Summary
To investigate whether left ventricular performance can be described independent of loading conditions, twelve patients underwent intraoperatively two cineangiographies of the left ventricle with simultaneous pressure recordings. The first ventriculography was performed with ejecting left ventricle without assistance by the extracorporeal circulation. The second one was performed with ejecting left ventricle partially unloaded by the extracorporeal circulation. Myocardial perfusion pressure (mean aortic pressure) was held constant. Due to this procedure marked decreases in preload (end-diastolic wall stress: −54%) and modest changes in afterload (mean systolic wall stress: −23%) were achieved. End-diastolic volume index was reduced from 84 ml/m2 to 57 ml/m2, whereas end-systolic volume index decreased slightly from 33 ml/m2 to 29 ml/m2. Left ventricular end-diastolic pressure decreased from 12 mm Hg to 7 mm Hg, while peak pressure remained nearly unchanged. Usual parameters of ejection phase (EF, Vmw) as well as power per wall volume (PW) were markedly affected by unloading. In contrast to these parameters, the power index (PI), i.e., the ratio of power per wall volume and enddiastolic wall stress, remained unchanged when left ventricular preload was reduced: PI under control: 5.2±1.8 sec−1; PI under unloading: 5.2±1.5 sec−1.
This power index can easily be determined from routine angiographies. It may provide a new approach to the assessment of left ventricular function in man.
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References
Brower RW, Meester GT, Hugenholtz PG (1975) Quantification of ventricular performance: A computer-based system for the analysis of angiographic data. Cathet Cardiovasc Diag 1:133–155
Dodge HT, Sandler H, Baxley AW, Hawley RR (1966) Usefulness and limitations of radiographic methods for determining left ventricular volume. Am J Cardiol 18:10–24
Dodge HT, Kennedy JW, Petersen JL (1973) Quantitative angiocardiographic methods in the evaluation of valvular heart disease. Progr Cardiovasc Dis 16:1–23
Gunther S, Grossman W (1979) Determinants of ventricular function in pressure-overload hypertrophy in man. Circulation 59:679–688
Huber D, Grimm J, Koch R, Krayenbuehl HP (1981) Determinants of ejection performance in aortic stenosis. Circulation 64:126–134
Hugenholtz PG, Kaplan E, Hull E (1969) Determination of left ventricular wall thickness by angiocardiography. Am Heart J 78:513–522
Jacob R (1966) Die Dynamik des linken Ventrikels im natürlichen Kreislauf und ihre muskelphysiologischen Grundlagen. Habilitationsschrift Würzburg
Jacob R, Gülch R (1972) Kritische Bemerkungen zur Aussagekraft der “Kontraktilitätsindizes”. Verh Dtsch Ges Kreisl Forsch 38:241–246
Jacob R, Gülch R, Holubarsch C, Kissling G (1975) Die Bewertung der myokardialen Leistungsfähigkeit. Muskelphysiologische Grundlagen und methodische Probleme. Med Klin 70:1347–1365
Jehle J, Pehle R, Neuhaus KL, Schmiel FK, Spiller P (1981) Experimentelle Untersuchungen zur Kontrastmittelwirkung auf die Funktion des linken Ventrikels. Z Kardiol 70:670–677
Mangano DT, Van Dyke DC, Ellis RJ (1980) The effect of increasing preload on ventricular output and ejection in man. Limitations of the Frank-Starling mechanism. Circulation 62:535–541
Mason DT (1969) Usefulness and limitations of the rate of rise of intraventricular pressure (dp/dt) in the evaluation of myocardial contractility in man. Am J Cardiol 23:516–527
McHale PA, Greenfield JC Jr (1973) Evaluation of several geometric models for estimation of left ventricular circumferential wall stress. Circ Res 33:303–312
Noble MIM (1972) Problems concerning the application of concepts of muscle mechanics to the determination of the contractile state of the heart. Circulation 45:252–255
Quinones MA, Gaasch WH, Cole JS, Alexander JK (1975) Echocardiographic determination of left ventricular stress-velocity relations in man with reference to the effects of loading and contractility. Circulation 51:689–700
Rackley CE, Dodge HT, Coble YD, Hay RE (1964) A method for determining left ventricular mass in man. Circulation 29:666–671
Raff U, Stauber W, Kissling G (1974) Die Aussagekraft verschiedener Kontraktilitätsindizes beim Herzen in situ. Basic Res Cardiol 69:58–73
Rönsberg D, Benn M, Karsch KR, Kreuzer H, Neuhaus KL, Spiller P (1978) Der Einfluß der Nachbelastung auf normales und ischämisches Myokard beim Hund. Z Kardiol 67:595–600
Ross J Jr (1976) Afterload mismatch and preload reserve: a conceptual framework for the analysis of ventricular function. Progr Cardiovasc Dis 18:255–264
Russell RO, Porter CG, Frimer M, Dodge HT (1971) Left ventricular power in man. Am Heart J 81:799–808
Sandler H, Dodge HT (1968) The use of single plane angiocardiograms for the calculation of left ventricular volume in man. Am Heart J 75:325–334
Sarnoff SJ, Berglund E (1954) Ventricular function. I. Starling's law of the heart studied by means of simultaneous right and left ventricular function curves in the dog. Circulation 9:706–718
Snell RE, Luchsinger PC (1965) Determination of the external work and power of the left ventricle in intact man. Am Heart J 69:529–537
Sonnenblick EH (1962) Implications of muscle mechanics in the heart. Fed Proc 21:975–990
Starling EH (1918) The linacre lecture on the law of the heart. Longmans, Green and Co (1915) Given at Cambridge, London
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Supported by Deutsche Forschungsgemeinschaft, Sonderforschungsbereich 30
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Unterberg, R.H., Körfer, R., Pölitz, B. et al. Assessment of left ventricular function by a power index: an intraoperative study. Basic Res Cardiol 79, 423–431 (1984). https://doi.org/10.1007/BF01908142
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DOI: https://doi.org/10.1007/BF01908142