The key to using a pocket mask properly and knowing if a breath is given effectively is by the rescuer using the victim's chin to guide the pocket mask to the correct position and then delivering each breath over 2 seconds.
To know the pocket mask has been properly fitted, the rescuer uses the victim's chin as the guide to correctly position the pocket mask. The rescuer should also ensure the mask is properly sealed on the victim's face. When giving breaths to a victim using a pocket mask, the rescuer would deliver each breath over 2 seconds. The rescuer should use just enough force to make the chest rise.
The accumulation of atheroma plaque on the wall of the aorta leads to a stiffness of the aorta, which makes the intraluminal pressure greater, which is reflected in a greater force that the ventricle has to make to eject the blood to the aorta.
