Introduction

Antihypertensive medications

Antihypertensive medications are a group of medications used to lower blood pressure. These drugs are usually prescribed by a doctor to people who have symptoms and signs consistent with increased blood pressure and heart failure in to manage and improve cardiovascular risks as well as cardiovascular diseases.

Now, there are various types of medications used for the management of hypertension and heart enlargement, but they all have different mechanisms of action. The most common of them are discussed here, along with how their basic mechanisms of action work. Antihypertensive medications aim to reduce the risks of heart problems, stroke, diabetes, kidney failure and other cardiovascular diseases

Heart enlargement (cardiomegaly)

Cardiomegaly or heart enlargement means that the heart structure has increased in size. It is not a disease; rather, it is a condition that arises from other conditions created in the body itself. Many things may cause this enlargement of the heart, such as high blood pressure, pregnancy,¹ and diseases affecting the heart valves. These problems force the heart to work very hard to pump blood into the cardiovascular system. Consequently, the heart becomes stressed out and stretches and widens. At first, it might give the body what it requires, but eventually, it leads to extreme health complications that require rapid medical attention.

Hypertension

Blood pressure (BP) is the force in arteries, which are present in the body, to circulates the blood.

Hypertension is a condition in which a person has higher BP levels than usual. 

The normal blood pressure readings of a healthy adult below the age of 80 are considered to be in the range of 90/60 mmHg and 120/80 mmHg, while for adults over 80 years old, BP should be less than 150/90 mmHg.² So the next time you notice your BP is elevated above the normal range, it's best for you to make an appointment with your doctor to determine the cause of hypertension.

The causes of hypertension can vary from person to person, such as stress, obesity, diet, age, diabetes, kidney disease or any other underlying condition.³

How does hypertension lead to heart enlargement?

High blood pressure, or hypertension, is closely linked to heart enlargement because when blood pressure is high, the heart pumps harder to ensure an adequate amount of blood is supplied to all parts of the body.⁴ This puts an extra workload on the heart, resulting in a change of its structure in the form of widening and thickening of the cardiac muscles.⁵ Thissignificantly affects the left ventricle, resulting in a condition known as left ventricular hypertrophy.⁸ The thickening of the ventricles reduces the efficiency of the blood supply, which can be manifested in critical health conditions.¹¹

Types of Antihypertensive Medications

Antihypertensive drugs are important for the management of high blood pressure. There are many classes, and each class has a specific method to control blood pressure. These classes include:

Diuretics

They act in the kidney and stop the absorption of excess water and salt, thus decreasing blood volume and blood pressure. Some diuretics commonly used are:

• Thiazide diuretics, e.g, hydrochlorothiazide
• Loop diuretics, e.g, furosemide
• Potassium-sparing diuretics, e.g, spironolactone

Beta-blockers

Beta blockers are drugs that block the effect of adrenaline on the beta receptors, which results in reduced heart rate, minimised contraction strength of the heart and decreased blood pressure.⁹ Some common examples include:

• Tenolol
• Atenolol
• Metoprolol 
• Propranolol
• Carvedilol

Calcium channel blockers

Calcium channel blockers (CCBs) decrease blood pressure by not allowing the influx of calcium ions into the heart or blood vessels. This leads to relaxed blood vessels and reduced blood pressure. Calcium ions are necessary for the heart’s contraction; so when there is less supply of the ions, there is less contraction, and therefore lower blood pressure. Some CCBs include:

• Amlodipine
• Diltiazem
• Verapamil

ACE inhibitors (Angiotensin-converting enzyme inhibitors)

Angiotensin II is responsible for vasoconstriction (narrowing of the arteries), thereby increasing blood pressure and potentiating heart enlargement. Therefore, ACE inhibitors stop the formation of Angiotensin II, which causes widening of the blood vessels and reduces blood pressure.¹³

They also cause the elimination of excess water and salts from the body, lowering blood pressure by reducing the blood volume. This decreases the on the heart and thereby manages the heart enlargement. Some include:

• Lisinopril
• Enalapril 
• Ramipril

ARBs (Angiotensin II receptor blockers)

They block Angiotensin II receptors, so angiotensin, a powerful vasoconstrictor, can't be attached to it to show its effects and therefore causes vasodilation and reduced blood pressure.

Some of the Angiotensin II receptor blockers include:

• Losartan 
• Valsartan 
• Candesartan

Alpha-blockers

They block the alpha receptors, which leads to the relaxation of blood vessels and decreased blood pressure.¹³ Some common examples include:

• Doxazosin
• Prazosin
• Terazosin

How do Antihypertensives help manage heart enlargement?

Antihypertensives of any class play a very important role in the management of heart enlargement. They eliminate the symptoms and help in management through the following ways:

Reducing strain on the heart

Antihypertensives help lower blood pressure. This directly makes it easier for the heart to work. High blood pressure makes the heart pump extremely fast and hard, which causes the cardiac muscle to thicken with time. So if blood pressure is controlled, the strain on the heart will lessen. This is what antihypertensives do; they reduce the extra workload on the heart so that the heart works better and decreases the chance of more damage.

Preventing further enlargement

Antihypertensive therapy reduces the size of the left ventricle. More importantly, various studies has shown that treatment to reduce high blood pressure stops the enlargement of the heart and can even reverse the thickening of the heart. Therefore, the risk of developing heart disease, experiencing a stroke, or progressing to heart failure is significantly reduced, contributing to improved cardiovascular health.⁶ 

Improving heart function

Antihypertensives enable the heart to function better by reducing blood pressure and thus facilitating less tension on the heart. For instance, studies have shown that beta blockers improve the diastolic function.¹⁴ The diastolic or filling phase of the heartbeat is where the heart fills with blood; patients with LVH or an enlarged heart usually have an inefficient diastolic function. Efficient diastolic function means that the heart chamber fills better and pumps blood adequately through the body.

Side effects and risks of Antihypertensives

Antihypertensive medications are important to improve the quality of life by managing high blood pressure, but they can have side effects. Here are some common ones:

Diuretics

Side Effects: Frequent Urination, electrolyte imbalances, dehydration, increased thirst.

Beta Blockers

Side Effects: Fatigue, dizziness, cold extremities, bradycardia.

ACE Inhibitors

Side Effects: Cough, elevated potassium levels, angioedema (swelling).

Angiotensin II Receptor Blockers (ARBs)

Side Effects: Dizziness, rare angioedema.

Calcium Channel Blockers

Side Effects: Swelling of the legs, flushing, palpitations.

Alpha Blockers

Side Effects: Dizziness when standing, fatigue.

Natural alternatives to Antihypertensive medications

Natural alternatives are also a great option if you are considering home management and lifestyle modification. They are slow-acting and do not always give the desired outcome. Some natural alternatives include:

Garlic

Garlic is known to be helpful in lowering blood pressure, cholesterol and decreasing inflammation. It may be used as an alternative to reduce heart attacks and strokes.⁷

Omega-3 Polyunsaturated fatty acids (PUFA)

Fatty acids, specifically PUFA, can decrease elevated blood pressure and reduce the risk of blood clots and cardiovascular diseases. Some foods that are high in these fatty acids include fatty fish such as salmon, as well as flaxseeds and walnuts.¹⁵

Hawthorn

It is used in herbal medicine for heart conditions. It improves heart symptoms associated with heart failure. It can be used as a tea or supplement.

L-arginine

Some amino acids are in the arginine class, which produces nitric oxide, which causes relaxation of blood vessels, leading to a lowering of blood pressure. Sources include meat, poultry, nuts, and leafy greens.

Linseeds

They are high in omega-3 fatty acids and fibre; flaxseed decreases cholesterol levels and reduces inflammation.⁷

Lifestyle modifications

Lifestyle modifications include eating a healthy, balanced diet; avoiding highly processed food with elevated salt content, increasing fruits, vegetables, and whole-grain products; and regularly exercising. Exercise strengthens the heart muscle while maintaining its normal function.

Summary

Hypertension or elevated blood pressure causes enlargement of the heart. People suffering from this condition usually have symptoms like trouble breathing, a fast heartbeat, fatigue and may have a secondary illness. But these can be managed by the use of antihypertensive medications, which work by decreasing the blood pressure and reducing excessive workload on the heart. There are many classes of antihypertensives, amongst which diuretics are most commonly used. Antihypertensive medications don't necessarily treat the problem entirely; nonetheless, evidence indicates that they do contribute to improved quality of life.