59:. Impairment of these systems may occur e.g. following stroke, trauma or anaesthesia, in premature babies and has been implicated in the development of subsequent brain injury. The non-invasive measurement of relevant physiological signals like cerebral blood flow, intracranial pressure, blood pressure, CO
43:
that maintain blood flow at an appropriate level during changes in blood pressure. However, due to the important influences of arterial carbon dioxide levels, cerebral metabolic rate, neural activation, activity of the sympathetic nervous system, posture, as well as other physiological variables,
180:
The quantification of cerebral autoregulation always involves variation seen in cerebral blood flow in relation to changes in blood pressure. This blood pressure variation can either be evoked or spontaneous. Evoked blood pressure changes can be the result of:
113:
The vascular smooth muscle actuators in the resistance arterioles are controlled via sympathetic innervation, receiving the input from the appropriate brainstem autonomous control center. Nitric oxide released by parasympathetic fibers may also play a role.
63:
levels, cerebral oxygen consumption, etc. is challenging. Even more so is the subsequent assessment of the control systems. Much remains unknown about the physiology of blood flow control and the best clinical interventions to optimize patient outcome.
31:
is essential for life, since the brain has a high metabolic demand. By means of cerebral autoregulation, the body is able to deliver sufficient blood containing oxygen and nutrients to the brain tissue for this metabolic need, and remove
104:
The effect of transmural blood pressure changes is directly detected by the vascular smooth muscle in arterioles, probably via a stress sensing mechanism. Then, the calibers are adjusted accordingly to keep blood flow constant.
207:
Measuring and understanding cerebral autoregulation remains a big challenge. Despite great clinical interest and much research effort, benefit to patients has so far been limited.
145:. However, noninvasive finger arterial pressure can also be measured using a volume clamp technique. This technique uses a combination of an inflatable finger cuff and an infrared
204:
The quantification depends on the experimental setup and can involve methods such as regression, cross-correlation, transfer function analysis or fitting mathematical models.
92:
Metabolic regulation is driven by the difference between cerebral metabolism (demand) and oxygen delivery through cerebral blood flow (supply) and acts by means of a
55:
This regulation of cerebral blood flow is achieved primarily by small arteries, arterioles, which either dilate or contract under the influence of multiple complex
299:
44:
cerebral autoregulation is often interpreted as encompassing the wider field of cerebral blood flow regulation. This field includes areas such as CO
122:
In order to assess cerebral autoregulation one must at least continuously measure arterial blood pressure and cerebral blood flow. Because CO
522:
794:
292:
56:
40:
285:
81:
73:
96:
substance. In principle, this is a negative feedback control system that seeks to balance blood flow to its demand.
77:
27:. Cerebral autoregulation plays an important role in maintaining an appropriate blood flow to that region. Brain
435:
812:
567:
545:
126:
levels are of great influence to cerebral autoregulation it is recommended to also continuously measure CO
72:
Three different mechanisms are thought to contribute to the process of cerebral autoregulation. These are
807:
552:
633:
169:
165:
160:
can be quantified in various ways of which three noninvasive means are currently much used. These are
24:
837:
784:
660:
640:
604:
527:
487:
308:
23:. While most systems of the body show some degree of autoregulation, the brain is very sensitive to
655:
645:
535:
774:
719:
620:
540:
424:
402:
138:
420:
779:
769:
683:
429:
387:
382:
628:
377:
360:
161:
277:
8:
891:
724:
562:
557:
392:
365:
157:
146:
20:
832:
697:
450:
49:
468:
440:
263:
817:
412:
667:
397:
236:
827:
752:
744:
338:
325:
216:
885:
445:
355:
348:
333:
142:
859:
849:
822:
711:
702:
499:
473:
93:
267:
254:
Paulson OB, Strandgaard S, Edvinsson L (1990). "Cerebral autoregulation".
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483:
802:
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28:
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493:
19:
is a process in mammals that aims to maintain adequate and stable
757:
597:
592:
185:
releasing leg cuffs that were inflated above systolic pressure
729:
316:
175:
307:
253:
237:"CV Physiology | Autoregulation of Organ Blood Flow"
117:
200:
pharmaceutical methods to raise or lower blood pressure
133:
883:
152:
293:
194:performing squat-stand or sit-stand maneuvers
52:and other aspects of cerebral haemodynamics.
256:Cerebrovascular and Brain Metabolism Reviews
229:
67:
300:
286:
176:Quantification of cerebral autoregulation
108:
309:Physiology of the cardiovascular system
87:
884:
99:
39:Cerebral autoregulation refers to the
281:
118:Assessment of cerebral autoregulation
141:can be measured invasively using an
13:
14:
903:
134:Measuring arterial blood pressure
247:
191:performing a Valsalva maneuver
1:
436:Aortic valve area calculation
222:
153:Measuring cerebral blood flow
57:physiological control systems
197:lower body negative pressure
7:
553:Effective refractory period
432:) / End-diastolic dimension
210:
10:
910:
170:Near Infrared Spectroscopy
166:Magnetic Resonance Imaging
36:and other waste products.
838:Tubuloglomerular feedback
793:
785:Critical closing pressure
743:
710:
696:
676:
613:
605:Hexaxial reference system
528:Cardiac electrophysiology
515:
459:
411:
324:
315:
188:breathing at a fixed rate
813:Renin–angiotensin system
68:Physiological mechanisms
41:physiological mechanisms
25:over- and underperfusion
843:Cerebral autoregulation
808:Kinin–kallikrein system
775:Jugular venous pressure
425:End-diastolic dimension
403:Pressure volume diagram
139:Arterial blood pressure
17:Cerebral autoregulation
780:Portal venous pressure
770:Mean arterial pressure
684:Ventricular remodeling
430:End-systolic dimension
388:Cardiac function curve
50:neurovascular coupling
421:Fractional shortening
109:Neurogenic regulation
361:End-diastolic volume
241:www.cvphysiology.com
162:Transcranial Doppler
88:Metabolic regulation
725:Vascular resistance
563:Electrocardiography
558:Pacemaker potential
488:Conduction velocity
393:Venous return curve
366:End-systolic volume
158:Cerebral blood flow
100:Myogenic regulation
21:cerebral blood flow
833:Myogenic mechanism
451:Left atrial volume
383:Frank–Starling law
879:
878:
875:
874:
692:
691:
532:Action potential
523:Conduction system
469:Cardiac pacemaker
441:Ejection fraction
899:
818:Vasoconstrictors
795:Regulation of BP
708:
707:
641:pulmonary artery
614:Chamber pressure
322:
321:
302:
295:
288:
279:
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272:
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251:
245:
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233:
909:
908:
902:
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896:
882:
881:
880:
871:
789:
739:
701:
698:Vascular system
688:
672:
609:
511:
496:(Contractility)
455:
407:
398:Wiggers diagram
311:
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276:
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252:
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136:
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90:
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62:
47:
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12:
11:
5:
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835:
828:Autoregulation
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815:
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805:
799:
797:
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790:
788:
787:
782:
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772:
767:
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753:Pulse pressure
749:
747:
745:Blood pressure
741:
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738:
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705:
694:
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631:
623:
621:Central venous
617:
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570:
560:
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550:
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548:
543:
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530:
525:
519:
517:
513:
512:
510:
509:
503:
502:(Excitability)
497:
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481:
471:
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453:
448:
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433:
427:
417:
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409:
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400:
395:
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385:
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370:
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368:
363:
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339:Cardiac output
336:
330:
328:
326:Cardiac output
319:
313:
312:
305:
304:
297:
290:
282:
274:
273:
262:(2): 161–192.
246:
227:
226:
224:
221:
220:
219:
217:Autoregulation
212:
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202:
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177:
174:
154:
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147:plethysmograph
135:
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98:
89:
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69:
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60:
45:
33:
9:
6:
4:
3:
2:
905:
904:
893:
890:
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851:
848:
844:
841:
839:
836:
834:
831:
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829:
826:
824:
821:
819:
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811:
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786:
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764:
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750:
748:
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742:
736:
733:
731:
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723:
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653:
651:
647:
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619:
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584:
581:
579:
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533:
531:
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520:
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507:
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479:
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458:
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449:
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446:Cardiac index
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442:
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428:
426:
422:
419:
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416:
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404:
401:
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389:
386:
384:
381:
379:
376:
374:
371:
367:
364:
362:
359:
358:
357:
356:Stroke volume
354:
350:
349:Stroke volume
347:
345:
342:
341:
340:
337:
335:
334:Cardiac cycle
332:
331:
329:
327:
323:
320:
318:
314:
310:
303:
298:
296:
291:
289:
284:
283:
280:
269:
265:
261:
257:
250:
242:
238:
232:
228:
218:
215:
214:
208:
205:
199:
196:
193:
190:
187:
184:
183:
182:
173:
171:
167:
163:
159:
150:
148:
144:
143:arterial line
140:
131:
115:
106:
97:
95:
85:
83:
79:
75:
65:
58:
53:
51:
42:
37:
30:
26:
22:
18:
860:Carotid body
842:
823:Vasodilators
703:hemodynamics
508:(Relaxation)
500:Bathmotropic
474:Chronotropic
259:
255:
249:
240:
231:
206:
203:
179:
164:sonography,
156:
137:
121:
112:
103:
91:
71:
54:
48:reactivity,
38:
16:
15:
865:Glomus cell
855:Aortic body
850:Paraganglia
661:ventricular
634:ventricular
583:QT interval
578:QRS complex
573:PR interval
546:ventricular
484:Dromotropic
892:Physiology
803:Baroreflex
720:Compliance
712:Blood flow
588:ST segment
516:Conduction
506:Lusitropic
478:Heart rate
461:Heart rate
413:Ultrasound
344:Heart rate
223:References
94:vasoactive
82:neurogenic
763:Diastolic
735:Perfusion
494:Inotropic
373:Afterload
74:metabolic
29:perfusion
886:Category
758:Systolic
536:cardiac
211:See also
78:myogenic
378:Preload
268:2201348
668:Aortic
656:atrial
629:atrial
625:Right
598:U wave
593:T wave
568:P wave
541:atrial
266:
730:Pulse
677:Other
652:Left
646:wedge
317:Heart
264:PMID
168:and
80:and
423:= (
888::
258:.
239:.
172:.
149:.
130:.
84:.
76:,
32:CO
700:/
490:)
486:(
480:)
476:(
301:e
294:t
287:v
270:.
260:2
243:.
128:2
124:2
61:2
46:2
34:2
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