The Relationship between P rola psing Mitral Leaflet Syndrome and Normal Coronary Arteriograms* F. Khan Nakh;avan, M.D., F.C.C.P.; Gangaiah Natara;an, M.B., B.S.;t Paravasthu Seshachary, M.D.;:j: and Harry Goldberg, M.D., F.C.C.P. Patients with a prolapsing mitral leaftet frequently have chest pain while their coronary arteriograms are normal. In this regard, these patients are similar to tbe group of patients with angina and normal coronary arteriograms. In tbe present study, c6nical, electrocardiographic, cardiac hemodynamic, angiograpbic, and metabolic findings in patients witb a prolapsing mitral leaflet were compared to those of 16 patients with angina and normal coronary arteriograms. Except for the presence of mitral leaftet prolapse and systolic clicks, tbe findings were similar in both groups. We postulate that prolapsing mitral leaflet is prob&bty related to two difterent mechanisms. In one the primary pathologic change is in the mitral valve (mainly myxomatous transformation), and the abnormalities of ventricular contraction are secondary to unloading of the heart because of a volume shift into the distended and enlarged mitralleaftets. In the other group, the primary pathologic change is in the myocardium, with secondary prolapse of the mitral valve. The myocardial abnormality itself is probably related to primary underlying myocardial disease or to arteriolar pathologic changes. The latter group bas probably the same pathophysiologic abnormality as patients witb angina and normal coronary arteriograms. patients with prolapsing mitral leaflet syndrome frequently have a multitude of symptoms, including chest pain which may even have anginal characteristics; however, the coronary cineangiograms do not usually reveal obstructive lesions. In this regard, patients with a prolapsing mitral leaflet resemble the group of patients with "angina and normal coronary arteriograms." 1-6 We have previously reported that patients with prolapsing mitral leaflet syndrome have abnormalities in the myocardial lactate metabolism similar to those found in patients with "angina and normal coronary arteriograms. "7 Frequently, chest pain may be the dominant clinical feature, and, thus, patients with a prolapsing mitral leaflet or with angina and normal coronary arteriograms are frequently admitted to coronary care units with the diagnosis of preinfarctional angina. The correct diagnosis, especially differentia- From the Deparbnent of Medicine, Section of Cardiology, and the Women's League for Medical Research Laboratory, Albert Einstein Medical Center, Philadelphia. Director, Cardiac Hemodynamic Unit, and Associate Professor of Medicine, Temple University School of Medicine, Philadelphia. t Associate in Cardiology Section. icardiology Fellow. Director, Cardio-Pulmonary-Renal Laboratories, and Professor of Medicine, Temple University School of Medicine, Philadelphia. Manuscript received March 15; revision accepted May. Reprint requests: Dr. Nakhj(Jt)(Jfl, Albert Einstein Medical Center, Northern Division, Philadelphia 19147 76 NAKHJAYAN ET AL tion from coronary arterial disease, is usually made by angiographic studies. During the past two years in our coronary care unit, 34 patients have undergone emergency coronary arteriographic studies. Six of these patients had normal coronary arteriograms; three of them had an associated prolapsing mitral leaflet. It is the aim of this communication to report our findings in two groups of patients, ie, those with a prolapsing mitral leaflet vs those with angina and normal coronary arteriograms, and to focus on the similar clinical, electrocardiographic, metabolic, and coronary arteriographic findings. MATERIALS AND METHODS A total of 36 patients formed the material of this study. All of the patients were referred for cardiac evaluation because of typical or atypical "angina." Frequently the pain was long in duration, lasting more than one hour, and often was unrelated to exertion. There were nine men and 7 women, ranging in age from 31 to 61 years old. A complete history and physical examination, 1-lead resting electrocardiogram, vectorcardiogram, phonocardiogram, and chamber analysis with barium swallow were obtained in all. Cardiac catheterization studies were performed in the postabsorptive state after intramuscular premedication with diphenhydramine hydrochloride and sodium pentobarbital ( 5 mg each). Left ventriculograms in the 3 right anterior oblique view were obtained at 6 frames per second after injection of 4 to 5 ml of a solution of meglumine diatrizoate CHEST, 7: 6, DECEMBER, 1976
( 66 percent) and sodium diatrizoate ( 1 percent) ( Renogratin 76) through a No. 7F NIH catheter. Selective coronary cineangiograms in multiple views were obtained using Sones' technique.8 During the control state and during tachycardia induced by right atrial pacing, myocardial metabolic studies were performed using a bipolar-electrode catheter and a generator (Cordis Chronocor III) at threshold MA. The paced rate was increased by increments of 1 until the occurrence of chest pain or Wenckebach's type of block, or until a heart rate of 16 beats per minute was reached. Lactate levels of arterial and coronary sinus blood were determined in duplicate by the enzymatic method. Myocardial metabolism of lactate was considered abnormal if there was production of lactate or less than 1-percent extraction. After reviewing the left ventriculograms, the patients were divided into two groups. Group 1 consisted of patients in whom the left ventriculogram revealed prolapse of the anterior leaflet or posterior leaflet, or both, of the mitral valve. Group consisted of 16 patients with no prolapse of the mitral valve. Mitral valve prolapse was considered to be present when there was definite bulging of one or both leaflets into the left atrium during systole with or without mitral regurgitation. In this regard the findings by Ranganathan et aj9 and JeresatylO were considered. Special attention was paid to the left ventricu!ograms with retention of the contrast material behind the fornix but no bulge of the leaflets. The left ventriculograms were also analyzed for abnormalities of contraction (akinesia, hypokinesia, dyskinesia, and asyneresis) during systole and diastole. Ejection fraction was determined using the area-length method and a modification of the method of Greene et al.ll The zonal mean velocity of circumferential fiber shortening ( V., ) in proximal, middle, and distal segments of the heart was used according to a previously described technique.1 All of the pressure recordings were made on a photographic recorder ( Electronics for Medicine DR-8) at a paper speed of 5 and 1 mm/sec. Clinical Features REsULTS The two groups were basically in the same age range, 31 to 61 years for those with a prolapsing mitral leaflet vs 33 to 61 years for those with angina and normal coronary arteriograms (Table 1). There was a predominance of women in both groups. Chest pain was less frequent ( 17 I or 85 percent) while palpitation was more frequent in the group with prolapsing mitral leaflets. Nonejection systolic clicks were heard and recorded in four patients with a prolapsing mitral leaflet. No click was heard in the group with angina and normal coronary arteriograms. An apical systolic murmur more frequently occurred in the group with prolapsing mitralleahets, while a fourth heart sound ( S4) was more frequent in the group with angina and normal coronary arteriograms. Electrocardiographic Findings Resting ECGs (Fig 1 and Table ) were normal in only two patients with a prolapsing mitral leaflet Table I --Clinical Findins Finding Leaflet Arteriograms No. of patients 16 Range of ages, yr 31-61 33-61 Sex ratio, M/F 7/13 /14 Chest pain 17 16 Palpitation 13 7 Dyspnea 6 6 Smoking 8 8 Cardiomegaly (1+) Apical systolic murmur 1 Systolic click 4 Heart sounds Sa 1 s, 7 1 and in six patients with angina and normal coronary arteriograms. ST-segment depression was frequently present in both groups. In addition, abnormalities of conduction were present in four patients with a prolapsing mitral leahet and in one patient with angina and normal coronary arteriograms. Documented arrhythmias were more frequent in the group with prolapsing mitral leaflets and included premature ventricular contractions (five patients), ventricular tachycardia (one patient), and paroxysmal atrial tachycardia (one patient). Only two patients in the group with angina and normal coronary arteriograms had premature ventricular contractions. Normal ECG Table -Electrocardiosraphic Findins Finding ST-segment depression Inferolateral Anterolateral Diffuse Prolapsing Mitral Leaflet T-wave inversion Inferior.3 Inferolateral 1 Anterior 3 Anterolateral 4 Diffuse 3 Conduction defects First-degree atrioventricular block Intraventricular conduction defect Right bundle-branch block Arrhythmias Premature ventricular contractions 5 Ventricular tachycardias Paroxysmal atrial tachycardia 4 Normal Coronary Arteriograms 6 4 3 1 CHEST, 7: 6, DECEMBER, 1976 PROLAPSING MITRAL LEAFLET SYNDROME, ANGINA AND NORMAL ARTERIOGRAM$ 77
l. L l... V1 V4 V1 V4 Cardiac hemodynamic Findings (; ; I I The mean cardiac index was 3.51 ±.8 L/min/ sq m ( ±SE) in the group with prolapsing mitral leaflets and 3.5 ±.3 L/ min/ sq m ( -+- SE) in the group with angina and normal coronary arteriograms. The left ventricular end-diastolic pressure was abnormal in three patients with prolapsing mitral leaflets ( 17, 14, and 14 mm Hg) and in one patient with angina and normal coronary arteriograms ( 17 mm Hg). The ejection fraction was more than.56 in all of the patients with prolapsing mitral leaflets, while it was diminished in two patients in the group with angina and normal coronary a r t e r i ~ grams (.48 and.49). Left Ventriculographic Findings Abnormalities of myocardial contraction were present in all of the patients in the group with prolapsing mitral leaflets (Table 3). These consisted of inferior and anterior bulges (which contract but maintain their bulging configuration and, hence, are not considered true aneurysms), hypokinesia, FIGURE 1. Representative ECCs from patient with prolapsing mitral leaflet (top ) and patient with angina with normal coronary arteriograms (bottom). Diffuse ST-T changes are present in both tracings, while premature ventricular contractions are present only in tracing from patient with prolapsing mitral leahet (top). Table ~ L ey entriculographic f t Firulinlf Findings Leaflet Arteriograms Left ventricular contractile pattern Normal 6 Anterior bulge 7 4 Inferior bulge 13 3 Hypokinesia and akinesia Anterior 5 7 Apex 1 4 Inferior 4 Reduced v., Distal 1 6 Middle 6 3 Proximal 6 4 Dyskinesia Anterior 3 Apex Inferior 4 Leaflet Prolapse Posterior Anterior 3 Mitral regurgitation 78 NAIHJAYAN T AL CHEST, 7: 6, DECEMBER, 1976
FIGURE. Representative left ventriculograms (right anterior oblique view) in patient with prolapsing mitral leaflet (left) and patient with angina and normal coronary arteriograrns ( right). AmJWs indicate mitral valve prolapse. akinesia, dyskinesia, and diminished zonal Vcr (below 1.13, 1., and 1.64 circumferences per second in proximal, middle, and distal zones, respectively). 1 Prolapse of the posterior leaflet was present in all (Fig ), while in three patients, both leaflets were prolapsing. Mitral regurgitation was present in only two patients. In the group with angina and normal coronary arteriograms, six patients did not have any abnormality of the geometry or contractile pattern of the left ventricle. In addition, mitral regurgitation was not present in any patient. Coronary Cineangiographic Findings The coronary cineangiograms were basically similar in both groups (Table 4). Tortuosity of the coronary arteries was frequently present. The distal circumflex artery was absent in three patients with prolapsing mitral leaflets and in two patients with "angina and normal coronary arteriograms." Myocardial Metabolic Studies Myocardial lactate abnormalities in the control state were present in two patients with prolapsing mitral leaflets (Table 4). During pacing, two additional patients developed lactate abnormalities. In addition, chest pain and ST-segment depression during pacing occurred in five and three patients, respectively. In the group with angina and normal coronary arteriograms, myocardial lactate abnormalities in the control state were present in four patients; however, during pacing, only two patients continued to have lactate abnormalities. Chest pain and ST -segment depression occurred in six and two patients, respectively. DISCUSSION The data in the present series are indicative of the similarity of clinical, hemodynamic, angiographic, and metabolic findings in the two groups. This raises the P<>ssibility that the prolapsing mitral leaflet and angina with normal coronary arteriograms may have similar underlying mechanisms; however, the "underlying mechanism" is not known in either group. When the entity of "angina and normal coronary arteriograms"t-6 was introduced, the frequency of prolapsing mitral leaflet was not known. In addition, after description of prolapse of the mitral valve by Barlow and Bosman, 13 it was noted that prolapsing mitral leaflet syndrome may include milder degrees of prolapse and is, in fact, a fairly common syndrome. Thus, it is possible that in retrospect, many patients with "angina and normal coronary arteriagrams" have had prolapsing mitral leaflet syndrome. In the present study, out of 36 patients with "angina" Table ~ o r o Arteriopaplaic n a r y Findiq and Myocardial Lactate Abnormaliziu Angina with Finding Leaflet Arteriograrns Coronary arteriographic findings Right dominant 18 1 Absent circumflex artery 3 Left dominant Balanced Corkscrew pattern 17 1 Myocardial lactate abnormalities Control state 4 Pacing-induced tachycardia 4 Chest pain 5 6 ST -segment depression 3 CHEST, 7: 6, DECEMBER, 1976 PROLAPSING MITRAL LEAFL T SYNDROME, ANGINA AND NORMAL ARTERIOGRAM$ 79
PML: Primary mitral valve pathology - - t ) Prolapse: l l ~ Click Murmur Mitral regurgitation LV contraction abnormality: unloading wear and tear Arrhythmia: contact Chest pain: tension on papillary muscle click ANG: Primary myocardial or arteriolar pathology -..... J LV ) contraction I I ~ abnormalities'- )II Prolapse: murmur ~ mitral regurgitation Arrhythmias Chest pain: ischemic, hypoxic No prolapse FiGURE 3. Prolapsing mitral leaflet syndrome ( PML) and angina with normal coronary arteriograms ( ANG) may produce similar clinical findings while their underlying pathologic changes are quite different. In prolapsing mitral leaflet syndrome, primary pathologic change is in the valve, and abnormalities of myocardial contraction are secondary to unloading of heart. In angina with normal coronary arteriograrns, primary pathologic change fs in myocardium or coronary arterioles, and mitral prolapse, if present, is secondary. who had normal coronary arteriograms, had angiographic evidence of mitral valve prolapse. In the absence of pathologic specimens and pathophysiologic understanding of the mechanism of prolapsing mitralleahet and "angina with normal coronary arteriograms," the present data are not conclusive; however, the similarity of clinical features in both groups may suggest that in certain patients with a prolapsing mitralleahet, the underlying mechanism or mechanisms are the same as those in angina with normal coronary arteriograms. If this assumption is correct, then prolapsing mitral leahet probably has two different mechanisms. 7 In one, there is a primary abnormality of the mitral valve, such as myxomatous transformation of the valve, with abnormalities of contraction of the left ventricle secondary to unloading of the heart. 14 In the other group the primary pathologic changes are in the arterioles or myocardium, with secondary prolapse of the mitral valve (Fig 3). It should be mentioned also that obstructive coronary artery disease, by causing papillary muscular dysfunction, can produce prolapse of mitralleahets and, hence, a similar clinical picture. REFERENCES 1 Likoff W, Segal BL, Kasparian H : Paradox of normal selective coronary arteriograms in patients considered to have unmistakable coronary heart disease. N Eng! J Med 76:163-166, 1967 Kemp HG, Elliott WC, Gorlin R: The anginal syndrome with normal coronary arteriography. Trans Assoc Am Physicians 8:59-7, 1967 3 Neill WA, Kassebaum DG, Judkins MP: Myocardial hypoxia as the basis for angina pectoris in a patient with normal coronary arteriograms. N Engl J Med 79:789-79, 1968 4 Campeau L, Lesperance J, Bourassa MG, et al: Myocardial infarction without obstructive disease at coronary arteriography. Can Med Assoc J 99:837-843, 1968 5 Eliot RS, Bratt G: The paradox of myocardial ischemia and necrosis in young women with normal coronary arteriograms. Am J Cardiol3:633-638, 1969 6 Glancy DL, Marcus ML, Epstein SE: Myocardial infarction in young women with normal coronary arteriograrns. Circulation 44:495-5, 1971 7 Natarajan G, Nakhjavan FK, Kahn D, et al: Myocardial metabolic studies in prolapsing mitral leaflet syndrome. Circulation 5:115-111, 1975 8 Sones FM, Shirey EF: Cine coronary arteriography. Mod Concepts Cardiovasc Dis 31:735-738, 196 9 Ranganathan N, Silver MD, Robinson TI, et al: Angiographic-morphologic correlation in patients with severe mitral regurgitation due to prolapse of the posterior mitral valve leaflet. Circulation 48:514-518, 1973 1 Jeresaty RM : Ballooning of the mitral valve leaflets: Angiographic study of 4 patients. Radiology 1:45-5, 1971 11 Greene DG, Carlisle R, Grant C, et al: Estimation of left ventricular volume by one-plane cineangiography. Circulation 35:61-69, 1967 1 Nakhjavan FK, Natarajan G, Goldberg H: Comparison of ejection fraction and zonal mean velocity of myocardial fiber shortening. Circulation 5:64-67, 1975 13 Barlow JB, Bosman CK: Aneurysmal protrusion of the posterior leaflet of the mitral valve. Am Heart J 61 :166-178, 1966 14 Jeresaty RM : Etiology of the mitral valve prolapse-click syndrome. Am J Cardiol36:11-113, 1975 71 NAKHJAYAN ET AL CHEST, 7: 6, DECEMBER, 1976