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: DissociationVs. Restriction: Dissociation of Intrathoracic and Intracardiac
Pressures
Hatle LK, et. al.Circ. 1989;79357-370
Ventricular Interdependence
Insp Expir
Hatle LK, et. al.Circ. 1989;79357-370
Ventricular PressuresAre DISCORDANT
Little. Circulation 2006, 113: 1629.
Kussmaul’s Sign• Pericardial constriction• Restrictive cardiomyopathy• Congestive Heart Failure:RV
failure– Right ventricular infarction
• Acute pulmonary embolism• COPD