European Journal of Echocardiography 2005 6(4):297-300; doi:10.1016/j.euje.2004.10.010
Copyright © 2004, The European Society of Cardiology
Underestimation of severity of mitral regurgitation with varying hemodynamics
A.J.H.A. Scholtea,*,
E.R. Holmana,
M.C.P. Haverkampa,
D. Poldermansb,
E.E. van der Walla,
R.A.E. Dionc and
J.J. Baxa
aDepartment of Cardiology, Leids University Medical Center, Albinusdreef 2, Postbus 9600, 2300 RC Leiden, The Netherlands
bDepartment of Cardiology, Erasmus Medical Center, Rotterdam, The Netherlands
cDepartment of Cardiothoracic Surgery, Leids University Medical Center, Leiden, The Netherlands
Received 6 July 2004; received in revised form 11 October 2004; accepted after revision 25 October 2004.
* Corresponding author. Tel.: +31 71 5262020; fax: +31 71 5266809. E-mail: a.j.h.a.scholte@lumc.nl
 |
Abstract
|
|---|
Transesophageal echocardiography (TEE) is a valuable technique
to assess mitral valve anatomy and the mechanism of mitral regurgitation
(MR). We present the case of a 35-year-old woman with severe
MR due to restrictive motion of the posterior mitral leaflet,
who was referred for mitral annuloplasty. Under physiologic
circumstances, a severe (grade 3+) MR was present, whereas in
the operating room during general anesthesia, the MR had disappeared
almost completely. The downgrading of MR due to general anesthesia
and the associated mechanisms of this phenomenon are discussed
in this case.
Keywords: Transesophageal echocardiography; Mitral regurgitation; Anesthesia
|
Case report
|
|---|
A 35-year-old woman with congestive heart failure underwent
transesophageal echocardiography (TEE) for pre-operative assessment
of evaluation of the severity and mechanism of mitral regurgitation
(MR) at the out patient clinic. Her medical history revealed
a Wilms' tumor at the age of 2 years, treated by nephrectomy
and adjuvant chemotherapy and local radiotherapy. Two years
later she has been treated again with radiotherapy because of
left-sided lung metastases.
Five years ago a DDD-R pacemaker was implanted because of a total AV-block. Over the last years she has stable (NYHA class II) congestive heart failure due to a diminished left ventricular function (ejection fraction 25%) with moderate MR and pulmonary hypertension (mean pulmonary artery pressure 50–60mmHg). Because of increasing dyspnea (NYHA class III), transthoracic echocardiography was performed and demonstrated a non-dilated left ventricle with moderate function (LVEDD 50mm, LVESD 36mm, LVEF 25%); color Doppler echocardiography revealed a grade 3+ MR. Further evaluation demonstrated systolic restriction of the posterior mitral leaflet, resulting in malcoaptation and a grade 3+ MR, best fitting type IIIB according to Carpentier's classification.1
Multiplane TEE confirmed the severe (grade 3+) mitral regurgitation due to restrictive motion of the posterior leaflet; the left ventricular annulus measured 29mm (measured at a 0° 4-chamber view, normal value<40mm), with an anterior mitral leaflet of 26mm and a coaptation distance of 4mm (normal value>7mm) (Fig. 1). Angiography excluded coronary artery disease. Accordingly, the patient was scheduled for restrictive mitral annuloplasty. During general anesthesia an intraoperatively performed TEE showed a relatively hypovolemic left ventricle with a significant reduction in mitral annular size (25mm) and MR (grade 1+) (Fig. 2). After a preload test, by rapid infusion of volume until the pulmonary artery capillary wedge pressure reached 15mmHg, the severity of MR was grade 3+ (Fig. 3).
Stringent restrictive mitral annuloplasty was subsequently performed
and a size 24 Physio-Ring (Carpentier–Edwards Physio Annuloplasty
Ring; Baxter–Edwards Laboratories, Irvine, CA) was implanted.
The procedure was uncomplicated. Control echocardiography in
the operating room excluded residual MR with a coaptation distance
of 8mm (
Fig. 4). Six months after surgery the patient had improved
in symptoms (NYHA class I–II). Repeat transthoracic echocardiography
showed no residual MR, preserved coaptation and a LVEF of 49%.
|
Discussion
|
|---|
The assessment of MR in congestive heart failure is complex
and interpretation can be hampered by its dynamic nature. As
illustrated in this case, the severity may change significantly
with varying hemodynamic circumstances. In the current report,
a grade 3+ MR (Carpentier type IIIb) was demonstrated by transthoracic
echocardiography and TEE under physiologic circumstances. This
is frequently observed in ischemic MR or in dilated cardiomyopathy,
but in this patient may have been secondary to the previous
radiation therapy. Under general anesthesia and hypovolemia,
the MR had reduced dramatically to grade 1+. Different studies
report dramatic downgrading for all etiologies of MR except
flail leaflet due to ruptured chordae.
2 The mechanism underlying
this phenomenon is almost certainly the unloading effect of
general anesthesia. It is observed more often in patients presenting
with MR secondary to ischemic heart disease or
dilated cardiomyopathy (frequently with systolic restriction, type IIIb MR) with or
without annular dilatation, these types of MR are predominantly
susceptible to changes in hemodynamics including hypovolemia
resulting in reduction of annular dimensions. In addition, arterial
and venous vasodilatations decrease afterload and preload, respectively.
Grewal et al. reported a significant reduction in parameters
of MR severity in 22 of 43 patients (51%) under general anesthesia
resulting in a significant reduction in blood pressure and LV
cavity dimensions. Eleven patients (26%) had a reduction from
3–4+ preoperatively, to 1–2+ in the operating room.
2 Particularly in patients undergoing coronary artery bypass surgery
with moderate MR it is frequently unclear whether concomitant
mitral valve repair is needed. In a retrospective study by Aklog
et al., in which 136 patients with a pre-operative diagnosis
of moderate ischemic MR underwent isolated CABG alone, 40% of
patients continued to have at least moderate (3–4+) MR,
whereas 51% improved to mild (2+) and only 9% had resolution
of the MR (0–1+).
3
In the current patient, the severity of the MR was assessed under physiological circumstances before entering the operating room. In those patients in whom the unloading effects of general anesthesia may have downgraded MR and the precise severity is unclear, provocative testing under TEE guidance before the start of the operation may help resolve the problem and determine whether mitral valve repair is indicated. Byrne and colleagues reported these procedures.4,5 A preload test can be done by rapid transfusion of volume until the pulmonary artery capillary wedge pressure reaches 15–18mmHg. Alternatively, an afterload challenge can be done with intravenous phenylephrine bolus injection until the mean arterial pressure reaches about 100mmHg. After these hemodynamic interventions, the severity of MR is re-evaluated with TEE, and adequate decisions can be made whether to perform CABG alone or in combination with a mitral valve annuloplasty.
|
Conclusion
|
|---|
This case report illustrates that compared with pre-operative
assessment, a significant reduction in severity of MR can be
observed in the operating room due to major changes in hemodynamics
and loading conditions.
In patients with ischemic mitral regurgitation or dilated cardiomyopathy a pre-operative echocardiographic evaluation is thus preferred under physiological circumstances to evaluate and appreciate the severity and mechanism of the MR. If the severity of the MR is unclear and the only possibility to analyze is in the operating room during general anesthesia, provocative testing should be included to guide management in terms of performing mitral valve repair or not.
|
References
|
|---|
- Carpentier A.F., Lessana A., Relland J.Y., Bellie E., Mihaileanu S., Berrebi A.J., et al. The "Physio-ring": an advanced concept in mitral valve annuloplasty. Ann Thorac Surg (1995) 60:117–186.[Abstract/Free Full Text]
- Grewal K.S., Malkowski M.J., Piracha A.R., Astbury J.C., Kramer C.M., Dianzumba S., et al. Effect of general anesthesia on the severity of mitral regurgitation by transesophageal echocardiography. Am J Cardiol (2000) 85:199–203.[CrossRef][Web of Science][Medline]
- Aklog L., Filsoufi F., Flores K.Q., Chen R.H., Cohn L.H., Nathan N.S., et al. Does coronary artery bypass grafting alone correct moderate ischemic mitral regurgitation? Circulation (2001) 104(Suppl. I):I68–I75.[Web of Science][Medline]
- Byrne J.G., Aklog L., Adams D.H. Assessment and management of functional or ischaemic mitral regurgitation. Lancet (2000) 355(9217):1743–1744.[CrossRef][Web of Science][Medline]
- Dion R., Benetis R., Elias B., Guennaoui T., Raphael D., Van Dyck M., et al. Mitral Valve procedures in ischemic regurgitation. J Heart Valve Dis (1995) 4(Suppl. II):S124–S131. (discussion S129–S131).[Medline]
CiteULike 
Connotea 
Del.icio.us What's this?
Top
Abstract
Case report
