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The section shows: 1) the opened ventricles contracting once per heartbeat—that is, once per each cardiac cycle; 2) the (partly obscured) mitral valve of the left heart; 3) the tricuspid and pulmonary valves of the right heart—note these paired valves open and close oppositely. + (The aortic valve of the left heart is located below the ...
Schematic representation of a normal sinus rhythm ECG wave. Diagram showing how the polarity of the QRS complex in leads I, II, and III can be used to estimate the heart's electrical axis in the frontal plane. The QRS complex is the combination of three of the graphical deflections seen on a typical electrocardiogram (ECG or EKG). It is usually ...
Electrocardiography is the process of producing an electrocardiogram (ECG or EKG [a]), a recording of the heart's electrical activity through repeated cardiac cycles. [4] It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the heart [ 5 ] using electrodes placed on the skin.
ECG beat. The Pan–Tompkins algorithm [1] is commonly used to detect QRS complexes in electrocardiographic signals . The QRS complex represents the ventricular depolarization and the main spike visible in an ECG signal (see figure). This feature makes it particularly suitable for measuring heart rate, the
Electrical waves track a systole (a contraction) of the heart. The end-point of the P wave depolarization is the start-point of the atrial stage of systole. The ventricular stage of systole begins at the R peak of the QRS wave complex; the T wave indicates the end of ventricular contraction, after which ventricular relaxation (ventricular diastole) begins.
“The heart will pump what it receives”- Starling’s law of the heart. The Frank–Starling mechanism describes the ability of the heart to change its force of contraction (and, hence, stroke volume) in response to changes in venous return. In other words, if the end-diastolic volume increases, there is a corresponding increase in stroke ...
Major factors influencing cardiac output – heart rate and stroke volume, both of which are variable. [1]In cardiac physiology, cardiac output (CO), also known as heart output and often denoted by the symbols , ˙, or ˙, [2] is the volumetric flow rate of the heart's pumping output: that is, the volume of blood being pumped by a single ventricle of the heart, per unit time (usually measured ...
Cardiac physiology or heart function is the study of healthy, unimpaired function of the heart: involving blood flow; myocardium structure; the electrical conduction system of the heart; the cardiac cycle and cardiac output and how these interact and depend on one another.