afterload


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afterload

 [af´ter-lōd]
the tension developed by the heart during contraction; it is an important determinant of myocardial energy consumption, as it represents the resistance against which the ventricle must pump and indicates how much effort the ventricles must put forth to force blood into the systemic circulation. Factors that increase afterload include aortic and pulmonarystenosis, systemic and pulmonary hypertension, and high peripheral resistance.

af·ter·load

(af'ter-lōd),
1. The arrangement of a muscle so that, in shortening, it lifts a weight from an adjustable support or otherwise does work against a constant opposing force to which it is not exposed at rest.
2. The load or force thus encountered in shortening.

afterload

/af·ter·load/ (-lōd″) the force against which cardiac muscle shortens: in isolated muscle, the force resisting shortening after the muscle is stimulated to contract; in the intact heart, the pressure against which the ventricle ejects blood.

afterload

Etymology: AS, aefter + ME lod
the load, or resistance, against which the left ventricle must eject its volume of blood during contraction. The resistance is produced by the volume of blood already in the vascular system and by the constriction of the vessel walls.

Afterload

Cardiology The amount of haemodynamic pressure (peripheral vascular resistance) downstream from the heart, which increased in heart failure secondary to aortic stenosis and hypertension. Cf Preload.
Physiology The tension produced by heart muscle after contraction.

afterload

Cardiology The amount of hemodynamic pressure–peripheral vascular resistance downstream from the heart–which ↑ in heart failure 2º to aortic stenosis and HTN. Cf Preload Physiology The tension produced by heart muscle after contraction.

af·ter·load

, after-load (af'tĕr-lōd)
1. The arrangement of a muscle so that, in shortening, it creates a force from an adjustable support or otherwise work against an opposing force to which it is not exposed at rest.
2. The load or force thus encountered in shortening.
3. That resistance against which the left ventricle must eject its volume of blood during contraction.

afterload

see cardiac afterload.
References in periodicals archive ?
The device is designed to rest and heal the heart by reducing afterload while simultaneously improving blood flow to vital organs.
Second, the possibility of impeding venous return and augmenting right ventricular afterload by high airway pressure needed to be confronted.
beta]-blockers decrease pulse rate, cardiac output, afterload and renin release.
The sudden elevation of right ventricular pressure and consequently increased right ventricular afterload produced by pulmonary artery outflow obstruction results in right ventricular failure and dilatation inducing myocardial ischemia.
The ProAQT monitoring range has been expanded to include variables such as blood flow, volume responsiveness, afterload and contractility.
2+], reduce coronary artery spasms, and reduce afterload and blood pressure.
Pulmonary emboli result in increased right ventricular afterload, leading to right ventricular dysfunction and failure.
The reason for this is unclear but indicates that the SV in HF patients is more dependent on LV contractility (the 'limiting' factor), whereas the SV in normal and septic subjects is likely to be dependent on other factors such as HR, preload, afterload, increased LV wall thickness and the use of vasoactive medication.
Also, with VA-ECMO the high returning arterial pressure in the aorta may cause 'cardiac stun', because the heart is ejecting against an increased afterload.
The clinical benefits of RAAS inhibition with ACE inhibitors, ARB therapy, or aldosterone blockade after ACS appear to be greatest in patients with large infarcts and depressed LV function, in whom RAAS inhibition improves survival through afterload reduction and improved myocardial remodeling (7, 8, 15-22).
If there is increased afterload (pressure in the aorta or, for the right ventricle, in the pulmonary circulation) then less blood can be pushed out of the ventricle.