Hyperbaric Oxygen Therapy For Cardiovascular Conditions

Introduction

Hyperbaric Oxygen Therapy (HBOT) is a method of treatment that involves breathing very high concentrations of oxygen at high pressures within a special chamber. It is often used in many different therapies to speed up the healing of certain conditions. Due to the unique methods used in HBOT, it can be applied to certain cardiovascular conditions by providing high concentrations of oxygen to certain tissues for better healing. We will take a look at how HBOT works and which cardiovascular conditions it can be used for.

Understanding hyperbaric oxygen therapy

HBOT involves the individual being placed in a large cylindrical chamber with glass panelling. The chamber is then exposed to near pure oxygen (close to 100% oxygen) at a pressure that can be greater than 2-3 atm (2-3 times greater than air pressure at sea level). Throughout this process, the individual's body will be exposed to very large amounts of oxygen, so their blood becomes highly saturated with oxygen². In normal conditions, the body gains oxygen from the air via the lungs. At the border between the lungs and the blood vessels, there is a difference in the concentration of oxygen (the blood will have less oxygen than the air in the lungs). This is what drives the movement of oxygen from the lungs into the blood until the amount of oxygen in the lungs and blood is almost the same. If the concentration of oxygen is increased, along with the pressure of that oxygen in the lungs, then more oxygen is forced into the blood. This can be very useful in treating certain conditions where the body is in a state of low oxygen concentration and cannot function properly (hypoxia). In states of hypoxia or when oxygen cannot be delivered to a certain tissue adequately, HBOT can help increase oxygen within the body to a level where it can reach these places and have a positive therapeutic effect.³   

Cardiovascular conditions

Coronary artery disease (CAD)

Coronary artery disease is a condition that affects the blood vessels that supply the heart. These blood vessels can become narrowed or blocked over time due to the buildup of plaque (which is made of cholesterol). When these blood vessels become blocked, certain areas of the heart will lose the supply of oxygen and nutrients. If this continues for long enough, the muscle tissue will not be able to survive and will die, which can lead to heart failure.⁴ In coronary artery disease, HBOT is not the first line of treatment. Most commonly, doctors recommend bypass surgery, where surgeons join the blood vessels around the blockage to resume proper blood flow to the heart. However, there is evidence to suggest that hyperbaric oxygen therapy can be conducted before the surgery to reduce the time an individual would spend in recovery and improve outcomes for the patient in the future by reducing the risk of further complications such as infections. This is because having a high oxygen environment in the body helps to stimulate wound healing and promotes the immune system.⁵

Peripheral arterial disease (PAD)

Similar to coronary artery disease, peripheral artery disease is the narrowing or blockage of arteries that take blood from the heart to all areas of the body. The most common type is lower-extremity PAD, which affects the arteries of the legs. As with CAD, it is caused by the buildup of a cholesterol plaque within the arteries, leading to blockage of blood flow to the muscles further down. When using HBOT to treat individuals with PAD, it can help to improve wound healing and reduce the chance of infection following any surgical procedures. It can also help in reducing or reversing to some extent any tissue death that may have occurred, given that HBOT is given within a certain timeframe.⁶ 

Heart failure

Heart failure is described as the inability of the heart to pump blood around the body. This could be due to abnormal muscle contractions of the heart meaning that blood is not ejected correctly. Depending on which side of the heart has failed, there can be varying symptoms and differences in severity. Across all types of heart failure, the common theme is that there is less blood being pumped around the body, so the body receives less oxygen than normal7. It seems that HBOT would be very useful in this situation as it can help to pack more oxygen into the smaller volume of blood so that the body receives enough. However, there is evidence that may suggest some people who suffer from heart failure react negatively to HBOT. A research study published in October 2023 stated that out of 23 investigated patients, 2 of them experienced an acute heart failure attack following HBOT. While this may be a relatively rare occurrence, it happens to patients with severe heart failure. The benefits of HBOT in heart failure are well documented, but it is important to get fully assessed by a qualified health professional before beginning HBOT when you have heart failure. If a doctor has said that it is safe and if you are being monitored throughout HBOT sessions, then it can be a very helpful therapy to improve the symptoms of heart failure.⁸

Practical application of HBOT

In practice, many of these conditions still require conventional treatment for the disease itself. Hyperbaric Oxygen Therapy can help patients recover from these treatments and improve their general well-being. There are also other conditions that are more commonly treated with HBOT, such as gangrene (infection of dead tissue), carbon monoxide poisoning and certain burns.¹⁰

Risks and limitations

The most common limitation of HBOT is the fact that you will have to lie in the chamber for a long period of time. This can be very difficult for some, especially those with claustrophobia, as the small chamber can feel confining. This can cause anxiety and panic while in the chamber, leading to some physiological distress. To help with this, the doctors may choose to give a mild sedative to help the individual remain calm while in the chamber. Another risk is the high-pressure air while within the chamber. The pressure may, in some cases, lead to middle ear injuries such as earache or fluid in the ears. High pressure can also cause sinus congestion, which means patients may experience a runny nose or sinus headache within and shortly after exiting the chamber. A rare side effect of HBOT is temporary short-sightedness (inability to see objects far away very clearly). This affects around 30% of patients who have HBOT long-term, and in most people, this corrects itself after some time.⁹

Summary

Hyperbaric Oxygen Therapy is the use of high-pressure, highly concentrated oxygen while inside a full-body chamber. It is effective in treating a range of conditions that result in low oxygen in the body. There are many cardiovascular conditions, such as coronary artery disease, peripheral artery disease and heart failure, which have been shown to have better rates of recovery when HBOT is used. It can help to improve oxygen delivery to areas of the body that may be lacking it. In doing so, the body is able to heal wounds faster, improve the effectiveness of the immune system, and reduce the strain of recovery on the body. It is important to understand the procedure as there are some risks involved, and HBOT should only be used after consultation with a doctor.