Heart Failure: Treatment Methods and Mechanisms of Action

Heart failure is a serious condition that affects the heart’s ability to pump blood. Here are some common treatment methods and their mechanisms of action:

1. Digoxin:

• Mechanism: Digoxin inhibits the Na-K ATPase pump, leading to increased myocardial contractility and increased vagal tone, resulting in decreased heart rate.

• Application: Digoxin is used for unstable heart failure.

• Note: Digoxin has a long half-life, a narrow therapeutic range, and requires monitoring blood levels and dosage adjustments for each patient.

• Indications: Heart failure, arrhythmias, atrial fibrillation, atrial flutter.

• Side effects and contraindications: Digoxin can cause arrhythmias, atrioventricular block, especially in those with low potassium levels. Contraindicated in people with low potassium, atrioventricular block, severe arrhythmias, severe bradycardia, before pacemaker implantation, Wolff-Parkinson-White syndrome (WPW).

2. Angiotensin-Converting Enzyme Inhibitors (ACE-I):

• Types of drugs: Captopril, Lisinopril, Fosinopril, Enalapril, Ramipril, Quinapril.

• Mechanism: ACE-I reduces structural changes in the heart, increases sodium and water excretion, reducing preload. At the same time, ACE-I dilates blood vessels, reducing afterload.

• Preferred indication: Heart failure with left ventricular dilatation.

3. Angiotensin II Receptor Blockers (ARB):

• Types of drugs: Losartan, Irbesartan, Olmesartan, Valsartan, Candesartan.

• Mechanism: ARBs block the effects of angiotensin II, helping to lower blood pressure and improve heart function.

• Sacubitril/Valsartan: Combined drug that inhibits neprilysin (degrades ANP, BNP) and ARB. Used for heart failure patients who cannot tolerate ACE-I.

4. Beta-Blockers:

• Types of drugs: Bisoprolol, Metoprolol, Nebivolol, Carvedilol.

• Mechanism: Beta-blockers slow heart rate, improve ejection fraction, prevent arrhythmias, and sudden death.

• Contraindications: Stage 4 heart failure.

5. Ivabradine:

• Mechanism: Inhibits the If channel/Na-K current in the sinoatrial node, helping to regulate heart rate.

• Indications: Heart failure with ejection fraction (EF) ≤ 35% and heart rate > 70.

• Contraindications: Acute heart failure, blood pressure < 90/50 mmHg, heart rate < 60, third-degree atrioventricular block.

6. Diuretics:

• Types of drugs: Hydrochlorothiazide, Metolazone, Bumetanide, Furosemide, Torsemide, Eplerenone, Spironolactone.

• Mechanism: Diuretics help to excrete sodium and water, reducing preload.

• Note: Care should be taken with diuretic use when taking digoxin due to the risk of hypokalemia. It should be combined with a low-salt diet.

7. Medications for Acute Heart Failure:

• Vasodilators: Nitroprusside, Nitroglycerin, Nesiritide.

• Vasodilators + Increased Contractility: Levosimendan, Milrinone, Dobutamine.

• Blood pressure support in case of hypotension: Dopamine, Epinephrine, Phenylephrine, Vasopressin.

Note: The choice of heart failure medication should be based on the specific condition of each patient. Consulting a doctor for advice and effective treatment is essential.