Br Heart3' 1993;70:471-473

Two unusual complications after surgicalinterruption of an accessory pathway

Emile C Cheriex, Joep L R M Smeets, Hein J J Wellens

AbstractIn a patient with the Wolff-Parkinson-White syndrome, Ebstein's anomaly ofthe tricuspid valve, a right atrial Chiarinet and a patent foramen ovale twounusual complications developed aftersurgical epicardial dissection combinedwith cryoablation of the anomalous path-way.The first complication was that abla-

tion of the right atrial wall led to changesin interatrial pressure gradients and thedevelopment of a right to left shuntnecessitating surgical closure of theatrial septal defect. The second compli-cation was the development of a throm-botic mass in the Chiari net simulatingon intracavity tumour, which also had tobe removed surgically.

(Br HeartJ' 1993;70:471-473)

Two unusual complications occurred aftersurgery for the Wolff-Parkinson-White syn-drome in a patient with Ebstein's anomaly ofthe tricuspid valve with a patent oval foramenwho had recurrent circus movement tachycar-dias through a right-sided accessory atrioven-tricular pathway.

Department ofCardiology oftheAcademic Hospital ofMaastricht, UniversityofLimburg,Maastricht, TheNetherlandsE C CheriexJ L RM SmeetsH J J WellensCorrespondence to:Dr E C Cheriex,Department of Cardiology,Academic HospitalMaastricht, University ofLimburg, P.O. Box 5800,6202 AZ Maastricht, TheNetherlands.

Case reportA 19 year old man was examined in 1981because of Wolff-Parkinson-White syndromeand circus movement tachycardia. Echo-cardiography showed Ebstein's anomaly ofthe tricuspid valve. The septal leaflet was

attached 3 cm apical to the attachment of themitral valve, so that the ratio of the atrialisedpart of the right ventricle to the ventricularpart of right ventricle was 1:1. Echo-cardiography also showed an aneurysm of theinteratrial septum, indicating patency of theforamen ovale. A Chiari network was clearlypresent in the right atrium. An electrophysio-logical study proved the presence of a rightlateral accessory atrioventricular connection.During catheterisation it was possible to cross

the foramen ovale. Oximetry showed no

shunt at the atrial level (saturations: superiorvena cava 76%, inferior vena cava 82%, rightatrium 77%, pulmonary artery 77%, pul-monary veins and left atrium 97% and leftventricle 96%). The patient's exercise toler-ance was normal and no cyanosis was noticedduring exercise.

In January 1989 poorly controlled tachy-cardia prompted epicardial dissection com-

bined with cryoablation of his accessoryconnection without the use of extracorporal

circulation. Postoperatively the patient hadsignificant systemic arterial undersaturation,believed to be caused by central shunting.A transoesophageal echocardiogram

showed a freely moving flap valve of the fora-men ovale and contrast echocardiographyshowed right to left shunting. The right lat-eral part of the right atrium above the annu-lus fibrosis appeared completely akinetic foralmost 3 cm. The shunting was thought to bemainly the result of a change in pressure gra-dient between right and left atrium. Right-sided catheterisation was performed duringmechanical ventilation. The mean right atrialpressure was 14 mm Hg and mean left atrialpressure was 7 mm Hg.The oxygen saturations were as follows:

superior vena cava 51 %, inferior vena cava53%, right atrium 50%, pulmonary artery53%, pulmonary veins 98%, left atrium47-95% depending upon the sampling site,and left ventricle and aorta 85%. These val-ues indicated considerable right to left shunt-ing in a patient whose general condition wasdeteriorating. The patient was operated onand the atrial defect was closed successfully.Recovery was uneventful and an echocardio-graphic investigation one week after the sec-ond operation showed no signs of shunting orother additional abnormalities. At routine fol-low up six months later echocardiographyshowed a large partially mobile tumour in theright atrium. Because this tumour seemed tobe connected to the Chiari network a venousthrombus entrapped in the Chiari networkwas diagnosed (figs 1 and 2). After threeweeks treatment with intravenous heparin thetumour did not decrease in size. Indium-IIIlabelling of platelets did not show any activityin the right atrium and venous system, sug-gesting absence of active thrombus formation.Reoperation was performed and the throm-bus was removed together with the Chiarinetwork. The postoperative course wasuneventful and the patient is currently symp-tom free.

CommentEbstein's anomaly of the tricuspid valve is anuncommon congenital abnormality, charac-terised by apical displacement of the septalleaflet of the structurally abnormal tricuspidvalve into the right ventricle without displace-ment of the annulus fibrosis. Wolff-Parkinson-White syndrome is reported tooccur in 5-25% of patients with Ebstein's dis-ease. 1-5 An atrial septal defect or patent fora-men ovale was reported in 60-80%.'26 Rightto left shunting through the defect causesvariable degrees of cyanosis in 60-80% of

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Cheriex, Smeets, WeUlens

Figure 1 Transthoracicechocardiogram(parasternal short axis)showing the Chiarinetwork (C) in the rightatrium (RA) and itsrelation to the inferior venacava (VCI). The atrialseptal defect was closedduring the secondoperation.

patients.'3 Right ventricular failure, tricuspidincompetence, and increasing right atrialpressure are the main reasons for right to leftshunting. The patient presented here isexceptional. To our knowledge an abruptchange in inter-atrial flow, from absence ofany clinical shunting to severe symptomaticright to left shunting has not been reportedbefore. In this patient cryosurgical trauma tothe right atrium, causing akinesia of a consid-erable part could have influenced the inter-atrial pressure gradient.The second unusual complication in this

patient was the entrapment of a venousthrombus in the Chiari network. Entrapment

Figure 2 Transthoracic echocardiogram (parasternal short axis) showing a largethrombus (T) entrapped in the Chiari network (RVOT, right ventricular outflow tract;LVOT, left ventricular outflow tract).

prevented pulmonary embolism.Echocardiographically detected right-sided

heart thrombi are uncommon. The 'reportedmortality associated with these echocardio-graphically detected thrombi is 29-100%.7Most thrombi visualised in the right heart areparts of a larger thrombus that is still partly"fixed" in the inferior vena cava. We know ofno other descriptions of thrombi entrapped inthe Chiari network. Two case reports, how-ever, describe paradoxical embolisation andpulmonary emboli in patients with Ebstein'sanomaly.89 In one the thrombus was detectedechocardiographically before death.9 Survivalmainly depends on the prevention of pul-monary emboli. The calculated probability ofsurvival without treatment in this patient was50% according to the logistic regression cal-culation of Kinney and White.7 Afer threeweeks of unsuccessful heparinisation thethrombus was removed surgically. We do notknow why venous thrombosis developed inthis patient. The Chiari network preventedthe thrombus from causing pulmonaryembolism. Paradoxical embolisation was nota possibility because the atrial septal defecthad been closed.

1 Vacca JB, Bussmann DW, Mudd JG. Ebstein's Anomaly.Complete review of 108 cases. Am 7 Cardiol 1958;2:210-26.

2 Kumar AE, Fyler DC, Miettinen OS, Nadas AS.Ebstein's anomaly. Clinical profile and natural history.Am J Cardiol 1971;28:84-95.

3 Bialostozky D, Horwitz S, Espino-Vela J. Ebstein'smalformation of the tricuspid valve. A review of 65cases. Am Y Cardiol 1972;29:826-36.

4 Sealy WC, Gallagher JJ, Pritchet ELC, Wallace AG.Surgical treatment of tachycardias in patients with bothan Ebstein's anomaly and a Kent bundle. J ThoracCardiovasc Surg 1978;75:847-53.

5 Guiliani ER, Fuster V, Brandenburg RO, Mair DD.Ebstein's anomaly. The clinical features and naturalhistory of Ebstein's anomaly of the tricuspid valve.Mayo Clin Proc 1979;54:163-73.

6 Watson H. Natural history of Ebstein's anomaly of tri-cuspid valve in childhood and adolescence. An

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international cooperative study of 505 cases. Br Heart J1974;36:417-27.

7 Kinney EL, Wright RJ. Efficacy of treatment of patientswith echocardiographically detected right-sided heartthrombi: A meta-analysis. Am Heart Jf 1989;118:569-73.

SHORT CASES

8 Mathews JL, Pennington WS, Isobe JH, Gaskin TA,Dumas JH, Kahn DR. Paradoxical embolization withEbstein's anomaly. Arch Surg 1983;118:1 101.

9 Fomace J, Rozanski LT. Right heart thrombeombolismand suspected paradoxical embolism in Ebstein's anom-aly. Am Hearty 1987;114:1520-2.

IN CARDIOLOGY

Primary hyperparathyroidism presenting astorsades de pointesPeter Kearney, Michael Reardon, James O'Hare

Department ofCardiology, CorkRegional Hospital,Wilton Cork, Republicof IrelandP KearneyM ReardonDepartment ofEndocrinology andGeneral Medicine,Limerick RegionalHospital, Dooradoyle,Limerick, Republic ofIrelandJ O'HareCorrespondence to:Dr Peter Kearney, 2ndMedical Clinic, JohannesGutenberg UniversityClinic, Langenbeckstrasse 1,D 6500 Mainz, Germany.

Electrocardiogramsrecorded shortly afteradmission. (A) Short runof multiformn ventriculartachycardia folows a longRR interval of thedominant cycle, startingwith an R on T ventricularextrasystolic beat. (B) Uwaves (indicated byarrow) and a run ofmultiform tachycardiawith typical axis changesand variable rate. STdepression may be theresult ofhypokalaemiaandlor hypercalcaemia.

A previously well 47 year old -woman pre-sented to hospital complaining of syncopalepisodes -over the preceding 24 hours and ofanorexia, nausea, polyuria, polydipsia, andgeneralised aches and pains for 2 weeks. Shelost consciousness and her electrocardiographshowed short runs of multiform ventriculartachycardia (figure). These worsened, degen-erating into ventricular fibrillation thatrequired repeated DC cardioversion. Thearrhythmia was refractory to intravenous lig-nocaine, magnesium, and amiodarione andstabilised only after a transvenous pacemakerset to 100 beats/min was inserted. Clinicalexamination was unremarkable. Serum bio-chemistry showed hypokalaemia (3 1 mmol/l)and hypercalcaemia (3 12 mmolIl). Twentyfour hour urinary calcium was increased(13-5 mmol) and a parathormone assay(INTACT IRMA) showed a concentration of517 pg/ml (normal range 5-15 pg/ml) thatconfirmed the diagnosis of primary hyper-parathyroidism. A parathyroid adenomaweighing 2-79 g was located and excised andthe patient made an uneventful recovery.

Hypokalaemia, a well recognised precipi-tant of torsades de pointes' is noted inapproximately 5% of cases of primary hyper-parathyroidism.2 It is probably a result ofproximal (type II) and, to a lesser extent, typeI renal tubular acidosis. Secondary hyper-aldosteronism resulting from intravascularvolume depletion can also occur.

Hypercalcaemia also may have contribu-ted. The increases in heart rate and contrac-tility caused by parathormone are thought tobe the result of direct induction of calciuminflux into myocardial cells and the release ofendogenous myocardial adrenaline.' Hyper-calcaemia shortens the plateau phase of theaction potential, leading to a shorter QTinterval. Re-entry is one proposed electro-physiological mechanism underlying torsadesde pointes and in this context the positivechronotropic and QT-shortening effect ofparathormone might be expected to protectagainst the arrhythmia by decreasing intra-ventricular dispersion of refractoriness.Calcium administration reduced the propen-sity to ventricular fibrillation by shorteningthe QT interval in dogs.4

There is, however, also evidence that anincreased calcium concentration might havean arrhythmogenic effect by enhancing earlyafterdepolarisations, which have more re-cently been hypothesised to underlie torsadesde pointes.1

1 Surawicz B. Electrophysiologic substrate of torsade depointes: dispersion of repolarisation or early afterdepo-larisations? JAm Coll Cardiol 1989;14:172-84.

2 Stewart AF, Broadus AE. Mineral metabolism. In: FeligP, Baxter J, Broadus A, Frohman L, eds. Endocrinologyand metabolism. New York: McGraw, 1987:1396.

3 Bogin E, Massry SG, Harary I. Effect of parathormone onrat heart cells. J Clin Invest 1981;67:1215.

4 Murdock D, Euler D, Becker D, Murdock J, Scanion P,Gunnar R. Ventricular fibrillation during coronaryangiography: an analysis of mechanisms. Am Heart J

1985;109:265-73.

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