""Some people teach that choking can be safely done if pressure on the windpipe is avoided. Their belief is that pressing on the arteries leading to the brain while avoiding pressure on the windpipe can safely cause unconsciousness. The reality, unfortunately, is that pressing on the carotid arteries, _exactly_ as they recommend, presses on baroreceptors known as the carotid sinus bodies. These bodies then cause vasodilation in the brain, thus there is not enough blood to perfuse the brain and the recipient loses consciousness. However, that's not the whole story.
Unfortunately, a message is also sent to the main pacemaker of the heart, via the vagus nerve, to decrease the rate and force of the heartbeat. Most of the time, under strong vagal influence, the rate and force of the heartbeat decreases by one third. However, every now and then, the rate and force decreases to zero and the bottom "flatlines" into asystole -- another, and more difficult to treat, form of cardiac arrest. There is no way to tell whether or not this will happen in any particular instance, or how quickly. There are many documented cases of as little as five seconds of choking causing a vagal-outflow-induced cardiac arrest."
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Date: 2011-10-31 05:31 am (UTC)""Some people teach that choking can be safely done if pressure on the windpipe is avoided. Their belief is that pressing on the arteries leading to the brain while avoiding pressure on the windpipe can safely cause unconsciousness. The reality, unfortunately, is that pressing on the carotid arteries, _exactly_ as they recommend, presses on baroreceptors known as the carotid sinus bodies. These bodies then cause vasodilation in the brain, thus there is not enough blood to perfuse the brain and the recipient loses consciousness. However, that's not the whole story.
Unfortunately, a message is also sent to the main pacemaker of the heart, via the vagus nerve, to decrease the rate and force of the heartbeat. Most of the time, under strong vagal influence, the rate and force of the heartbeat decreases by one third. However, every now and then, the rate and force decreases to zero and the bottom "flatlines" into asystole -- another, and more difficult to treat, form of cardiac arrest. There is no way to tell whether or not this will happen in any particular instance, or how quickly. There are many documented cases of as little as five seconds of choking causing a vagal-outflow-induced cardiac arrest."