What Really Happens During a Heart Bypass Surgery?

Worried About What Bypass Surgery Involves? Let’s Break It Down Step by Step So You Know Exactly What to Expect

Heart bypass surgery, or Coronary Artery Bypass Grafting (CABG), is one of the most performed heart procedures worldwide. It’s designed to restore blood flow to the heart muscle when coronary arteries are blocked, improving heart function and overall quality of life. While the term “bypass surgery” may sound daunting, knowing exactly what happens during the process can help ease anxiety and prepare you for a smoother recovery.

Pre-Surgery Preparation

Before the operation, your medical team will carry out a thorough health assessment. This often includes:

• Blood tests to check overall health.
• Electrocardiogram (ECG) to assess heart rhythm.
• Chest X-ray to view the heart and lungs.
• Coronary Angiography to pinpoint blockages in the arteries.Coronary artery angiogram maps out the number and site of coronary artery blockages.

You’ll meet with your Cardiothoracic Surgeon, who will explain the procedure in detail, and your Anaesthetist, who will discuss the type of anaesthesia to be used, explain about general Anaesthesia and timing of fasting before surgery. Fasting instructions will be given, and Physiotherapist may introduce breathing exercises to help recovery. Most importantly a “pump talk” will be conducted by the ICU staff on the orientation of ICU care while the patient is in ICU. This would alleviate the patient’s anxiety while in ICU.

During Surgery

1. Anaesthesia & Monitoring – You’ll be placed under general Anaesthesia, so you remain asleep and pain-free.
2. Graft Collection – Surgeons take a healthy blood vessel from your chest (Internal Mammary Artery), leg (Saphenous Vein), or arm (Radial Artery) to use as the bypass graft.
3. Bypassing the Blockage – The graft is attached to reroute blood flow around the blocked coronary artery.
4. Heart-Lung Machine (if used) – In some cases, your heart is temporarily stopped, and a machine takes over the pumping function. The heart-lung machine acts as an artificial heart-lung that will pump oxygenated blood to the rest of the body. Utilisation of the heart-lung machine would require administration of IV Heparin, a blood thinner medication that will be reversed back to normal once surgery is completed
5. Restarting the Heart & Closing the Incision – Once grafting is complete, the heart is restarted, and the chest is closed.

Post-Surgery Recovery

Recovery starts in the Intensive Care Unit (ICU), where you’ll be closely monitored. After 1–2 days, most patients are moved to a regular ward for further healing. The hospital stay is typically 5–7 days. Over the next few weeks, you’ll gradually increase your activity levels, guided by your care team. Cardiac Rehabilitation is highly recommended to rebuild strength, monitor progress, and provide emotional support. Full recovery usually takes 6–12 weeks, depending on overall health.

Who Needs Bypass Surgery?

Bypass surgery may be recommended for patients who:

• Have severe blockages in multiple coronary arteries.
• Experience chest pain (Angina) that medications can’t relieve.
• Have Left Main Coronary Artery disease.
• Have had or are at high risk of a Heart Attack.
• Are not suitable candidates for Angioplasty or stenting.

What Does a Patient Need to Do After a Bypass Surgery?

Your Cardiologist may consider, management and optimisation of risk factors: 

• Medication management – To control symptoms and manage risk factors. Optimization of care for control of Diabetes, High Cholesterol and Hypertension
• Lifestyle changes – Healthy diet, exercise, quitting smoking, and stress management.

With good control of risk factors, CABG has proven to provide better long-term outcomes.

A Second Chance for Your Heart Starts Here! 

Heart bypass surgery is not just about clearing blockages, it’s about giving the heart a second chance and improving quality of life.

If you or someone you care about has been advised to undergo bypass surgery, speak to our Cardiothoracic Surgeons at Gleneagles Hospital Kuala Lumpur to find the safest and most effective treatment plan: https://gleneagles.com.my/kuala-lumpur/medical-specialties/cardiothoracic-surgery