Лечение заболеваний сердечной мышцы: какие лекарства может прописать врач, если у вас кардиомиопатия?

Cardiomyopathy is a group of heart muscle diseases in which the heart undergoes changes in structure that affect its ability to pump blood. This group accompanies diverse conditions that can have a variety of causes, from genetic acquired later in life. While many people don’t have symptoms of heart disease, they are still at risk of life-threatening complications like stroke, heart failure, or sudden cardiac death.

In most cases, cardiomyopathy can’t be cured and damage that’s already done can’t be reversed. The goal of treatment is to: 

• Relieve the symptoms and prevent the disease from progressing. Managing the symptoms improves your quality of life and prevents worsening of the condition.​
• Prevent life-threatening complications. One of the common symptoms of cardiomyopathy are arrhythmias, abnormalities in the timing and/or pattern of the heartbeat. The heart contracts in a tightly regulated way which is orchestrated by electrical impulses arriving from special groups of cells in the heart. Disruption of electrical signaling can cause your heart to beat too fast, too slow, or erratically. While some types of arrhythmia can be harmless, others can cause your heart to stop beating (sudden cardiac arrest) which leads to death if not treated immediately with a defibrillator. In rare instances, prolonged periods of tachycardia (a type of arrhythmia in which the heart beats too fast) can be a cause of CM.

Treatment for cardiomyopathy aims to regulate the heartbeat and avoid those situations. Unfortunately, for some people with arrhythmias medications might not be enough, in which case implantable devices are considered. Another complication of cardiomyopathy that needs to be prevented is stroke.

When there’s an underlying systemic condition that causes cardiomyopathy (and affects other organs too), treating the underlying condition can sometimes lead to a reversal of cardiomyopathy.

What are the symptoms of cardiomyopathy?

Cardiomyopathy often doesn’t have any symptoms until the disease has progressed, in which case there are symptoms of heart failure. Heart failure is a condition in which the heart can’t meet the demands of the body. The part of the heart that’s usually most affected in CM is the left ventricle, the heart’s main pumping chamber that pumps the blood from the lungs to the rest of the body. When it works at reduced capacity, the following symptoms can occur:

• Breathlessness. A weakened left ventricle might have problems with processing all of the blood that comes from the lungs. That leads to the accumulation of fluid in the lungs, that disrupts the exchange of gasses. Lowering the amount of fluid in the body (through diet and medications) helps with this symptom.
• Swelling of the legs, ankles, feet and other body parts. Swelling is due to fluid accumulation that happens as a result of the heart’s reduced pumping power. It’s important for this symptom to be managed, as it often leads to elevated blood pressure which puts a strain on an already vulnerable heart muscle.
• Arrhythmia (irregular heart rhythm). Abnormalities in the timing and pattern of heartbeats can happen as a symptom of heart failure or it can be an inherent part of the cardiomyopathy. Treating them is a priority since they can lead to fatal outcomes. 
• Fatigue, tiredness, and weakness. When there’s a limited amount of oxygen-rich blood circulating the body, the heart focuses on keeping the most important internal organs working, like the brain and kidneys. Blood is redirected towards them, which means that your skeletal muscles have less oxygen available. This means that they’re not as efficient in producing energy and essentially every movement is harder, which might make everyday activities that once seemed easy exhausting. 
• Dizziness and fainting. Lack of oxygen and arrhythmias contribute to these effects.

Which medications are used to treat cardiomyopathy?

Depending on your symptoms, your doctor might prescribe some of the following medications. In most cases, a combination of two or more drugs is needed. Groups of medications used to treat cardiomyopathy include the following.

1. ACE (angiotensin-converting enzyme) inhibitors

One of the body’s ways to regulate blood pressure is the so-called renin-angiotensin-aldosterone system. The liver secrets a precursor of angiotensin (angiotensinogen) in the blood, while the kidneys secrete renin, a protein that transforms it into angiotensin I (ANGI). The angiotensin-converting enzyme (ACE) transforms ANGI to ANGII, an active form which acts as a vasoconstrictor.

That means that it narrows the arteries and the veins and consequently causes elevated blood pressure. In addition to its direct effect on blood vessels, ANG II also stimulates the production of other hormones that lead to elevated blood pressure. It can also contribute to structural changes in the heart muscle that happen in cardiomyopathy, so removing it from the circulation has several beneficial effects.
ACE inhibitors act to:

• Prevent the ANGII from forming
• Raise the level of bradykinin which dilates the blood vessels and thus lowers the blood pressure
• Decrease the blood volume (taking some strain off of the heart)

2. Angiotensin II receptor blockers (ARBs)​​

Some people don’t respond well to ACE inhibitors, in which case angiotensin II receptor blockers can be helpful. The principle is similar — the goal is to prevent ANGII from affecting the body. The way that cells sense things around them and react to them is through cell receptors. This group of drugs doesn’t affect the level of ANGII in the blood, but it prevents the cells in the heart, blood vessels and kidneys from seeing that ANGII is there.

3. Beta-blockers (beta-adrenergic blocking agents)

One of the most important reactions in nature for the survival of animals is the so-called fight or flight response. It’s mediated by adrenalin (epinephrine), which prepares you for a rapid reaction: heart rate and breathing rate are accelerated, blood vessels are constricted in many parts of the body but dilated in the muscles to provide a quick response, and the blood clotting-activity speeds up to prevent eventual blood loss.

Adrenalin causes these effects once it binds to beta-adrenergic receptors. Beta-blockers are substances that have more affinity for beta-adrenergic receptors than adrenaline-they bind to the receptors before the adrenaline does. If adrenaline can’t bind to its receptors it can’t mediate the effects. This is why beta-blockers are used to lower blood pressure.

4. Digoxin (Lanoxin) and digitalis​

Digoxin is on the World Health Organization’s list of essential medicines, a group of the most effective drugs known so far. Both digoxin and digitalis make the heart contractions stronger, meaning that the heart pumps with greater efficiency. They also help with some types of arrhythmia.

5. Diuretics (water pills)

Medications for regulating the blood pressure like beta-blockers, ACE inhibitors, and ARBs are often used in combination with diuretics. Diuretics increase urination and help get excess fluid out of the body, which helps not only with blood pressure but also with symptoms of heart failure connected to increased fluid retention (breathlessness, swelling).

6. Anticoagulants (blood-thinning medications)

These medications prevent the blood for clotting, which is why they’re used in the prevention of stroke, a possible complication of cardiomyopathy.

7. Antiarrhythmics (cardiac dysrhythmia medication)

As the name suggests, this group is used to treat arrhythmia. Unlike the other groups mentioned, this group accompanies several classes of medications including some beta-blockers, calcium-channel blockers and fast-channel blockers (sodium and potassium channel blockers).

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