What Is Coronary Perfusion Pressure?

Coronary perfusion pressure (CPP) is a measure of how well blood flows within the heart. The metric is used to monitor the transit of blood through the coronary arteries. The coronary arteries are blood vessels responsible for supplying your heart with oxygen.

If your CPP is low, then this may indicate that your heart is not receiving enough nutrients to function well. CPP needs to be maintained at a specific level in order for the heart to function properly. 

If you have heart disease, especially coronary artery disease or heart failure, then understanding how CPP works may be helpful.

This article provides details on CPP calculation and regulation.

Calculating Coronary Perfusion Pressure

To calculate your CPP you need to know your:

• Diastolic blood pressure (DBP): The bottom number when you measure your blood pressure. For example, if your blood pressure is 130/85 then your diastolic blood pressure would be 85.
• Pulmonary capillary wedge pressure (PCWP): A measure of pressure within your lungs. The pulmonary capillary wedge pressure is not easy to measure. Accurate measures are only obtained when a healthcare provider inserts a catheter into the heart to measure blood flow. As a result, we often use estimates for PCWP. The normal PCWP ranges from 4 to 12 mmHg.

These two variables can be measured and subtracted to determine the CPP.

CPP and Cardiac Arreest

CPP will naturally change with different heart diseases, like coronary artery disease or heart failure.

Problems occur when CPP is low because this is a sign that the heart is not receiving enough blood flow. If your heart is not receiving enough blood flow then it can become irritated and in some cases, ischemia—or tissue damage—can occur.

CPP can help doctors understand if a heart is at risk for going into cardiac arrest. If a person does have cardiac arrest, then a major goal of CPR and other resuscitation measures is to increase CPP. 

Regulating Coronary Blood Flow

Coronary blood flow is extremely important for your heart to function well.

Medications such as nitrates (usually in the form of pills that dissolve under your tongue) are commonly used to relax the coronary arteries. Nitrate medications can help ensure blood flow is efficient through the coronary arteries. 

Invasive treatments such as mechanical devices are sometimes used in the hospital in order to perfuse the coronary arteries.

When someone is very ill, devices called intra-aortic balloon pumps may be used to help pump blood through the coronaries. The intra-aortic balloon pump sits just outside of the heart in the aorta and pushes blood into the coronary arteries when the heart is weak. Pump devices are not permanent however and are only used when someone is in critical condition.

Frequently Asked Questions

What factors affect CPP?

CPP is impacted by blockages in the arteries, called plaque. High levels of plaque can impede the flow of blood through the artery and require higher pressures to feed into the heart. These blockages, or plaques, limit blood flow and can cause damage known as ischemia.

How do you calculate CPP?

CPP is calculated using your diastolic blood pressure, the lower number on a blood pressure cuff, and also your pulmonary capillary wedge pressure. You can’t easily measure your own pulmonary capillary wedge pressure, but a normal value lies between 4 to 12 mmHg. 

A Word From Verywell

If you have recently been diagnosed with coronary artery disease, it can be alarming to learn that you have heart disease. Fortunately, there are many steps you can take to improve heart health such as:

• Eating a heart healthy diet
• Exercising regularly
• Avoiding risk factors like smoking

Making healthy changes can significantly improve heart function and overall health.