Heart Basics Archives | Dr C RAGHU Cardiologist


The heart has 3 layers of tissue:

  • Pericardium – The thin outer layer that protects the heart
  • Myocardium – a thick muscular middle layer that contracts and pumps out blood
  • Endocardium – a thin inner lining

Inside the heart, there are four chambers- the upper two are right and left atria and lower two are right and left ventricles. The atria receive the blood that comes to the heart and the ventricles pump blood out from the heart. The right and left side of the heart is separated by a septum.

The heart also has 4 valves which allow unidirectional flow of blood every time the heart beats.

  • the tricuspid valve is between the right atrium and right ventricle.
  • The pulmonary valve is between the right ventricle and the pulmonary artery.

The electrical system of heart:

The pumping action of the heart is controlled by the heart’s electric system. As an electrical impulse moves through the heart muscles, the various chamber of heart coordinate and pump out blood.

An electrical stimulus is generated by the sinus node (also called the natural pacemaker) which is located in the right atria of the heart. This stimulus activates the atrial muscles. The electrical stimulus then travels down through the conduction pathways and causes the heart’s ventricles to contract and pump out blood. The atria contract first, just a few milliseconds before the ventricles. This allows the blood from the atria to enter into the ventricles which is pumped out later.

Your heart needs to work 24/7 to keep your body systems working. Like any other body tissue, the heart too needs oxygen and nutrients to function efficiently. For this, we have a network of arteries that supply blood to the heart muscles which are called the coronary arteries. There are two chief coronary arteries:

the left and right coronary arteries, that branch out from the aorta near the point where the aorta and the left ventricle meet.

The right coronary artery supplies blood to the right atrium, the right ventricle, a small bottom area of the left ventricle and the back portion of the septum.

The left coronary artery supplies blood to the left atrium and ventricles and the front portion of the septum.

These coronary arteries give out various branches that supply blood to different parts of the heart.

Coronary artery disease:

When there is high level of unhealthy fats in the blood, they gradually start depositing in the insides of the coronary artery vessel wall and form a fatty plaque(atherosclerosis). This gradually narrows the lumen of the coronary arteries which obstructs blood supply to the heart. This condition is called as coronary artery disease. disruption of blood supply to the heart gives rise to a cluster of symptoms, the most important being chest pain or angina.

  • Warning signs of heart disease
  • Risk factors for heart disease
  • Possible complications of heart disease

Your lifestyle, age, family history and your other health condition can dictate your risk to develop a heart disease. However, the three key risk factors are- smoking, high blood pressure and high cholesterol. Learn about the risk factors and see if you are at risk:

  1. High blood pressure: It is an important factor for many diseases. Blood pressure, if not controlled, can lead to heart disease, stroke, kidney failure and other organ system disorders. Decreasing blood pressure by lifestyle changes and medication can greatly reduce your risk for heart disease.
  2. High cholesterol: Did you know that our hardworking liver can generate all the cholesterol that our bodies need? But we all do take in extra bad cholesterol from diet. These bad cholesterol tend to get deposited in our blood vessels and cause heart disease.
  3. Smoking: Cigarette smoking damages your heart and blood vessels. Nicotine present in cigarette smoke also reduces the amount of oxygen that your blood can carry. Not only that, if you smoke, the people around you are also at a higher risk of getting heart disease.
  4. Obesity: Obesity is linked with high level of bad cholesterol level and low levels of good cholesterol levels. Obesity is not only a risk factor for heart disease, but also increases risk of diabetes and high blood pressure.
  5. Diabetes: People with diabetes or high blood sugars are at greater risk of having heart disease than those who don’t have diabetes.
  6. Unhealthy diet: Oily, junk foods which are high in bad cholesterol, saturated fats and trans fats an can increase your risk of heart disease. Foods that are very salty(have high sodium levels) can also increase your risk of high blood pressure and heart disease.
  7. Physical inactivity: Physical inactivity increase your risk of having high blood pressure and diabetes and eventually heart disease.
  8. Alcohol: Excess and frequent alcohol intake can increase the risk of high blood pressure and hypercholesterolemia. Ideally, women shouldn’t have more than 1 drink a day and men shouldn’t have more than 2 drinks a day.
  9. Family history: Genetic factors seem to play a role in conditions like high blood pressure and heart diseases. However, it is also likely that the members of the family sharing common external environments and culture may be exposed to the same set of risk factors for heart diseases.
  10. Age: The risk of heart disease increases as the a person ages.

There are an array of heart diseases but they do share some common symptoms. If you experience any of these symptoms, it is perhaps a good idea to get yourself tested. Check these out here:

  1. Angina or chest pain described as heaviness, pressure, aching, burning, fullness, squeezing, or painful feeling in your chest.It is often accompanied by pain in the n the neck, jaw, throat, upper abdomen or back
  2. Shortness of breath
  3. Easy fatiguability
  4. Palpitation and rapid heartbeat
  5. Weakness/dizziness
  6. Sweating
  7. Nausea and vomiting
  8. Swelling in the lower extremities
  9. Fainting(syncope)
  10. Coughing and wheezing

For continuous circulation, the left and the right side of the heart must work together. Here are the series of steps that causes the blood to flow in the heart, lungs and body.

  • The right atria receives deoxygenated blood from two large veins- the superior and inferior venacava.
  • When the atria contracts and the blood passes from the right atrium to the right ventricle through the tricuspid valve.
  • When the ventricle fills, the tricuspid valve closes.
  • Next, the ventricle contracts and pushes blood to the pulmonary artery through the pulmonary valve.
  • The pulmonary artery carries the blood to the lungs where the blood gets oxygenated.
  • This oxygenated blood enters the left atria of the heart through the pulmonary vein.
  • Next, the left atria contracts and the blood flows from left atrium into your left ventricle through the open mitral valve.
  • When the ventricle is full, the mitral valve shuts,
  • Next, the ventricle contracts and oxygenated blood is passed to the aorta through which it is sent to various parts of the body.






Copyright © 2019, Dr C Raghu. All rights reserved.
Designed & Developed by R R Deepak Kambhampati.

Copyright © 2019, Dr C Raghu. All rights reserved.
Designed & Developed by R R Deepak Kambhampati.