DOI: 10.1111/j.1540-8175.2009.01143.xC 2010, Wiley Periodicals, Inc.

REVIEW ARTICLE

Parachute Mitral Valve in AdultsA SystematicOverview

CME

Fayaz A. Hakim, M.D., Christopher B. Kendall, R.D.C.S., Mohsen Alharthi, M.D.,Joel C. Mancina, R.D.C.S., R.V.T., Jamil A. Tajik, M.D., F.A.S.E., F.A.C.C.,and Farouk Mookadam, M.Sc., F.R.C.P.C., F.A.C.C.Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota, USA; andDivision of Cardiovascular Diseases, Mayo Clinic, Scottsdale, Arizona, USA

Parachute mitral valve (PMV) is a rare congenital anomaly of the mitral valve apparatus seen in infantsand young children. In most instances PMV is associated with other congenital anomalies of the heart,in particular obstructive lesions of the mitral inflow (mitral valve ring) and left ventricular outflow tract(subaortic stenosis), and coarctation of aorta and is referred to as Shones complex or Shones anomaly.PMV may also occur as an isolated lesion or in association with other congenital cardiac anomalies.Not much is known about PMV in adults as an isolated anomaly or in association with other congenitalcardiac anomalies. We reviewed the literature to identify cases of PMV (isolated or associated with otherlesions) in adults, to address prevalence, clinical presentation, diagnosis, treatment, and outcome ofsuch patients. (Echocardiography 2010;27:581-586)

Key words: parachute, isolated, mitral valve, outcomes, adults

True parachute mitral valve (PMV) is charac-terized by a unifocal attachment of the mitralchordae tendinae resulting in mitral inflow ob-struction.1,2 This developmental anomaly is mostoften associated with other obstructive lesions onthe left side of heart (supravalvular mitral ring,subaortic stenosis, and coarctation of aorta) and isknown as Shones complex or Shones anomaly.3Shones complex has been almost exclusively re-ported in infants and children and the outcomeis generally poor, due to the presence of mul-tiple hemodynamically significant lesions requir-ing several complex surgical interventions with ahigh mortality.4,5 The outcome of patients withisolated PMV depends upon the severity of themitral inflow obstruction resulting from this car-diac anomaly.

Pathophysiology:A normal mitral valve has two leaflets (a largeranterior leaflet and a smaller posterior leaflet),and chordae tendinae diverge to get inserted intotwo papillary muscles (anterolateral and postero-medial) (Fig. 1A). PMV exists because the chor-

No conflict of interest exists.

Address for correspondence and reprint requests: FaroukMookadam, M.Sc., F.R.C.P.C., F.A.C.C., Mayo Clinic Col-lege of Medicine, 13400 E Shea Blvd, Scottsdale,Arizona 85255, USA. Fax: 480 301 8018; E-mail:mookadam.farouk@mayo.edu

dae tendinae from both mitral valves leaflets in-stead of diverging to insert into two papillarymuscles converge on a centrally placed, singlepapillary muscle (Fig. 1B). This occurs due to dis-turbed delamination of the anterior and poste-rior parts of the trabecular ridge (which normallyforms anterolateral and posteromedial papillarymuscles respectively) between the 5th and 19thweek of gestation, thereby forcing these embry-onic predecessors of the papillary muscles to con-dense into a single papillary muscle.2 The chor-dae tendinae in PMV are often underdevelopedand hence short, thick, and adherent causing de-creased mobility of the valve leaflets and reducingthe size of mitral orifice. Furthermore, narrow-ing of the interchordal spaces results in a smallersecondary mitral orifice causing mitral inflow ob-struction. Most patients present during infancywith mitral stenosis of variable severity.4 Rarelythe chordae tendinae may be long and lax pre-cluding complete coaptation of the leaflet cusps,which may even prolapse into the left atriumresulting in mitral regurgitation (MR). Uncom-monly there may be no functional abnormalityof the mitral valve apparatus. PMV usually oc-curs either as a part of Shones complex3 or inassociation with other congenital heart diseasesincluding aortic valve stenosis (32%), atrial septaldefects (54%), and hypoplastic left heart (19%).6Isolated PMV is rare accounting for less than 1%of all cases.6 This systematic overview will fo-cus on PMV in adults as an isolated lesion or in

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Figure 1. Photographs, Showing nor-mal mitral valve (A) with chordaetendinea attached to two papillarymuscles (ALPM = anterolateral papil-lary muscle and PMPM = posterome-dial papillary muscle) and PMV (B) withsingle papillary muscle receiving chor-dae tendinae from both mitral valveleaflets.

association with other congenital lesions, but ex-clusive of Shones complex.

Methods:We conducted an electronic database search ofMedline and PubMed for English language pa-pers from January 1, 1960 to December 31, 2008using the search terms: isolated, parachute,mitral valve, adults, and Shones complex.Further search terms incorporating associatedlesions, congenital, and cardiac anomalieswere used. An independent search was con-ducted by two qualified librarians using similarsearch terms. Bibliographies of the retrieved ar-ticles were scanned to identify further reportedcases. Care was taken to avoid duplication ofthe cases. We reviewed and analyzed the de-mographic profile, clinical features, diagnosticmodalities, treatment and outcome of adult pa-tients with PMV. All adult patients with PMVoccurring either as an isolated lesion or in associ-ation with other congenital cardiac lesions wereincluded.

Results:Nine cases of adult PMV meeting inclusion crite-ria were identified in the literature over a 49-yearperiod from January 1960 to December 2008.Table I summarizes demographic data, clinicalcharacteristics, and outcome of each patient.Mean age was 44 17 years (range 2265),the majority of the patients (77.77%) were males.Among nine adult patients identified with PMV,five (55.5%) had an isolated PMV, and the re-mainder (44.4%) had an associated congenitalcardiac lesions (double orifice mitral valve with bi-cuspid aortic valve and coarctation of the aorta inone patient, bicuspid aortic valve with an insignif-icant coarctation of the aorta in one patient, ven-tricular septal defect (VSD) with supramitral ring

in one patient and double orifice, single ventricle,and pulmonary stenosis in one patient. One adultpatient with complete Shones complex and onepatient with incomplete Shones anomaly wereidentified during our search. The patient withcomplete Shones was excluded from the study.

Clinical Presentation:Among adult patients with isolated PMV (Patients1, 2, 3, 7, and 8), one patient (Patient 2)7 pre-sented with sudden death and was found to havesubvalvular stenosis of the PMV on autopsy. Threepatients (Patient 1,6 Patient 3;8 Patient 7,9) pre-sented with progressive dyspnea. Patient 810 wasasymptomatic undergoing evaluation for uncon-trolled hypertension.

Among adult PMV with an associated con-genital cardiac lesion (Patients 4, 5, 6 and9), atrial fibrillation was the presenting fea-ture in two patients: one had an associatedcongenital double orifice mitral stenosis, bicus-pid aortic valve, and status post coarctationrepair (Patient 4)11; the second (Patient 5)12with mild obstructive lesions in both mitraland aortic valves (bicuspid aortic valve) andinsignificant coarctation of aorta. One patient(Patient 9),13 with double orifice, single ventri-cle, and pulmonary stenosis presented with pro-gressive shortness of breath due to congestiveheart failure and one patient with a subaortic VSD(Patient 6),14 presented with an asymptomaticholo-systolic murmur.

Diagnosis:Seven (78%) of the nine patients were diag-nosed by echocardiography. Six patients hadboth transthoracic echocardiography (TTE) andtransesophageal echocardiography (TEE). An in-cremental diagnostic value of TEE has beendescribed in two (Patients 3 and 4).8,11 In

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Parachute Mitral Valve in Adultsa Systematic Overview

TABLE

I

Dem

ographicCha

racteristic

s,Clin

ical

Features,D

iagn

ostic

Mod

alities,T

reatmen

tan

dOutco

mein

Patie

ntswith

PMVin

Adu

lts

Isolated

orDiagn

osisof

PMV

Trea

tmen

ts

Autho

rAge

/othe

rPresen

ting

Clin

ical

Clin

ical

NYe

arsex

Con

genitalH

DCom

plaints

Find

ings

Diagn

osis

Echo

Surgery

Autop

syMed

ical

Surgical

Outco

mes

1Glanc

yet

al.6

1971

22/M

Isolated

Dyspne

a

hemop

tysis

Murmurs(M

R,

TR,a

ndAR)

Severe

MRMild

ARan

dTR

PMV

Hea

rtfailu

re

med

ication

Dea

thafter2yrs

Hea

rtfailu

re

2da

Silvaan

d

Edwards

719

73

59/M

Isolated

Sudd

ende

ath

MS

PMV

Sudd

ende

ath

3Sh

apira

etal.8

1995

65/F

Isolated

Symptomsof

CHF

Holo-systolic

murmur

CHF

CHFclassIII

s/p

CABG

TTE:

MR(+

3);

TEE:

PMV

PMVwith

infarcted

Sing

le

pap

illary

muscle

MVR

CABG

Postop

1yr

F/U:

Asymptomatic

4Ye

silbursa

etal.11

2000

31/M

CoA

(s/p

repair)BA

V

Dou

bleorifice

MV

Recu

rren

t

palpita

tion

Diastolic

murmur

with

open

ing

snap

Paroxy

smal

atria

l

fibrillatio

n

TTE:

Dou

ble

orifice

MV,

severe

MS;

TEE:

PMV,

BAV

Echo

finding

confi

rmed

MVR

Une

ventful

reco

very

5Prun

ieret

al.12

2001

33/M

CoA

(insign

ificant)

BAV

Jaun

dice

Palpita

tion

Atrialfi

brillation,

rapid

Paroxy

smal

atria

l

fibrillatio

n

TTE:

PMV,

mild

MS;

TEE:

PMV,

BAVan

d

LAthrombu

s

DCshoc

k

Cou

mad

in

2yrsF/U:

Asymptomatic

6Abe

lson

1420

0128

/MVS

D(sub

aortic)

supravalvular

ring

Asymptomatic

Holo-systolic

murmur,

mid-diastolic

murmur

VSD

(Qp/Q

s

3.9);M

R

(mild

)

TTE,

TEE:

PMV,

VSD,

Supramitral

ring

Echo

finding

confi

rmed

VSD

closure,

Ring

resection,

PMV

untouc

hed

Postop

1yr

F/U:

Asymptomatic

7Fitzsimon

san

d

Koch

920

05

57/F

Isolated

Worsening

SOB

Hom

eox

ygen

PPH;s/p

AVR

,

s/pPP

M,C

HB

TTE,

TEE:

PMV,

Severe

MS

Echo

finding

confi

rmed

MVR

NA

8Pa

tsou

raset

al.10

2007

55/M

Isolated

Asymptomatic

HighBP

Unc

ontrolled

Hyp

ertension

TTE:

PMV,

MVP

with

MR

(mild

)

Hyp

ertension

med

ication

NA

9Pa

rket

al.1320

0741

/MDISVPS

Worsening

SOB

Palpita

tion

Apical

pan

systolic

murmur

and

irreg

ular

pulse

MR,

AFan

dCHF

TTE,

TEE:

DISV,

PMVwith

severe

MR,

mild

MS,

PS

Med

icationfor

AFan

dhe

art

failu

re

N=

case

numbe

r;TT

E=

tran

stho

racicecho

cardiograp

hy;TE

E=

tran

sesopha

geal

echo

cardiograp

hy;HD

=he

artdisease;

PMV

=parachu

temitral

valve;

MR

=mitral

regu

rgita

tion;

MS

=mitral

sten

osis;MVP

=mitral

valveprolapse;MVR

=mitral

valvereplacemen

t;AR

=ao

rtic

regu

rgita

tion;

BAV

=bicu

spid

aortic

valve;

AVR

=ao

rtic

valvereplacemen

t;VS

D=

ventric

ular

septalde

fect;CoA

=co

arctationof

aorta;

PPH

=prim

arypulmon

aryhy

pertension;

PPM

=perman

entpacem

aker;CHB

=co

mplete

heartbloc

k;BP

=bloo

dpressure;

SOB

=shortnessof

brea

th;CHF

=co

ngestiv

ehe

artfailu

re;CABG

=co

rona

ryartery

bypassgraftin

g;Po

stop

=post-op

erative;

F/U

=follo

w-up;DISV

=do

uble

inlet,sing

leventric

le;

PS=

pulmon

arysten

osis;N

A=

notap

plicab

le.

583

Hakim, et al.

Patient 3, a preoperative TTE failed to diagnosePMV but intraoperative TEE diagnosed a PMVwith a single papillary muscle.8 In Patient 4, TTEshowed severe mitral stenosis with a double ori-fice mitral valve, and intraoperative TEE was su-perior in defining the anatomy of the subvalvularapparatus with a single papillary muscle that sup-ported both mitral valve orifices with a parachutefeature.11 In Patient 5, a TTE showed character-istic parachute leaflets with a shortened chor-dae tendinea converging into a single papillarymuscle in the parasternal long-axis view, andthickened mitral valve leaflets and thickened anddysplastic chordae tendinea in the apical four-chamber view. TEE further revealed a bicuspidaortic valve and a left atrial thrombus.12 In Pa-tient 6, both TTE and TEE revealed a suprami-tral ring and a single papillary muscle in four-chamber views.14 In Patient 7, both TTE and TEEwere performed, and TEEs mid-esophageal four-chamber view showed a pear-shaped mitral con-figuration.9 In Patient 8, only TTE was performed.The parasternal long-axis view showed prolapseof both mitral leaflets with mild MR, while theparasternal short-axis view at themitral valve levelshowed an eccentric nonstenotic mitral valve ori-fice, and at the papillary muscle level a largeposteromedial papillary muscle that received allthe chordae was seen. An apical long-axis viewshowed a typical parachute deformity of the mi-tral valve with a normal opening and commonattachment of all the chordae. The chordae wereelongated which was atypicaltypically the chor-dae are shortened and thickened.11 Two patients(Patients 1 and 2)6,7 had the diagnosis of PMVmade at autopsy.

Hemodynamic Consequences of the AdultPMV:Four (44%) patients had mitral subvalvular orvalvular stenosis: three had either severe (Patients2 and 7)7,9 or mild (Patient 5)12 subvalvular steno-sis, and one patient (Patient 4)11 had a severe mi-tral valve stenosis with a congenital double orificemitral valve.

Five (56%) patients had MR: one (Patient 1)6had severe mitral valve regurgitation with cal-cium noted on fluoroscopy, one (Patient 9)13had severe MR associated with mild mitral steno-sis, and another (Patient 3)8 with severe mitralvalve regurgitation due to infarction of the singlepapillary muscle. In this patient the PMV wasfunctionally normal until infarction occurred. Theremainder had mild MR with (Patient 8)10 orwithout (Patient 6)14 mitral valve prolapse.

Treatments and Prognosis:Mitral valve replacement (MVR) was performedin three (38%) patients: Patient 3 with severe

mitral valve regurgitation secondary to ischemicpapillary muscle dysfunction underwent MVRcombined with coronary artery bypass graft-ing. At 1-year follow-up she was asymptomatic.8Patient 4 with significant mitral stenosis in a dou-ble orifice underwent MVR with a 31-mm Car-bomedics (Austin, TX, USA) prosthesis withoutcomplication and no long-term follow up coursewas mentioned.11 Patient 7 with significant mi-tral subvalvular stenosis underwent MVR witha CarpentierEdwards pericardial mitral valve(Edwards Lifesciences, Irvine, CA, USA) and nofollow-up course was described.9

Patients without surgical correction of thePMV are described below: One patient (Patient2) with hemodynamically significant subvalvularstenosis presented with sudden death.7 Patient 1presented with dyspnea, combined with severeMR and mild aortic regurgitation he was med-ically managed for 2 years eventually dying ofheart failure.6 Patient 5 presented with rapid atrialfibrillation, sinus rhythmwas restored by an exter-nal electric shock and was asymptomatic duringthe 2 years follow-up.12 Patient 6 presented witha large subaortic VSD undergoing VSD patch clo-sure, and supramitral ring resection at which timethe presence of a PMV was confirmedit was leftuntouched. At 1-year follow-up, the patient re-mained asymptomatic with a small residual VSDand mild MR.14 In Patient 8, the diagnosis of anisolated PMV was made incidentally during inves-tigations for hypertension.10 One patient (Patient9) with associated double orifice single ventricleand pulmonary stenosis refused surgical interven-tions and was lost to follow-up.13

Discussion:From the literature search spanning almost fivedecades it appears that PMV is rarely seen inthe adult population. The majority is male (sevenout of nine). Isolated PMV was seen in five outof nine of this group. PMV in association withother congenital lesions was seen in four out ofnine of patients. Combined bicuspid aortic valveand coarctation of the aorta was seen in twopatients.11,12 Compared to pediatric PMV,4 con-comitant cardiac abnormalities are uncommonin adult PMV. We speculate that this is becausecombined complex lesions present early in lifeand usually requires multiple surgical correctionswith high mortality. Adults with PMV representa smaller group of patients with milder lesionswho escape detection until adulthood. Further-more, the condition may be underdiagnosed inasymptomatic adults who never have the need forechocardiography. Finally adults with PMV evenafter echocardiography may not have a diagno-sis confirmed. The diagnostic criteria for PMV areshown in Table II.

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Parachute Mitral Valve in Adultsa Systematic Overview

TABLE II

Diagnostic Characteristics of PMV

Pathology Single papillary muscleShortened/thickened chordaetendinea converge into a singlepapillary muscle or one majorpapillary muscle

Echocardiography LV short-axis viewAt mid-papillary level: single papillary

muscleAt basal level: Parachute leaflets

LV long-axis viewShorten /thickened (typical) or

elongated chordae converge into asingle papillary muscle

Four-chamber viewThickened mitral valve leaflets and

thickened and dysplastic chordaetendinea

Pear-shaped mitral configuration witha diastolic dome shape

LV = left ventricular.

Adult PMV may have normal hemodynamics(three out of nine) or Doppler evidence of signi-ficant stenosis (three out of nine) or regurgitation(three out of nine). Only one adult patient withcomplete Shones complex15 was identified dur-ing our search suggesting that in general Shonesanomaly presents early or are fatal during infancyor childhood.

Echocardiography establishes the diagnosis inthe majority of the patients with PMV (77.77%).The typical parachute deformity of the mitralvalve is best demonstrated in parasternal shortaxis views of the left ventricle (LV): a single pap-illary muscle is confirmed at the mid- level of LV(Fig. 2), and the typical parachute leaflets arenoted at the basal level short axis view. In addi-tion, a long axis of the LV confirms a single papil-

Figure 2. Transthroacic echocardiogram of patient with PMV(A) compared with normal mitral valve (B) at the papillarymuscle level of LV short axis view. LV= left ventricle; RV= rightventricle; SPM = single papillary muscle; PM = posteromedialpapillary muscle; AL = anterolateral papillary muscle.

Figure 3. Transesophageal echocardiogram (transgastric 0degree view) of the mid-level of the LV short axis shows athickened single papillary muscle (arrow) in posteromedialpart of the left ventricle (LV). RV = right ventricle; ANT =anterior wall of the LV.

lary muscle accepting all the chordae tendinaeinsertions. Currently, two-dimensional Dopplerechocardiography is the diagnostic method ofchoice16 whereas TEE is confirmatory in morechallenging cases suspected on TTE imaging(Figs. 3 and 4).8,9,12,14 This study shows the in-cremental value of TEE compared with TTE in two(28.57%) out of seven echo cases.8,11 The PMVmay have mimickers such as a pseudo-parachuteor parachute-like-mitral valve where chordae ten-dinae are attached to major papillary muscles andthe other being hypoplastic and close to the ma-jor one. Careful interrogation by echocardiogra-phy that often requires TEE will identify the differ-ences between true parachute and parachute-likemitral valve. Echocardiography helps to define thefunctional status of the mitral valve and to de-fine other associated cardiac anomalies. MRI andmultidetector computed tomography may be

Figure 4. Transesophageal echocardiogram (transgastric109 degree view) reveals single papillary muscle, where allthe chordae tendinae inserted (arrow). LV = left ventricle;LA = left atrium; ANT = anterior wall of the LV.

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reasonable complementary imaging techniquesin patients with poor echocardiographic acousticqualities.17

Adult patients with isolated PMV usuallypresent with dyspnea and have hemodynamicallysignificant lesions of variable severity across mi-tral valve.6,8,9 However, may be incidentally di-agnosed during echocardiography with normalhemodynamics across the mitral valve.10 Suchpatients generally require no medical or surgi-cal treatment. MVR or repair when feasible needsto be performed only in those patients withhemodynamically significant stenosis or regurgi-tation.18 Surgical correction of associated con-genital cardiac lesion should be performed only ifsuch lesions are hemodynamically significant andaccount for symptoms.

Limitations:This study is a systematic overview of literature,which by definition means that asymptomaticcases will likely be under represented. The rarity ofadult PMV lends itself nicely to scrutiny with theresearch methodology of a qualitative systematicoverview.

Conclusions:Adult PMV is an uncommon condition with onlynine cases identified after a systematic literaturereview over the last half century. Asymptomaticpatients may be discovered incidentally. Mitralstenosis is the usual abnormality in symptomaticpatients, with atrial fibrillation or dyspnea beingthe presenting symptoms. Sudden death can oc-cur. Half of the cases identified required MVR.These findings are in contrast to the pediatricage group. An international registry of adults withPMV from the American and European societiesof echocardiography will go a long way to im-prove diagnosis and give insights into the naturalhistory of this uncommon condition.

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3. Shone JD, Sellers RD, Anderson RC, et al: The develop-mental complex of parachute mitral valve, supravalvu-lar ring of left atrium, subaortic stenosis, and coarctationof aorta. Am J Cardiol 1963;11:714725.

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