Constrictive pericarditis

Question 1

Pathophys of pericardial dz

Answer 1

constrictive or restrictive
o Impaired cardiac filling
o ↑ atrial pressures

• Constrictive physiology: ↑atrial pressure with steep X and Y descent on pressure waveforms
• Usually, these disease processes will lead to R sided CHF
  o Systemic capillaries will leak at 10-15mmHg
  o Pulmonary capillaries will leak at 30mmHg

Question 2

Hemodynamic criteria for constrictive pericardial dz

Answer 2

o Equalization of ventricular pressure
o Abrupt cessation of ventricular filling in early diastole
o Restriction of further filliing → plateau of diastolic L/RVP

Question 3

Etiology constrictive pericarditis

Answer 3

• Parietal/visceral pericardium fused or fibrosed
  o ↓ compliance
  o Constriction is uniform → all chambers involved equally
   ↓ diastolic volume
   ↑ atrial and ventricular filling P

Question 4

Pressure waveform: RA and LA

Answer 4

• ↑RAP and PCWP (LAP)
  o Magnitude of ↑ determined by degree of constriction
   Moderate 12-15mmHg
   Severe 20-25mmHg
  o RAP = PCWP in pure constriction
   If significant MR: PCWP > RAP
   Equalization of PCWP, RAP, LAP, PAP, RVP, LVP,
• Atrial pressure waveform: W shape
  o Rapid filling in early diastole
   Steep Y descent
  o Atrial contraction → ↓ atrial volume
   Steep X descent

Question 5

Pressure waveform RV

Answer 5

Dip and plateau = square root sign
o Rapid, normal early ventricular filling
o Abrupt cessation in mi diastole when limit of ventricular distensibility is reached
 Plateau: little additional volume expansion occurs

Question 6

Respiratory pressure variation

Answer 6

o Inspiratory ↓ R sided pressure does not occur
 ↓ or absent flow in Ca/CrVC
 Non compliant pericardium limit transmission of intrathoracic pressures to the heart

Question 7

What is Kussmaul’s sign

Answer 7

Inspiratory ↑ in RAP/venous pressures (normally decreases)

Question 8

DDX for kussmaul sign

Answer 8

• RV infarction
• R sided CHF
• Cardiac tumors
• TV stenosis
• Pulmonary embolism

Question 9

What is pulsus paradoxus

Answer 9

Exaggeration of physiologic phenomenon
↑ pulse pressure in expiration

Question 10

Why does pulsus paradoxus happen

Answer 10

o Exaggeration of physiologic phenomenon
 Manifestation of ventricular interdependence → ↑RV filling in inspiration impairs LV filling since fixed intracardiac volume
o ↑ pulse pressure in expiration due to ↑ LV filling
o >10% or >10mmHg fall in inspiratory pulse pressure
 Pulse may disappear for several beats during inspiration

Question 11

DDX pulsus paradoxus

Answer 11

 Pulmonary: embolism, pneumothorax, asthma, COPD
 Non-pulmonary/cardiac: anaphylactic shock, hypovolemia, CrVC obstruction, pregnancy, obesity

Question 12

Hemodynamic changes with constrictive pericarditis

Answer 12

Pulsus paradoxus
Repsiratory pressure variation
Dip and plateau RV waveform
W RA waveform
Incr RA and PCWP
Decr SV

Question 13

Pathophys effusive constrictive pericarditis

Answer 13

• Constriction of the heart by pericardium + pericardial fluid accumulation btw visceral and parietal pericardium
  o Small volume of effusion → dramatic ↑ in intrapericardial P
• Progressive phenomenon as fluid accumulates
  o ↑ intrapericardial P will equilibrate RV filling pressures → R sided tamponade
   ↓CO
   ↑venous systemic pressures (resistance to venous return)
  o Further ↑ will equilibrate LV filling pressures → L sided tamponade

Question 14

Hemodynamic findings tamponade

Answer 14

o Hemodynamic compromise is proportional to intrapericardial pressure

Question 15

Pressure rise with fluid accumulation depend on

Answer 15

 Volume
 Rate of fluid accumulation
* Slow fluid accumulation → ↓CO and systemic congestion
o Can accommodate larger amount of fluid
* Sudden fluid accumulation → can develop acute cardiogenic shock
o Small volume can cause c/s
 Physical nature of pericardium
* Normally holds 2.5-15ml
* Can accommodate 50-150ml w/o significant change in P

Question 16

Pressure waveform in tamponade

Answer 16

 Pressure waveform: prominent X descent, absent/↓ Y descent
* Rapid emptying of RA prevented when Tv opens (lack of Y descent)
* Transient fall in intrapericardial P in systole
o Total intracardiac volume is ejected
o Venous return into atrial chamber → prominent X decsent

o RA = PCWP

Question 17

How to differentiate pericardial constriction vs tamponade in effusive constrictive dz

Answer 17

o Removal of fluid will highlight constriction
 Pressure waveform: prominent X + Y descent (X = Y or X < Y)

Question 18

What is the feature of restrictive dz

Answer 18

↑ myocardial stiffness affect ventricular filling throughout diastole’

Question 19

Hemodynamic criteria for dx of constrictive pericarditis

Answer 19

• End diastolic P equalization (<5mmHg discrepancy)
• PAP <55mmHg
  o Restrictive disease will typically have PAP >50mmHg
• RV end diastolic P/RV systolic P >1/3
• LV pressure waveform shape: dip and plateau
• Kussmaul’s sign

Question 20

Restrictive CM vs constrictive pericarditis

Answer 20

o Normal chamber compliance in early diastole
o Mid diastole: abrupt ↓ in ventricular filling as maximal volume fixed by rigid pericardium is reached
o ↑ventricular interdependence because of fixed intra cardiac volume
 Filling of one ventricle impairs other
o Dissociation of intracardiac and intrathoracic pressures
 Normally → inspiratory ↓ intrathoracic pressures
* Transmitted to pulmonary capillaries + L side of heart
* PG driving blood flow into L heart = effective filling gradient = PCWP – intracardiac P
o Constant through respiratory cycle
 ↑ intracardiac and pericardial P
* Inspiratory ↓ intrathoracic P → ↓ PCWP
o Effective filling gradient is reduced if ↓ P not transmitted into heart
 Enhanced respiratory variation in ventricular filling → ventricular interdependence
* Discordant ventricular pressures: ↓LVP/↑RV systolic P in inspiration