(1) The Cardio First Angel (CFA) is designed to give a bystander more confidence when carrying out CPR. How? the CFA signals an audible “click” sound when correct compressions are being administered, which is a depth of 5-6 cm.

When carrying out CPR , correct compressions occurs when The Cardio First Angel makes an audible “click” sound when the device has been allowed to recoil satisfactorily . This is vital for good CPR, as the full recoil of the chest is required to create a negative pressure in the chest cavity. It is this negative pressure that sucks blood back into the heart. A full recoil of the chest is just as important as a good compression.

(2)  The Cardio First Angel distributes the force of the compression on a larger surface area of the chest and so will reduce the likelihood of breaking a rib.

(3) The Cardio First Angel distances the bystander from the patient and prevents them from actual having to push directly on the patient.

(4) The Cardio First Angel provides an audible click just like the training manikins used in CPR classes. This will help the bystander to draw upon prior learning and muscle memory.

The Cardio First Angel helps ensure effective delivery of bystander CPR until emergency services arrive. When a click is not heard on a compression the bystander knows that their ‘push’ effort was not strong enough to deliver effective CPR and compression of the heart. The cardio first angel also distributes the force of the compression on a larger surface area of the chest and so will reduce the likelihood of breaking a rib. The second audible noise is the ‘clack’ which you hear when you allow the device and chest to fully recoil, creating a negative pressure in the chest and allowing the heart to fill with blood.   

The Cardio First Angel’s main function is to ensure that the correct depth of compression is performed during manual CPR. This is known to be a major problem when bystanders perform CPR. In a recent study which used live video to provide feedback to bystanders performing CPR 63%  were not achieving the correct compression depth (1). The Cardio First Angel monitors the strength of the compressions to ensure that the CPR is effective. If no click is heard the bystander knows they need to push harder or allow another bystander to take over for a while.

The Cardio First Angel is not designed to take away the physical labour of CPR as that is always hard work. The Cardio First Angel assists in improving effective CPR, by signalling when the compressions are strong enough to deliver effective CPR.  In a randomized controlled trial of ICU patients in cardiac arrest, the cardio first angel had improved rate of return of spontaneous circulation (ROSC) (66.7% vs. 42.4%, p<0.001) and survival to hospital discharge (54% vs. 28.4%, p<0.001) compared to standard manual compression (2). A second randomized controlled trial of 80 patients who arrested in ICU, also found that the cardio first angel had improved CPR quality (p<0.001) and ROSC (72% vs. 35%, p=0.001) (3).

No; as per all CPR instructions…. you always work with a bare chest.

We believe that the Cardio First Angel will encourage some bystander to start hands-only chest compressions who would not have done so without it, as it distances them from the patient. We know that females or less likely to receive bystander CPR if the suffer an out-of-hospital cardiac arrest (4). We believe that the Cardio First Angel may encourage more males to perform CPR on females, as it will reduce their apprehension and the appearance that they are touching the patient inappropriately.

The main benefit of having the Cardio First Angel in a Cardio Emergency Kit is that it will ensure that you are providing compression of a sufficient depth and so ensuring the patient ahs the best change of recovery. It also has the advantage that it has no electronics or batteries, so it will be ready to use when required.

This has more to do with the patient being in a suitable position to perform CPR and not to do with the Cardio First Angel. However, if you attempt to perform CPR using the Cardio First Angel when the patient is on a table, you will know if your CPR is effective if you hear a click. If you don’t hear a click you either need to kneel on the table or move the patient to the floor.

The main benefit of the Cardio First Angel is that it will help ensure that the correct force is used in delivering bystander CPR and so the recommended depth of 5-6 cm is achieved. The additional benefits are that it highlights when a bystander is getting tired and needs to swap off CPR, it reduces the risk a breaking a rib, it avoids bystanders having to place their hand on the patient’s chest and it will allow the bystander to draw on prior learning and muscle memory when performing bystander CPR.

Yes, the two randomized controlled trials were in hospital ICUs.

No, it is a single-use device as once it has been used it cannot be cleaned.

Yes, but it affects any CPR, not just with the Cardio First Angel. However, as the Cardio First Angel will not click if the correct pressure is achieved the bystander will know to remove the patient from the bed.

It is for use on adults only (see – https://youtu.be/P7WqIKEcpg4), so roughly about 12 years of age and upwards.

Linderoth G, Rosenkrantz O, Lippert F, Østergaard D, Ersbøll AK, Meyhoff CS, et al. Live video from bystanders’ smartphones to improve cardiopulmonary resuscitation. Resuscitation. 2021.

Goharani R, Vahedian-Azimi A, Farzanegan B, Bashar FR, Hajiesmaeili M, Shojaei S, et al. Real-time compression feedback for patients with in-hospital cardiac arrest: a multi-center randomized controlled clinical trial. Journal of intensive care. 2019;7(1):1-11.

Vahedian-Azimi A, Hajiesmaeili M, Amirsavadkouhi A, Jamaati H, Izadi M, Madani SJ, et al. Effect of the Cardio First Angel™ device on CPR indices: a randomized controlled clinical trial. Critical Care. 2016;20(1):1-8.

Souers A, Zuver C, Rodriguez A, Van Dillen C, Hunter C, Papa L. Bystander CPR Occurrences in Out of Hospital Cardiac Arrest Between Sexes. Resuscitation. 2021.