Therapies for Acute Decompensated Heart Failure (ADHF)

Various therapies are required for the treatment and management of Acute Decompensated Heart Failure. In this blog, we will read about them in detail. However, it is highly recommended that you watch the video lecture from the PrepLadder app with it. 

Vasoactive Therapy 

Uses of Vasoactive Therapy

• Reduce preload and afterload.
• Increase the BP.
• Increase end-organ perfusion.
• Also, it reduces systemic vascular tone.

Drugs Used in Vasoactive Therapy

• Nitroglycerin – via IV
  • Impacts the venous tone.
  • Reduces ventricular preload.
  • Adjunct to diuretics.
  • Reduces Pulmonary Edema.
  • It can be used in the acute management of acute decompensated heart failure.
• Sodium nitroprusside - Arterial and venous dilator.
  • Reduces preload and afterload.
  • Significant hypotension is caused, so close monitoring is done.
  • Given in patients with adequate BP.
• Nesiritide - a form of recombinant brain natriuretic peptide.
  • The intermediate effect between nitroglycerin and sodium nitroprusside. 
  • Head-to-head trials are done for NTG and nesiritide.
  • NTG causes rapid reduction in pulmonary capillary wedge pressure and vascular resistance.
  • Nitroglycerin is better than Nesiritide.
  • Adverse effects - High risk of renal insufficiency. 
  • High risk of mortality.
  • Hence its usage is reduced..
• Novel vasodilators - Recombinant human Relaxin 2 or serelaxin.
  • It is a Vasodilator hormone.
  • It contributes to cardiovascular or renal adaptations, Particularly during pregnancy. 

Inotropic Therapy

Drugs used in Inotropic Therapy

• Sympathomimetic amines
  • These cause a direct increase in intracellular cAMP.
  • Norepinephrine – acts on both alpha and beta receptors.
  • Dopamine (inotropic agent)
    • Increase blood pressure.
    • Has a Dose-dependent effect.
  • Dobutamine
    • Positive inotropic agent.
    • It may reduce BP.
• Phosphodiesterase 3 inhibitors - Indirect increase in intracellular cAMP.
  • Milrinone 
  • Increase in cytoplasmic calcium levels.

Also read : Drugs Used in Acute and Chronic Congestive Heart Failure 

Advantages of inotropic therapy

• Augments cardiac output.
• Reduces systemic vascular resistance.
• Improves perfusion.
• Relieves congestion acutely.
• It is given in patients with a low output state.

We will now discuss these inotropic drugs to get a better understanding of the topic.

Dopamine

It is a sympathomimetic inotropic agent and has dose-dependent effects. The patient is given a low dose of < 2 micrograms/kg/min. It acts on Dopaminergic & Alpha, and beta receptors.

It has a vasodilator property at low doses, called renal dose. This low dose increases renal perfusion, which preserves renal function and increases diuresis.

At a Moderate dose,  2 to 10 micrograms/kg/min, it acts on beta receptors and has an inotropic effect.

It acts on Alpha receptors at a High dose of> 10 micrograms/kg/min. It has a vasoconstrictor effect, which increases blood pressure.

Milrinone – Phosphodiesterase inhibitor

Milrinone's mechanism of action is to decrease systemic and Pulmonary vascular resistance. It also decreases afterload on the left and right ventricles.

It has a risk of systemic hypotension. It has a long Half-life. It is excreted through the Kidneys.

In case of renal impairment, the dose of milrinone is adjusted. It has an inotropic effect.

Long-term therapy with milrinone increases the risk of mortality as it Causes arrhythmias - leading to sudden death.

Based on this study, routine use of inotropic support in acute decompensated heart failure is discouraged. It is principally in the short term, and it acts as a bridge therapy until the patient is placed on LVAD or for cardiac transplantation. It is used in cardiogenic shock.

Novel Inotropic Agents

It causes myofilament calcium sensitization. Hence, there is isotropicity. An example of such a Drug is Levosimendan. It is a calcium sensitizer, it sensitizes myofilament with calcium. It produces inotropic activity. It also has phosphodiesterase 3 inhibitory activity and causes vasodilation.

Also read : Constrictive Pericarditis: Pathogenesis, Etiology

Summary of drugs

Adjuvant Diuretics

• Metolazone
• Chlorthalidone
• Spironolactone 

Clinical guiding principles 

Management is a large goal-directed and focused on Decongestant to relieve symptoms, Investigation and suppression of triggers for recurrent decompensation, and Careful transition to longitudinal HF management.

Admit the patient, stabilize the patient with ADHF, and then convert the patient into longitudinal HF management. A useful clinical scheme to identify treatment targets for the various phenotypic presentations and management goals in ADHF is depicted.

Also read: Paroxysmal Supraventricular Tachycardia

Frequently Asked Questions:

Q: What are the uses of Vasoactive Therapy in ADHF?

Ans: vasoactive therapy Reduces preload and afterload and Increases the BP.

Q: What is the Long-term risk associated with therapy with milrinone?

Ans: Milrinone increases the risk of mortality as it Causes arrhythmias - leading to sudden death.

Q: Which inotropic drug is not given in low BP in a patient of ADHF?

Ans: Nesiritide.

Q: What are the Adjuvant Diuretics used in the treatment of ADHF?

Ans. The drugs used in the treatment of ADHF are Metolazone, Chlorthalidone and Spironolactone.

Hope you found this blog helpful for your NEET SS Medicine Cardiovascular Preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.

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