236
Echocardiographic Evaluation of Systolic Left-ventricular Function in Infants with Critical Aortic Stenosis Before and After Aortic Valvotomy R. Hofst etter ", B. Ze ike", B. J. Mes smer"; G. von Bernuth " Departm ent oCPaed iatri c Cardiology Departm ent of Thoracic . Cardiac. and Vascula r Surgery
Medical Faculty. Aachen University of Technology, Aachen. FRG
Infants with cr itical aort ic stenosis may have globa l or regional left vent ricular contraction abnormalities. In orde r to evalua te the clinical significan ce of these contraction a bnorma lities . we examined the systolic left ventricular function befor e and after aortic valvotomy in 16 infants opera ted on between 1980 a nd 1987. Leftvent ricular free wall a nd se pta l motion were stud ied by cross sectional echoca rdiogra phy using the apical 4-chamber view. Enddias tolic a nd cndsystolic left ventricu lar fram es were digitized. The rela tive sys tolic redu ction ofthe total left vent ricu lar area (reflecting ejec tion fra ction) as well as of 5 left ventricular sectors (reflecting regional wa ll mot ion) was ca lculated a nd compa red to previously established normal values . Before valvotomy. 8 infants had norma l a nd the ot he r 8 impaired left ventricular systo lic wa ll motion. These latter infants showe d hypokinesia of the ap ex and/or the post ero la teralleft vent ricula r wa ll resulting in a de creased systolic redu ction of the total left vent ricular a rea . Four of these infants had evide nce of myocard ial infa rction on int rao pe ra tive inspection. Early after opera tion. the systolic redu ction of the total left ventr icular ar ea was norm al in all infants. and the left ventricular ap ex a nd poster o-lateral wall were eithe r normo- or hyperkinetic. Follow-up studies of all infa nts mo re than 10 mont hs a nd of 7 infants more than 3 yea rs after operatio n showed tha t the left ventri cula r systolic wall mot ion rem ained norma l in a ll. irres pective of wh ether it was normal or a bnormal preop eratively. The study suggests that left ventric ular contraction abnormalities in infa nts with critica l ao rtic stenosis may be reversible a nd thus do not cons titute a contra indication again st aorti c va lvotomy. This reversibili ty of left ventricular contrac tion a bnorma lities sugges ts that they a re cause d at least in pa rt by increased left vent ricular afte rload wh ich is red uced by aortic valvotomy. and in pa rt by ischemic myocardial damage which may be comp letely compe nsa ted by adja cent myocard ium.
Keywords Critical ao rtic ste nos is - Infa nts - Left ventricle - Wall motion a nalysis - Cross sectiona l eehoca rdiogra phy
Thorae. cardiovasc. Surgeon 38 119901 236 -2 40 © Georg Thieme Verlag Stuttgart - New York
Sauglin ge mit kriti scher valvular er Aortenstenose kon nen globale ode r regionale linksven tr ikular e Kontr akt ionsstdrun gen a ufweisen. Urn die klinische Hclevan z diese r Kontraktionsstorun gen zu beurteilen. unte rsuc hten wir se ktorec huka rdiogra phis ch die systoli sche linksventrikular e Funk tion pr a- und postopera tiv bei 16 zwische n 1980 und 198 7 valvulot omierten Sauglingen,
Unte rsu cht wurde sekto rechokardiogra phisch das Wan dbewegun gsmuster des linken Vent rikels im Vierka mmerblick durch Digitalisieren der enddiastollschen und endsystolische n Vcntrik elsilhouettc . lli eraus wur de n mittels Kleinr echn e r die pr ozentuale Fla chenv erklcin er ung (ver glcichb ar dor Ejektionsfra ktion l sowle die regionale Wandbew egung der in 5 Sektoren eingeteilten Vent rikelflache berechn et und mit eigenen Norma lwe rte n vergliche n. Vor der Valvulotom ie ze lgten 8 Sa ugllnge eine normale und 8 Sau glinge cine gestorte linksvent rikulare Wa ndbewegung. Diese letzrgen annten Saugftnge hatten cine lIypokinesie dcr Spitze un d/ oder der postern-lateralen Wand des Iinken ventrt kels mit konsekutiver Vermind erung der prozen tualen systol lsc he rr Flache nver kleine rung. Vier diese r Kinder zeigte n bei der intrao perativen Myokardinspektion lnfarkte. Frtihp ostoper ativ wa r die sys tclisc he Flache nverkl ein erun g des Iinken Vcntrikels bel allen Kindem norm al. die a pikale und Seite nhi nterwa ndbewegu ng emwe de r normal ode r hype rkinet isch. Postoper at ive Ve rlaufsbeob a chtungen von meh r a ls 10 Monate n bet a llen Kinde m sowie mehr als 3 J ahre n bel 7 Kindem zeigten. daB das linksvent rikular e Wan dbewegu ngsmuster bel allen norma l blieb . unnbha ngtg davon, ob sic praoporauv norm a le oder gosto rte Wa ndbew egungs muste r au fwiesen . Die Studie legt na he. daB linksventrikula re Wa ndb ewegungsstOrungen bei Sa uglrngcn mit kritisch er Aortenkl appenstenose reversi bcl se in kon nen und som it keine Kontr ain dikalion fur cine rasche Valvuloto mie dar stellen. Diese Reversibilitat laBt vermuten . daB die Kontraktions sttirungen nur zum Te il durch cine tscham tsch e Myoka rdschadigung bed ingt sind . die zude m durch benachbartes gesundes Myokard kom pensiert werden ka nn . Zum a nde re n Te il beruhen sie wa hrsc heinlich au f einer extremen Nachlaste rhohung des Iinken Ventrikels. die durch die Valvulotom ie vermindert wird .
Received for Publication : January 8. 199 0
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Summary
Echo ka rdiog raphische Beurteilu ng der llnksventr lkul are n Fn nktlo n bci Sauglinge n ver und na eh v a lvulotom te e iner kri ti sch en Aortenklappcnstcnose
Introduction In infants with critical valvula r aortic stenosi s left ventricular ejection may be impaired by inc reased a fterload or myocardi al necrosis. Myocardial necrosis is related to diminished perfusion of the corona ry arter ies which originate dista l to the stenosis. The corona ry perfusion pressu re. therefore, is relatively low compared to the diastoli c left ventricular intracavitary and intra myocardia l pressu re (6, 13). Myoca rdial und er perfusion an d hence myocardial necrosis is promoted by myocar dial hypertrophy developing as a consequence of increased afterloa d. Increased afterload itself causes, if at all, a globa l impairm ent of ventr icular ejection which should be reversible following afterload reduction (I, 14). Myocard ial necrosis , in contrast, depending on its extension, causes a globa l or regional impa irment ofsystolic left ventr icular wa ll motion which may persist after relief of the aortic st enosis . Global redu ction of left ventricular ejection as well as regional impai rment of wall motion ma y be recognized and quantified by cross-sectional echoca rdiography. The present stud y examined the left ven tricular systolic function of infants with critical valvula r aorti c ste nos is before and a fter valvotomy. Patients a nd Method s Between August 1980 and Decembe r 1987 21 young infants with critical valvular aorti c stenos is underwe nt aortic valvotomy at our instituti on. From 16 of these infants high quality pre- an d postoperat ive cross-sectional echocardiograms are available enabling us 10 quan tify systolic left ventricular wall motion and to compare it with previously established nor mal values . The clinical data of the 16 infants are summ arized in Table 1. Normal values of left-ventricular enddiastolic ar ea and oft left-ventri cular systolic wall motion in the apical 4-chamber view we re obtai ned from crosssectional echocardiograms of 43 infants without hea rt disease. The cross-sectiona l echoca rdiogra ms were obtai ned in the usual manner (12). We used . in chronological order. an electro nic sector scanner lRT 400. Kontro n) and two mechanical sector scanners (Mark 300 C. Ultrama rk 8. SMS Kran zbiihler ). Depen ding on the scanner and the infants ' age, 3.5. 5.0 or 7.5 MHz tran sdu cers were utilized. The echocard iogram s were registered on videotape (Umatic, Sony). For analysis of left-ventr icular wall motion we used the apical 4-chamb er view which for th is purp ose appea rs to be superior to other views (91.
Age (days)at Operation
Symptoms on Admiss.
t
105
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
III
+++ +++ + + +++ +++ + ++ +++ ++ + +++ + +++ + + +
Pat. No.
35 35 9 40 73 45 12 29
7 9 3 2 9 70
Pressure-Grad. (mmHg)
65 50 55 80 70
For qu an tification of left-ventr icular wall motion we used a commercial computer program Iw allexcurstcn Version 9.2. Fa. Kont ron) especially developed for this pur pose. The enddiastolic an d endsys tolic left-ventricular contoures on the videoscreen were manually tra ced with a light pen and fed into the computer. For compensa tion of ventricular movement due to cardiac action and respiration. the long left-ventr icular axes and their centres were superimposed. Part ing from the centre an d excluding the mitra l valve plane. the left-vent ricular silhouette was subdivided into 5 sectors. The relative systolic reduction of the sector ar ea expressed in per cent of the enddiastolic area was calculated and served as a measure of the regional wall motion (2. 7. 9). Using this method. regional left-ventri cular contraction abnor malities are shown by an abnormally low systolic redu ction of sector size. Normokinctic wall ar eas may be differentiated from hyper-. hypo- and akineticor even dyskinetic wall ar eas (5.10). We defined a left-ventr icular contraction a bnor mality as an abn orm al systolic reduction of at leas t two adjacent sectors . In order to evaluate global systolic left-ventricular function we determ ined the fra ctional systolic diminution of the total left-ventricula r area SO-LV expressed in percent of the enddiastolic area . This parameter is compara ble to the left-ven tr icular ejection fraction calculated from enddiastolic and endsystolic left-ventr icular volumes.
Resul ts
Norma l infants In the 43 infants wihout heart disease we found, in accordan ce with the findings in healthy adu lts, a mean systolic dimin ution of the sector area betwee n 35 and 40 %. The lower 2-Sigma -value for the apical, lateral. and posteri or sectors was 20 %, and for the interventricular se ptum 15 %. The left-ventricular enddistolic a rea was 32 .1 ± 5.2 cm' / m' body surface area. The fractional systolic diminution of the total left-ventricular a rea SD-LV in norm alinfants was 38.2 ± 6.9 %.
Inf ants with critical aortic st enosis The pr eoper ative severity of symptoms of ca rdiac insufficiency together with age at opera tion, invasively measured or continuous-wave-Doppler-estimated pressure gradient between left ventricle and aorta a nd additional hea rt defects a re listed in Table 1. The enddiastolic left-ventricular a rea in the apical four chamber view together with pr eoperative wa ll excursion abnormalities, electroca rdiographic abn or-
Additional Heart Defects
MI MI.MS GoA, MS
POA
50 65 60 64
100 70 90 110
Thorae. cardiovas c. Surgeon 38 (1990)
PDA PDA
+ - mild, ++ "" moderate, +++ - severe,eoA = coarctation of the aorta,MI = mitral insufficiency, MS mitral stenosis.PDA = patent ductus arteriosus
Table 1 Preoperative clinical. electrocardiographic and hemodynamic dataof 16 infants with critical valvalar aortic stenosis.Thepressuregradientsbetween left ventricle and aorta weremeasured either invasively or by Doppler-scnography
237
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Hchocardiographic Evaluation ofSystolic Left -ventricular Function in Inf ants
R. Hofst etter. 8 . Zelke. B. 1. Messm er. G. l..'Ofl Bernuth
Thom e. curdiol'uSC. Surgeo1l38 (1990) Preop. LV-Size Icm2/m~
Preop. WE
Preop. ECG
Intraop. Inspection
I
37
+
2 3
44
+
my. info my. inf. abn. repel.
my. info my. inf.
Pat. No.
31 35 15 38
4
5 6 7 8
abn. repel.
+ +
59 46 24
9
10 11 12
35
13 14 15 16
17 21
Table 2 Preoperative echocardiographic. electrocardiographic and intraoperative find ings of 16 infants with criticalvalvular aortic stenosis
my. inf. my.inf.
abn. repel. my. inf.
+ +
abn. repel.
28 24
abn. repel.
+
20 31
+
my. inf.:myocard infarction,abn. repol: abnormalrepolarization, WE: wall excursion, +: abnormal
mali ties. and abnormalities on intraoperative myocardial inspection ar c listed in Table 2. Ufthe 16 infa nts with valvular aortic stenosis 8 infants showed preoperatively regional left-ventricular contraction abnormalities as defined above. In these infants. the leftventri cular a pex a nd the postero-Iateral wall were a ffected. In one infant. also the proximal intervent ricular septum contra cted abno rmally. In the remaining 8 infants. Ieft-ven tricular contraction was normal. One of these infants showe d a diminished contraction only of the apical sec tor with norma l contractions of the adjacent secto rs (Fig. 1).
the apical sector was high-norm al or slightly increased. This was also tr ue for infants with preoperative contraction abnormalities who could be followed over a particularl y long peri od of time (Fig. 3). All infants with preoperative regional contraction abnorma lities also had a diminished global left-ventr icular systolic function. In all infants except one without regiona l contraction abno rmalities . global left-ventricular systolic function before operation was found to lie in the normal range. Postoperatively. all infant s had a normal or increased global left-ventricula r systolic function irr espec90
70
80
60
70
E 60
E 50 c 0
~
, u
••
c 0
40
~
30
••
, u
'0
'0 20
50
40
30
• 20
•
10
...... ....
10
o ~-,--_----:-_--:-,--
sept. pro>:.
sept. diet.
apikol
~
lat erol
wall segm ents
0 sept. prO>:.
sept. disl.
opikal
lat eral
posterior
wall segm ents
Fig. 1 Analysisof preoperative regionalleft-ventricular contractionpattern. The horizontal axisshowstheseptal proximal(sept.prox.), septal distal(sept. dist.). apical,lateraland posteriorwall segmentsoftheleftventricle.The normal range isshaded. Dottedhnesindicate patients withregional left-ventricular contractionabnormalities beforeaortic valvotomy
Fig.2 Analysisofregionallett-ventricular contractionpattern 1/2- 4 months after aortic valvotomy. Explanationsee Fig. 1
Within the first 4 months after ao rtic valvotomy regional left-ventricular contraction was normal or hyperactive in all infants with the exception of one who showed a slightly diminished contraction of the left-ventricular a pex. The 8 ventricles with preoperatively diminish ed contraction were not different from the 8 other ventricles (Fig. 2). During furth er follow-up all ventricles retained a normal or hyperactive contraction pattern irrespective of whethe r this was preoperatively normal or not. Regional left-ventricular contraction with the exception of
tive of whet her this was normal or dec rease d preoperatively (Fig. 4). In a ll infants with preoperative left-ventr icula r wall excursion abnormalities the left-ventricular s ize was either normal or increas ed before valvotomie. The eight infants with preoperative normal left-ventricular wall excursions had either normal or decreased left-ventricular sizes (Table 2). The infan t with the sma llest left-ventri cular size died 3 months postoperatively; autopsy in this case showed left-ventricular endocardial fibroelastosis. The 8 infants
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238
Thom c. cardia/'ase. .f.,·urgeof/ 38 (199OJ
f:'clwcardiograph ic f:'valuation a/Systolic Left-u entrlcular Function in Infuntn
2 :~ 9
90 80 70
g
'0
e
.s ,eu ••
50 40 30
"0
•
.. _ .... '.... ....
20
~
~
"
10 0 sept. prc x.
sept. dist.
opikol
lateral
poster ior
wa ll s egments
70
Fig. 5a Parasternal shortaxis viewofthe left ventricle inpatient 1witha myocard ial infarctionintheregion oftheleft-ventricular posteriorwall (/ )6 years postoperative ly. LV = left ventricle
'0
20 10
pre o p.
1-4 mo
3- 6 yra
postop.
postop.
Fig.4 Time course of thesystolicdiminutionof theleft-ventriculararea (SDLV) inall16 infants. Dotted linesindicate patients withregional left-ventncular contractionabnormalities before aortic valvotomy
with preoperative regiona l left-ventricular wa ll exc ursion abnormalities tended to be olde r at operation a nd had more seve re signs of heart failure tha n the infan ts wit h pr eopera tive nor mal wa ll excu rs ions (Tab le 1). Five infants with and 3 infan ts without pr eoperat ive wall exc ursion abnormalities had electroca rdiographic s igns of ischemia. Four infants had myocardial infarction on intraoperative inspection ; all 4 had regional left-ven tricular
REGIONAL WALL MOTION 2 %
0
J
4
4CH
wall excursion abno rma lities. Four further infants had repolarisation abnormalities in the electroca rdiogram sugges ting myocardial ischemia ; on ly one of these also had reg ional left-ventricular wa ll exc ursion ab normalities (Tab le 2). In so me infants echoca rdiogra phy showed hyperdensity of pa pillary mu scles sugges ting papi llary muscle fibrosis as res idue of myocard ial necrosis. The electrocardiogram of one infant (No 1) continues to show 6 years postope ratively signs of myoca rdi al infa rction with bro ad Qwaves and diminished Il-arnplitudes in sta nda rd-lead III. This infant's echoca rdiogram showed in the parasternal s hort axis an echode nse struct ure of th e poster ior wa ll sugges ting a myocardial scar (Fig. Sal. The pat ient's inc rease d globa l left-ventricular systolic function docu ments a good co mpensation of his myocardial sca r by increa sed contractility of th e adjace nt myocardium (Fig. 5b).
Discussion In critical valvular aortic stenos is there may be impairment of left-ventr icular systolic function . Global impairme nt may
Fig. 5b Left-ventricular regional wallmotionin thea-chamber-view(4CH),dividedinto thefive sectors(1 -5) septalproximal(sept. prox.), septal distal (sept dist], apical [ap.l.tatera l (Iatl and posterior(post.) of thesame patientasin Fig. 5a 6 yearsafter aortic valvotomy
· T'> (
Echocardiographic Evaluation of Systolic Left-ventricular Function in Infants with Critical Aortic Stenosis Before and After Aortic Valvotomy R. Hofst etter ", B. Ze ike", B. J. Mes smer"; G. von Bernuth " Departm ent oCPaed iatri c Cardiology Departm ent of Thoracic . Cardiac. and Vascula r Surgery
Medical Faculty. Aachen University of Technology, Aachen. FRG
Infants with cr itical aort ic stenosis may have globa l or regional left vent ricular contraction abnormalities. In orde r to evalua te the clinical significan ce of these contraction a bnorma lities . we examined the systolic left ventricular function befor e and after aortic valvotomy in 16 infants opera ted on between 1980 a nd 1987. Leftvent ricular free wall a nd se pta l motion were stud ied by cross sectional echoca rdiogra phy using the apical 4-chamber view. Enddias tolic a nd cndsystolic left ventricu lar fram es were digitized. The rela tive sys tolic redu ction ofthe total left vent ricu lar area (reflecting ejec tion fra ction) as well as of 5 left ventricular sectors (reflecting regional wa ll mot ion) was ca lculated a nd compa red to previously established normal values . Before valvotomy. 8 infants had norma l a nd the ot he r 8 impaired left ventricular systo lic wa ll motion. These latter infants showe d hypokinesia of the ap ex and/or the post ero la teralleft vent ricula r wa ll resulting in a de creased systolic redu ction of the total left vent ricular a rea . Four of these infants had evide nce of myocard ial infa rction on int rao pe ra tive inspection. Early after opera tion. the systolic redu ction of the total left ventr icular ar ea was norm al in all infants. and the left ventricular ap ex a nd poster o-lateral wall were eithe r normo- or hyperkinetic. Follow-up studies of all infa nts mo re than 10 mont hs a nd of 7 infants more than 3 yea rs after operatio n showed tha t the left ventri cula r systolic wall mot ion rem ained norma l in a ll. irres pective of wh ether it was normal or a bnormal preop eratively. The study suggests that left ventric ular contraction abnormalities in infa nts with critica l ao rtic stenosis may be reversible a nd thus do not cons titute a contra indication again st aorti c va lvotomy. This reversibili ty of left ventricular contrac tion a bnorma lities sugges ts that they a re cause d at least in pa rt by increased left vent ricular afte rload wh ich is red uced by aortic valvotomy. and in pa rt by ischemic myocardial damage which may be comp letely compe nsa ted by adja cent myocard ium.
Keywords Critical ao rtic ste nos is - Infa nts - Left ventricle - Wall motion a nalysis - Cross sectiona l eehoca rdiogra phy
Thorae. cardiovasc. Surgeon 38 119901 236 -2 40 © Georg Thieme Verlag Stuttgart - New York
Sauglin ge mit kriti scher valvular er Aortenstenose kon nen globale ode r regionale linksven tr ikular e Kontr akt ionsstdrun gen a ufweisen. Urn die klinische Hclevan z diese r Kontraktionsstorun gen zu beurteilen. unte rsuc hten wir se ktorec huka rdiogra phis ch die systoli sche linksventrikular e Funk tion pr a- und postopera tiv bei 16 zwische n 1980 und 198 7 valvulot omierten Sauglingen,
Unte rsu cht wurde sekto rechokardiogra phisch das Wan dbewegun gsmuster des linken Vent rikels im Vierka mmerblick durch Digitalisieren der enddiastollschen und endsystolische n Vcntrik elsilhouettc . lli eraus wur de n mittels Kleinr echn e r die pr ozentuale Fla chenv erklcin er ung (ver glcichb ar dor Ejektionsfra ktion l sowle die regionale Wandbew egung der in 5 Sektoren eingeteilten Vent rikelflache berechn et und mit eigenen Norma lwe rte n vergliche n. Vor der Valvulotom ie ze lgten 8 Sa ugllnge eine normale und 8 Sau glinge cine gestorte linksvent rikulare Wa ndbewegung. Diese letzrgen annten Saugftnge hatten cine lIypokinesie dcr Spitze un d/ oder der postern-lateralen Wand des Iinken ventrt kels mit konsekutiver Vermind erung der prozen tualen systol lsc he rr Flache nver kleine rung. Vier diese r Kinder zeigte n bei der intrao perativen Myokardinspektion lnfarkte. Frtihp ostoper ativ wa r die sys tclisc he Flache nverkl ein erun g des Iinken Vcntrikels bel allen Kindem norm al. die a pikale und Seite nhi nterwa ndbewegu ng emwe de r normal ode r hype rkinet isch. Postoper at ive Ve rlaufsbeob a chtungen von meh r a ls 10 Monate n bet a llen Kinde m sowie mehr als 3 J ahre n bel 7 Kindem zeigten. daB das linksvent rikular e Wan dbewegu ngsmuster bel allen norma l blieb . unnbha ngtg davon, ob sic praoporauv norm a le oder gosto rte Wa ndbew egungs muste r au fwiesen . Die Studie legt na he. daB linksventrikula re Wa ndb ewegungsstOrungen bei Sa uglrngcn mit kritisch er Aortenkl appenstenose reversi bcl se in kon nen und som it keine Kontr ain dikalion fur cine rasche Valvuloto mie dar stellen. Diese Reversibilitat laBt vermuten . daB die Kontraktions sttirungen nur zum Te il durch cine tscham tsch e Myoka rdschadigung bed ingt sind . die zude m durch benachbartes gesundes Myokard kom pensiert werden ka nn . Zum a nde re n Te il beruhen sie wa hrsc heinlich au f einer extremen Nachlaste rhohung des Iinken Ventrikels. die durch die Valvulotom ie vermindert wird .
Received for Publication : January 8. 199 0
Downloaded by: University of British Columbia. Copyrighted material.
Summary
Echo ka rdiog raphische Beurteilu ng der llnksventr lkul are n Fn nktlo n bci Sauglinge n ver und na eh v a lvulotom te e iner kri ti sch en Aortenklappcnstcnose
Introduction In infants with critical valvula r aortic stenosi s left ventricular ejection may be impaired by inc reased a fterload or myocardi al necrosis. Myocardial necrosis is related to diminished perfusion of the corona ry arter ies which originate dista l to the stenosis. The corona ry perfusion pressu re. therefore, is relatively low compared to the diastoli c left ventricular intracavitary and intra myocardia l pressu re (6, 13). Myoca rdial und er perfusion an d hence myocardial necrosis is promoted by myocar dial hypertrophy developing as a consequence of increased afterloa d. Increased afterload itself causes, if at all, a globa l impairm ent of ventr icular ejection which should be reversible following afterload reduction (I, 14). Myocard ial necrosis , in contrast, depending on its extension, causes a globa l or regional impa irment ofsystolic left ventr icular wa ll motion which may persist after relief of the aortic st enosis . Global redu ction of left ventricular ejection as well as regional impai rment of wall motion ma y be recognized and quantified by cross-sectional echoca rdiography. The present stud y examined the left ven tricular systolic function of infants with critical valvula r aorti c ste nos is before and a fter valvotomy. Patients a nd Method s Between August 1980 and Decembe r 1987 21 young infants with critical valvular aorti c stenos is underwe nt aortic valvotomy at our instituti on. From 16 of these infants high quality pre- an d postoperat ive cross-sectional echocardiograms are available enabling us 10 quan tify systolic left ventricular wall motion and to compare it with previously established nor mal values . The clinical data of the 16 infants are summ arized in Table 1. Normal values of left-ventricular enddiastolic ar ea and oft left-ventri cular systolic wall motion in the apical 4-chamber view we re obtai ned from crosssectional echocardiograms of 43 infants without hea rt disease. The cross-sectiona l echoca rdiogra ms were obtai ned in the usual manner (12). We used . in chronological order. an electro nic sector scanner lRT 400. Kontro n) and two mechanical sector scanners (Mark 300 C. Ultrama rk 8. SMS Kran zbiihler ). Depen ding on the scanner and the infants ' age, 3.5. 5.0 or 7.5 MHz tran sdu cers were utilized. The echocard iogram s were registered on videotape (Umatic, Sony). For analysis of left-ventr icular wall motion we used the apical 4-chamb er view which for th is purp ose appea rs to be superior to other views (91.
Age (days)at Operation
Symptoms on Admiss.
t
105
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
III
+++ +++ + + +++ +++ + ++ +++ ++ + +++ + +++ + + +
Pat. No.
35 35 9 40 73 45 12 29
7 9 3 2 9 70
Pressure-Grad. (mmHg)
65 50 55 80 70
For qu an tification of left-ventr icular wall motion we used a commercial computer program Iw allexcurstcn Version 9.2. Fa. Kont ron) especially developed for this pur pose. The enddiastolic an d endsys tolic left-ventricular contoures on the videoscreen were manually tra ced with a light pen and fed into the computer. For compensa tion of ventricular movement due to cardiac action and respiration. the long left-ventr icular axes and their centres were superimposed. Part ing from the centre an d excluding the mitra l valve plane. the left-vent ricular silhouette was subdivided into 5 sectors. The relative systolic reduction of the sector ar ea expressed in per cent of the enddiastolic area was calculated and served as a measure of the regional wall motion (2. 7. 9). Using this method. regional left-ventri cular contraction abnor malities are shown by an abnormally low systolic redu ction of sector size. Normokinctic wall ar eas may be differentiated from hyper-. hypo- and akineticor even dyskinetic wall ar eas (5.10). We defined a left-ventr icular contraction a bnor mality as an abn orm al systolic reduction of at leas t two adjacent sectors . In order to evaluate global systolic left-ventricular function we determ ined the fra ctional systolic diminution of the total left-ventricula r area SO-LV expressed in percent of the enddiastolic area . This parameter is compara ble to the left-ven tr icular ejection fraction calculated from enddiastolic and endsystolic left-ventr icular volumes.
Resul ts
Norma l infants In the 43 infants wihout heart disease we found, in accordan ce with the findings in healthy adu lts, a mean systolic dimin ution of the sector area betwee n 35 and 40 %. The lower 2-Sigma -value for the apical, lateral. and posteri or sectors was 20 %, and for the interventricular se ptum 15 %. The left-ventricular enddistolic a rea was 32 .1 ± 5.2 cm' / m' body surface area. The fractional systolic diminution of the total left-ventricular a rea SD-LV in norm alinfants was 38.2 ± 6.9 %.
Inf ants with critical aortic st enosis The pr eoper ative severity of symptoms of ca rdiac insufficiency together with age at opera tion, invasively measured or continuous-wave-Doppler-estimated pressure gradient between left ventricle and aorta a nd additional hea rt defects a re listed in Table 1. The enddiastolic left-ventricular a rea in the apical four chamber view together with pr eoperative wa ll excursion abnormalities, electroca rdiographic abn or-
Additional Heart Defects
MI MI.MS GoA, MS
POA
50 65 60 64
100 70 90 110
Thorae. cardiovas c. Surgeon 38 (1990)
PDA PDA
+ - mild, ++ "" moderate, +++ - severe,eoA = coarctation of the aorta,MI = mitral insufficiency, MS mitral stenosis.PDA = patent ductus arteriosus
Table 1 Preoperative clinical. electrocardiographic and hemodynamic dataof 16 infants with critical valvalar aortic stenosis.Thepressuregradientsbetween left ventricle and aorta weremeasured either invasively or by Doppler-scnography
237
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Hchocardiographic Evaluation ofSystolic Left -ventricular Function in Inf ants
R. Hofst etter. 8 . Zelke. B. 1. Messm er. G. l..'Ofl Bernuth
Thom e. curdiol'uSC. Surgeo1l38 (1990) Preop. LV-Size Icm2/m~
Preop. WE
Preop. ECG
Intraop. Inspection
I
37
+
2 3
44
+
my. info my. inf. abn. repel.
my. info my. inf.
Pat. No.
31 35 15 38
4
5 6 7 8
abn. repel.
+ +
59 46 24
9
10 11 12
35
13 14 15 16
17 21
Table 2 Preoperative echocardiographic. electrocardiographic and intraoperative find ings of 16 infants with criticalvalvular aortic stenosis
my. inf. my.inf.
abn. repel. my. inf.
+ +
abn. repel.
28 24
abn. repel.
+
20 31
+
my. inf.:myocard infarction,abn. repol: abnormalrepolarization, WE: wall excursion, +: abnormal
mali ties. and abnormalities on intraoperative myocardial inspection ar c listed in Table 2. Ufthe 16 infa nts with valvular aortic stenosis 8 infants showed preoperatively regional left-ventricular contraction abnormalities as defined above. In these infants. the leftventri cular a pex a nd the postero-Iateral wall were a ffected. In one infant. also the proximal intervent ricular septum contra cted abno rmally. In the remaining 8 infants. Ieft-ven tricular contraction was normal. One of these infants showe d a diminished contraction only of the apical sec tor with norma l contractions of the adjacent secto rs (Fig. 1).
the apical sector was high-norm al or slightly increased. This was also tr ue for infants with preoperative contraction abnormalities who could be followed over a particularl y long peri od of time (Fig. 3). All infants with preoperative regional contraction abnorma lities also had a diminished global left-ventr icular systolic function. In all infants except one without regiona l contraction abno rmalities . global left-ventricular systolic function before operation was found to lie in the normal range. Postoperatively. all infant s had a normal or increased global left-ventricula r systolic function irr espec90
70
80
60
70
E 60
E 50 c 0
~
, u
••
c 0
40
~
30
••
, u
'0
'0 20
50
40
30
• 20
•
10
...... ....
10
o ~-,--_----:-_--:-,--
sept. pro>:.
sept. diet.
apikol
~
lat erol
wall segm ents
0 sept. prO>:.
sept. disl.
opikal
lat eral
posterior
wall segm ents
Fig. 1 Analysisof preoperative regionalleft-ventricular contractionpattern. The horizontal axisshowstheseptal proximal(sept.prox.), septal distal(sept. dist.). apical,lateraland posteriorwall segmentsoftheleftventricle.The normal range isshaded. Dottedhnesindicate patients withregional left-ventricular contractionabnormalities beforeaortic valvotomy
Fig.2 Analysisofregionallett-ventricular contractionpattern 1/2- 4 months after aortic valvotomy. Explanationsee Fig. 1
Within the first 4 months after ao rtic valvotomy regional left-ventricular contraction was normal or hyperactive in all infants with the exception of one who showed a slightly diminished contraction of the left-ventricular a pex. The 8 ventricles with preoperatively diminish ed contraction were not different from the 8 other ventricles (Fig. 2). During furth er follow-up all ventricles retained a normal or hyperactive contraction pattern irrespective of whethe r this was preoperatively normal or not. Regional left-ventricular contraction with the exception of
tive of whet her this was normal or dec rease d preoperatively (Fig. 4). In a ll infants with preoperative left-ventr icula r wall excursion abnormalities the left-ventricular s ize was either normal or increas ed before valvotomie. The eight infants with preoperative normal left-ventricular wall excursions had either normal or decreased left-ventricular sizes (Table 2). The infan t with the sma llest left-ventri cular size died 3 months postoperatively; autopsy in this case showed left-ventricular endocardial fibroelastosis. The 8 infants
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238
Thom c. cardia/'ase. .f.,·urgeof/ 38 (199OJ
f:'clwcardiograph ic f:'valuation a/Systolic Left-u entrlcular Function in Infuntn
2 :~ 9
90 80 70
g
'0
e
.s ,eu ••
50 40 30
"0
•
.. _ .... '.... ....
20
~
~
"
10 0 sept. prc x.
sept. dist.
opikol
lateral
poster ior
wa ll s egments
70
Fig. 5a Parasternal shortaxis viewofthe left ventricle inpatient 1witha myocard ial infarctionintheregion oftheleft-ventricular posteriorwall (/ )6 years postoperative ly. LV = left ventricle
'0
20 10
pre o p.
1-4 mo
3- 6 yra
postop.
postop.
Fig.4 Time course of thesystolicdiminutionof theleft-ventriculararea (SDLV) inall16 infants. Dotted linesindicate patients withregional left-ventncular contractionabnormalities before aortic valvotomy
with preoperative regiona l left-ventricular wa ll exc ursion abnormalities tended to be olde r at operation a nd had more seve re signs of heart failure tha n the infan ts wit h pr eopera tive nor mal wa ll excu rs ions (Tab le 1). Five infants with and 3 infan ts without pr eoperat ive wall exc ursion abnormalities had electroca rdiographic s igns of ischemia. Four infants had myocardial infarction on intraoperative inspection ; all 4 had regional left-ven tricular
REGIONAL WALL MOTION 2 %
0
J
4
4CH
wall excursion abno rma lities. Four further infants had repolarisation abnormalities in the electroca rdiogram sugges ting myocardial ischemia ; on ly one of these also had reg ional left-ventricular wa ll exc ursion ab normalities (Tab le 2). In so me infants echoca rdiogra phy showed hyperdensity of pa pillary mu scles sugges ting papi llary muscle fibrosis as res idue of myocard ial necrosis. The electrocardiogram of one infant (No 1) continues to show 6 years postope ratively signs of myoca rdi al infa rction with bro ad Qwaves and diminished Il-arnplitudes in sta nda rd-lead III. This infant's echoca rdiogram showed in the parasternal s hort axis an echode nse struct ure of th e poster ior wa ll sugges ting a myocardial scar (Fig. Sal. The pat ient's inc rease d globa l left-ventricular systolic function docu ments a good co mpensation of his myocardial sca r by increa sed contractility of th e adjace nt myocardium (Fig. 5b).
Discussion In critical valvular aortic stenos is there may be impairment of left-ventr icular systolic function . Global impairme nt may
Fig. 5b Left-ventricular regional wallmotionin thea-chamber-view(4CH),dividedinto thefive sectors(1 -5) septalproximal(sept. prox.), septal distal (sept dist], apical [ap.l.tatera l (Iatl and posterior(post.) of thesame patientasin Fig. 5a 6 yearsafter aortic valvotomy
· T'> (
