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In cardiology, ventricular remodeling (or cardiac remodeling) [1] refers to changes in the size, shape, structure, and function of the heart.This can happen as a result of exercise (physiological remodeling) or after injury to the heart muscle (pathological remodeling). [2]
Strain means Deformation, and is defined as relative change in length.The Lagrangian formula ε L = (L-L 0)/L 0 = ΔL/L 0, where L 0 is baseline length and L is the resulting length, defines strain in relation to the original length as a dimensionless measure, where shortening will be negative, and lengthening will be positive.
As with skeletal muscles the heart can increase in size and efficiency with exercise. [1] Thus endurance athletes such as marathon runners may have a heart that has hypertrophied by up to 40%. [ 3 ] : 1063–64 The difference between maximum and minimum cardiac outputs is known as the cardiac reserve and this measures the residual capacity to ...
The heart muscle may become inflamed in a condition called myocarditis, [46] most commonly caused by a viral infection [47] but sometimes caused by the body's own immune system. [48] Heart muscle can also be damaged by drugs such as alcohol, long standing high blood pressure or hypertension, or persistent abnormal heart racing. [49]
This rate can be altered, however, by nerves that work to either increase heart rate (sympathetic nerves) or decrease it (parasympathetic nerves), as the body's oxygen demands change. Ultimately, muscle contraction revolves around a charged atom (ion), calcium (Ca 2+), [3] which is responsible for converting the electrical energy of the action ...
Left ventricular mass can be further estimated based on geometric assumptions of ventricular shape using the measured wall thickness and internal diameter. [7] Average thickness of the left ventricle, with numbers given as 95% prediction interval for the short axis images at the mid-cavity level are: [ 8 ]
Heart rate; Conduction velocity; Preload; Afterload; Contractility; By this model, if myocardial performance changes while preload, afterload, heart rate, and conduction velocity are all held constant, then the change in performance must be due to a change in contractility. However, changes in contractility alone generally do not occur.
However, cardiac muscle cells contain a diad, which is a linking of only one sarcoplasmic reticulum with its respective t-tubule. Another notable distinction between all muscle cells and cardiac muscle cells is the presence of intercalated discs. These tight connections between the cardiomyocytes allows for the accelerated sending of action ...