Br Heart J 1993;70:70-74

Complementary role of transoesophagealechocardiography to coronary angiography in theassessment of coronary artery anomalies

P J Giannoccaro, R A Sochowski, B C Morton, K-L Chan

AbstractObjectives-To examine the role of

UHnversituof Ottawa transoesophageal echocardiography in

Ottawa, Ontario, the assessment of patients with coronaryCanada artery anomalies.P J Giannoccaro Background-Coronary artery anom-R A Sochowski alies are difficult to detect clinically.B C MortonK-L Chan Most are benign but some may produceCorrespondence to symptoms that can be life threatening.Dr K-L Chan, University of Until recently the non-invasive assess-Ottawa Heart Institute,1053 Carling Avenue, ment of coronary artery anomalies hasH-210 Ottawa, Ontario, been limited.Canada K1Y4E9.benlmtdCaceda for pub n Methods-The data base of trans-Accepted for publication10 November 1992 oesophageal echocardiographic studies

Table 1 Clinicalprofile of the six patients with coronary artery disease

PresentingPatient Age Sex Murmur CAD Symptoms Surgery

1 58 M 0 0 Dyspnoea +2 48 M + + Angina +3 61 M 0 + Angina +4 58 M 0 + Angina +5 40 F + 0 Angina +6 63 F + 0 Endocarditis +

CAD, atherosclerotic coronary artery disease.

Table 2 Echocardiographic and angiographic findings in patients with coronary arteryanomalies

Patient 7TE TOE Angio

1 AI, MR, Ectopic origin ofLCA Ectopic origin of LCADilated LV, from right sinus of from right sinus ofRWMA Valsalva coursing Valsalva,

between aorta and MPA, course not seenAI, MR, RWMA

2 Negative Dilated and tortuous LCx Dilated, tortuous LCxwith fistula to LV, with fistula coursinghypokinetic posteriorly; drainageinferior wall, site not identified,mild MR CAD

3 Negative Dilated LCA with fistula Dilated LM and LCx,from LCx coursing fistula from LCx seenbetween LA and aorta, but drainage site notaround SVC, and draining identifiedinto RPA

4 Negative Dilated, tortuous LCx Dilated, tortuous LCxwith fistula to the with fistula coursingposterior aspect of posteriorly probablyproximal RPA, draining into RPAdilated RCA supplying or LA,collaterals to LCx dilated RCA supplying

collaterals to LCx,dilated SVG tomarginal

5 Dilated RCA with Dilated tortuous RCA and Ectopic origin ofLCAfistula to RV PIV branch with fistula from MPA,

to RV apex, dilated, tortuous RCALCA not seen supplies collaterals

to dilated LAD(QP:QS = 2:1)

6 Aortic Vegetation on AoV, Dilated, tortuous RCAinsufficiency dilated RCA with with fistula to SVC

fistula to SVC (QP:QS = 1-2:1)

AI, aortic insufficiency; Angio, coronary angiography, Aov, aortic valve; CAD, atheroscleroticcoronary artery disease; LA, left atrium; LCA, left coronary artery; LCx, left circumflex; LM,left main; LV, left ventricle; MPA, main pulmonary artery; MR, mitral regurgitation; PIV, pos-terior interventricular artery; QP:QS, pulmonary to systemic shunt ratio; RCA, right coronaryartery; RPA, right pulmonary artery; RV, right ventricle; RWMA, regional wall motion abnor-mality; SVC, superior vena cava; SVG, saphenous vein graft; TOE, transoesophageal echocar-diography; TTE, transthoracic echocardiography.

performed between September 1988 andApril 1991 were reviewed to identify allcases of coronary artery anomalies.There were six patients with such anom-alies who had also had coronary angio-graphy. The findings of these two imagingtechniques were analysed to determinewhether transoesophageal echocardio-graphy added useful data in these cases.Results-Of the six patients, the coro-nary anomaly was discovered duringangiography in four patients, during atransthoracic echocardiographic study inone patient, and as an incidental findingin the other patient. Aberrant origins ofthe left coronary artery were detected intwo patients, and coronary artery fistulaewere present in the other four. Trans-oesophageal echocardiography providedunique information on the course of anaberrant left coronary artery in onepatient and the precise location ofdrainage sites of coronary artery fistulasin three patients.Conclusion-Transoesophageal echocar-diography was complementary to angio-graphy in the assessment of coronaryartery anomalies. It can locate and delin-eate the course of an ectopic coronaryartery and the drainage site of a coronaryfistula. These anatomical data can becrucial to the management of thesepatients.

(Br Heartj_ 1993;70:70-74)

The incidence of coronary artery anomaliesidentified during coronary angiography is0 6%-1 3%.' Most coronary artery anomaliesare benign and are incidental findings butsome may produce symptoms or can bepotentially life threatening. There are twomain groups of coronary artery anomalies:those with aberrant origin of one or morecoronary arteries and those with a fistularcommunication between a coronary arteryand a cardiac chamber or another vessel.

Transoesophageal echocardiography, withits improved view of the structures at the baseof the heart, provides a novel method toassess the coronary artery ostia and theirproximal portion.2- This imaging techniqueis potentially useful for both the identificationof anomalous coronary arteries and the accu-rate assessment of their anatomical course.The complementary role of transoesophagealechocardiography to coronary angiography

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Detection ofcoronary artery anomalies

Figure 1 (A) Transoesophageal echocardiographic scan sectioning the great arteries inshort axis. The aberrant left coronary artery (arrow) coursing between the two greatarteries is shown well by colourflow imaging. Ao, aorta; PA, pulmonary artery.(B) Coronary angiography shows the aberrant origin of the left coronary arteryfrom theright coronary sinus.

for the diagnosis and management of patientswith coronary artery anomalies is examined.

Patients and methodsThe records of all transoesophageal echocar-diographic studies performed betweenSeptember 1988 and April 1991 were

assessed and all cases where a coronary arteryanomaly was identified were reviewed.Transthoracic echocardiography was per-formed in all cases. Various commerciallyavailable systems (Hewlett-Packard, Toshiba,and Siemans) were used. Transthoracic stud-ies were performed from standard windowswith phased array transducers ranging from

2-5 to 3-75 MHz. Transoesophageal studieswith a 5 MHz single plane probe were per-formed as previously described.5The right and left coronary ostia were rou-

tinely seen during the transoesophageal study.The coronary arteries were sequentially seenby imaging at the level of the aortic root, ini-tially in a short axis view, and manipulatingthe transducer with a combination of probetip flexion, side to side tip translation, androtation to follow their proximal course.4When a coronary artery anomaly was identi-fied the origin, course, and drainage site wereclosely examined. Colour flow imaging wasused to aid location of the course of a tortu-ous coronary fistula.

ResultsEight patients were found to have coronaryartery anomalies. Of these six had coronaryangiography and a comparison of angiograph-ic with transoesophageal echocardiographicfindings in these patients forms the basis ofthis report. Table 1 shows the clinical fea-tures of these six patients. The two patientswho did not undergo coronary angiographyhad a fistula from the circumflex artery toeither the coronary sinus or the left atrium,and are not discussed further.Of the six patients studied, the coronary

anomaly was discovered during prior angio-graphy in four patients (patients 1 to 4), wassuspected due to an abnormal transthoracicechocardiographic study in patient 5, and wasdiscovered incidentally during trans-oesophageal echocardiography in patient 6.Patients 5 and 6 subsequently had coronaryangiography.

CORRELATION BETWEEN ECHOCARDIOGRAPHYAND ANGIOGRAPHYTable 2 shows a summary of the echocardio-graphic and angiographic findings. Therewere two aberrant origins of a left coronaryartery: one from the right sinus of Valsalva(patient 1) and the other from the main pul-monary artery (patient 5). The remainingfour patients had fistulas: one involved theright coronary artery as the feeding vessel anddrained into the superior vena cava (patient6), and the remaining three involved the cir-cumflex artery draining into the left ventriclein one case (patient 2) and into the right pul-monary artery in two cases (patients 3 and 4).

Transoesophageal echocardiography iden-tified the origin of the right coronary artery inall cases and the left coronary artery in fivecases. The left coronary artery was not seenin the single case where it arose aberrantlyfrom the main pulmonary artery. The coro-nary artery fistulas were correctly assessed inall four patients. Their courses were followedand the drainage sites accurately identified inall cases.

In the four cases where the coronary arteryanomaly was detected by prior angiography,transoesophageal echocardiography was per-formed specifically to obtain further anatomi-cal detail. In patient 1 the ectopic origin of

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Giannoccaro, Sochowski, Morton, Chan

Figure 2 (A) Transoesophageal echocardiographic colourflow scan of the right pulmonaryartery shows the drainage site of the coronary artery fistula (arrow). The orngin and courseof the fistula are identified on different imaging planes. RPA, right pulmonary artery;SVC, superior vena cava. (B) Coronary angiogram of the coronary artery fistula (arrows)shows the posterior course but the exact drainage site cannot be determined.

the left coronary artery arising from the rightsinus of Valsalva was clearly identified onangiography, but its exact course in relationto the great vessels could not be determinedwith certainty. Transoesophageal echocardio-graphy showed that the left coronary arterycoursed between the aorta and the main pul-monary artery (fig 1). In patients 2, 3, and 4,the coronary fistulas were correctly identifiedby angiography, but the exact drainage sitescould not be confirmed. Transoesophagealechocardiography located the drainage sitesin all three cases. Figure 2 shows the findingsin patient 3. In patients 5 and 6, coronaryangiography was performed after trans-oesophageal echocardiography. In patient 5,an ectopic origin of the left coronary artery

was not seen during the transoesophagealechocardiographic study, but as no left mainostium was identified originating from theaorta and the right coronary artery was great-ly dilated ectopic origin of the left coronaryartery was suspected. Angiography confirmedthe ectopic origin of the left coronary arteryarising from the main pulmonary artery.Considerable collateralisation between theright and left coronary arteries was also seen.Patient 6 had transoesophageal echocardio-graphy for assessment of aortic valve endo-carditis. A fistula communicating the rightcoronary artery with the superior vena cavawas detected incidentally and this was con-firmed by subsequent angiography (fig 3). Ashunt ratio of 1 2:1 was found.

SURGICAL OUTCOMEAll six patients underwent surgery and thefindings were confirmed in five patients. Inpatient 1, bypass grafts were constructedfrom the aorta to the branches of the leftcoronary artery. In patient 3 the fistula wassuccessfully closed at its drainage point onthe right pulmonary artery, which was easilyaccessible. In patient 4, who also had a cir-cumflex artery to a right pulmonary artery fis-tula, the drainage site was located posteriorly.A previous surgical attempt had been unsuc-cessful at locating and ligating its drainagesite. Intraoperative transoesophageal echocar-diography guided the surgical team in locat-ing the fistula and led to its successfulclosure. Patient 5 underwent surgical correc-tion by ligation and bypass grafting of the leftmain coronary artery, which originated fromthe main pulmonary artery. In patient 6 theright coronary artery fistula was successfullyclosed at the time of aortic valve replacement.In patient 2, the main indication for surgerywas considerable coronary artery disease andat surgery the fistula could not be identified.

DiscussionClinical diagnosis of coronary artery anom-alies is difficult. Often there are no signs orsymptoms and they are discovered as inciden-tal findings at the time of catheterisation.'Others are identified when they cause a con-tinuous murmur, myocardial ischaemia, con-gestive heart failure, or endocarditis.

TRANSTHORACIC ECHOCARDIOGRAPHYTransthoracic echocardiography may identifythe origin of coronary arteries in selectedpatients. The left main coronary artery ismost easily seen, and is identified in 58%-99% of patients.67 Although the course anddrainage sites of anomalous coronary arteriescan be visible from the transthoracicapproach, success may be a function ofpatient age and size8 and has been describedin paediatric populations89 where the acousticwindow is optimum. A recent study of pre-dominantly adult patients showed a high suc-cess rate with transthoracic colour flowimaging to identify drainage sites of fistulas,'0but other reports have shown limitations of

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Detection of coronary artery anomalies 73

Figure 3 (A) Transoesophageal echocardiographic scan shows the tortuous and dilatedcoronary artery fistula (arrow) draining into the superior vena cava. Ao, aorta; SVC,superior vena cava. (B) Coronary angiogram shows the coronary artery fistulacommunicating with the superior vena cava (open arrows).

this approach both in patients with coronaryartery fistulas" 12 and in patients with anom-alous coronary vessels.'3 14

TRANSOESOPHAGEAL ECHOCARDIOGRAPHYThe advantages of the transoesophagealapproach include the proximity of the trans-ducer to the area of interest as well as higherfrequency transducers that allow better spa-tial resolution and assessment of detail. Whenspecifically searching for coronary arteries,transoesophageal echocardiography can iden-tify the left main coronary artery in 77%-100% and the right coronary artery in

26%-100% of cases.3415 Often the left maincoronary artery can be traced to its bifurca-tion where portions of the left anteriordescending and circumflex arteries can beseen. The right coronary artery may also betraced for part of its proximal course.3 4The superior imaging of the proximal coro-

nary arteries from the oesophageal windowmakes transoesophageal echocardiographyparticularly useful in patients with an ectopicorigin of a coronary artery or a coronaryartery fistula, where dilatation of part orwhole of the coronary tree is common.Colour flow imaging can further aid in thelocation of the origin, course, and drainagesite of these abnormal vessels. Our experiencesuggests that the course of a dilated coronaryartery or fistula can be readily identified bythis imaging technique, a finding suggestedby recent case reports'2 141617 and shortseries." 'I

Coronary angiography remains the goldstandard for imaging the coronary tree' byproviding high quality images of both proxi-mal and distal coronary arteries, identifyingocclusive disease, and allowing views of col-lateral vessels. Nevertheless, transoesophagealechocardiography was found to have a com-plementary role even in those patients withangiographically proved coronary arteryanomalies. Coronary angiography successful-ly showed the ectopic origin of the left coro-nary artery in both patients 1 and 5, but onlytransoesophageal echocardiography accurate-ly found the course of the anomalous vesselbetween the aorta and pulmonary artery inpatient 1. Coronary angiography may also failto detect the drainage site of a coronary fistu-la.'2 18 In this selected series of patients trans-esophageal echocardiography was performedto help locate the course and drainage site offistulas in three patients. In each case trans-oesophageal echocardiography was able toprovide that information, which is importantin planning the optimal surgical approach anddetermining the need for cardiopulmonarybypass.'920 In patient 4, in whom the fistulahad not been found during previous surgery,intraoperative transoesophageal echocardio-graphy located the drainage site in the poste-rior right pulmonary artery, and allowedsuccessful ligation.

LLMITATIONS OF TRANSOESOPHAGEALECHOCARDIOGRAPHYAlthough transoesophageal echocardiographyviews proximal coronary arteries and theirabnormalities well some limitations remain.The ability to trace a segment of a coronaryartery or a fistula may be limited by the posi-tion of the transducer (especially with singleplane probes), cardiac motion, and the curvi-linear nature of the vessel along the epicardialsurface, which impairs the view of distal seg-ments unless considerably dilated. Collateralvessels, usually of small calibre, are not seenand underlying occlusive coronary diseasecannot be accurately assessed.

In conclusion transoesophageal echocar-diography serves a useful role complementary

Giannoccaro, Sochowski, Morton, Chan

to angiography in the assessment of coronaryartery anomalies. It can locate and delineatethe course of an ectopic coronary artery andthe drainage site of a coronary fistula. When acoronary artery fistula is present, a dilatedfeeder vessel with an abnormal flow patterncan be readily identified. Transoesophagealechocardiography not only confirms the pres-ence of coronary artery anomalies detected byangiography, but can also provide uniqueanatomical information that may have animpact on management. Conversely, angio-graphy should be considered when a coronaryartery anomaly is detected by trans-oesophageal echocardiography to providebetter delineation of the distal coronary ves-sels, to find the degree of collateralisation,and to identify any coexistent occlusive coro-nary disease. In this clinical setting, these twoimaging techniques are indeed complemen-tary. As technology improves and applicationof biplane and multiplane transoesophagealechocardiographic probes become wide-spread, further improvements in the ability toassess coronary artery anomalies will bepossible.

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