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Premature ventricular contractions may be associated with underlying heart disease, and certain characteristics are therefore elicited routinely: the presence of signs of heart disease or a known history of heart disease (e.g. previous myocardial infarction), as well as heart disease or sudden cardiac death in close relatives.
Coronary artery disease (CAD) or ischemic heart disease are the terms used to describe narrowing of the coronary arteries. [8] As the disease progresses, plaque buildup can partially block blood flow to the heart muscle. Without enough blood supply , the heart is unable to work properly, especially under increased stress.
Ectopic beats are considered normal and are not indicative of cardiac pathology. Ectopic beats often remain undetected and occur as part of minor errors in the heart conduction system. They are rarely indicative of cardiac pathology, although may occur more frequently or be more noticeable in those with existing cardiac abnormalities.
Purkinje fibers also have the ability of firing at a rate of 20–40 beats per minute if upstream conduction or pacemaking ability is compromised. [9] In contrast, the SA node in normal state can fire at 60-100 beats per minute. [9] In short, they generate action potentials, but at a slower rate than the sinoatrial node. [9]
The action potential passes along the cell membrane causing the cell to contract, therefore the activity of the sinoatrial node results in a resting heart rate of roughly 60–100 beats per minute. All cardiac muscle cells are electrically linked to one another, by intercalated discs which allow the action potential to pass from one cell to the ...
The heart is a muscular organ situated in the mediastinum.It consists of four chambers, four valves, two main arteries (the coronary arteries), and the conduction system. The left and right sides of the heart have different functions: the right side receives de-oxygenated blood through the superior and inferior venae cavae and pumps blood to the lungs through the pulmonary artery, and the left ...
Anatomy figure: 20:04-01 at Human Anatomy Online, SUNY Downstate Medical Center – "Posterior view of the heart." [dead link ] Anatomy photo:20:09-0104 at the SUNY Downstate Medical Center [dead link ] – "Heart: The Left Coronary Artery and its Branches" Image at merck.com Archived 14 April 2006 at the Wayback Machine
The bundle of His (BH) [1]: 58 or His bundle (HB) [1]: 232 (/ h ɪ s / "hiss" [2]) is a collection of heart muscle cells specialized for electrical conduction.As part of the electrical conduction system of the heart, it transmits the electrical impulses from the atrioventricular node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the ...