Mitral Stenosis Flashcards
Hemodynamic findings in severe MS:
1. Early finding ___________
2. Finding in advanced stage
3. What happens in LV A wave and LVEDP
Important hemodynamic finding:
- Large LA A wave
- Large LA V wave
Early on in MS, the LA A wave is large, but with long-standing severe MS, the atrial compliance becomes overwhelmed, and V wave enlarges as well particularly with exercise; A wave may diminish in size as a result of LA contractile dysfunction. A large V wave indicates an advanced MS stage and correlates with exercise intolerance and with the severity of pulmonary hypertension.
- Small LV A wave and reduced LVEDP
Although LA A wave is large, LV A wave is usually small and LVEDP reduced because the ventricle is underfilled.
Important hemody finding:
LV - LA end diastolic gradient
The LA-LV pressure gradient in MS is a diastolic gradient that is highest in early diastole and decreases afterward. Typically, in severe MS, LV and LA pressures do not equalize at the end of diastole (diastasis is not reached)
How to obtain transmutral valve gradient
Simultaneous LA - LV pressures or PCWP - LV pressures
Simultaneous LA-LV pressures should be obtained, and ideally, LA pressure should be directly accessed through a transseptal puncture. Pulmonary capillary wedge pressure is often used as a surrogate of LA pressure, and PCWP-LV simultaneous recordings are often used to assess MS.
** PCWP tracing is delayed by 50 to 150 milliseconds in comparison with LA pressure tracing, and PCWP is more damped than LA pressure with less deep and steep Y descent.
Characteristic of a true PCWP tracing:
1. Pressencd of distinct ______ and ______ waves
2. V wave peaks ______________, ____________ LV descent
3. ____________/____________ diastolic segment
4. Mean PCWP _________ mean PA pressure
5. O2 sat _________
(1) well-defined A and V waves are present
(2) as opposed to the systolic PA pressure, V wave of PCWP peaks after T wave, and its peak intersects with LV descent
(3) if a diastolic segment is well seen between pressure peaks, it is horizontal or upsloping in case of PCWP vs downsloping in case of damped PA pressure
(4) mean PCWP < mean PA pressure
(5) oximetric sampling from the wedged catheter tip confirming O2 saturation >95% (this is the most accurate proof of proper wedging
Two situations particularly affect the use of PCWP as a surrogate of LA pressure, even when the catheter is appropriately wedged:
1.
2.
Pulmonary Hypertension
-The retrogradely transmitted LA pressure dampens through the arteriolar obstruction which leads to a flattened PCWP with flattened V downslope, and, therefore, a waveform that will more strikingly overestimate the transmitral gradient.
-MV prosthesis
Large V wave
-MS, severe MR, or decompensated LV failure, the simultaneous PCWP-LV pressure recording strikingly overestimates the true transmitral gradient (>5 – 10 mmHg) and can actually create the impression of a large PCWP-LV gradient in patients without any MS
Pulmonary vein stenosis (obstruction and a pressure gradient exist between the wedged PA catheter on the one hand and LA/LV on the other hand, but not between LA and LV)
-reflects the retrograde pressure transmission from the obstructed pulmonary vein. The pressure of the obstructed pulmonary vein is higher but more damped than the LA pressure, with less distinct waves/descents.
Effect of tachycardia or short RR intervals in MS gradient?
Increase MS gradient
Gradient is actually higher during exercise testing than during short R-R cycles encountered in AF because of?
Increas in HR and CO in exercise
Effect of exercise testing among patients with symptomatic mild MS?
PCWP and transmitral gradient increase with exercise, whereas LV diastolic pressure remains unchanged
LV failure, both PCWP and LV diastolic pressure increase with exercise, whereas the gradient remains unchanged
Mitral stenosis is clinically significant and would likely benefit from an intervention after exercise testing
Transmitral gradient?
PA peessure?
PCWP?
LVEDP?
Gradient increases > 15 mm Hg
PA pressure > 60 mm Hg
PCWP > 25 mm Hg
No significant increase in LVEDP
Stress testing is helpful in asymptomatic moderate-to-severe MS. An increase of systolic PA pressure to >60 mmHg with exercise is an abnormal response
ESC Class 1 indications for treatment for severe MS
PMC is recommended in symptomatic patients without unfavourable characteristics for PMC
PMC is recommended in any symptomatic patients with a contraindication or a high risk for surgery
Mitral valve surgery is recommended in symptomatic patients who are not suitable for PMC in the absence of futility
ESC Contraindications for percutaneous mitral commissurotomy in rheumatic mitral stenosis
MVA >1.5 cm2
LA thrombus
More than mild mitral regurgitation
Severe or bi-commissural calcification
Absence of commissural fusion
Severe concomitant aortic valve disease, or severe combined tricuspid stenosis and regurgitation requiring surgery
Concomitant CAD requiring bypass surgery
Criteria for a successful PBMC
Final valve area >1.50 cm2 without moderate or severe MR
Decrease in MVG > 50%
Hemodynamics after PBMC
The appearance of _________________ during the procedure is concerning for MR as well as ________________ after the procedure
V wave
Increase in LA pressure
It may take few days for the LA compliance to improve and for the LA pressure to normalize; however, the LA pressure and the mitral gradient are substantially reduced by the end of the procedure
PHT - inaccurate
The reduction of PCWP and mitral gradient with a longer diastole makes b-blocker therapy an important therapy in patients who have decompensated MS with pulmonary edema
Computation of balloon size in PTMC
Height in cm / 10 + 10
