Opening Snap Research Articles

Echocardiographic studies of mitral valve motion. Genesis of the opening snap in mitral stenosis

In an effort to delineate the origin of the mitral opening snap, 29 patients with rheumatic mitral stenosis and audible opening snaps were studied by means of simultaneous external recordings including phonocardiography, mitral echocardiography, and apex cardiography. Comparison was made with 10 normal volunteer subjects. Discrepancies were noted when the apex cardiogram was utilized to time the opening snap or isovolumic relaxation of the left ventricle. This method, however, remains a useful tool for differentiation of heart sounds. Echocardiographic timing of the opening snap is more precise than heretofore available reference methods. Opening snap and completion of anterior mitral leaflet opening movement were simultaneous within the error of measurement, 5 msec., in all patients with clinically pure mitral stenosis and in 74 per cent of those with mixed or bivalvular lesions. In the remainder of the latter group these events occurred within 10 msec. apart. This study supports the hypothesis that opening snap originates from the diseased mitral leaflets as they reach completion of their opening movement.

Haemodynamic factors influencing opening snap interval in mitral stenosis.

Various haemodynamic measurements were correlated with the A2-OS interval in 35 patients with pure or predominant mitral stenosis. There was good correlation of left atrial V wave pressure, left ventricular systolic pressure, and mitral mean diastolic gradient with A2-OS. There was no significant correlation of mitral valve area with A2-OS. When the left ventricular pressure was arbitrarily assigned to one particular pressure (100 mm. Hg) correlations with all other variables improved. There was still no correlation of A2-OS interval with mitral valve area. These and other haemodynamic factors influencing the A2-OS interval are briefly discussed.

Mitral valve movement: a study using an ultrasound technique.

The movement of the anterior leaflet of the mitral valve has been recorded with an ultrasound echo technique. The intrinsic mobility of the valve cusps and the rate of ventricular filling are thought to influence the closure of the valve during diastole. Atrial contraction occurs at the end of ventricular diastole and reopens the valve before the mitral valve returns to the closed position before the onset of ventricular systole. The relation of the opening snap and third heart sound to the movement of the cusp is shown. In mitral stenosis ventricular systole occurs when the mitral valve is still far away from the closed position and the rapid movement of the cusp to the closed position may be the cause of the high intensity vibrations of the first heart sound. The EF slope (representing the rate of the closing movement of the cusp in end diastole) is decreased and a good correlation has been found with the degree of stenosis. After mitral valvotomy the EF slope increases significantly. The validity of these methods in assessing mitral incompetence or relative predominance of stenosis or incompetence in mixed mitral lesions is discussed. The ultrasound cardiograph is a fairly simple and completely atraumatic technique with proven diagnostic value in mitral valve disease. In addition, because of the new type of information that is given, it has potential as a research tool which is, as yet, largely unexplored.

The left atrial pressure pulse of mitral stenosis in sinus rhythm

The left atrial pressure pulse of isolated, severe mitral stenosis (sinus rhythm, noncalcified valve) is compared with the normal left atrial pressure pulse (indirect, esophageal); the left atrial sound and pressure relations are described in both groups. Micromanometers mounted on cardiac catheters and nasogastric tubes were used for recording. The left atrial pressure pulse of noncalcified mitral stenosis in sinus rhythm differs from the normal in several important respects. Fusion of the a - c waves in mitral stenosis reflects the overlap of atrial contraction with initial ventricular contraction. The delayed left atrial a wave peak is consistent with prolonged atrial systole. The c wave occurs during the ascent or eversion phase of the mitral complex and terminates abruptly with the initial vibrations of the delayed, accentuated first heart sound. The initial y descent reflects descent or inversion of the mitral complex toward the ventricle and terminates abruptly at the opening snap notch with the mitral opening snap occurring before mitral valve diastolic flow.

The first derivative thoracic impedance cardiogram.

When an alternating current of high frequency is applied to the thorax, the first derivative of the impedance to this current is affected by the cardiac cycle resulting in a characteristic wave form. Phonocardiograms, electrocardiograms, and first derivative thoracic impedance cardiograms were recorded simultaneously in 91 subjects. The first derivative thoracic impedance cardiograms were found to have sharply demarcated points which occur synchronously with the first heart sound, aortic second sound, pulmonic second sound, mitral opening snap, third heart sound, and fourth heart sound. The first derivative thoracic impedance cardiogram may thus be used not only as a reference tracing to help identify heart sounds on the phonocardiogram, but also for directly timing the intervals within the cardiac cycle.

Constrictive Pericarditis Masquerading as Mitral Stenosis

The five patients presented were considered to have mitral stenosis because of a history of dyspnea on exertion or paroxysmal atrial fibrillation, the presence of a loud first heart sound with an “opening snap,” a loud pulmonary component of the second heart sound, electrocardiographic evidence of right axis deviation and left atrial enlargement or radiological evidence of cardiomegaly, especially left atrial and right ventricular enlargement. The correct diagnosis of constrictive pericarditis was made by cardiac catheterization and confirmed at surgery. The echocardiogram was found to be very helpful in the differential diagnosis. The demonstration of normal motion of the anterior mitral leaflet ruled out the presence of mitral stenosis. The five patients presented were considered to have mitral stenosis because of a history of dyspnea on exertion or paroxysmal atrial fibrillation, the presence of a loud first heart sound with an “opening snap,” a loud pulmonary component of the second heart sound, electrocardiographic evidence of right axis deviation and left atrial enlargement or radiological evidence of cardiomegaly, especially left atrial and right ventricular enlargement. The correct diagnosis of constrictive pericarditis was made by cardiac catheterization and confirmed at surgery. The echocardiogram was found to be very helpful in the differential diagnosis. The demonstration of normal motion of the anterior mitral leaflet ruled out the presence of mitral stenosis.

Isolated tricuspid valvular stenosis

The seventh case of isolated tricuspid valvular stenosis is reported. Despite the rarity of this lesion, a number of distinguishing clinical features warrant emphasis. The patient is generally a woman who has had a known heart murmur since childhood and who complains of fatigue, dyspnea and edema. Helpful physical signs include a prominent jugular venous a wave, left parasternal presystolic rumble with little if any mid-diastolic component, and generally no opening snap. Both the a wave and the rumble are accentuated during inspiration. Signs of pulmonary vascular congestion are absent, and both the electrocardiogram and the chest roentgenogram reveal only right atrial enlargement. Cardiac catheterization demonstrates a tricuspid diastolic mean gradient of 4 to 8 mm Hg and a valve area ranging from 0.8 to 1.5 cm 2. The clinical course is variable. In some cases tricuspid valvulotomy or valvuloplasty has resulted in considerable improvement.

Apex cardiography. II. Changes in the apex cardiogram in several phases of the cardiac cycle in the aged and patients with various heart diseases

Recently it has been shown that the apexcardiogram (ACG) is an useful procedure to evaluate the pathophysiological state of the heart in various diseases. In the previous paper the author reported the data of analyses of rapid filling wave and diastolic filling wave of the ACG and of cardiac dynamics by the ACG method in normal subjects. The present paper is concerned with the data of analyses of these factors in older subjects, hypertensives and patients with ischemic heart disease and with various valvular diseases. In addition, relationships between the O point of the ACG and the opening snap in mitral valvular diseases have been studied. Subjects and Methods Investigations were carried out on 151 individuals. Group of older subjects consisted of 39 individuals without cardiovascular and pulmonary diseases, ranging from 60 to 86 years of age with an average of 68 years. Fifty hypertensive individuals had no marked changes in the ECG, and ranged in age from 20 to 76 years, with an aver-age of 46 years. The group with coronary heart disease (CHD) consisted of 20 patients who had ischemic findings in the ECG or old myocardial infarction, but no high blood pressure, ranging from 45 to 74 years of age, with an average of 61 years. The group with valvular diseases consisted of 18 patients with mitral stenosis, ranging from 30 to 62 years of age, with an average of 45 years, 6 patients with mitral stenoinsufficiency, ranging from 25 to 58 years of age, with an average of 43 years, 6 patients with mitral insufficiency, ranging from 17 to 74 years of age, with an average of 41 years, and 12 patients with aortic valvular diseases (aortic stenosis- 2 cases, aortic stenoinsufficiency- 4 cases and aortic in-sufficiency- 6 cases) who ranged from 17 to 71 years of age, with an average of 31 years. Method of recording the ACG and analysis of cardiac dynamics by the ACG method were reported in the previous paper.

A Clinical Study on the Pattern of Mitral Valvular Disease in a Peripheral Tertiary Hospital in Bangladesh

Background: Rheumatic mitral valvular disease (MVD) is a common cause of cardiovascular morbidity and mortality in Bangladesh. Many patients are diagnosed late, get maltreated, and develop complications, which can be minimized if early diagnosis could be made. Objectives: The study was carried out to determine the common symptoms and signs of mitral valvular disease in our population, to find out the incidence and pattern of complications, to list the pattern of valve lesions, to identify the common findings in different investigations and to find out the causes of delay in diagnosis. Methods: Fifty consecutive cases of isolated MVD of rheumatic origin admitted in Rajshahi Medical College Hospital, Rajshahi, Bangladesh, from July, 2002 to March, 2003 were included. Detailed history was taken, and clinical examination was performed. Chest skiagram, 12-lead ECG and echocardiography were performed in all patients. Other investigations include complete blood counts, anti-streptolysin O (ASO) titre, C-reactive protein (CRP), blood sugar, serum creatinine and routine urinalysis. Results: The peak incidence of MVD was found in the third decade (34%), 14 (28%) patients were <20 years of age. Thirty two (64%) patients had poor socio-economic condition. A previous history suggestive of rheumatic fever was found in 28 (56%). Twenty six (52%) patients received treatment from the registered medical practitioners and/or from the hospitals, 11 (22%) consulted with the quacks only, 5 (10%) had treatment from both sources. Significant delay was found in 28 (56%) patients. Illiteracy and ignorance was found to be the cause in 14 (28%) cases, poverty in 12 (24%) and misdiagnosis in 7 (14%). Six (12%) patients adopted indigenous treatment. Forty three (86%) patients experienced moderate to severe limitation of day-to-day activities all had breathlessness. Palpitation, fatigue and cough were found in 49 (98%), 45 (90%) and 42 (84%) cases respectively. Nineteen (38%) patients had haemoptysis, 15 (30%) had dysphagia. Apex beat was normally situated in 32 (64%), and shifted in 16 (32%) cases. Forty two (84%) patients had left parasternal heave and palpable P2 was found in 41 (82%) patients. Diastolic thrill was palpable in 28 (56%) cases, systolic thrill in 8 (16%) patients. The first heart sound (S1) was loud in 34 (68%) and soft in 8 (16%) cases. Mid-diastolic murmur of MS was audible in 46 (92%) cases, pansystolic murmur of mitral regurgitation in 19 (38%) patients and pansystolic murmur of tricuspid regurgitation in 10 (20%). Opening snap was found in 30 (60%), and presystolic accentuation in 27 (54%) cases. Roentgenographic study revealed moderate to huge enlargement of cardiac shadow in 29 (58%), straightening of the left border of the heart with fullness or outward bulging of the pulmonary conus in 43 (86%), double contour of the right border in 35 (70%), upper lobe diversion of pulmonary vasculature in 31 (62%), Kerley B lines in 10 (20%) and pulmonary oedema in 16 (32%) patients. The ECG showed P-mitrale in 32 (64%), atrial fibrillation in 14 (28%) and atrial flutter in 2 (4%) cases. Echocardiography revealed thickening of mitral valve leaflets in all patients, changes in subvalvular apparatus in 28 (56%) and calcification in mitral valve apparatus in 3 (6%) cases. Mitral valve area was <1 cm2 in 33 (66%), 1.0 to 1.4 cm2 in 14 (28%) and e”1.5 cm2 in 1 (2%) patients. The left atrial size was 41 to 50 mm in 20 (40%) and >50 mm in 10 (20%) cases. Two patients had left atrial thrombus. Evidence of pulmonary hypertension was found in 34 (68%) patients. Conclusion: Rheumatic MVD and the accompanying complications can be detected with an appreciable degree of accuracy by skillful clinical assessment and judicial use of simple investigations like roentgenography, electrocardiography and echocardiography which are available in many parts of our country at affordable costs. So every effort should be made to utilize these invaluable resources to tackle this public health problem more efficiently. Key Words: Rheumatic; Mitral valvular disease; Clinical. DOI: 10.3329/cardio.v3i1.6421Cardiovasc. j. 2010; 3(1): 11-21

Backward masking

Forward masking occurs when a less intense sound follows a more intense one, and is difficult to appreciate. Backward masking occurs when the less intense, masked sound precedes the louder sound. Examples of this situation are: (1) the difficulty in appreciating splitting of S 2 followed closely by a loud opening snap; (2) difficulty hearing S 1 followed by a loud pansystolic murmur.

A new theory about the origin of the mitral opening snap.

A new theory about the origin of the mitral opening snap.

Use of the ultrasonic Doppler method for timing of valvular movement. Application in the differential diagnosis of extra heart sounds.

The ultrasonic Doppler method was employed to time the rapid movements (opening and closure) of the mitral and aortic valves. To exclude signals due to slowly moving structures (heart walls), the Doppler tracing was processed by a filter that eliminated low frequencies. Clear tracings containing two deflections, one due to the opening and the other to the closure of each valve, were obtained. The valvular origin of the deflections was verified by recordings simultaneous with intratardiac pressures in five dogs. The ultrasonic Doppler tracing was found to be a satisfactory aid in the differentiation of various extra heart sounds in 24 patients. Thus, the second heart sound precedes, the third heart sound follows, and the opening snap is simultaneous with the signal due to mitral opening. The fourth heart sound is simultaneous with the atrial component of the unfiltered Doppler signal. Ejection clicks and systolic clicks are simultaneous with or follow the signal due to aortic opening. Because of its simplicity and safety, this method used in conjunction with the phonocardiogram should prove helpful in distinguishing the opening snap, third and fourth heart sounds, and certain additional auscultatory phenomena.

Diagnosis of atrial tumors by ultrasound.

A rapid, harmless, noninvasive technic using ultrasound to diagnose intra-atrial mass lesions is described. The technic permits detection of those tumors which pass through the atrioventricular orifice. Two patients with left atrial myxomata and one with a right atrial myxoma were studied with pulsed, reflected ultrasound, cardiac catheterization, and cineangiography. The diagnosis in each case was confirmed at surgery. The ultrasound technic for detecting atrial tumors was based on recording a mass of echoes immediately behind the echoes originating from the mitral or tricuspid valve leaflets. The mass held the leaflet open during diastole, causing abnormal valve motion. In one case of left atrial myxoma, the tumor plop sound, clinically confused with an opening snap, was shown to occur at a different time in the ultrasound cycle than the true opening snap. This examination is simple enough to be considered as a screening examination for the detection or exclusion of this rare but potentially dangerous abnormality.

Use of phenylephrine in the detection of the opening snap of mitral stenosis

The effect of phenylephrine on the 2-OS interval in cases of mitral stenosis is described. This drug prolongs regularly the 2-OS interval and thereby facilitates recognition of the opening snap. By contrast, there was no significant change in the splitting of the second sound in normal subjects or in the patients with mitral stenosis, but of 3 patients with atrial septal defect, the drug causes considerable increase of the splitting interval in one. Because of the characteristics delay of the opening snap in response to phenylephrine, the use of this drug is potentially useful in identification of the opening snap particularly in situations where such a sound is confused with splitting of the second heart sound.

Left atrial and left ventricular sound and pressure in mitral stenosis.

Left atrial and left ventricular pressure and sound were recorded at the time of mitral commissurotomy in 18 patients with severe, isolated, noncalcific mitral stenosis and sinus rhythm. Catheter tip micromanometers were used, and in eight studies, two equisensitive micromanometers were employed to examine pressure crossover relationships. Analysis of the left atrial and left ventricular sound and pressure crossover relationships is presented; viewed in the perspective provided by cineangiographic studies and surgical observations, a unifying concept of the auscultatory events in mitral stenosis is proposed. Beginning with left ventricular pressure rise, the left ventricle drives the mitral complex through its ascent (or eversion) phase toward the left atrium, clearing the anterior leaflet from the left ventricular outflow tract. The ascent (eversion) terminates abruptly at the first heart sound (S 1 ). Following systole, left ventricular and left atrial pressure fall together after v peak, during and after pressure crossover, until the point where left atrial pressure fall ceases abruptly (opening snap notch), left atrial pressure exceeding that in the left ventricle, and the mitral opening snap occurs. During this interval, the mitral valve complex descends or inverts toward the left ventricle and terminates abruptly with the mitral opening snap. Thus, the mitral opening snap may be considered as the reciprocal of the delayed, accentuated S 1 , in noncalcific mitral stenosis in sinus rhythm.

LEFT-VENTRICULAR ENDOMYOCARDIAL FIBROSIS AND MITRAL INCOMPETENCE: A New Syndrome

The main clinical findings in twelve patients with left-ventricular endomyocardial fibrosis (E.M.F.) have been aggregated and form a unique syndrome of mitral incompetence. The syndrome is characterised by an early mitral systolic murmur, a third sound, and often an opening snap, ascribed to a mobile anterior cusp. Proof of the diagnosis of left-ventricular E.M.F. was obtained by cineangiography and at necropsy.

The rule of six.

To the Editor:— The art of phonocardiography may seem difficult to many physicians. This is mainly due to inability to remember the time intervals between the various components of the heart sounds. By applying the rule of six, phonocardiography can be greatly simplified. The interval between the Q-wave of the electrocardiogram and the first heart sound (Q-S 1 interval) can normally be up to 0.06 seconds. On inspiration, the aortic (A 2 ) and pulmonic components (P 2 ) of the second sound may normally reach a maximum of 0.06 seconds. The opening snap of mitral stenosis may occur from 0.06 to 0.12 seconds after the aortic component of the second sound. The third heart sound or its pathologic counter part, the protodiastolic gallop, may occur from 0.12 to 0.18 seconds after the aortic component of the second sound. Thus, by using the number six or its multiples the various time intervals

Ultrasound Cardiogram in Clinical and Physiological Studies

Ultrasound cardiograms have been obtained from over 3000 subjects over the past 6 yr. The accuracy of this method for the assessment of mitral valve disease, as described in earlier reports, has been confirmed in this large patient study. This method of external, safe study has been found to equal cardiac catherization in accuracy when judged by findings at operation. Equally reliable evaluation of tricuspid valve disease has been obtained, and actually found superior to catherization in preoperative assessment. Valve substance, pliability, and mobility can be determined from the ultrasound records. The prediction of valve characteristics determining whether replacement of a valve with a prosthesis is needed, has been quite accurate. This preoperative information is not obtained from catherization studies. The behavior of the mitral valve, accounting for the opening snap in mitral stenosis, and the Austin-Flint murmur of aortic regurgitation, have been defined by simultaneous record of direct video display of the mitral valve ultrasound with the phonocardiogram. The use of the mitral ultrasound as a reference for analysis of sound records will be presented. The ultrasound method of determining pericardial fluid has been confirmed as valid but subject to record error and misinterpretation. The ultrasound cardiogram is 100% accurate in prediction of mitral valve sizes and valve leaflet character. The accuracy in determination of pericardial fluid is less reliable.

Myxoma of the left atrium. Hemodynamic and phonocardiographic consequences of sudden tumor movement.

Two patients with myxoma of the left atrium were studied by left heart catheterization and cineangiography, and the diagnosis was confirmed at operation in both cases. An electrocardiographic timing signal on the cineradiographs permitted correlation of heart sounds and pressure waves with movement of the tumor between the left atrium and the left ventricle. In early systole, the tumor suddenly moved from the left ventricle to the left atrium, and a notch in the rising left ventricular pressure, a prominent c wave, and loud, late elements of the first sound were noted. In early diastole, the tumor moved rapidly through the mitral valve, causing an abrupt diminution in the left atrial volume, thus causing a rapid y descent despite severe obstruction of the mitral valve. An early diastolic sound, thought to be an opening snap, appeared to be related to the checking of the tumor in the left ventricle ("tumor plop"). The unusual left atrial pressure pulse seen in these two cases resembles data from other cases of myxoma reported in the literature, and recognition of these unusual pressures may permit accurate preoperative diagnosis in other patients. Diagnostic changes may be present on apexcardiograms.

Movement of mitral valve cusps in relation to first heart sound and opening snap in patients with mitral stenosis.

Movement of mitral valve cusps in relation to first heart sound and opening snap in patients with mitral stenosis.