Mitral commissurotomy—I

LETTERS TO THE EDITOR

Department of Pediatrics University of Minnesota Minneapolis, Minnesota References 1. Hwuy WL, Clark CE, Eprleln SE. Asymmetric septal hypcwtrophy: echocardiographic ldentiflcation of the oathofmomonic anatomic abnormality of IHSS. Clrculatlorl 1973; 47~225-33. . 2. Abassl AS, [email protected] RN, Ebw LM, Pearce ML Left ventricular hypertrophy diagnosed by echocardIography. N Engl J Med 1973;289:118-21. 3. Popp RL, Fllfy K. Brown OR. Harrbon DC. Effect of transducer placement on echoE!zaphlc measurement of left ventricular dimensions. Am J Card101 1975;35:

ECHOCARDIOGRAPHIC FEATURES OF PORCINE VALVE DYSFUNCTION

Alam et al.’ were able to record systolic or diastolic fluttering, or both, of the valve cusps in five patients with porcine mitral insufficiency. They describe this as a typical echocardiographic pattern of severe regurgitation due to a tear of one or more cusps. They also state that systolic fluttering of cusp echoes is never seen in patients with clinically normal porcine valves. We have examined 125 patients with porcine mitral valve prostheses2 at a short interval after operation; none of these patients with clinically normal bioprostheses exhibited a systolic fluttering of cusp echoes. However, in two patients who manifested paravalvular leaks late after operation, echocardiographic examination showed a very coarse diastolic fluttering, in the absence of aortic regurgitation (Fig. I). Both patients underwent operation, which demonstrated a major detachment of the valve with normal cusps. Moreover, the same pattern could be recorded in one patient after suture of the leak had yielded optimal clinical results and the systolic murmur had disappeared. We therefore do not agree that diastolic fluttering in itself is a typical diagnostic sign of a torn porcine valve cusp. In two additional patients with prosthetic valve regurgitation due to a torn cusp, the latter reflected quite chaotic echoes mimicking exactly those that can be recorded from flail native mitral valves. Gaja Jacovella, MD Caterina Narducci, MD Paolo G. Pino, MD Antonio Salati, MD Ospedale S. Camilla Dipartimento di Cardiologia Rome, Italy References 1. Alam M, Madrazo AC. [email protected] RI, Goldstein S. M mode and two dimensional echocardiographic features of porcine valve dysfunction. Am J Cardiol 1979:43: 502-g. 2. Salati A, Pin0 PG, 0, DeBenedlctls F. Jacovella 0. Aspetti ecocardiografici delle protesi valvolari porcine: osservazioni in 125 casi personali. Gicwn ltal Cardiol, in press.

Manoccl

REPLY

Since our initial report, we used M mode echocardiography to study eight additional patients with severe mitral porcine valve insufficiency. Of these patients, one had paravalvular insufficiency and the other seven had insufficiency due to tear in one or more porcine cusps. The echocardiogram of the patient with paravalvular leak was within normal limits; however, that of all other seven patients showed systolic or dia-

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FlGURE 1. M mode echocardiogram from patient with paravalvular leak of a prxcine mitral valve prosthesis. Note the diastolic coarse echoes of the cusps (arrow).

stolic fluttering, or both, of the porcine cusp. We believe that the diastolic fluttering of the porcine cusp is not specific for torn and regurgitant porcine mitral valve. Diastolic fluttering of the porcine cusp has also been reported in aortic insufficiency. We have observed it in patients with atria1 flutterfibrillation and now Jacovella et al. have reported this finding in patients with paravalvular leak. Therefore, all these factors should be considered in the differential diagnosis of diastolic fluttering of the porcine valve. However, the presence of systolic fluttering of the porcine valve, if present, remains very specific and suggestive of a torn and flail porcine mitral valve. Mohsin Alam, MD Division of Cardiovascular Diseases Henry Ford Hospital Detroit, Michigan

MITRAL COMMISSUROTOMY-I

The excellent review by Fowler and van der Bel-Kahn’ on mitral valve surgery reiterates that mitral commissurotomy is the first choice in the surgical treatment of mitral stenosis for selected patients. This conclusion is supported by, among others, the excellent long-term results reported by Ellis et aL2 in a large number of patients after closed mitral valve commissurotomy. However, perioperative systemic embolization is a definite risk associated with closed mitral commissurotomy. Ellis and Harken found that 89 (6 percent) of 1,500 patients undergoing closed mitral commissurotomy had early systemic thromboembolism, with a fatality rate of 43 percent. Most of the emboli occurred within 12 hours of operation, often in the operating room. These early emboli usually came from detachment of mural atrial thrombi or calcified material in the mitral valve. Thus it is important to determine before surgery whether left atria1 thrombi are present, which would then influence the surgeon to decide between closed and open commissurotomy. The criteria laid out by Fowler and van der Bel-Kahn’ for the preoperative exclusion of left atrial thrombi (namely, the presence of sinus rhythm and the lack of history of systemic embolism) are useful, but by themselves not sufficient to exclude the presence of left atria1 thrombosis. Forward pulmonary angiography looking for left atria1 filling defects has been shown to be very insensitive.4 We5 recently found in a consecutive series of 20 patients with mitral stenosis studied with coronary arteriography that 5 had neovascular-

The American Journal of CARMOLOOY Volume 46

LETfERS

TO THE EDITOR

ization of the left atrium with the aberrant vessels arising from the left main or left circumflex coronary artery. All surgically treated patients with left atrial neovascularization in our series had left atria1 thrombi proved at open heart surgery. This 25 percent incidence rate of left atria1 neovascularization suggesting left atrial thrombus matches the reported incidence of left atria1 thrombi in mitral stenosis at surgery6 and autopsy.’ Our data therefore indicate that coronary arteriography with attention to the presence of left atria1 neovascularization may be the most sensitive means for the preoperative diagnosis of left atria1 thrombosis. We suggest that coronary arteriography should be performed in every patient with mitral stenosis who is considered a potential candidate for closed mitral commissurotomy based on the criteria of Fowler and van der Bel-Kahn.

the Texas Heart Institute 15 years ago, the rate of risk has been low (2.1 percent in 903 cases) in comparison with an average risk rate of 5 percent from mitral valve replacement (2.4, 5, 6 and 7.5 percent as mentioned by Fowler and van der Bel-Kahn). Many of these patients had previous operations with closed mitral commissurotomy elsewhere.

Raul E. Falicov, MD, FACC Anthony Bochna, MD Cardiac Catheterization Laboratory Christ Hospital of the Evangelical Hospital Association Oak Lawn, Illinois

We agree that it is desirable to evaluate the possibility of left atrial thrombi in patients with mitral stenosis who are to have commissurotomy. In addition to the history of embolism, and the existence of atrial fibrillation, other methods of study may be useful. One of these is radiologic contrast study of the left atrium. Echocardiography1s2 has been used to identify left atria1 thrombi. Coronary arteriography, as described by Falicov and Bochna, offers yet another method to diagnose intracardiac thrombi. Unfortunately, soft, unorganized, recently formed thrombi, the most dangerous for embolism, are unlikely to show the neovascularization described by Falicov and Bochna. Although we can only make an estimate with regard to the evolution of left atria1 thrombi, in the case of intravascular thrombi, gross evidence of adherence between the thrombus and a vessel wall is rarely noted before the 4th or 5th day.3 When there is severe damage to the vessel or heart chamber wall, overlying thrombi may fail to organize, but remain as a potential source of emboli for years. Falicov and Bochna’s series of 20 patients is small. The risk of emboli during closed commissurotomy is 4 to 6 percent$ thus, more patients should be studied in order to determine the merit of this proposal. We await with interest further reports of a larger series. The report of Price and Cooley of a mortality rate of 2.1 percent in 903 cases of open mitral commissurotomy compares very favorably with Glenn’s reported mortality rate4 of 3.8 percent in 560 cases of closed mitral commissurotomy in a much older series. However, Glenn now reports (personal communication) no operative fatality with closed commissurotomy during the last 20 years. Further, there were only 2 deaths from systemic arterial embolism in Glenn’s first 566 cases of closed commissurotomy. One of the greatest difficulties in comparing mortality experiences in different institutions is that one group may be operating on patients with milder or earlier mitral disease, a group in whom a lower death rate is to be expected. We would welcome a controlled clinical trial to compare open and closed mitral commissurotomy, but doubt that such a study will be forthcoming. A comparison of long-term results after open or closed commissurotomy in addition to immediate mortality rates is badly needed.

References 1. Fowfer NG, ven der Ed-Kahn JM. lndicetions for surgical replacement of the mitral v&e. Am J Card&l 19?9;0):146-57. 2. EUlr~,~~4~M,Hrlr~DE.Fl~eerrtotw~-~shdyofonemousand patients wdergolng closed m&al valvuloplasty. Circulation 19733463357-64. 3. EMS LG. Herkee GE. Arterial emboflzatlon in relation to m&al valwloplasty. Am Heart J 1961;82:611-15. 4. Parker GM, Frfedwbq MJ, Tem~felen AW, Betford Tti. Preoperative angiocardiogfaphic diagnosis of left atrial thrombi in mitral stenosis. N Engl J Med 1965;273: 136-40. 5. Bedma AJ, Fslkov RE. The diagnosis of intracardiac thrombi by selective coronary arterlogmphy In mitral stenosis and left ventricular dysfunction. Arch Intern Med. in

press.

6. Nfohefs HT, Gfenco 0, Mme DP, Adam A, Baftazar N. Open mitral ccfnmissurotomv-exoerlence with 200 consecutive casas. JAMA 1962:162:266-70. 7. Weiech b, kaesh L, [email protected] AA. An fntqfetation of the lncldenw of mwal tiombi in the left aulcle and appe&age wi* perticuler reference to mitral commisswotomy. Am Heart J 1953;25:252-54.

MITRAL COMMISSUROTOMY-II

We are concerned about the comments of Fowler and van der Bel-Kahn regarding patient selection for commissurotomy. We agree that patients should have a pliable valve (often indicated by a loud first heart sound and opening snap as well as a characteristic movement on angiocardiography) and should not have severe calcification or significant mitral regurgitation. However, we see no need to limit this low risk operation to patients with sinus rhythm, no systemic embolism, or even absence of other major valve dysfunction. Replacement of the aortic valve in conjunction with an open mitral commissurotomy can be done with less risk than double valve replacement and with less subsequent risk of thromboembolism or deterioration of a prosthetic mitral valve. Of even greater importance is the use of isolated open mitral commissurotomy for patients with noncalcific mitral stenosis even when they have atrial fibrillation or have had a history of systemic embolism. With cardiopulmonary bypass, thromhi can be removed from the left atrium with ease and a better mitral commissurotomy can be performed than with the closed technique. The risk of subsequent embolism seems to be significantly less with preservation of the mitral valve rather than with a prosthetic valve as well as having a significantly lesser operative mortality from commissurotomy than from mitral valve replacement. Admittedly, closed mitral commissurotomy seems unwise in patients with known systemic embolism or in cases where left atrial thrombi might be suspected. Since open mitral commissurotomy became the accepted approach here at

Everett C. Price, MD, FACC Denton A. Cooley, MD, FACC Price Cardiology Associates Texas Heart Institute Houston, Texas

REPLY

Noble 0. Fowler, MD, FACC Johanna M. van der Bel-Kahn, MD Division of Cardiology Department of Pathology University of Cincinnati College of Medicine Cincinnati, Ohio References 1. Peehfmem HW, Gesto LL. Bmwn RE. Left aVial thrombus detected by [email protected] A case report. J Clin Ultrasound 1975;3:65-7. 2. Spangler RD. Echocardicgraphlc demonstration of a left atrial thrombus. Chest 1975;

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