The Square Left Ventricle: An Angiographic and Radionuclide Sign of Left Ventricular Thrombus 1

Diagnostic Radiology

James Goolsby, M.D., Peter Steele, M.D., Dennis Kirch, M.S.E.E., Dennis Battock, M.D., and Hywel Davies, M.D. The association of mural thrombus with left ventricular aneurysm is well documented, though angiographic documentation of left ventricular thrombus can be difficult. The authors describe the unique appearance of the left ventricular cavity in 5 patients. In all cases, ventriculograms obtained in the right anterior oblique position showed a squared apex. In 2 patients this phenomenon was also demonstrated by radionuclide angiocardiography. All 5 patients were found to have left ventricular thrombus at operation or autopsy. INDEX TERMS:

Aneurysm, cardiac. Heart, abnormalities. Heart, radionucJide studies

Radiology 115:533-537, June 1975

is a common feature of left ventricular aneurysm, although its incidence varies considerably in reported series. We wish to describe the unusual angiographic appearance of the left ventricular cavity in 5 patients with coronary artery disease and left ventricular aneurysm. In all cases ventricular thrombus was confirmed at operation or autopsy. One patient had an episode consistent with embolic stroke. All patients demonstrated a characteristic squared left ventricular apex which persisted throughout the cardiac cycle.

M

URAL THROMBUS

METHODS

Five patients were studied during the period 1969 to

1973 at the Denver Veterans Administration Hospital. Each of them underwent right and left heart catheterization, including left ventricular cineangiography and selective coronary arteriography. Left ventricular cineangiography was performed in the right anterior oblique projection (30-40°). Two patients were also studied by radioisotope angiocardiography. CASE REPORTS CASE I (A. T.): An anterolateral myocardial infarction was seen in a 48-year-old man in May 1970. Congestive heart failure without angina developed in September. Right-sided pressures were normal at cardiac catheterization in May 1971. The pulmonary arterial wedge

Fig. 1. CASE I. A and B. End-diastolic (A) and end-systolic frames (B) from the left cineventriculogram (RAO). An apical aneurysm containing thrombus was found at surgery. 1 From the Division of Cardiology, Department of Medicine (V. G., P. S., D. B., H. D.) and the Nuclear Medicine Service (D. K.), Denver Veterans Administration Hospital, and the University of Colorado Medical Center, Denver, Colo. Revised version accepted for publication in January 1975. 2 Supported by research funds from the Veterans Adrtlinistration. sjh

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Fig. 2. CASE II. A and B. End-diastolic (A) and end-systolic frames (B) from the cineventriculogram (RAO). A left ventricular aneurysm containing thrombus was noted at surgery.

Fig. 3. CASE III. firmed at autopsy. Fig. 4. CASE IV.

End-diastolic frame from the cineventriculogram. An apical aneurysm containing thrombus was conEnd-systolic frame from the cineventriculogram. A thrombotic aneurysm was noted at autopsy.

pressure was elevated, with a mean of 17 mm Hg, and the left ventricular end-diastolic pressure was 19 mm Hg. The cardiac index was 2.2 l/min./m2 . Left ventricular cineangiography in the right anterior oblique position revealed a large left ventricular cavity with an akinetic apex (Fig. 1). The left ventricular ejection fraction was 27 %. Mild mitral regurgitation was also noted. Coronary arteriography revealed a lesion narrowing the lumen to 50 % of the expected diameter in the proximal left anterior descending coronary artery. At surgery (June 1971), a 4-cm apical aneurysm containing thrombus was resected.

CASE III (J. D.): A 57-year-old man presented in June 1972 with a history of angina for three years and acute myocardial infarctions in December 1971 and February 1972. Symptoms and signs of left ventricular failure had been noted. Cardiac catheterization revealed an elevated left ventricular end-diastolic pressure of 26 mm Hg. Selective coronary arteriography revealed high-grade occlusive lesions involving the right, left main, and left anterior descending coronary arteries. Left cineventriculography showed markedly reduced function and a squared apex (Fig. 3). Thrombus within the apex of the left ventricle was confirmed at autopsy in September 1972.

CASE II (J. M.): A 47-year-old man presented in January 1972 with angina pectoris of one year duration. An anterolateral myocardial infarction had developed in June 1971. Thereafter the angina persisted, but there were no signs or symptoms of left ventricular failure. Cardiac catheterization now revealed normal pressure on both sides. The cardiac index was 2.2 I/min./m2 . Left ventricular cineangiography revealed a large left ventricular cavity with akinesis of the apex (Fig. 2). Coronary arteriograms demonstrated nearly total occlusion of the proximal right and left anterior descending coronary arteries. At surgery in February 1973, an apical aneurysm containing thrombus was resected and a saphenous-vein aortocoronary bypass was performed.

CASE IV (C. F.): A 51-year-old man presented with angina pectoris in December 1973. He had had an anterior myocardial infarction in 1961. In 1970, increasing angina was treated with a saphenousvein aortocoronary bypass graft of the left anterior descending coronary artery. The angina subsided for 18 months but recurred in 1972. An acute anterolateral myocardial infarction developed in October 1973. Sudden left hemiparesis occurred during convalescence. Congestive cardiac failure was noted in December 1973, and cardiac catheterization was undertaken in January 1974. At catheterization, the left ventricular end-diastolic pressure was 16 mm Hg. Selective coronary arteriography revealed severe occlusive disease involving the left anterior descending and circumflex

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Diagnostic Radiology

Fig. 5. CASE IV. Sequential 2-second summed images obtained in the 40° RAO projection. A. Left atrial image (arrow). B. Ascending aorta (arrow). C. Squared left ventricular apex (arrow). D. Descending aorta (arrow). system. The vein graft could not be identified and was presumed to be occluded. Left ventriculography revealed a squared, immobile ventricular apex with markedly diminished contraction (Fig. 4). Radionuclide angiocardiography was then performed, using the wedged pulmonary angiographic technique (1). A tomographic collimator with slanted holes (20°) was used to reduce the distance between the patient and the collimator. The patient was placed under a Searle Pho/Gamma HP Anger camera in the 40° right anterior oblique position. 12 ml of 99 m Tc-pert ec hnetate was injected into the wedged catheter and flushed. The Polaroid image revealed a squared left ventricular apex (Fig. 5). Apical thrombus was confirmed at autopsy in November 1973. CASE V (M. W.): A 46-year-old man presented in January 1972 with incapacitating angina pectoris and a past history of several myocardial infarctions. Cardiac catheterization revealed normal pressure on both sides. Left ventricular cineangiography was not performed. The right coronary injection demonstrated a lesion in the distal right coronary artery, occluding the lumen to 30-40 % of the expected diameter. Selective left coronary artery injection demonstrated a 60-70 % narrowing of the proximal left anterior descending coronary artery and the proximal diagonal branch. In March the patient underwent a saphenous-vein bypass graft of the diagonal branch and an internal mammary artery anastomosis to the left anterior descending coronary artery. His subsequent course was unremarkable until June, when he suffered an acute inferior myocardial infarction. Congestive heart failure became manifest, though angina was not present. Repeat cardiac catheterization in February 1973 showed a mean pulmonary artery wedge pressure of 34 mm Hg and a left ventricular end-diastolic pressure of 40 mm Hg. Left ventricular

cineangiography showed a poorly contracting left ventricle with a large filling defect in the apex (Fig. 6). The internal mammary bypass was found to be patent on selective angiography; however, the saphenous vein could not be identified. At repeat catheterization, radionuclide angiocardiography performed via the wedged pulmonary artery revealed a squared left ventricular apex (Fig. 7).

DISCUSSION

Autopsy series have been concerned mainly with aneurysms that are well defined anatomically. Dubnow et al. found thrombus in 65 % of 80 cases of left ventricular aneurysm at autopsy (2). Schlichter et al. found thrombus in 53.9% of an autopsy series of 102 left ventricular aneurysms (3). On the other hand, Abrams et al. reported that only 14 % of 65 well-circumscribed aneurysms contained thrombus (4). Likewise, thrombus has frequently been found within a ventricular aneurysm at surgery. Cooley et al. found thrombus in 95 % of 80 resected aneurysms (5), and 49% of the 130 patients in Favaloro's series of operated aneurysms had thrombus at operation (6). The frequency of left ventricular thrombus may be underestimated by radiographic methods. Kluge et el. suspected mural thrombi in 6 of 36 patients on the basis of ventricular wall calcification or filling defects at left ventricular angiography, but 25 patients were found to

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Fig. 6. CASE V. A and B. End-cliastolic (A) and end-systolic frames (B) from the left ventriculogram, showing the squared apex with irregular contrast material distribution. A ventricular aneurysm containing thrombus was demonstrated at al!top~y.· .

Fig. 7. CASE V. Sequential 2-second summed images obtained in the 40 0 RAO projection. A and C. Serial filling of the left atrium (A, arrow). left ventricle, and ascending aorta (C, arrow) is demonstrated. B. The squared left ventricular apex is apparent (arrows).

have mural thrombus at operation (7). Conversely, Gorlin points out that contrast material often does not mix well in an akinetic or dyskinetic portion of the left ventricular cavity (8). Pooling and puddling of contrast material. may occur in these areas, producing a mottled, streaked, or "mackerel-sky" pattern which may mimic the filling defects produced by thrombus. Conceivably, filling defects due to papillary muscle or a prominent trabecular pattern may also simulate thrombus. A filling defect should be constant throughout the cardiac cycle before it can be said to indicate thrombus (9).

Our 5 patients all had coronary artery disease with aneurysm involving predominantly the apical portion of the left ventricle as well as major occlusive disease involving the left coronary artery. In each case the left cineventriculogram demonstrated a squared-off left ventricular apex. The end-diastolic and end-systolic images from a patient with an apical aneurysm are shown in Figure 8. The ventriculogram shows a rounded, akinetic apex, and the aneurysm did not contain thrombus at autopsy. This last ventriculogram is characteristic of the angiographic appearance of left ventricular aneu-

THE SQUARE LEFT VENTRICLE

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Fig. 8. A and B. End-diastolic (A) and end-systolic (B) frames from the left cineventriculogram of a patient shown to have a ventricular aneurysm but no thrombosis. Note the rounded apex. rysm formation in coronary disease. Similar ventriculograms showing rounded apices can be seen in Figures

14 (CASE III) and 38 (CASE IX) of the paper by Kittredge and Cameron (10); however, they do not mention the presence or absence of thrombus formation in their series of 11 cases of ventricular aneurysm. Thus the square ventricle seems to be a ventriculographic sign of an immobile cardiac apex containing thrombus and is one of the manifestations of endocardial thrombosis. We feel that it is a characteristic sign of left ventricular thrombus. Surgical confirmation was obtained in CASES I and II and autopsy confirmation in CASES IV, V, and VI. The patient in CASE IV had an episode entirely consistent with embolic stroke. Irregular contrast material distribution in CASES III and V suggest that it became mixed around laminations of thrombus. In CASES IV and V the squared left ventricular apex was demonstrated scintigraphically as well as by contrast ventriculography. Since scintigraphic studies can be performed without left heart catheterization (11-13), radionuclide angiocardiography may prove useful in screening patients for left ventricular thrombus. Peter Steele, M.D. Division of Cardiology Denver VA Hospital 1055 Clermont Denver, Colo. 80220

REFERENCES 1. Steele P, Kirch 0, Matthews M, et al; Measurement of left heart ejection fraction and end-diastolic volume by a computerized

scintigraphic technique using a wedged pulmonary artery catheter. Am J Cardiol 34: 179-186, Aug 1974 2. Dubnow MH, Burchell HB, Titus JL: Postinfarction ventricular aneurysm. A clinicomorphologic and electrocardiographic study of 80 cases. Am Heart J 70:753-760, Dec 1965 3. Schlichter J, Hellerstein HK, Katz IN: Aneurysm of the heart: a correlative study of 102 proved cases. Medicine 33:43-86, Feb 1954 4. Abrams Dl, Edelist A, Luria MH, et al: Ventricular aneurysm. A reappraisal based on a study of sixty-five consecutive autopsied cases. Circulation 27:164-169, Feb 1963 5. Cooley DA, Hallman GL: Surgical treatment of left ventricular aneurysm: experience with excision of postinfarction lesions in 80 patients. Progr Cardiovasc Dis 11:222-228, Nov 1968 6. Favaloro RG, Effler DB, Groves LK, et al: Ventricular aneurysm-clinical experience. Ann Thorac Surg 6:227-243, Sep 1968 7. Kluge TH, Ullal SR, Hill JD, et al: Dyskinesia and aneurysm of the left ventricle. Surgical experience in 36 patients. J Cardiovasc Surg 12:273-280, Jul-Aug 1971 8. Gorlin R, Klein MD, Sullivan JM: Prospective correlative study of ventricular aneurysm. Mechanistic concept and clinical recognition. Am J Med 42:512-531, Apr 1967 9. Cheng TO: Incidence of ventricular aneurysm in coronary artery disease. An angiographic appraisal. Am J Med 50:340-355, Mar 1971 10. Kittredge RD, Cameron A: Abnormalities of left ventricular wall motion and aneurysm formation. Am J Roentgenol 116: 100124, Sep 1972 11. Kriss JP, Enright lP, Hayden WG, et al: Radioisotopic angiocardiography. Wide scope of applicability in diagnosis and evaluation of therapy in diseases of the heart and great vessels. Circulation 43:792-808, Jun 1971 12. Zaret Bl, Strauss HW, Hurley PJ, et al: A noninvasive scintiphotographic method for detecting regional ventricular dysfunction in man. N Engl J Med 284: 1165-1170, 27 May 1971 13. Mason DT, Ashburn Wl, Harbert JC, et al: Rapid sequential visualization of the heart and great vessels in man using the wide-field Anger scintillation camera. Radioisotope-angiography following the injection of technetium-99m. Circulation 39: 19-28, Jan 1969