134

Cross-sectional echocardiography. therefore. is ex- 2

tremely useful in the diagnosis of a free-floating

thrombus in the left atrium. The interruption of di- astolic mitral flow, demonstrated by Doppler ultra- 3

sound. explains the particular auscultatory and clinical features of this rare condition.

4

References

5 1 Shrestha NK. Moreno FL, Narciso FV. Torres L. Calleta

HB. Two-dimensional echocardiographic diagnosis of left

atrial thrombus in rheumatic heart disease. A clinicopatho-

logic study. Circulation 1983;67:341-347.

CARD10 09297

Collateral circulation to the diagonal artery from the infundibular coronary artery in obstructive coronary arterial disease

Fraser AG. Angelini CD. Ikram S. Butchart EG. Left atria1

ball thrombus: echocardiographic features and clinical im-

phcations. Em Heart J 1988:9:6722677.

Furokawa K. Katsume H, Matsukubo H. Daisuke I. Echo-

cardiographic findings of floating thromhus in left atrium.

Br Heart J 1980;44:599-601.

Warda M. Garcia J. Pechacek L. MassumKhani A, Hall R.

Auscultatory and echocardiographic features of mobile left

atrtal thrombus. J Am Co11 Cardiol 1985:5:379%3X2.

Szkopiec RL. Torstveit J. Prakash NS, Desser KB. Benchi-

mol A. Non-invasive diagnosis of a free-floating left atrial

thromhus wrth emphasis on two-dimensional echocardio-

graphic features. Angiology 1983;34:102~110.

_

fntrm~troncr/fourna/ of Cardwlo~\: ‘5 (1989) 134-136 Elsevier

Sanjiv Sharma ‘, Upendra Kaul ’ and Mira Rajani ’

Depurtments of Rudmdiqnom t and Curdiofogr ‘, Cardiothoracrc Cmtre. Afi fndiu institute of Medical Sciences. New Delhi, Indra

(Received 16 November 1988; revision accepted 17 April 1989)

We report an unusual collateral pathway from the isolated infundibular (third coronary) artery to the diagonal artery in a young adult male with a history of recent anteroseptal myocardial infarction and apparently angiographically normal left and right coronary arteries. The isolated infundibular (conus) artery is an important source of collateral pathways in obstructive coronary arterial disease. Its selective arteriography is essential for complete angiographic evaluation of these patients.

Key words: Angiography: Coronary angiography; Coronary arterial disease; Collateral artery; Myocardial infarction

Introduction

The infundibular (conus) branch of the right coronary artery provides an important collateral pathway to the left anterior descending artery in patients with obstruc- tive coronary arterial disease [l-3]. Failure to opacify the infundibular branch during coronary arteriography

Correspondence to: Dr. S. Sharma. Dept. of Radiodiagnosis, All India Institute of Medical Sciences, Ansari Nagar, New Delhi-110029, India.

can, therefore. result in serious underestimation of the extent of coronary collateral circulation. In this regard, awareness of the anatomic variations about the origin of the infundibular branch is essential for performing di- agnostically adequate coronary arteriography.

In approximately 50 percent of the human hearts. the infundibular artery is actually not a branch of the right coronary artery but arises instead from a discrete orifice in the right sinus of Valsalva close to. but separate from, the orifice of the right coronary artery. It is then sometimes called the third coronary artery [4].

0167-5273/89/$03.50 F’ 1989 El sevier Science Publishers B.V. (Biomedical Division)

Fig. 1. Selective left coronary arteriogram in the left (a) and right (b) anterior oblique VEWS showing apparently normal left anterior

descending and circumflex arteries. Note, however. that no large 1st diagonal branch is seen and there is an indistinct outline of the proximal left anterior descending artery (arrow).

We recently witnessed an interesting angiographic ob- servation involving this infundibular branch in a patient with anteroseptal myocardial infarction of recent onset with apparently normal right and left coronary arterio- grams.

Case Report

A 35-year-old male surgeon with family history of ischaemic heart disease suffered an acute anteroseptal myocardial infarction in February, 1988. He had no history of hypertension, diabetes melhtus or cigarette smoking. During follow-up, he complained of episodes of non-angina1 chest pain. A treadmill test and exercise

radionuclide ventriculography done three months after acute myocardial infarction were negative for exercise- induced ischaemia. In view of his young age, and the persistent complaints of episodic chest discomfort. left ventriculography and selective coronary arteriography were performed by the percutaneous right transfemoral route and by utilizing pre-shaped Judkin’s coronary catheters and urografin 76% (sodium and meglumine diatrizoate) as contrast material.

Left ventriculography in the right anterior oblique view showed an akinetic segment involving the ante- rolateral border of the left ventricle. The left and right coronary arteriograms were normal. except that no large diagonal branch was seen arising from the proximal left

Fig. 2. a. Selective right coronary arteriogram in the left anterior oblique view showing normal right coronary artery. b. Selective

injection in the infundibular (conus) branch in the left anterior oblique view showing filling of the diagonal artery by collateral

pathways (arrows).

136

anterior descending artery, and there was an indistinct outline of the proximal left anterior descending artery (Figs. 1, 2a). Subsequently, selective injection of the infundibular coronary artery opacified the diagonal artery in retrograde manner via the collateral pathways (Fig. 2b).

Discussion

Separate origin of the infundibular (conus) branch of the right coronary artery from the right sinus of Valsalva is the most commonly observed anatomic variation of coronary arterial anatomy [4]. This artery assumes an important role in providing collateral circulation in patients with obstructive coronary arterial disease. Iso- lated opacification of the diagonal artery by these col- laterals has, to the best of our knowledge, not previ-

ously been reported [l-3]. These collateral pathways do

not result from the formation of new vessels but are

secondary to the development and enlargement of the

preexisting vessels that were nonfunctional until a sig-

nificant pressure gradient developed between the prox-

imal and distal parts of the obstructed coronary artery

[3,5]. Collateral circulation is seen at angiography only

if there is total (or near total) arterial occlusion. The

presence of such collateral circulation does not correlate

with abnormalities of left ventricular wall motion [5]. In

Interncrtronul Journal of Curdtolog~. 25 (1989) 1366 139

Elsevier

CARD10 09198

the present case a good collateral arterial circulation was associated with akinesia of the corresponding ventricular segment.

At the time of coronary angiography, it is important to look for the “third” coronary artery in view of its potential to supply collateral circulation to an ob- structed coronary artery. Selective arteriography of the third coronary artery may, in such circumstances, pro- vide crucial information for coronary arterial by-pass surgery or angioplasty.

References

Levin DC, Beckmann CF. Garnic JD. Carey P. Bettmann MA. Frequency and clinical significance of failure to visual-

ize the conus artery during coronary arteriography. Circula-

tion 1981;63:8333837.

Yamagishi M. Haze K. Tamai J. et al. Visualization of

isolated conus artery as a maJor collateral pathway in pa-

tients with total left anterior descending artery occlusion.

Cathet Cardiovasc Diagn 1988;15:95-98.

Levin DC. Pathways and functional sigmficance of the

coronary collateral circulation. Circulation 1974:50:X31-837.

Schlesinger MJ. Zoll PM, WeshIer S. The conus artery: a

third coronary artery. Am Heart J 1949;38:823-836.

Elayda MA. Mathur VS. Hall RJ. Nassumi GA, Garcia E.

DeCastro CM. Collateral circulatron in coronary artery tiis-

ease. Am J Cardiol 1985;55:58-60.

Rudimentary dysplastic valvar tissue guarding the tricuspid orifice with dilatation of the right ventricle and a patent outflow tract

J.C. Mohan, Medha Tatke and Ramesh Arora

Depurtntents of Cardiology and Pathologv. G. B. Punt Mosprtal. Neu, Delhi, Indta

(Received 20 February 1989: revrsion accepted 2X April 1989)

Tricuspid regurgitation due to rudimentary and dysplastic tricuspid valvar tissue associated with a patent right

ventricular outflow tract is described in a lo-year-old child presenting with cyanosis since birth. The diagnosis was

confirmed by cross-sectional echocardiography, angiocardiography and subsequently by histopathological data. We

discuss the differentiation of these findings from Uhl’s anomaly and from the congenitally unguarded tricuspid orifice.

Key words: Tricuspid valve dysplasia: Uhl’s anomaly

Correspondence to: Dr. J.C. Mohan. Dept. of Cardrology. G.B. Pant Hc>\prtal. J.L. Nehru Marg, New Delhr-I 10002. India

0367-5273/X9/$03.50 ‘~ 1989 Elaevier Science Publishers B.V. (Biomrdlcal Drvisron)