Depolarization Vs Ventricular Contraction

Resting heart contractions were recorded for thirty seconds until the heart rate was less than 60 beats per minute. A stimulator electrode to be used was set to the following states: Amplitude of 4.00 Volts, a stimulus delay of 50ms, stimulus duration of 10ms, a frequency of 1.0Hz, and a pulse number of 30. The electrode was then placed in direct contact with the heart for 30 seconds at which time the data was observed and recorded.

At the latter end of the p-q interval, atrial contraction occurs forcing additional blood into the ventricles. At the beginning of the QRS interval on an ECG reading, the mitral valve closes and the ventricles are at EDV (135ml). During the QRS interval, ventricular contraction occurs increasing the pressure in the ventricle and the aorta. When the pressure continues in the ventricle exceeds the pressure in the arteries, the aortic valve opens and blood is ejected. The increased pressure continues through the t peak. The ventricles are now in ESV (65ml) and the aortic valve is closed. Now the ventricles are relaxed causing pressure to fall and the cardiac cycle starts over again. This ECG reading was from a normal tracing. Keep in mind that an ECV is easy to obtain, but there are some subtleties that are very complex.

Table 2. This table shows the recording of the amplitude, period, and BPMs for the ventricular contractions before and the effects of the Warm Ringer’s after.

*Both sides of the heart are doing this at the same exact time and contracting/relaxing is what pumps the blood from one place to the other.

In normal heart activity, the ventricles are depolarized by the depolarization wave spreading from the atria.

There are two common types of ectopic heartbeats, PVC -Premature ventricular contractions and PAC -Premature atrial contractions. First one, PVC can be found in both healthy and diseased hearts. “PVC is a premature beat (in the ventricle) that occurs earlier than the next expected beat. The normal (sometimes the P wave is not the same shape as other P waves) and these can be hard to pick out of a normal ECG. The identifying feature: The R-R interval between the PAC and the preceding beat is shorter than any of the other R-R intervals”

The atrial contraction is represented by the P wave. This is an upward, or positive wave of the line on the graph. The ventricular contraction is displayed by the QRS complex. The QRS

The S-A node signal is delayed by the atrioventricular node to allow the full contraction of the atria that allows the ventricles to reach their maximum volume. A sweeping right to left wave of ventricular contraction then pumps blood into the pulmonary and systemic circulatory systems. The semilunar valves that separate the right ventricle from the pulmonary artery and the left ventricle from the aorta open shortly after the ventricles begin to contract. The opening of the semilunar valves ends a brief period of isometric (constant volume) ventricular contraction and initiates a period of rapid ventricular ejection.

Heart period variability (HPV) is a physiological process where the time interval between heart beats varies. It is measured by the variation in the beat-to-beat interval. Other terms used include: "cycle length variability", "RR variability" (where R is a point corresponding to the peak of the QRS complex of the ECG wave; and RR is the interval between successive peaks), and "heart rate variability". Methods used to detect beats include: ECG, blood pressure, and the pulse wave signal derived from a photoplethysmograph (PPG). ECG is considered superior because it provides a clear waveform, which makes it easier to exclude heartbeats not originating in the sino-atrial node. The term "NN" is used in place of RR to emphasize the fact that the processed beats are "normal" beats.

Regular electrical impulses are sent within the conduction system of the heart prompting contraction (Marieb, 2015). These electrical signals can be identified and documented by the use of an electrocardiography (ECG) machine. In a familiar ECG recording, three waves will occur; The P wave, QRS complex and

In the current decade, human circulatory system illness has been recognized as the prominent reason of morbidities and mortalities worldwide [1, 2]. Heart hemodynamics parameters measurements, such as sonic tools, could be the key factor to diagnose the progression of the circulatory system abnormalities and diseases [3, 4] and support physician for supplementary medical decisions to detect heart diseases, such as ischemia and hypertrophy or even heart failing [5-8]. Furthermore, observation and quantifying the heart hemodynamics parameters, i.e., heart outward volume and heart performance factors during pump action of the heart have a key asset in detecting and realizing of these diseases. Numerous medical schemes are accessible for such quantifying, such as angiography, catheterization, Magnetic Resonance Imaging (MRI), and ultrasound.

Cardiac vagal tone is proposed to be an index for” ...psychiatric impairment, including risk for depression” (Rottenberg 2005). In like manner, respiratory sinus arrhythmia (RSA), is proposed to be an index for cardiac vagal tone. In research, this “biological construct” is measured by means of an EKG (ECG). RSA varies during the breathing cycle (inhalation and exhalation) so then one will note heart rate variability. Interest in this topic drove me to look at, on a basic level, what exactly varies. Research on the topic explained that in the EKG the R-R intervals will be shorter during inhalation than in exhalation. And so studying RSA researchers can quantify the extent of the vagus nerve’s part in cardiac control.

During stage one the pressure in both ventricles decreases as they relax, the atrioventricular valves open slightly and blood is pumped through them due to a contraction of the atria. Blood is prevented from flowing backwards as the valves of the vena cava and pulmonary vein close. During stage two pressure in the ventricles increases

reports the amount of force exerted by the blood into the arteries during ventricular contraction.

An electrocardiogram can be used to record activity during the cardiac process of pumping and returning blood to the body and heart because of the electric current that spreads through the tissue of the heart and to the surface of the body. By