Let’s start with some definitions. The Cardiac Cycle is an asymmetrical cyclical process with four stages: initiating, creating, sustaining, and disposal. Or, it could be more relevant to Section G3, “models of heart failure and their development” (p. 5), “function,” “organ systems,” “development,” and “life processes.” Each stage has a single purpose in a process. For example, the initiating step is where the Cardiac Cycle Creates Life, as we know it, by triggering the appropriate cells to divide.
As the heart rhythm attains its maximum threshold, new cells start, and a new structure begins. In the maintenance phase, the Cardiac Cycle Sustained Cardiac Relaxation or CRAS slows the heartbeat frequency and lowers blood pressure. The next stage is the maintenance phase, where the CRAS stays at its maximal level, and the Cardiac Cycle resumes its rhythmic activity, that is, the pumping of blood and the generation of new cells. At the end of the cardiac cycle is the termination or E cessation phase, the gradual process of heart disposal.
The conclusion is that heart failure develops because of abnormal processes beyond the control of the heart and kidneys. When beyond the heart and kidneys’ ability to do their work, these processes cause potassium and sodium to build up in the blood. As more potassium and sodium build up in the blood, more potassium ions are generated. This generates more acid in the blood, increases blood pressure, and creates a negative feedback loop that results in heart failure.
This is one of the most straightforward explanations of cardiac cycle phases and functions. However, it makes sense that to understand how these different phases of the Cardiac Cycle might function in a specific individual who has had coronary artery disease, more details must be known. For example, the first two Cardiac Cycle Phases (the T Waves) occur in the heart’s right ventricular and left atrial regions. And the last two Cardiac Cycle Phases (the A and the S Wave) occur only in the right ventricular area.
To better understand how these Cardiac Cycle Phases affect the heart, it is helpful to understand what causes these Cardiac Cycle Phases to occur. The Cardiac Cycle Phases are due to the contractions and relaxing of the atria and ventricles. Atria and ventricles are muscle groups located in the front of the chest wall. When the heart muscle contracts, the atria expands, and the heart chambers fill with blood, while the Ventricles contract and cause the ventricle to relax.
A simple Cardiac Cycle phase drawing is required to understand better how the Cardiac Cycle Phases affect the heart. For this, a person needs to have a blood pressure monitor device such as the Omron HEM-eda or Arq-MEDixx. This device measures the heart’s electrical activity by monitoring the pressure that is applied to the arm. Also necessary is an ECG or electrocardiograph, which measures the quantity of “pulse” generated by the heart muscle and its electrical activity. These types of equipment help you know the normal functioning of your heart.
Another essential device used to help you understand Cardiac Cycle Phases is the NMRF-1 probe, which measures the heart’s action potential and enables you to determine what phase the heart is in. The action potential is the amount of electrical activity generated by the heart muscle, and it helps you determine what the heart is undergoing. The action potential is measured by attaching a magnet to the inside of the body part that is being tested. For us to see what the heart’s current is like, we can use an EKG machine, which measures the electrical activity of the heart. These devices are widely available in medical stores nowadays.
The last device that we will discuss here is the Atria, which is the previous component that determines the cardiac cycle. Atria, or the ventricular system, is where the heart of a person beats at its maximum rate during cardiovascular functions. Atria is essential when the heart is pumping blood from the lungs into the entire body. The Atria acts as the distributing center of all the blood that is pumped throughout the body. Atria is essential because it is the site of the distribution of the residual blood after performing the cardiac function. As such, the Atria controls the volume of the blood being pumped into the body’s different organs, such as the heart, the lungs, and the stomach.
