Stroke Volume
Stroke Volume - Related Videos
01:27
Regulation of Stroke Volume
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2025
The regulation of stroke volume, which is the amount of blood the heart pumps out during each heartbeat, is critical for maintaining a healthy circulatory system. Stroke volume is influenced by three main factors: preload, contractility, and afterload. Preload refers to the degree of stretch on the heart before it contracts. It's analogous to the stretching of a rubber band; the more it's stretched, the more forcefully it snaps back. This concept is encapsulated in the Frank-Starling law of the...
01:11
Cardiac Output and Stroke Volume
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2025
Cardiac output (CO) is an integral aspect of human physiology, reflecting the heart's efficiency and responsiveness to the body's needs. It represents the volume of blood that the left or right ventricle ejects into the aorta or pulmonary trunk each minute. The CO is calculated by multiplying the heart rate (HR)—the number of heartbeats per minute—by the stroke volume (SV)—the amount of blood pumped out with each heartbeat. In an average resting adult male, the typical cardiac output averages...
01:22
Cardiac Output II: Effect of Stroke Volume on Cardiac Output
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2025
Cardiac output (CO), the amount of blood the heart pumps per minute, is a parameter in cardiovascular physiology determined by stroke volume and heart rate. Stroke volume, the amount of blood pushed from one of the ventricles per heartbeat, is influenced by preload, afterload, and contractility. Preload Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...
08:14
Modeling Stroke in Mice: Permanent Coagulation of the Distal Middle Cerebral Artery
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Cited by 104 •
2014
Various murine models of middle cerebral artery occlusion (MCAO) are widely used in experimental brain research. Here, we demonstrate the model of transcranial permanent distal MCAO which produces consistent cortical infarction of a size corresponding to damage imposed by the majority of human ischemic strokes.
06:38
The Stroke Preclinical Assessment Network Multi-Laboratory Model of Thromboembolic Stroke with Thrombolysis: TE-MCAo
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2025
To simulate thromboembolic stroke, emboli prepared from heterologous rat blood were injected into the middle cerebral artery, followed by administration of systemic thrombolysis for recanalization. This version of the model is optimized for use in a multi-laboratory network and supports testing multiple candidate therapeutics.
FAQs
Preload reflects ventricular filling before contraction, so changes in filling alter the amount of blood available for ejection. Greater filling can increase stroke volume when the ventricle can respond effectively, whereas reduced filling can limit ejection. Clinically, this relationship helps explain why changes in circulating volume may affect tissue perfusion and cardiovascular status.
Afterload represents the arterial resistance the ventricle must overcome, while contractility describes the strength of myocardial contraction. Increased resistance can reduce ventricular ejection, whereas stronger contraction can increase it. Because these factors act together with filling, interpreting stroke volume requires considering the combined effects of preload, afterload, and myocardial performance rather than examining one variable alone.
Cardiac output depends on both the amount ejected per heartbeat and the heart rate. Consequently, a change in stroke volume can alter overall blood flow even when the heart rate remains unchanged, while a heart-rate change can modify cardiac output without directly indicating improved ventricular ejection. Clinicians therefore consider both measures when evaluating circulation and tissue perfusion.
Repeated measurements show whether ventricular ejection is changing over time rather than providing only a single snapshot. This trend can help clinicians evaluate evolving cardiovascular performance, identify responses to management, and follow circulation during illness. Serial assessment is particularly relevant when preload, afterload, or contractility may change, because each factor can shift the measured value.
These conditions can disturb the interaction among ventricular filling, myocardial contraction, and arterial resistance, producing altered ejection and potentially impaired tissue perfusion. Stroke volume provides one measure of that disturbance and can be interpreted alongside cardiac output and clinical findings. Tracking it may support assessment of disease-related circulatory changes and help guide cardiovascular monitoring.
Because ventricular filling affects the amount ejected, changes in stroke volume can provide information about how circulation responds as clinical conditions evolve. Clinicians may use serial values, together with cardiac output, to assess circulation and support fluid-management decisions. Interpretation still requires attention to contractility and arterial resistance, since filling alone does not determine ventricular ejection.