HemodynamicsEqualization of diastolic pressures (RA, RV, LV, Wedge) and pericardial pressureTotal intracardiac volume fixed, so flow into heart occurs mainly during systole; X-descent is the dominant waveLoss of Y-descent: No overall change in intracardiac volume in diastoleZipes. Braunwalds Heart Disease, 7th ed. Ch. 64.
Paradoxical Pulse and InterdependenceHallmark of tamponadeInspiration causes increased venous return with fixed intracardiac volumeRV size increases, septum shifts, LV size decreases (180 degrees out of phase)
Zipes. Braunwalds Heart Disease, 7th ed. Ch. 64.
TamponadeCritical point where effusion reduces volume of cardiac chambers Last Drop PhenomenonDecreases stroke volume in both left and right heartPrimarily affects the right heart due to lower pressuresFixed total cardiac volume accentuates interdependenceZipes. Braunwalds Heart Disease, 7th ed. Ch. 64.
Hemodynamic FindingsHigh RA, RVEDP, LVEDP and intrapericardial pressure prior to tapCardiac output reducedLow RA transmural pressurePost-tap, intrapericardial pressure dropped, RA transmural pressure increased, RA and RVEDP dropped slightly and LVEDP was unchangedCO increased slightlyY-descent returnedDip-plateau visibleSagrista-Sauleda. NEJM 350: 2004.
Constriction HemodynamicsChief characteristic: Failure of transmission of intrathoracic pressure changes of respiration to the cardiac chambersInterdependence: Pressure changes continue to transmit to the pulmonary circulation, so inspiration decreases pulmonary venous pressureDrops the PV-LA gradient, with reduced LA inflow and reduced transmitral flowUnderfilled LV permits septal shift to left and increased RV filling
HemodynamicsEquilibration 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. Braunwalds Heart Disease, 7th ed. Ch. 64.
HemodynamicsRV and LV show dip and plateau or square root signReflects lack of mid-to-late diastolic fillingZipes. Braunwalds Heart Disease, 7th ed. Ch. 64.
Constriction vs. TamponadeBoth restrict cardiac filling and raise systemic and pulmonary venous pressuresVenous pressure waveforms differZipes. Braunwalds Heart Disease, 7th ed. Ch. 64.
Vs. Restriction: Dissociation of Intrathoracic and Intracardiac PressuresHatle LK, et. al.Circ. 1989;79357-370
Ventricular InterdependenceInspExpirHatle LK, et. al.Circ. 1989;79357-370Ventricular PressuresAre DISCORDANT
Little. Circulation 2006, 113: 1629.
Kussmauls SignPericardial constrictionRestrictive cardiomyopathyCongestive Heart Failure:RV failureRight ventricular infarction Acute pulmonary embolismCOPD
Y-descent begins when TV opens: No overall change in volume in heart, so no Y-descentIn veins/RA, pressure is the mirror-image of flow; when the pressure drops, you are getting flow into the chamberNote the clear separation between the RA and pericardial pressure as well as the drop in the RA pressure.This is one of the things we saw in the patients echo.This forms part of the basis for pulsus paradoxus in the clinical exam (multifactorial: increased afterload, traction on pericardium increases pericardial pressure, etc).Increased venous return means lower JVP so Kussmauls sign is absentPP may be absent with AI, ASD or pre-exisiting elevated LVEDP due to LVH or dilatation.Right side drops first, and the left sided effects are mostly secondary to underfillingNote that RA and intrapericardial pressures are not exactly the same (off by about 4mmHg) which is slightly different than in classic tamponadeThe heart is insulated from the changes by the rigid pericardium.Another example of ventricular interdependenceW configuration if you are republicanPericardial knock: early diastolic high-pitched sound, heard at LLSB or Apex, corresponds to early abrupt cessation of ventricular fillingRemember that none of these findings are absolutely present.Example: Pericardial thickness normal in 18% of cases in a Mayo series (Little 1628)Also seen in constriction: Preserved diastolic mitral annular velocity (on TDI), which is decreased in restrictionAdolf Kussmaul; german physician who noted that the venous pressures rise with inspiration is associated with cardiac diseaseDecreased compliance of the right ventricle.