudden development of tachycardia or bradycardia
  • Pallor of mucosae
  • Absence of pulse
  • Falling
  • Unconsciousness
  • Clonic convulsions


  • AHF is usually managed with symptomatic treatment.
    • In case of excessive bradycardia Adrenaline both IV and IM.
    • In case of tachycardia, Lignocaine without adrenaline should be injected intravenously.

In case of arrest of the cardiac system cardiopulmonary resuscitation (CPR) is given.

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