Therapeutic basics of cardiovascular system & Drugs | MPO training 20

Therapeutic basics of cardiovascular system

Understanding the therapeutic basics of cardiovascular system & drugs is a key part of preparing for your journey as a Medical Promotion Officer (MPO). This content introduces how cardiovascular conditions are managed through different drug classes and mechanisms.

If you're planning to build a pharma career, this topic will help you communicate medical knowledge clearly with healthcare providers. It presents real insights that are essential for MPO training and fieldwork.

Table of contents: Therapeutic basics of cardiovascular system & Drugs

Check out the table of contents of this article and you can click on the part you want to read from-

Part 1 : Therapeutic basics of cardiovascular system & Drugs
Part 2 : Classification Chart With Brand and Generic
FAQs
Conclusion

Part 1 : Therapeutic basics of cardiovascular system & Drugs

The therapeutic basics of cardiovascular system & drugs includes how different medicines help control heart diseases like hypertension, arrhythmia, and heart failure. Medical Promotion Officers (MPOs) should know how these drugs work to explain them to doctors effectively.

This knowledge helps you understand the purpose and effects of each drug group used in cardiovascular care. It forms a foundation for your medical communication skills.

What is the cardiovascular system and why is it important?

The cardiovascular system includes the heart and blood vessels. It delivers oxygen and nutrients to the body and removes waste products. Its proper function is vital for life.

What are the common cardiovascular diseases (CVDs)?

The most common CVDs include hypertension, heart failure, angina, myocardial infarction (heart attack), and arrhythmias.

We will learn this article by dividing it into two parts. For example:

Part 1 : Therapeutic Basic of Cardiovascular System & Drugs.
Part 2 : Classification Chart With Brand and Generic.

Let's start the detailed discussion now.

What is Blood Pressure?

It is the lateral pressure exerted on the wall of the blood vessel by the flowing blood.

Cross-sectional-View-of-an-Artery-Showing-Lumen-and-Lateral-Wall

Blood pressure is the force of blood pushing against the walls of arteries as it flows through them.

Digital-Illustration-of-Blood-Pressure-Flow-Through-an-Artery

Blood Flow in the Heart

Blood Flow in the Heart:

Our body needs oxygen to stay alive. The heart is the organ that pumps oxygen-rich blood to every part of the body. It also brings back oxygen-poor blood to send it to the lungs for fresh oxygen. Let’s understand this step by step.

1. Oxygen-poor blood returns from the body to the heart

After delivering oxygen to different parts of the body, blood becomes oxygen-poor. This blood returns to the heart through two large veins:

From the upper body: Superior Vena Cava
From the lower body: Inferior Vena Cava

This blood enters the Right Atrium (upper right chamber of the heart).

2. Blood goes to the lungs for oxygen

From the Right Atrium, the blood flows into the Right Ventricle (lower right chamber).

The Right Ventricle then pumps the blood to the lungs through the Pulmonary Artery.

In the lungs, the blood picks up fresh oxygen and releases carbon dioxide.

3. Oxygen-rich blood comes back to the heart

The oxygen-rich blood returns from the lungs to the heart through the Pulmonary Veins.

It enters the Left Atrium (upper left chamber).

4. Oxygen-rich blood is pumped to the whole body

From the Left Atrium, blood flows into the Left Ventricle (lower left chamber).

The Left Ventricle is the strongest part of the heart. It pumps the blood into the Aorta, the largest artery, which carries the oxygen-rich blood to the entire body.

Quick Summary of the Blood Flow Path:

Body → Right Atrium → Right Ventricle → Lungs → Left Atrium → Left Ventricle → Body

Important Valves in the Heart:

The heart has four main valves that keep the blood moving in the right direction:

Tricuspid Valve: Between Right Atrium and Right Ventricle
Pulmonary Valve: Between Right Ventricle and Pulmonary Artery
Mitral Valve: Between Left Atrium and Left Ventricle
Aortic Valve: Between Left Ventricle and Aorta

Final Words: The heart works like a smart pump that keeps blood moving, delivering oxygen and removing waste. This continuous blood flow is what keeps us alive every second.

Quick Summary:

Right side of the heart: Handles oxygen-poor blood and sends it to the lungs.
Left side of the heart: Handles oxygen-rich blood and sends it to the body.

Cardiac Output

It is the amount of blood discharged by the left ventricles into the aorta per minute.

It depends on:

Blood Volume
Venous Return
Force of Contraction of Myocardium or Inotropic property
Frequency of heart beat

Peripheral Vascular Resistance

It is the resistance offered by the blood vessel to the circulating blood.

It depends on:

Elasticity of Arterial Wall
State of lumen of Blood Vessel
Velocity of Blood
Viscosity of Blood

Blood Pressure: Controlling Factors

Blood Pressure = Cardiac Output X Peripheral Vascular Resistance.

BP = CO X PVR
BP = Blood Pressure
CO = Cardiac Output
PVR = Peripheral Vascular Resistance

BP can be increased or decreased depending on CO and PVR change.

Regulation of Blood Pressure Mechanisms

There are three main mechanisms involved in the regulation of Blood Pressure.

They are:

Nervous Mechanism
Renin Angiotensin Aldosterone System (RAAS)
Calcium Influx Mechanism

1) Nervous Mechanism

Sympathetic and parasympathetic nervous both can influence BP. Sympathetic nervous system secretes hormones Epinephrine and Norepinephrine.

They have:

Vasoconstricting Effect
Myocardial Contractility
Heart Rate

2) Renin Angiotensin Aldosterone System (RAAS)

The RAAS is a hormone system that helps regulate blood pressure and fluid balance in the body.

Step-by-Step Explanation:

Step 1: Drop in Blood Pressure or Blood Volume

When there is a decrease in blood pressure or low fluid volume, the kidneys detect this change.
In response, the kidneys release a hormone called Renin.

Step 2: Renin Converts Angiotensinogen into Angiotensin I

The liver continuously produces a protein called Angiotensinogen.
Renin acts on angiotensinogen and converts it into Angiotensin I.

Step 3: Angiotensin I is Converted to Angiotensin II

In the lungs, an enzyme called ACE (Angiotensin-Converting Enzyme) is released.
ACE converts Angiotensin I into Angiotensin II, which is the active form.

Step 4: Actions of Angiotensin II

Angiotensin II has two main effects:

It causes vasoconstriction – narrowing of blood vessels, which increases blood pressure.
It stimulates the adrenal glands to release Aldosterone.

Step 5: Aldosterone Acts on the Kidneys

Aldosterone signals the kidneys to reabsorb salt (NaCl) and water (H₂O).
This increases blood volume and helps raise blood pressure.

Final Result: Together, these steps restore blood pressure and maintain fluid balance in the body.

In Short: Low BP → Renin ↑ → Angiotensin II ↑ → Vasoconstriction + Aldosterone ↑ → NaCl + H₂O reabsorption → BP ↑

Renin is an enzyme secreted by kidneys. Renin converts Angiotensinogen to active Angiotensin - I.
Angiotensinogen is a plasma protein. It is secreted from the liver.
Angiotensin is a hormone.
Aldosterone is a hormone secreted by the Adrenal Cortex responsible for reabsorption of Na+(salt) and water.

Angiotensinogen —> Renin —-> Angiotensin - I
Angiotensin - I —--> ACE —> Angiotensin - II

ACE: Angiotensin Converting Enzyme.

Angiotensin - II increases blood pressure in two different ways:

Angiotensin - II is a potent vasoconstrictor. It increases secretion of Noradrenaline, a hormone from the adrenal gland. Noradrenaline constricts blood vessels.
Angiotensin II increases reabsorption of both salt (Na+) and water. It increases secretion of aldosterone, a hormone, from the adrenal gland. Aldosterone also decreases excretion of salt and water from the body.

Calcium Influx Mechanism

Calcium ions play an important role in the contraction of muscles of the heart and of the blood vessel.

Rise in Ca2+ lon.

A rise in Calcium ion increases contraction of the cardiac and vascular smooth muscles leading to increase in BP.

Decrease in Ca2+ lon:

A decrease in calcium ion lowers the contraction of Cardiac and
vascular smooth muscle leading to decrease in BP.

Calcium ion (Ca2+) Influx in Cardiac Muscle:

Effect of Calcium Ion (Ca²⁺) in Cardiac Muscle-

When calcium ions (Ca²⁺) enter the cardiac muscle.
They make the heart muscle contract more strongly.
This causes the heart rate to increase.
As the heart pumps faster and harder, the cardiac output (amount of blood pumped per minute) goes up.
As a result, the blood pressure increases.

In short: More calcium → stronger heart contractions → faster heartbeat → more blood pumped → higher blood pressure.

Calcium ion Influx in Vascular Smooth Muscle:

Effect of Calcium Ion (Ca²⁺) in Vascular Smooth Muscle -

When calcium ions (Ca²⁺) enter the smooth muscles of blood vessels.
The blood vessels contract or become narrower – this is called vasoconstriction.
As the vessels get narrower, it becomes harder for blood to flow, which increases resistance.
This increased resistance leads to a rise in blood pressure (BP).

In short: Ca²⁺ enters → vessels constrict → resistance increases → blood pressure goes up.

Calcium ion (Ca2+) Influx in Coronary Artery:

What the image explains in simple terms -

When calcium ions (Ca²⁺) enter the coronary arteries in large amounts.
The blood vessels become narrow (this is called vasoconstriction).
As a result, less blood and oxygen reach the heart muscles.
This causes chest pain, also known as angina.
If this continues for a long time, it can lead to damage or death of heart tissue, which is called a heart attack (myocardial infarction).

In short: More calcium → narrowed blood vessels → less blood to heart → chest pain → heart attack.

This is a step-by-step process of how excess calcium can harm the heart.

Coronary Artery

Coronary Artery: Coronary artery is a major blood vessel in our body -that supplies blood to the heart muscle.

The heart muscles need the oxygen and nutrients in blood so they can pump blood through the heart and the rest of your body.

There are two coronary arteries, each containing several branches:

Right coronary artery (RCA): The RCA supplies blood to the right atrium and right ventricle. Its branches supply the sinoatrial (SA) and atrioventricular (AV) nodes. These nodes send electrical signals through the heart, so the heart muscles know when to contract.

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Left main coronary artery (LMCA): The LMCA supplies blood to the left atrium and left ventricle. Its branches supply blood to the other two-thirds of the interventricular septum.

Different Lipids

Lipid: The lipid is the building block of fatty substances. They are mainly composed of cholesterol, protein and triglyceride. protein and triglyceride. ই Lipids play important role in many physiological functions including the maintenance of normal metabolism and cellular structure.

Triglyceride: Triglycerides are a type of fat. They are the most common type of fat in your body. They come from foods, especially butter, oils, and other fats we eat. Triglycerides also come from extra calories. Our body changes these extra calories into triglycerides and stores them in fat cells. When our body needs energy, it releases triglycerides.

Lipoprotein: A lipoprotein is a biochemical substance whose purpose is to transport lipid molecules in the blood.

Cholesterol: A waxy, fat-like substance made in the liver and found in the blood and in all cells of the body.

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Cholesterol is an essential component of cell membranes, brain and nerve cells and of bile, which helps the body absorb fats and fat-soluble vitamins. The body uses cholesterol to make vitamin D and various hormones, such as estrogen, testosterone and cortisol.

The three main types of cholesterol include:

LDL-Low Density Lipoprotein: "Bad" cholesterol. Having high levels of LDL cholesterol can lead to plaque buildup in our arteries and result in heart disease or stroke.

HDL-High Density Lipoprotein: "Good" cholesterol. HDL is known as "good" cholesterol because high levels can lower our risk of heart disease and stroke.

VLDL-Very Low Density Lipoprotein: The VLDL particles mainly carry triglycerides. VLDL is similar to LDL cholesterol, but LDL mainly carries cholesterol to your tissues instead of triglycerides.

Total Cholesterol: The total amount of cholesterol in our blood based on our HDL, LDL and triglycerides numbers.

Desirable Cholesterol Levels:

Total cholesterol	Less than 200 mg/dL
LDL ("bad") cholesterol	Less than 100 mg/dL
HDL ("good") cholesterol	Greater than or equal to 60 mg/dL
Triglycerides	Less than 150 mg/dL

Medical Background Major Heart Diseases: Hypertension

What is called Hypertension?

Hypertension: Hypertension is known as high blood pressure. It is a long-term medical condition in which the blood pressure in the blood vessels remains continuously high.

Long-term high blood pressure, however, is a major risk factor for coronary artery disease, stroke, heart failure, atrial fibrillation, peripheral arterial disease, vision loss, chronic kidney disease, and dementia.

Hypertension: Grades

Category	Systolic (mm Hg)	and/or	Diastolic (mm Hg)
Normal	Less than 120	and	Less than 80
Elevated	120-129	and	Less than 80

**Hypertension**
Category	Systolic (mm Hg)	and/or	Diastolic (mm Hg)
Stage 1	130-139	or	80-89
Stage 2	140 or higher	or	90 or higher
Hypertensive Crisis	Higher than 180	and/or	Higher than 120

Primary Hypertension: Hypertension which has unknown cause is called primary hypertension or Essential hypertension or Idiopathic tension.

Secondary Hypertension: Hypertension which has known cause is called is called Secondary hypertension.

Hypertensions: Complications

Untreated hypertension can lead to the following medical conditions:

A. Heart and blood vessel

Arteriosclerosis/atherosclerosis
Heart attack
Stroke
LVH (Left Ventricular Hypertrophy)
Heart failure
Hypertensive encephalopathy

B. Eye

Hypertensive retinopathy

C. Kidney

Kidney damage / Renal failure

Ideal Antihypertensive: Qualities

Able to control all grades of hypertension.
Should not develop tolerance.
Effective even in monotherapy.
Regression of LVH.
Should not affect metabolic profile.
Long term Safety data.
Can be given in different concomitant diseases along with hypertension.
P/T Ratio will be more than 50%.
Should provide gradual onset of action rather than quick onset action.
Should be long acting rather than short acting.
Should not affect routine life.

Anti - Hypertensive Drugs (Generic Name only)

1. ACE Inhibitors : Lisinopril, Captopril, Enalapril

2. AT1 Receptor Blocker ARB : Losartan, Olmesartan, Irbesartan

3. Calcium Channel Blockers : Amlodipine, Nifedipine

4. Beta Blockers :

a. Non Selective : Propranolol
b. Cardio selective : Atenolol, Bisoprolol

4. Alpha-beta blockers : Carvedilol

5. Diuretics : Hydrochlorothiazide, Furosemide, Spironolactone

6. Vasodilators : Isosorbide mononitrate

7. Lipid Lowering Agent : Atorvastatin, Rosuvastatin, Simvastatin

8. Antiplatelet Agent : Clopidogrel, Aspirin

Difference: ACE Inhibitor & AT1 Receptor Blocker

ACE Inhibitor	AT1 Receptor Blocker
Inhibit ACE	Blocks Angiotensin II
Increases the level of kinins and other autacoids like Bradykinin and prostaglandin	Doesn't do like this
Possibility of causing Dry cough	Doesn't do like this
Captopril, Lisinopril, Enalapril	Losartan, Olmesartan

Difference: Non Selective & Cardioselective Beta- Blocker

Sl. No.	Cardioselective	Non-Cardioselective
01	Acts on beta receptor present in heart and vascular smooth muscle	Acts on beta receptor present in Lung and heart and vascular muscle
02	Do not cause asthma	Can cause asthma
03	Not contraindicated in asthma	Contraindicated in asthma
04	Atenolol	Propranolol

Carvedilol: More than a beta-blocker

Dual acting alpha and beta blocking agent. So it reduces PVR and are suitable for CHF with Hypertension.

Angina: Treatment

1. Beta-blockers:

a. Non Cardioselective - Propranolol
b. Cardioselective - Atenolol, Bisoprolol

2. Vasodilators:

a. Isosorbide mononitrate

3. Calcium Channel Blockers

Amlodipine, Nifedipine

4. Anti-Platelet Aggregator

a. Salicylic acid

Drugs: Congestive Heart Failure

1. Cardiac Glycosides: Provides positive inotropic effect and increases CO.

2. ACE Inhibitors: Increases cardiac out by reducing preload and afterload.

3. Diuretics: Decreases preload by reducing blood volume.

4. Vasodilators: Decreases afterload and increases CO.

Part 2 : Classification Chart With Brand and Generic

Therapeutic Class: CVS Drugs
Sl. No	Sub Class	Therapeutic Group
1	Antihypertensive	a) Angiotensin II Receptor Blockers (ARB) b) Calcium Channel Blocker (CCB) c) Beta Receptor Blocker d) Diuretic e) Angiotensin Converting Enzyme (ACE) Inhibitors
2	Antianginal	a) Nitrates b) Fatty Acid Oxidation Inhibitor
3	Lipid Lowering	a) HMG CoA Reductase Inhibitors (Statins) b) Fibrates
4	(Not Specified)	a) NSAID b) Antiplatelet (Antithrombotic)

CVS Combination Drugs:

1. Antihypertensive

a) ARB + CCB
b) ARB + Diuretic
c) CCB + Beta Blocker

2. Blood Thinner

a) NSAID + Antiplatelet (Antithrombotic)

1. Antihypertensive Drugs

**Therapeutic Sub Class: Antihypertensive Drugs**
Therapeutic Group	Total	Generic With Brand Name (ACME)
a) ARB	3	Losartan Potassium (Losart), Olmesartan Medoxomil (Orbas), Telmisartan (Telisa)
b) CCB	2	Cilnidipine (Duocard), Amlodipine (Amlopin)
c) Beta Receptor Blocker	2	Atenolol (Tenoloc), Bisoprolol (Betabis)
d) Diuretic	1	Spironolactone + Furosemide (Edemide)
e) ARB + CCB	2	Telmisartan & Amlodipine (Telisa-A), Olmesartan & Amlodipine (Orbapin)
f) ARB + Diuretic	2	Losartan Potassium + Hydrochlorothiazide (Losart plus), Olmesartan medoxomil & Hydrochlorothiazide (Orbas Plus)
g) CCB + Beta Blocker	2	Amlodipine + Atenolol (Amloten), Amlodipine + Bisoprolol (Betabis A)
(h) Beta blocker + diuretic	1	Betabis plus (Bisoprolol)

2. Antianginal Drugs

**Therapeutic Sub Class: Antianginal Drugs**
Therapeutic Group	Total	Generic With Brand Name (ACME)
a) Nitrates	1	Nitroglycerin (Angist SR)
b) Fatty Acid Oxidation Inhibitor	1	Trimetazidine HCI (Angirid MR)

3. Lipid Lowering Drugs

**Therapeutic Sub Class: Lipid Lowering Drugs**
Therapeutic Group	Total	Generic With ACME's Brand Name
a) HMG CoA reductase inhibitors/Statins	2	Atorvastatin (Liptor), Rosuvastatin (Rostab)
b) Fibrates	1	Fenofibrate (Lipidof)

4. Antiplatelet/Antithrombotic/Blood Thinner

**Therapeutic Sub Class: Lipid Lowering Drugs**
Therapeutic Group	Total	Generic With ACME's Brand Name
a) NSAID	1	Aspirin (Ecosprin)
b) Antiplatelet (Antithrombotic)	1	Clopidogrel (Dclot)
c) NSAID + Antiplatelet (Antithrombotic)	1	Aspirin + Clopidogrel (Ecosprin Plus)

FAQs for Therapeutic Basics of Cardiovascular System & Drugs

1. What does “therapeutic basic” mean in cardiology?

It refers to the basic treatment principles used to manage cardiovascular conditions using medicines and lifestyle changes.

2. What types of drugs are used to treat heart diseases?

Major types include antihypertensives, beta-blockers, calcium channel blockers, ACE inhibitors, diuretics, statins, and anticoagulants.

3. How do beta-blockers work in heart treatment?

Beta-blockers slow down the heart rate and reduce blood pressure, helping the heart to work more efficiently.

4. What is the role of ACE inhibitors?

ACE inhibitors help relax blood vessels, lower blood pressure, and reduce the workload on the heart. They are often used in heart failure and high blood pressure.

5. What is the difference between diuretics and statins?

Diuretics help remove excess fluid from the body, lowering blood pressure. Statins reduce cholesterol levels to prevent heart attacks and strokes.

6. Are side effects important to know for cardiovascular drugs?

Yes, Doctors often ask about side effects, and you must be ready to answer. Common side effects include dizziness, cough, fatigue, or swelling.

Conclusion

Mastering the therapeutic basic of cardiovascular system & drugs gives you a strong foundation for working as an effective Medical Promotion Officer (MPO). From drug types to their specific uses, this knowledge connects medical science with real-world applications. It helps you support healthcare professionals with correct information. For every MPO in training, this is an essential step toward becoming confident and informed in the pharmaceutical field.

Sarwar Hossain Himel

I am Sarwar Hossain Himel — a sports-loving person. Education: I have obtained a BBA and MBA degree in Accounting. Profession: Currently, I am working as a Medical Promotion Officer (MPO). In addition, I have over 5 years of experience in teaching. Freelance Work: I work as a Google Blogger and Article Writer in freelancing. Passion: I love doing web design and digital marketing. Especially, web design is one of my passions.