Cardiac output (CO) is determined by the heart rate (HR) and the volume of blood pumped by each beat (stroke volume - SV). Mathematically, cardiac output can be represented by the equation:
CO = HR x SV
As such, if total cardiac output falls as a result of decreased stroke volume, the heart rate can increase to keep the total cardiac output normal, to a certain extent.
Stroke volume is more complicated; it is determined by many different factors, including preload, afterload, competence of the atrioventricular valves, ventricular cavity size, and the strength of the squeeze of the cardiac muscle, amongst others. Any change in one of these factors requires a compensation in one or more of the others to maintain cardiac output.
--Sympathetic nervous system stimulation (inc. catecholemines) --RAAS activation --Myocardial hypertrophy --Increased CO, with a rise in left ventricular end-diastolic pressure
repolariztion of the cardiac cells. ie after they have depolarized so quickly it takes a while for them to get back to a normal state
Increase in heart rate as Cardiac Output = Heart rate x Stroke volume. As SV will be decreased, HR increases to compensate.
A compensatory pause on an ECG refers to a pause in heart rhythm that follows a premature beat or extra heartbeat. This pause allows the heart to reset and resume its normal rhythm. It is a normal mechanism of the heart's electrical system to ensure effective pumping.
Cardiac silhouette is prominent with a left ventricular configuration.
0.8 seconds
12%.
If the cardiac size is within the upper limits of normal, it means that the heart is still a normal size, but is on the larger size of all normal hearts. There is a range for how big the heart is allowed to be.
pottasium and sodium
defibrillators
There are baroreceptors located in the aorta and at the carotid bifurcation. These function to modulate the cardiac output and maintain normal blood pressure and an adequate perfusion pressure to the brain.
Drugs that help maintain normal blood pressure throughout the body can also help this condition; however, these drugs are only a temporary treatment.