Handling the human heart requires great precision.

It is delicate. Touching it can induce changes in the rhythm or affect the blood pressure. It's like touching a rare diamond – you must treat it with care. It is something precious, but at the same time it is forceful. You can feel its energy and strength as it beats, the power and triumph which pumps through it.

It is common when you become a doctor to want to cover all areas of medicine, but I was always interested in the heart. I did my first surgery in 1992 when I was 26. Nine years ago I became a consultant at the Edinburgh Royal Infirmary.

Being a heart surgeon is not only technically demanding – you are operating on an extremely delicate structure which necessitates precision – but also requires great knowledge of the function of the heart and how it keeps the body alive.

The first time a medical student sees a heart they tend to describe the experience as "cool". I remember having that same sense of excitement. I wasn't scared. What struck me was the immense sense of privilege to be able to see the heart beating and touch it with my hands.

When you have done this job for a while that becomes less impressive. Sometimes it becomes somehow routine because we do it every day. We can do what is essentially a dangerous procedure but in a relaxed way.

I do a lot of bypass surgery as well as valve repairs and replacements. The aim nowadays is to be as non-invasive as possible when accessing the heart. When you think about how the human body is designed, you have the rib cage covering this delicate organ and in a sense you must violate nature's protection to reach it.

When you open a chest and look at a heart the foremost thought in your mind is doing the right thing for the patient. You are all too aware of the consequences if something goes wrong. You are dealing with a vital organ so, if something does go wrong, the patient may not survive.

Sometimes the heart does stop. Those are tense moments. It's like when you are driving a car and have to stop before you hit something. You slam on the brakes but at the same time are thinking quickly about how to achieve the best possible outcome.

There is high pressure in that situation. You are trying to get the heart started again but also thinking of the next step if it doesn't restart.

When doing an internal massage of the heart while the chest is open you have to keep an eye on the pressure of your compression. It is a squeeze as you hold the heart but then you must let it relax to fill up with blood again, then you squeeze and push up again. You are conscious of maintaining a good blood pressure, as it is important to keep the brain alive and avoid any damage.

All the time you are hoping for the best possible outcome. Sometimes, however, things do go wrong. Compared to other surgeries, that usually means the patient dies. Losing a patient is always difficult.

Afterwards you ask the same questions: did I do everything right? Is there something else I could have done? What should I have done differently? You cope by analysing what has happened. You speak with your peers. You wouldn't be human if it didn't affect you.

Handling the human heart requires great precision. It is delicate. Touching it can induce changes in the rhythm or affect the blood pressure. It's like touching a rare diamond – you must treat it with care. It is something precious, but at the same time it is forceful. You can feel its energy and strength as it beats, the power and triumph which pumps through it.

It is common when you become a doctor to want to cover all areas of medicine, but I was always interested in the heart. I did my first surgery in 1992 when I was 26. Nine years ago I became a consultant at the Edinburgh Royal Infirmary.

Being a heart surgeon is not only technically demanding – you are operating on an extremely delicate structure which necessitates precision – but also requires great knowledge of the function of the heart and how it keeps the body alive.

The first time a medical student sees a heart they tend to describe the experience as "cool". I remember having that same sense of excitement. I wasn't scared. What struck me was the immense sense of privilege to be able to see the heart beating and touch it with my hands.

When you have done this job for a while that becomes less impressive. Sometimes it becomes somehow routine because we do it every day. We can do what is essentially a dangerous procedure but in a relaxed way.

I do a lot of bypass surgery as well as valve repairs and replacements. The aim nowadays is to be as non-invasive as possible when accessing the heart. When you think about how the human body is designed, you have the rib cage covering this delicate organ and in a sense you must violate nature's protection to reach it.

When you open a chest and look at a heart the foremost thought in your mind is doing the right thing for the patient. You are all too aware of the consequences if something goes wrong. You are dealing with a vital organ so, if something does go wrong, the patient may not survive.

Sometimes the heart does stop. Those are tense moments. It's like when you are driving a car and have to stop before you hit something. You slam on the brakes but at the same time are thinking quickly about how to achieve the best possible outcome.

There is high pressure in that situation. You are trying to get the heart started again but also thinking of the next step if it doesn't restart.

When doing an internal massage of the heart while the chest is open you have to keep an eye on the pressure of your compression. It is a squeeze as you hold the heart but then you must let it relax to fill up with blood again, then you squeeze and push up again. You are conscious of maintaining a good blood pressure, as it is important to keep the brain alive and avoid any damage.

All the time you are hoping for the best possible outcome. Sometimes, however, things do go wrong. Compared to other surgeries, that usually means the patient dies. Losing a patient is always difficult.

Afterwards you ask the same questions: did I do everything right? Is there something else I could have done? What should I have done differently? You cope by analysing what has happened. You speak with your peers. You wouldn't be human if it didn't affect you.