Physiology of cardiac tamponade and paradoxical pulse in conscious dogs
| Autor: | J. R. Elbeery, Michael P. Feneley, J. W. Davis, M. A. Savitt, D. D. Glower, C. H. Owen, G. S. Tyson, J. S. Rankin |
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| Rok vydání: | 1993 |
| Předmět: |
medicine.medical_specialty
Systole Physiology Hemodynamics Blood Pressure Ventricular Function Left Dogs Reference Values Physiology (medical) Internal medicine Cardiac tamponade Pressure medicine Animals Pericardium Interventricular septum Blood Volume business.industry Respiration Models Cardiovascular Stroke Volume Stroke volume medicine.disease Cardiac Tamponade medicine.anatomical_structure Anesthesia Circulatory system Ventricular Function Right Cardiology Pleura Tamponade Cardiology and Cardiovascular Medicine business |
| Zdroj: | American Journal of Physiology-Heart and Circulatory Physiology. 265:H1996-H2008 |
| ISSN: | 1522-1539 0363-6135 |
| DOI: | 10.1152/ajpheart.1993.265.6.h1996 |
| Popis: | The physiological mechanism of paradoxical pulse in cardiac tamponade remains controversial. In eight conscious dogs with intact pericardia, ultrasonic dimension transducers assessed biventricular geometry and volumes, while micromanometers measured right ventricular (RV), left ventricular (LV), pleural, and pericardial pressures. With normal inspiration, peak LV pressure fell by 7.7 +/- 1.3 mmHg at control and by 20.3 +/- 3.7 mmHg during tamponade (P < 0.001), consistent with the development of paradoxical pulse. At peak inspiration during tamponade, RV filling increased, the interventricular septum shifted leftward, transeptal pressure became negative, and LV septal arc length (l theta) became smaller than its respective unpreloaded value at maximal vena caval occlusion (l(o)). Analysis of stroke work (SW)-end-diastolic volume (EDV) and end-systolic pressure-volume coordinates at peak inspiration during tamponade revealed that end-systolic pressure was 19.1 +/- 10.2 mmHg below the baseline end-systolic pressure-volume curve (P < 0.01), and SW was 24.2 +/- 8.8% below the baseline SW-EDV curve (P < 0.01), indicating transient inspiratory LV dysfunction. It is proposed that inspiratory leftward interventricular septal shifting at low LV EDV during tamponade completely unloads the septum (l theta < l o), eliminates the septal contribution to global LV SW, results in transient inspiratory LV dysfunction, and contributes to the phenomenon of paradoxical pulse. |
| Databáze: | OpenAIRE |
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