The Final Heart Rhythm Doctors Often See Before Death

Agonal rhythm is an abnormal heart rhythm that often indicates impending death. It is very slow and involves only the ventricles, which compose the chambers at the bottom of the heart, as the atria (upper chambers) have ceased their functioning. In this case, blood cannot be effectively pumped to other parts of the body. Importantly, blood is the delivery system for oxygen, which is necessary for energy production and cellular function. When oxygen cannot be effectively transported, vital organs rapidly stop working, leading to death.

Agonal heart rhythms generally appear at the end phase of a heart attack or after extensive cardiac arrest. There are many potential incidents and conditions that could lead to these, including drug overdose, oxygen deprivation, traumatic brain injury, and severe blood loss. The primary treatment option for agonal rhythm is CPR.

Typically, this heart arrhythmia will appear on an electrocardiogram (ECG) with the peaks that represent electrical activity in the ventricles appearing unusually wide and at irregular intervals. Often, the heart rate at this point is slower than 20 beats per minute. For reference, a healthy resting heart rate is somewhere between 60 and 100 beats per minute. As opposed to asystole, which appears on an ECG as a flatline, during agonal rhythm, there is still some electrical activity, but it is simply insufficient to keep someone alive. This means that some medical intervention could be attempted at this point, but it is likely too late, and the rhythm will become asystolic.

The term agonal derives from the same root as the word "agony," but this name is misleading regarding the experience of the person exhibiting agonal rhythm. At this point, a person is completely unconscious and not likely able to feel pain. However, the brainstem is still mildly functioning, which can lead to involuntary movements or emitted noises that can appear frightening and might lead one to think the patient is in agony.

This can be a difficult experience to witness for a loved one. A condition this serious already leaves family and friends feeling vulnerable, and not being aware of what is going on within the patient's head can quickly become discomforting. Therefore, gaining an understanding of the biological processes that underlie such physical symptoms can help provide a modicum of peace.

We know that hearing is the last sense lost before death. Although higher neurological processing is required to interpret the meaning of what is heard, experts from the Cleveland Clinic have suggested that you can speak comforting words to your loved one if they have fallen into an agonal rhythm. This behavior could offer some reassurance for both you and the patient.