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 35mmHg 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
Insp
Expir
Ventricular Pressures
Are 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