summation gallop(redirected from S7 gallop)
gallop rhythm in which the gallop sound is due to superimposition of third and fourth heart sounds; sometimes heard in normal subjects with tachycardia, but usually indicative of myocardial disease.
a gallop rhythm in which the third and fourth heart sounds are superimposed, appearing as one loud sound. It may occur in some patients with tachycardia but is usually associated with cardiac disease. See also gallop.
summation gallopTriple gallop Cardiology An extra 'galloping' heart sound caused by tachycardia, best heard over the apex with the Pt in supine or left lateral position; it ↑ with inspiration, exercise, elevation of legs, ↑ venous return. Cf Fourth heart sound.
sum·ma·tion gal·lop(sŭm-ā'shŭn gal'ŏp)
Rhythm in which the gallop sound is due to superimposition of third and fourth heart sounds; sometimes heard in normal subjects with tachycardia, but usually indicative of myocardial disease.
accumulate, add up, aggregate a series of numbers or quantities or events.
summation of effects
a theory explaining clinical pruritus as the additive effects of pruritus from several causes which may raise the individual above the threshold, but pruritus from any single cause would be unlikely to do so.
see gallop rhythm.
physiological summation in synapses is a characteristic of the mammalian nervous system. It may be spatial, with additional synaptic junctions participating, or temporal, when succeeding stimuli catch up with the as-yet undischarged neurotransmitter. Seen in the retina of the cat, as an example of a nocturnal animal, where many millions of photoreceptors are connected to only one million axons, resulting in maximal sensitivity to light.
the sum obtained by adding the numerical value for individual clinical signs, each weighted to express their importance, when making a diagnosis. The total, as a fraction or a percentage, provides an estimate of the probability of each diagnosis being the correct one.