anesthetic goals in mitral regurgitation

1. MITRAL
REGURGITATION &
ANESTHETIC
CONSIDERATIONS

2. INTRODUCTION:
Mitral regurgitation is
defined as an abnormal
reversal of blood flow
from the left ventricle to
the left atrium. It is
caused by disruption in
any part of
the mitral valve
apparatus

3. ETIOLOGY:
Acute
• Endocarditis
• Papillary muscle rupture
(post-MI)
• Trauma Chordal rupture
• leaflet flail (MVP)
Chronic
• Myxomatous (MVP)
• Rheumatic fever
• Endocarditis (healed)
• Mitral annular
calcification
• Congenital (cleft, AV
canal)
• Ischemic (LV remodeling)
• Dilated cardiomyopathy

4. PATHOPYSIOLOGY:
 basic hemodynamic derangement decrease in
forward left ventricular stroke volume &cardiac
output.
 A portion of every stroke volume is regurgitated
through the incompetent mitral valve back into the
left atrium results in left atrial volume
overload& pulmonary congestion.
 Patients with a regurgitant fraction of more than 0.6
(60%)are considered to have severe mitral
regurgitation.

5.  The fraction of left ventricular stroke volume that
regurgitates into the left atrium depends on
i. the size of the mitral valve orifice
ii. heart rate, which determines the duration of
ventricular ejection
iii. pressure gradients across the mitral valve.
 Pharmacologic interventions that increase or
decrease systemic vascular resistance have a
major impact on the regurgitant fraction in
patients with mitral regurgitation.

6. CLINICAL FEATURES:
Symptoms
 Dyspnoea- pulmonary
venous congestion
 Fatigue - low cardiac
output
 Palpitation
 Oedema, ascites - right
heart failure
Signs
 Atrial fibrillation/flutter
 Cardiomegaly
 Apical pansystolic
murmur ± thrill
 Soft S1, apical S3
 Signs of pulmonary
venous congestion-
Crepitations, pulmonary
oedema, effusions
 Signs of pulmonary
hypertension and right
heart failure

7. SEVERITY OF MR:
Method MILD Moderate Severe
Regurgitant
volume
30-40 mL 40-60 mL >60 mL
Regurgitant
fraction
10%-30% 30%-50% >55%
Regurgitant
orifice area
<0.2 cm2 0.3-0.4 cm2 >0.4 cm2

8. MANAGEMENT:
Medical
 Diuretics
 Vasodilators . ACE
inhibitors
 Digoxin - AF
 Anticoagulants – AF
 Antibiotic prophylaxis -
IE
Surgical
 valvuloplasty
 with moderate
to severe
symptoms
 regurgitant
volume 30-60%

9. ANESTHETIC GOALS:
 Primary goal - maintaining forward systemic
flow & reduction regurgitant fraction
 HR- high-normal range -80 to 100 beats/min
 Avoid bradycardia -↑ duration of systole
 prolongs regurgitation
 Rhythm- maintain sinus rhythm
 Preload- Maintain or slightly increase- elevated preload cause
an ↑regurgitant flow- low preload inadequate cardiac output
 Afterload- Decrease to improve forward cardiac output-avoid
sudden increases in SVR
 Contractility- Maintain or increase to decrease left ventricular
volume

10. LV
PRELOA
D
HR RHYTHM CONTRA
CTILITY
SVR PVR
Maintain
or higher
rate
Maintain
orhigher
rate
Maintain
sinus
rhythm
Maintain ↓ ↓

11. INDUCTION OF ANESTHESIA:
 With an intravenous induction drug.
 Dosing adjusted to prevent ↑SVR & ↓HR
 muscle relaxant - Pancuronium modest ↑in
heart rate
 Spinal & epidural anesthesia are well tolerated,
provided bradycardia is avoided.

12. MAINTENANCE OF ANESTHESIA:
 Volatile anesthetics- isoflurane, desflurane &
sevoflurane - choices for maintenance of
anesthesia.
 Severely compromised myocardium - opioid-
based anesthetic is preferred - minimal
myocardial depression.
 Mechanical ventilation - adjusted to maintain
near-normal acid-base and respiratory
parameters.
 The pattern of ventilation - provide sufficient
time between breaths for venous return.