Talking about the heart: One Squish at a Time
Imagine standing at a door in a room filling with water and someone is on the other side pushing the door shut (don’t worry, you’re not drowning in this story. It turns out you ARE the room.🤯holy shit!)
Your job (The Heart) is to empty at least 50 to 70% (EF) of the water (blood) in this room by squishing the water so it pushes that door (Ao valve) open around 60 to 80 times a minute (heart rate) so the room can empty out and depressurize.
Afterload is how strong that other fellow (the pressure) on the other side of the door is. Preload is how much pressure or water is in the room pushing on the door from the inside. Contractility is your ability to squish the room. If you are not moving or can’t move, you are akinetic. If you are moving weird, or had a stroke, injury, etc… and can’t move one of your arms well, you (or your bad arm) are dyskinetic and may have issues squishing the water out well. If you are moving, but dragging ass and not moving as quick as your should, you are hypokinetic.
Afterload - the pressure in the aorta that ventricular contractions push against.
Akinetic - absence of movement. In general, you want the heart moving. Areas that do not may be old damage or scar tissue, or on the way to turning into scar tissue.
Aortic valve - The valve between the left ventricle and the aorta.
Cardiac output - the amount of blood ejected by the heart in one minute. There are a few ways to get the measurements to calculate this; stroke volume times heart rate.
Normal cardiac output range: 5 to 6 liters per minute at rest. Athletes can have a cardiac output of more than 35 liters per minute during exercise. (Cleveland Clinic link)
Contractility – The ability of heart muscle cells to contract.
Dyskinetic - impairment of voluntary movement; still moving, but oddly and ineffectively
Ejection Fraction (EF) - the % of blood ejected by the Left Ventricle with each heart beat- about 60%
Heart rate - Expressed in beats per minute or BPM; it’s how many cardiac contractions happen over the course of one minute.
Sometimes referred to as pulse, these might, technically, be different. Maybe this gets over specific to a “well, acthually….” degree, but there is probably a situation where it makes a difference to clarify exactly what you are talking about; heart beats or pressure waves received at distal points of the body. HR measures the beats of the heart, pulse measures the pulse waves in the arteries and these can differ if there is a low pressure pulse wave that does not reach the pulse point being palpated, like will happen with PVC’s or atrial fib beats that don’t carry as much pressure and won’t be felt at the wrist or fingertips.
Hypokinesis - diminished movement or activity
Preload - amount of pressure in the Left ventricle after relaxing, filling up, then (ideally; this can reduce w/ AF or A-flutter) getting topped off by the atria.
Pulse - Expressed per minute, this is the count of pressure wave coming from the heart and reaching the pulse point.
See the longwinded thought under Heart Rate; Pulse and Heart Rate may not be the same.
The Heart - Identified as one of the organs, it lives in the body and is suspected of having an important role in biological life.
