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Hemodynamic Rounds. 5/13/11. Hemodynamics. Equalization of diastolic pressures (RA, RV, LV, Wedge) and pericardial pressure Total intracardiac volume fixed, so flow into heart occurs mainly during systole; X-descent is the dominant wave
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Hemodynamic Rounds 5/13/11
Hemodynamics • Equalization of diastolic pressures (RA, RV, LV, Wedge) and pericardial pressure • Total intracardiac volume fixed, so flow into heart occurs mainly during systole;X-descent is the dominant wave • Loss of Y-descent: No overall change in intracardiac volume in diastole Zipes. Braunwald’s Heart Disease, 7th ed. Ch. 64.
Paradoxical Pulse and Interdependence • Hallmark of tamponade • Inspiration causes increased venous return with fixed intracardiac volume • RV size increases, septum shifts, LV size decreases (180 degrees out of phase) Zipes. Braunwald’s Heart Disease, 7th ed. Ch. 64.
Tamponade • Critical point where effusion reduces volume of cardiac chambers – “Last Drop Phenomenon” • Decreases stroke volume in both left and right heart • Primarily affects the right heart due to lower pressures • Fixed total cardiac volume accentuates interdependence Zipes. Braunwald’s Heart Disease, 7th ed. Ch. 64.
Hemodynamic Findings • High RA, RVEDP, LVEDP and intrapericardial pressure prior to tap • Cardiac output reduced • Low RA transmural pressure • Post-tap, intrapericardial pressure dropped, RA transmural pressure increased, RA and RVEDP dropped slightly and LVEDP was unchanged • CO increased slightly • Y-descent returned • Dip-plateau visible Sagrista-Sauleda. NEJM 350: 2004.
Constriction Hemodynamics • Chief characteristic: Failure of transmission of intrathoracic pressure changes of respiration to the cardiac chambers • Interdependence: Pressure changes continue to transmit to the pulmonary circulation, so inspiration decreases pulmonary venous pressure • Drops the PV-LA gradient, with reduced LA inflow and reduced transmitral flow • Underfilled LV permits septal shift to left and increased RV filling
Hemodynamics • Equilibration of RA, RV diastolic, Wedge and LV diastolic pressures (less than 3-5mmHg difference) • Atrial wave: Preserved X-descent, prominent Y-descent (“M” or “W” configuration) Zipes. Braunwald’s Heart Disease, 7th ed. Ch. 64.
Hemodynamics • RV and LV show “dip and plateau” or “square root” sign • Reflects lack of mid-to-late diastolic filling Zipes. Braunwald’s Heart Disease, 7th ed. Ch. 64.
Constriction vs. Tamponade • Both restrict cardiac filling and raise systemic and pulmonary venous pressures • Venous pressure waveforms differ Zipes. Braunwald’s Heart Disease, 7th ed. Ch. 64.
Vs. Restriction: Dissociation of Intrathoracic and Intracardiac Pressures Hatle LK, et. al. Circ. 1989;79357-370
Ventricular Interdependence Hatle LK, et. al. Circ. 1989;79357-370 Ventricular Pressures Are DISCORDANT Insp Expir
Kussmaul’s Sign • Pericardial constriction • Restrictive cardiomyopathy • Congestive Heart Failure:RV failure • Right ventricular infarction • Acute pulmonary embolism • COPD