Cardiac Pressure-Volume Loop Analyse Brug Ledningsevne Katetre i mus
Summary
Cardiac pressure-volume loop analysis is the most comprehensive way to measure cardiac function in the intact heart. We describe a technique to perform and analyze cardiac pressure volume loops, using conductance catheters.
Abstract
Cardiac pressure-volume loop analysis is the “gold-standard” in the assessment of load-dependent and load-independent measures of ventricular systolic and diastolic function. Measures of ventricular contractility and compliance are obtained through examination of cardiac response to changes in afterload and preload. These techniques were originally developed nearly three decades ago to measure cardiac function in large mammals and humans. The application of these analyses to small mammals, such as mice, has been accomplished through the optimization of microsurgical techniques and creation of conductance catheters. Conductance catheters allow for estimation of the blood pool by exploiting the relationship between electrical conductance and volume. When properly performed, these techniques allow for testing of cardiac function in genetic mutant mouse models or in drug treatment studies. The accuracy and precision of these studies are dependent on careful attention to the calibration of instruments, systematic conduct of hemodynamic measurements and data analyses. We will review the methods of conducting pressure-volume loop experiments using a conductance catheter in mice.
Introduction
Cardiac pres volumen loop analyse giver detaljerede oplysninger om hjertefunktion og er den gyldne standard for funktionel vurdering 1. Mens billeddiagnostiske teknikker såsom ekkokardiografi eller hjertefunktion MRI give funktionelle foranstaltninger, disse foranstaltninger er stærkt afhængige af belastningsforhold. Load-uafhængige målinger af hjertets sammentrækningsevne og afslapning kræver dynamiske målinger af den ventrikulære tryk og volumen forhold over et område af forbelastning og afterload. Denne forståelse af det pres-volumen forhold skyldes den banebrydende arbejde Sagawa og kolleger 2,3. De demonstrerede i ex vivo perfusionerede hunde hjerter, at trykket-volumen loop afledte kontraktilitet foranstaltninger var uafhængige af belastningsforhold 4.
In vivo anvendelse af disse analyser blev det muligt med udviklingen af konduktans katetre i 1980'erne. Denne tekniske fremskridt tilladt Kass og kolleger til at udføre Trykvolumen sløjfe analysen i mennesker 5,6. Miniaturisering af konduktans katetre og forbedringer i kirurgiske teknikker i slutningen af 1990'erne 7 lavet analyse af gnaver hjertefunktion muligt, giver mulighed for genetiske og farmakologiske undersøgelser, der skal udføres. Dette forskud har siden fører til den udbredte brug af tryk-volumen loop analyse og har genereret en stor indsigt i pattedyrs hjerte-fysiologi.
Et centralt begreb i brugen af konduktans katetre og fortolkning af data fra det er forholdet mellem volumen og ledningsevne. Konduktans er omvendt relateret til spænding, som måles under anvendelse af et kateter med elektroder placeret proksimalt, normalt placeret under aortaklappen, og distalt på LV toppunkt 8. Ændringer i spænding eller konduktans er målt ved ændringer i strøm fra proximal til distal elektrode. Selv blodet pool bidragerr væsentligt til konduktans bidrag ventrikelvæggen, betegnet parallel konduktans (Vp), at skal trækkes måles ledningsevne til opnåelse af absolutte LV volumen målinger.
Metoderne til at udføre denne korrektion, der kaldes en saltvandsopløsning kalibrering, diskuteres i protokollen nedenfor. Den matematiske forhold mellem ledningsevne og volumen, der er beskrevet af Baan og kolleger, er dette volumen = 1 / α; (ρ L2) (GG p), hvor α = ensartet felt korrektionsfaktor, ρ = blod resistivitet, L = afstanden mellem elektroderne, G = ledningsevne og G p = ikke-blod konduktans 9. Notatet ensartet felt korrektionsfaktoren i mus nærmer 1,0 på grund af små kammer bind 10. Kombineret med tryktransducere, ledeevne kateter giver real time samtidig tryk og volumen af data.
Cardiac tryk lore-volumen analyse præsenterer særlige fordele i forhold til andre mål for hjertefunktion, da de giver mulighed for måling af ventrikulær funktion uafhængigt af belastningsforhold og hjertefrekvens. Specifikke load-uafhængig hjerte- indekser for kontraktilitet inkluderer: ultimo systoliske tryk volumen forhold (ESPVR), d P / d tmax -end-diastoliske volumen forhold, maksimal elastans (Emax), og forbelastning recruitable slagtilfælde arbejde (PRSW). En belastning-uafhængig måling af diastolisk funktion er den endelige diastolisk tryk volumen forhold (EDPVR) 11. Følgende protokol beskriver afviklingen af hjerte-pres volumen loop analyse, ved hjælp af både en carotis og en apikal tilgang. Mens den metode til at udføre disse undersøgelser er blevet beskrevet i detaljer tidligere 8,11, vil vi gennemgå de vigtigste skridt til at opnå præcise tryk-volumen målinger, herunder både saltvand og kuvetten kalibrering korrektion, og giver en visuel demonstration af THESe procedurer. Forskning med dyr udført for denne undersøgelse blev håndteret i henhold til godkendte protokoller og dyrevelfærd forskrifter Duke University Medical Centers Institutional Animal Care og brug Udvalg.
Protocol
Representative Results
Discussion
Vi beskriver en fremgangsmåde til perfoming Trykvolumen sløjfe analysen under anvendelse af en konduktans kateter i mus, at udlede omfattende analyser af både hjertets sammentrækningsevne og afslapning. Suga, Sagawa og kolleger udnyttet tryk-volumen sløjfer til at definere mål for hjertets kontraktilitet, specielt hældningen på ESPVR, eller den endelige systoliske elastans (E r), og E max. Elastans, defineret ved forholdet mellem tryk og volumen (P / V), varierer over varigheden af sy…
Declarações
The authors have nothing to disclose.
Acknowledgements
Dette arbejde er støttet af American Heart Association 14FTF20370058 (DMA) og NIH T32 HL007101-35 (DMA).
Materials
| AnaSed (xylazine) | Lloyd Laboratories | NADA no. 139-236 | Anesthetic |
| Ketaset (ketamine) | Pfizer | 440842 | Anesthetic |
| VIP3000 | Matrx Medical Inc. | Anesthesia machine | |
| Ventilator | Harvard Apparatus | Model 683 | Surgical Equipment |
| Tubing kit | Harvard Apparatus | 72-1049 | Surgical Equipment |
| Homeothermic Blanket | Kaz Inc. | 5628 | Surgical Equipment |
| Stereo microscope | Carl Zeiss Optical Inc. | Stemi 2000 | Surgical Equipment |
| Illuminator | Cole–Parmer | 41720 | Surgical Equipment |
| Dumont no. 55 Dumostar Forceps | Fine Science Tools Inc | 11295-51 | Surgical Instruments |
| Graefe forceps, curved | Fine Science Tools Inc | 11052-10 | Surgical Instruments |
| Moria MC31 forceps | Fine Science Tools Inc | 11370-31 | Surgical Instruments |
| Mayo scissors | Fine Science Tools Inc | 14512-15 | Surgical Instruments |
| Iris scissors | Fine Science Tools Inc | 14041-10 | Surgical Instruments |
| Halsey needle holder | Fine Science Tools Inc | 12501-13 | Surgical Instruments |
| Olsen–Hegar needle holder | Fine Science Tools Inc | 12002-12 | Surgical Instruments |
| spring scissors | Fine Science Tools Inc | 15610-08 | Surgical Instruments |
| disposable underpads | Kendall/Tyco Healthcare | 1038 | Surgical Supplies |
| Sterile gauze sponges, sterile | Dukal | 62208 | Surgical Supplies |
| Cotton-tipped applicators, sterile | Solon | 368 | Surgical Supplies |
| Surgical suture, silk, 6-0 | DemeTECH | FT-639-1 | Surgical Supplies |
| 1 cc Insulin syringes | Becton Dickenson | 329412 | Surgical Supplies |
| Access-9™ Hemostasis Valve | Merit Medical | MAP111 | Hemodynamic equipment |
| Sphygmomanometer | Baumanometer | 320 | Hemodynamic equipment |
| Millar PV system MPVS-300/400 or MPVS Ultra (includes calibration cuvette) | ADInstruments Inc | Hemodynamic equipment | |
| 1.4F conductance catheter | ADInstruments Inc | SPR-839 | Hemodynamic equipment |
| PowerLab 4/30 with Chart Pro | ADInstruments Inc. | ML866/P | Hemodynamic software |
| animal clipper | Wahl | 8787-450A | Miscellaneous |
| Intradermic tubing PE-10 (Becton Dickinson, cat. no. ) | Becton Dickenson | 427401 | Miscellaneous |
| Intradermic tubing PE-50 (Becton Dickinson, cat. no.) | Becton Dickenson | 427411 | Miscellaneous |
| Needle assortment (18, 25 and 30 gauge; Thomas Scientific) | Miscellaneous | ||
| 0.9% (wt/vol) sodium chloride injection, USP , cat. no. ) | Hospira | NDC no. 0409-4888-50 | Miscellaneous |
| Surgical tape | Miscellaneous | ||
| Alconox (Alconox Inc.) for catheter cleaning | ADInstruments Inc. | Miscellaneous |
Referências
- Clark, J. E., Marber, M. S. Advancements in pressure-volume catheter technology – stress remodelling after infarction. Exp Physiol. 98 (3), 614-621 (2013).
- Sunagawa, K., Maughan, W. L., Burkhoff, D., Sagawa, K. Left ventricular interaction with arterial load studied in isolated canine ventricle. Am J Physiol. 245 (Pt 1), H773-H780 (1983).
- Suga, H., Sagawa, K., Demer, L. Determinants of instantaneous pressure in canine left ventricle. Time and volume specification. Circ Res. 46 (2), 256-263 (1980).
- Suga, H., Sagawa, K., Shoukas, A. A. Load independence of the instantaneous pressure-volume ratio of the canine left ventricle and effects of epinephrine and heart rate on the ratio. Circ Res. 32 (3), 314-322 (1973).
- Kass, D. A., et al. Improved left ventricular mechanics from acute VDD pacing in patients with dilated cardiomyopathy and ventricular conduction delay. Circulation. 99 (12), 1567-1573 (1999).
- Kass, D. A., et al. Diastolic Compliance of Hypertrophied Ventricle Is Not Acutely Altered by Pharmacological Agents Influencing Active Processes. Annals of Internal Medicine. 119 (6), 466-473 (1993).
- Georgakopoulos, D., et al. In vivo murine left ventricular pressure-volume relations by miniaturized conductance micromanometry. Am J Physiol. 274 (4 pt 2), H1416-H1422 (1998).
- Cingolani, O. H., Kass, D. A. Pressure-volume relation analysis of mouse ventricular function. Am J Physiol Heart Circ Physiol. 301 (6), H2198-H2206 (2011).
- Baan, J., et al. Continuous Measurement of Left-Ventricular Volume in Animals and Humans by Conductance Catheter. Circulation. 70 (5), 812-823 (1984).
- Pearce, J. A., Porterfield, J. E., Larson, E. R., Valvano, J. W., Feldman, M. D. Accuracy considerations in catheter based estimation of left ventricular volume. Conf Proc IEEE Eng Med Biol Soc. 2010, 3556-3558 (2010).
- Pacher, P., Nagayama, T., Mukhopadhyay, P., Batkai, S., Kass, D. A. Measurement of cardiac function using pressure-volume conductance catheter technique in mice and rats. Nature Protocols. 3 (9), 1422-1434 (1038).
- Hanusch, C., Hoeger, S., Beck, G. C. Anaesthesia of small rodents during magnetic resonance imaging. Methods. 43 (1), 68-78 (2007).
- Georgakopoulos, D., Kass, D. A. Estimation of parallel conductance by dual-frequency conductance catheter in mice. Am J Physiol Heart Circ Physiol. 279 (1), H443-H450 (2000).
- Esposito, G., et al. Increased myocardial contractility and enhanced exercise function in transgenic mice overexpressing either adenylyl cyclase 5 or 8. Basic Res Cardiol. 103 (1), 22-30 (2008).
- Kohout, T. A., et al. Augmentation of cardiac contractility mediated by the human beta(3)-adrenergic receptor overexpressed in the hearts of transgenic mice. Circulation. 104 (20), 2485-2491 (2001).
- Kim, K. S., et al. beta-Arrestin-biased AT1R stimulation promotes cell survival during acute cardiac injury. Am J Physiol Heart Circ Physiol. 303 (8), H1001-H1010 (2012).
- Suga, H., Sagawa, K. Mathematical Interrelationship between Instantaneous Ventricular Pressure-Volume Ratio and Myocardial Force-Velocity Relation. Annals of Biomedical Engineering. 1 (2), 160-181 (1972).
- Suga, H. Ventricular energetics. Physiol Rev. 70 (2), 247-277 (1990).
- Kass, D. A., et al. Influence of contractile state on curvilinearity of in situ end-systolic pressure-volume relations. Circulation. 79 (1), 167-178 (1989).
- Little, W. C. The left ventricular dP/dtmax-end-diastolic volume relation in closed-chest dogs. Circ Res. 56 (6), 808-815 (1985).
- Glower, D. D., et al. Linearity of the Frank-Starling relationship in the intact heart: the concept of preload recruitable stroke work. Circulation. 71 (5), 994-1009 (1985).
- Sharir, T., et al. Ventricular systolic assessment in patients with dilated cardiomyopathy by preload-adjusted maximal power. Validation and noninvasive application. Circulation. 89 (5), 2045-2053 (1994).
- Baan, J., Van der Velde, E. T. Sensitivity of left ventricular end-systolic pressure-volume relation to type of loading intervention in dogs. Circ Res. 62 (6), 1247-1258 (1988).
- Wei, C. L., et al. Volume catheter parallel conductance varies between end-systole and end-diastole. IEEE Trans Biomed Eng. 54 (8), 1480-1489 (2007).
- Porterfield, J. E., et al. Dynamic correction for parallel conductance, GP, and gain factor, alpha, in invasive murine left ventricular volume measurements. J Appl Physiol (1985). 107 (6), 1693-1703 (2009).
