Heart Transplant

A heart transplant is a surgical procedure in which a diseased or failing heart is replaced with a healthy donor heart. The donor heart is usually obtained from a deceased individual who has previously consented to organ donation.

Indications 

A heart transplant is typically considered when an individual is experiencing end-stage heart failure, a condition where the heart is severely damaged or weakened and can no longer pump blood effectively to meet the body's needs.

End-stage heart failure may result from various underlying causes, including:

• Cardiomyopathy: A disease of the heart muscle that can lead to enlargement, thickening, or stiffening of the heart, reducing its ability to pump blood.
• Coronary Artery Disease: Blockages or narrowing of the coronary arteries, which supply blood to the heart muscle, can cause significant damage over time.
• Congenital Heart Defects: Some individuals are born with structural abnormalities in the heart that can lead to heart failure later in life.
• Valvular Heart Disease: Malfunctioning heart valves can disrupt blood flow and strain the heart, potentially leading to heart failure.
• Viral Infections: Severe viral infections can affect the heart muscle causing an inflammation known as myocarditis, which can lead to irreversible damage and heart failure. 
• Severe Arrhythmias: Persistent and life-threatening irregular heart rhythms may compromise the heart's ability to pump effectively.

Before considering a heart transplant, medical professionals typically explore other treatment options, such as medications, lifestyle changes, and medical devices like ventricular assist devices (VADs). If these measures prove insufficient and the individual's cardiac health continues to deteriorate, a heart transplant may be recommended as a last resort.

Preparation

Candidates for heart transplantation undergo a thorough evaluation process to assess their overall health, suitability for the procedure, and the likelihood of successful outcomes. It is essential to meet specific criteria, including having a limited life expectancy without a transplant and being in relatively good health apart from the heart condition.

Additional presurgical preparation for a heart transplant may include:

• Routine blood work, imaging, and other tests specific to your condition
• Informing your doctor of any allergies to medications, anesthesia, or latex
• Providing your physician with a list of medications and supplements you are taking – especially those that may affect blood clotting
• Disclosing any recent illnesses or other medical conditions you may have
• Refraining from solids or liquids for at least 8 hours prior to surgery
• Signing an informed consent form after the pros and cons of the surgery have been explained

Surgical procedure

In general, heart transplant surgery usually involves the following steps:

• You will be administered general anesthesia to ensure you are unconscious and pain-free during the surgery.
• Monitoring devices are attached to measure vital signs such as heart rate, blood pressure, and oxygen levels.
• You will be connected to a ventilator, a machine that helps you breathe during the surgery.
• A midline incision is made in the chest, usually through the sternum (breastbone), to provide access to the heart.
• Your surgeon will connect you to a heart-lung bypass machine. This machine takes over the function of the heart and lungs, allowing the surgical team to stop the heart temporarily while the transplant is performed, and keep oxygen-rich blood flowing throughout your body.
• Your surgeon then removes the diseased heart and sews the healthy donor heart into place.
• Your surgeon then attaches the major blood vessels to the donor heart. The new heart usually starts beating when blood flow is restored. Sometimes an electric shock may be required to establish a normal heartbeat.
• You will be gradually weaned off the bypass machine, and the heart will be monitored to ensure proper function.
• Your surgical team carefully closes the chest incision, using wires to reconnect the sternum. The incision is then sutured or stapled.

Postoperative care

After the surgery, you will be transferred to the ICU where you will remain on the ventilator until you are stable enough to breathe on your own. Heart rate, blood pressure, and oxygen levels continue to be closely observed. You will be prescribed immunosuppressive medications to prevent the body's immune system from rejecting the transplanted heart. Routine screenings, such as blood tests and imaging studies, are performed to detect early signs of rejection or other complications. You should avoid strenuous activities and heavy lifting for a specified period. Gradual rehabilitation and physical therapy are initiated to help you regain strength, mobility, and overall physical fitness. Regular follow-up appointments are scheduled with the transplant team to monitor the recipient's health, assess the function of the transplanted heart, and address any potential issues.

Risks and Complications

Risks and complications associated with heart transplant surgery include:

• Bleeding
• Infection
• Blood clots
• Rejection of the donor heart
• Graft failure (this is where a section of the connection between the donor heart and your body fails for some reason)
• Side effects of immunosuppressive medications. These may include kidney failure, high blood pressure, and cancer

Summary

Heart transplantation can significantly improve the quality of life and increase the life expectancy of individuals with severe heart failure. However, it is not a cure for all heart-related conditions, and the success of the procedure depends on various factors, including the recipient’s overall health, the compatibility of the donor heart, and the effectiveness of post-transplant care and medication.