The QRS Complex combines three of the more visible graphical symbols seen on a normal electrocardiogram tracing. Specifically, the uppermost spike on the illustration is called the primary point, which is visible on the top half of the ECG; and the lowermost end is called the secondary tip, which can be seen below the immediate spike on the EKG. This spike's color is determined by the QRS component between the two uppermost vertical traces on the tracing. The QRS Complex is also the symbol used to indicate that the patient's heart activity is above average.
QRS Complex?
So, what exactly is this thing called the QRS Complex? On average, the QRS Complex consists of four separate spikes, namely the immediate spike, the middle point, the down deflection spike, and the bundle branch block spike. These spikes combine to form a single symbol called the QRS, or Quick Response Symmetry symbol. In essence, the spike sequence defines the heart's normal conduction process in which the ventricular valves relax and open during a heart rhythm. While some individuals' heart conduction process may differ, the general outline of the QRS Complex is consistent in most individuals.
spike description
While the spike description sheds light on the heart's normal conduction process, it fails to specify whether these deflections are normal or abnormal. If abnormal deflections appear on a normal electrocardiogram tracing, they are considered artifactual, meaning that they are not part of an underlying pathology causing the deflections. On the other hand, if typical deflections are found, then the QRS Complex is either normal or slightly elevated. Either way, finding the QRS Complex on an ECG demonstrates that a malfunctioning ventricular valve is present. Once the ventricular valves are functioning correctly again, the normal conduction process begins once again. It's as simple as that.
The visual cortex transmits two different wave:
Many researchers have compared the QRS Complex to the double wave pattern from the brain's visual cortex. Specifically, the visual cortex transmits two different waves: a light wave for visual processing and a dark wave for deeper brain processing. When the QRS Complex appears, the left ventricular depolarization (which occurs when the heart rate becomes too weak) creates an electric spike in the EEG interpreted by the nervous system as a visual stimulus. The result: the QRS Complex identifies a potential threat and initiates appropriate action.
Unfortunately, not all abnormalities cause the QRS Complex to show up. For example, when a patient has excessive left ventricular hypertrophy (less wall thickness), the QRS Complex will often not display because the standard action is an automatic slowing down of the heart rate. Unfortunately, many health practitioners are not familiar with this condition and cannot correctly predict whether a patient may have a QRS Complex. They are not aware that the brain's standard mechanism for recognizing an attack exists: the ventricles pump blood from the heart to the legs, while the atria blink the photoreceptors, causing the QRS to appear. In other words, there is a natural relaxation process within the brain that slow-zones the heart rate until the ventricles can begin pumping blood once again.
It is believed that the QRS Complex is initiated by frontotemporal waves that penetrate the layers of the cerebral cortex. These waves generate the narrow band of high-frequency electrical impulses that are observed in patients with QRS. These wave frequencies are generally kept in the human brain during states of relaxation or when a person is thinking deeply and without attention (related to dreaming or deep hypnosis). A direct pathway from the Atria to the brain's electrodes leads to the frontal cortex, where the QRS Complex is observed.
Suspected QRS Complex cases:
In suspected QRS Complex cases, medical professionals may use electroencephalography (EEG) to detect the presence of the little wave activity. This method has successfully seen the narrow band of low-frequency electrical activity, which are considered the hallmark of QRS. However, another technique reveals a lower level of electrical activity. The resting metabolic rate (RMR), measured with Bi-fold or BiFIT, shows a significantly lower spike in energy levels than QRS Complex. Furthermore, the resting metabolic rate lowers considerably during periods of cognitively task-relevant activity (i.e., reading, writing, math) or when tasks are easy (writing letters or numbers).
An alternative way to examine the relationship between ventricular repolarization and QRS complexes is to measure the effects of drugs on physiological measures such as heart rate and blood pressure. When the drugs used to treat QRS Complex increase heart rate and blood pressure without altering the ventricular repolarization, these drugs can be considered to have little effect on the underlying mechanisms underlying QRS complexes.
In contrast, when used to treat ventricular repolarization and QRS reduce heart rate and blood pressure without altering the underlying dynamics of QRS complexes, these drugs can be considered to have a beneficial effect on these mechanisms. Thus, there appears to be a good correlation between ventricular repolarization and QRS complexes. However, more study is needed to understand the etiology of these waves further.