Accuracy of the echocardiographic diagnosis of aortic regurgitation

Anterior mitral leaflet diastolic flutter and flutter of contiguous cardiac structures are accepted M-mode echocardiographic signs of aortic regurgitation. Ninety-four subjects (47 normal and 47 with aortic regurgitation on angiography) had echocardiograms evaluated (double-blind) by two observers for the presence of anterior mitral leaflet diastolic flutter or ventricular septal diastolic flutter. For the entire study population, sensitivity was 66 percent for anterior mitral leaflet diastolic flutter, 36 percent for ventricular septal diastolic flutter and 72 percent for diastolic flutter over-all (i.e., present on either or both). Severe chronic aortic regurgitation always revealed anterior mitral leaflet diastolic flutter. Mild to moderate aortic regurgitation without mitral stenosis had an 81 percent sensitivity for over-all diastolic flutter; with mitral stenosis, over-all sensitivity of diastolic flutter was 44 percent. Specificity of anterior mitral leaflet diastolic flutter was 83 percent, of ventricular septal diastolic flutter 98 percent, of diastolic flutter over-all 83 percent. There was no observer discordance over diastolic flutter in severe aortic regurgitation, but 19 percent discordance over diastolic flutter in mild to moderate aortic regurgitation without mitral stenosis, and 31 percent discordance in mild to moderate aortic regurgitation with mitral stenosis. There was 26 percent disagreement over the absence of diastolic flutter in normal subjects, predominantly regarding anterior mitral leaflet diastolic flutter. Predictive value of diastolic flutter was 81 percent when present and 75 percent when absent. We conclude the following: (1) In severe aortic regurgitation, interobserver agreement is good for anterior mitral leaflet diastolic flutter, which is a highly sensitive sign; (2) interobserver agreement is good for ventricular septal diastolic flutter, which is highly specific but insensitive; (3) disagreement was greatest over anterior mitral leaflet diastolic flutter in normal subjects; and, (4) with coexisting mitral stenosis, diastolic flutter is not a sensitive sign.     

Echocardiographic studies of left ventricular wall motion and dimensions after valvular heart surgery

Echocardiograms obtained from 50 patients after valvular heart surgery (in 33 cases within 2 months of the procedure) were examined to study patterns of interventricular septal motion and left ventricular dimensional changes. Preoperative echograms were available in 28 cases. Before and after mitral commissurotomy septal motion and left ventricular diameters as well as the percent systolic shortening of the echocardiographic transverse axis were within normal limits. Before operation, aortic and mitral regurgitation were associated with increases in end-diastolic and end-systolic diameters, septal motion and percent systolic shortening of the left ventricular diameter. Septal dyssynergy, defined as paradoxical motion or marked hypokinesia, was seen within 2 months of operation in 91 percent of patients after aortic valve replacement and in 42 percent after mitral valve replacement. Of subjects studied more than 2 months postoperatively, none with mitral valve replacement and only 33 percent with aortic valve replacement manifested septal dyssynergy. After valve replacement for aortic or mitral regurgitation there were significant decreases in end-diastolic diameter, septal excursion and total and percent left ventricular systolic shortening. Two subjects not having valve replacement also demonstrated paradoxical septal motion postoperatively. The cause of septal dyssynergy after valvular surgery was not apparent although the use of cardiopulmonary bypass was an essential condition.We conclude that echocardiography can be utilized to follow up changes in left ventricular wall motion and dimensions after surgery for valvular heart disease, and that it may be of value in assessing the early and late postoperative results.     

Comparison of Left Ventricular Contractility in Pressure and Volume Overload: A Strain Rate Study in the Clinical Model of Aortic Stenosis and Regurgitation

Objective: The aim of this study is to compare the impact of two different loading conditions on myocardial contractility in asymptomatic patients with normal EF by using stain rate imaging (SRI). Methods: A total of 27 patients with severe aortic regurgitation (mean age 50 ± 11 years) and 25 patients with severe aortic stenosis (mean age 53 ± 15 years) were prospectively recruited. Fifteen healthy subjects (mean age 50 ± 6 years) were enrolled as the control group. For the evaluation myocardial contractility, longitudinal LV function was chosen and, midventricular segment shortening was analyzed for the septum, LV lateral wall from apical four‐chamber view and for the anterior, inferior wall from apical two‐chamber view. Results: Longitudinal peak systolic strain rate values of each segment derived from analysis of a total of 804 segments were significantly decreased in the patients population (P < 0.001). Global longitudinal peak systolic strain rate was also significantly decreased in aortic stenosis and regurgitation compared to the control group (?1 ± 0.5, ?0.9 ± 0.3, and ?1.6 ± 0.3, P = 0.001). As far as the comparison between patients with aortic stenosis and aortic regurgitation, neither global strain rate nor strain rate for each wall was found to be different. Conclusion: We conclude that longitudinal LV function is reduced in both pressure and volume overload, and both of this overload patterns are equally harmful to the ventricle. (Echocardiography 2010;27:798‐802)     

Cineangiographic assessment of left ventricular function in the acute phase of transmural myocardial infarction.

One hundred fifteen patients underwent hemodynamic investigation including left cineangiography during the acute phase of transmural myocardial infarction. Patients were classified into two groups: those with anterior myocardial infarction (48 patients) and those with inferior myocardial infarction (67 patients). There was a good correlation between the electrocardiographic site of infarction and the location of ventricular dyssynergy. The extent of abnormally contracting segment was 39.3 ± 2 percent (mean ± standard error of the mean) in anterior infarction and 28 ± 1.7 percent in inferior infarction. Left ventricular end-diastolic volume was normal in inferior infarction and slightly increased in anterior infarction. Left ventricular end-diastolic pressure was significantly increased in both groups. The increase in left ventricular end-diastolic pressure was related to (1) depressed contractility as demonstrated by the significant reduction of ejection fraction and mean velocity of circumferential fiber shortening; and (2) changes in left ventricular compliance with a large scatter to the left as well as to the right of the pressure-volume curve.There was no correlation between the extent of dyssynergy and changes in left ventricular end-diastolic compliance but there was a good linear correlation between ejection fraction and the extent of abnormally contracting segment. In the group with anterior infarction, for the same extent of dyssynergy, patients with a decreased end-diastolic compliance had a better ejection fraction than those with an increased end-diastolic compliance. Finally, the extent of infarction seems to be the principal factor determining the degree of ventricular functional impairment because patients with anterior or inferior myocardial infarction carefully matched for similar extent of infarction demonstrated no significant differences in the variables of ventricular performance.     

Early changes in left ventricular size and function after correction of left ventricular volume overload

The ability to predict early postoperative left ventricular size and function in patients with isolated aortic or mitral regurgitation was determined utilizing multigated blood pool imaging before and 2 to 4 weeks after valve replacement (aortic valve, 20 patients; mitral valve, 20 patients). Early postoperatively, ejection fraction decreased significantly (p <0.001) in both patient groups (from 0.55 ± 12 to 0.40 ± 0.14 [mean ± 1 standard deviation] in patients with aortic regurgitation and from 0.66 ± 0.09 to 0.48 ± 0.11 in patients with mitral regurgitation). The decrease in ejection fraction was associated with a large decrease in stroke volume with minimal or no change in end-systolic volume; it was unrelated to the preoperative ejection fraction. Early postoperative ejection fraction correlated best with preoperative end-systolic volume and was normal in 14 (67 percent) of 21 patients with a preoperative ejection fraction above 0.60; 4 (27 percent) of 15 patients with a preoperative ejection fraction of 0.50 to 0.60; and in 0 of 4 patients with a preoperative ejection fraction below 0.50 (p <0.05). In addition, a repeated scan in 16 patients late (1 to 2 years) after operation showed a further reduction in endsystolic volume in patients with aortic regurgitation with an increase in ejection fraction toward preoperative values. There was no significant change in patients with mitral regurgitation.End-diastolic volume decreased significantly (p <0.001) early postoperatively (from 162 ± 60 to 102 ± 41 ml/m² in patients with aortic regurgitation and from 131 ± 40 to 78 ± 30 ml/m² in patients with mitral regurgitation). This decrease was closely related to a decrease in stroke volume and was unrelated to preoperative ejection fraction. Early postoperative end-diastolic volume correlated best with the preoperative end-systolic volume. The major part of the reduction in end-diastolic volume occurred within 2 weeks of valve replacement.Removal of chronic left ventricular volume overload due to aortic or mitral regurgitation produces a decrease in ejection fraction and end-diastolic volume. The early reduction is in part a result of altered loading conditions and may not necessarily imply alterations in myocardial contractile function. The reduction in ejection fraction appears to persist in patients with mitral regurgitation.     

Left ventricular function in mitral valve prolapse: Assessment with radionuclide cineangiography

Abnormalities of left ventricular contraction in patients with mitral valve prolapse have suggested a myocardial factor in this disease. To determine systolic left ventricular function in mitral valve prolapse, technetium-99m gated equilibrium radionuclide cineangiography was performed in 47 patients with this diagnosis. In 39 patients without mitral regurgitation the average ejection fraction was normal at rest (average [± standard error of the mean] 57 ± 3 percent, normal 57 ± 1 percent, difference not significant) and exceeded the lower limits of normal in all but 1 patient, whose ejection fraction was 41 percent. However, ejection fraction during maximal exercise was lower for the group of patients with mitral prolapse without mitral regurgitation than for normal subjects (average 64 ± 2 percent, normal 71 ± 2 percent, p < 0.005). In eight patients with mitral prolapse and mitral regurgitation, the average ejection fraction was normal at rest but was diminished with exercise in comparison with both normal subjects and patients with mitral valve prolapse without mitral regurgitation. Chest pain, arrhythmia and the pattern or extent of mitral valve prolapse on echocardlography were not independently associated with impaired left ventricular functional reserve. We conclude that, although many patients with mitral valve prolapse have normal left ventricular function, there is a subgroup without mitral regurgitation in whom diminished left ventricular functional reserve is suggestive of a cardiomyopathic process.     

Influence of acute mechanical overload on dimension and dynamics of interventricular septal thickness in dogs

To evaluate directly septal thickness and related dynamic changes, miniature ultrasonic crystals were Implanted across the Interventricular septum and left ventricular free wall and In the circumferential endocanNal segments of the left and right ventricles In 12 open chest dogs. In the control resting state, end-dlastollc wall thickness of the septum and the left ventricular free wall was 9.4 ± 2.1 and 9.6 ± 2.6 mm, respectively (mean ± standard deviation). Wall thickness Increased during systole by 15 percent In the septum and by 17 percent in the free wall. With constriction of the ascending aorta, left ventricular end-dlastollc segment Increased by 13 percent with reciprocal thinning In the end-dlaslollc thickness of the septum (by ?8.5 percent) and the left ventricular free wall (by ?5.2 percent); there were decreases in percent shortening of the left ventricular segment (from 21.0 to 15.5 percent) and In percent thickening of both the septum (from 14.6 to 11.8 percent) and the free wall (from 16.9 to 13.1 percent).Pulmonary arterial constriction resulted In significant right ventricular chamber enlargement; however, there was no direct change In dimension and dynamics of the septum. When mitral regurgitation was produced by sectioning the chordae tendlneae, left ventricular end-dlastollc segment length Increased (by 23.5 percent) with reciprocal thinning of the enddlastollc thickness of the septum (by ?8.6 percent) and the free wall (by ?6.9 percent). The left ventricular segment shortening and wall thickening of the septum and the free wall were equally augmented (from 18.6 to 37.5, from 16.1 to 31.0 and from 19.8 to 29.3 percent, respectively). Wtth the onset of acute tricuspld regurgitation, right ventricular end-dlastollc segment and its shortening Increased markedly, but there were no direct changes in the septum. Thus, the interventrlcular septum can be regarded as a functional part of the left ventricle, and any form of mechanical loading on the left ventricle will ultimately Induce proportionate changes in the septum and left ventricular free wall.     

Mitral valve dysfunction in the Marfan syndrome: Clinical and echocardiographic study of prevalence and natural history

Although mitral regurgitation and fibromyxomatous thickening of the mitral leaflets have long been recognized as such, mitral valve prolapse has only recently been added as one of the pleiotropic features of the Marfan syndrome, the prevalence, age of onset, and natural history of mitral valve dysfunction in this condition are uncertain. Therefore, all patients in one clinic who met strict diagnostic criteria for the Marfan syndrome and who had clinical and echocardiographic examinations before age 22 years were reviewed. Of the 166 patients (84 males, aged 11.9 ± 0.6 years [mean ± SEM]; and 82 females, 11.0 ± 0.6 years), 52 percent had auscultatory and 68 percent had echocardiographic evidence of mitral valve dysfunction, generally mitral valve prolapse. Prevalence did not differ between the sexes. Follow-up in 115 patients averaged five examinations over a mean of four years; 17 percent were followed for more than six years. Criteria for progression of mitral valve dysfunction were: (1) on auscultation, the appearance of new systolic clicks or apical systolic murmurs, a mitral regurgitant murmur increased by two grades, or appearance of congestive heart failure not due to aortic regurgitation; and (2) on echocardiography, the new appearance of mitral valve prolapse or abnormally increased left atrial dimension. Nearly half the patients met at least one criterion and one quarter had both auscultatory and echocardiographic evidence of progressive mitral valve dysfunction. Twice as many females demonstrated worse mitral valve function with time. Eight of the 166 patients either died as a result of mitral valve dysfunction or required mitral valve replacement. Severe mitral regurgitation developed in an additional 15 patients. Rupture of chordae tendineae was uncommon. Antibiotic prophylaxis was routine, and no cases of bacterial endocarditis of the mitral valve occurred. These results suggest that mitral valve dysfunction is extremely common in young patients with Marfan syndrome and usually presents as mitral valve prolapse. Serious mitral regurgitation develops in one of every eight patients by the third decade. Thus, the prevalence and natural history of mitral valve prolapse in the Marfan syndrome appear distinct from mitral valve prolapse associated with other conditions, including idiopathic or familial mitral valve prolapse.     

Serial noninvasive assessment of left ventricular hypertrophy and function after surgical correction of aortic regurgitation.

Serial echocardiographic analyses of left ventricular hypertrophy and function, with validation of extent of shortening by first pass radionuclide angiography, was performed in 16 patients before and after surgical correction of severe aortic valve regurgitation. All patients were symptomatic (predominantly in New York Heart Association functional class III or IV) before operation but were in class I or II after operation. The preoperative pattern of eccentric hypertrophy (increased mass with normal ratio of left ventricular cross-sectional wall area to cavity area) changed immediately after operation to a pattern of concentric hypertrophy (increased mass with increased ratio of left ventricular cross-sectional wall area to cavity area) because of a significant reduction in chamber size and increase in wall thickness. On late follow-up (9 to 35 months, average 15 months after operation), the hypertrophy lessened significantly, the cross-sectional area of the ventricular wall decreasing to 21.1 ± 5.4 (mean ± standard deviation) cm² from a preoperative average of 31.6 ± 4.8 cm² (P < 0.01), and the ratio of wall area to cavity area was once again normal. In the same period, left ventricular enddiastolic diameter decreased from 6.52 ± 0.68 to 4.64 ± 0.52 cm (P < 0.01). Preoperatively, ejection phase indexes were normal or only marginally depressed in 12 of 16 patients but were moderately depressed in the remaining 4. At early follow-up (average 4 months) ventricular shortening tended to increase; and at late follow-up the fractional shortening of the minor axis, the ejection fraction and the mean velocity of circumferential fiber shortening increased to 0.39 ± 0.07, 0.68 ± 0.10 and 1.26 ± 0.22 circumference/sec, respectively, from preoperative values of 0.33 ± 0.09, 0.60 ± 0.14 and 1.05 ± 0.31 circumferences/sec (P < 0.05 for each index). In the four subjects with preoperative depression of left ventricular function, the extent and speed of myocardial shortening at late follow-up became normal in three subjects and remained moderately depressed in one patient. Paradoxical septal motion was observed immediately postoperatively and in the early follow-up studies, but it was noted in only 3 of 16 cases by the late follow-up period. Provided septal dyskinesia was not present, echocardiographic and first pass radionuclide determinations of ejection fraction correlated highly (r = 0.92).It is concluded that when aortic valve replacement for symptomatic aortic regurgitation is undertaken prior to severe myocardial decompensation, improvement in clinical status is associated with significant regression of myocardial hypertrophy, reduction in left ventricular size, evolution of a normal $\text{mass}\text{volume}$ ratio, recovery of septal dyskinesia as revealed on echocardiography, and improvement in left ventricular function. These data do not define the type and degree of left ventricular dysfunction which is irreversible.     

Quantitation and significance of horizontal cardiac motion in M mode and two dimensional echocardiography

Cardiac structures are continuously moving during the cardiac cycle so that constantly changing acoustical interfaces are being recorded by the theoretically static echographic beam. The characteristic movement of the base of the heart toward the apex in systole appears as horizontal motion when imaged in two dimensional echocardiographic parasternal long axis views. The quantitative characteristics of horizontal motion were studied in 50 control patients, 25 patients with decreased cardiac output, 20 with volume overload and 10 with pericardial effusion. The angle of cardiac shift at the aorto-interventricular septal junction was 8 ± 2 ° (mean ± standard deviation) in control patients, and this change constituted 21 ± 6 percent of the area within the arc containing the standard M mode information. Horizontal shifts were decreased in patients with decreased cardiac output (4 ± 2 °; p < 0.001) and increased in patients with volume overload (11 ± 4 °; p < 0.001) or pericardial effusion (10 ± 3 °; p < 0.025).With use of the concept of horizontal motion, the interventricular septal hinge point was noted to be in the area of the membranous interventricular septum, rather than at the junction of the upper and middle thirds of the interventricular septum in 80 percent of normal subjects, 72 percent of patients with decreased cardiac output, 60 percent of those with pericardial effusion, 52 percent of those with left-sided volume overload and 40 percent of those with right-sided volume overload. The concept of horizontal cardiac motion was also pertinent to the interpretation of aortic valve opening, the transposition of aortic root information to apparent left ventricular outflow tract level, one form of pseudosystolic anterior mitral motion, abnormal left atrial echoes, echoes mimicking flail posterior mitral leaflet and interpretation of left atrial wall motion at the left atrial-left ventricular junction. In conclusion, horizontal cardiac motion is a significant physiologic phenomenon of potential clinical importance. It causes important changes in the echographic recording of acoustical information.     

Pre- and postoperative hemodynamic and cineangiocardiographic assessment of left ventricular function in patients with aortic regurgitation.

Hemodynamic and angiocardiographic analysis was performed prior to and 14 months on the average following valve replacement in 11 patients with severe, isolated, pure, chronic aortic regurgitation.The aortic diastolic pressure, reduced prior to surgery, reverted to normal as did the cardiac index. Left ventricular filling pressure, elevated prior to surgery, returned to normal while aortic systolic pressure did not vary substantially. The markedly increased stroke volume returned to normal as did the net left ventricular stroke work. Left ventricular end-diastolic and end-systolic volumes, also markedly elevated, decreased but did not return to normal levels.The shape of the left ventricle, which was more spherical than normal during end-systole prior to surgery, as evidenced by the decrease in the systolic axis ratio, reverted to normal.The ejection fraction, severely reduced before surgery, increased moderately (46 ± 13 vs 51 ± 19 per cent) as did the extent of circumferential fiber shortening (δD) (21 ± 8 vs 27 ± 12 per cent). The mean velocity of fiber shortening ($\text{VCF}$) increased significantly (0.68 ± 0.2 vs 1.03 ± 0.47 circ./sec.), as did the mean left ventricular ejection rate (1.32 ± 0.48 vs 1.91 ± 0.76).Comparative analysis of the evolution of left ventricular function indices and of extramyocardial factors (end-diastolic fiber stretching and impedance to ejection) showed that whereas in some cases myocardial damage appeared to be irreversible, in others dramatic improvement sometimes occurred following surgery. It was not possible, however, to determine the threshold below which the damage was irreversible.It may therefore be concluded that in some patients with severe regurgitation attended by profound myocardial insufficiency, correction of the valvular defect could produce not only clinical and hemodynamic improvement, but also improvement in myocardial contractile status.     

Maximal exercise in children with aortic regurgitation: an adjunct to noninvasive assessment of disease severity

Twenty-five asymptomatic children with chronic aortic regurgitation were evaluated by graded bicycle exercise testing and standard resting M-mode echocardiogram. These results were compared to those of 35 normal controls matched for age and body surface area. Twenty-one patients underwent cardiac catheterization to rule out associated lesions. Patients fell into two groups based upon the left ventricular end-diastolic volume per body surface area (LVEDVI): group I (n = 10) had LVEDVI less than or equal to 2 SD from the mean of normal; group II (n = 15) had LVEDVI greater than or equal to 4 SD from the mean of normal. All had normal shortening fraction and velocity of circumferential fiber shortening. At maximal exercise, patients in group I were found to have no significant differences from normals in maximal workload, total work, percent maximal oxygen consumption, heart rate, blood pressure, or ST segment depression. However, patients in group II had blunted mean maximal exercise heart rate (p less than 0.001), systolic hypertension (p less than 0.05), and increased frequency and maximal amplitude of ST depression (p less than 0.01, p less than 0.001, respectively) compared to normal controls. Within group II the mean maximal amplitude of ST depression was significantly related to increasing LVEDVI (r = 0.53, p less than 0.05). The mean maximal exercise heart rate, systolic blood pressure, and maximal amplitude of ST segment depression were significantly related to LVEDVI for patient groups and normal controls together (r = -0.384, p less than 0.01; r = 0.28, p less than 0.05; r = 0.70, p less than 0.001, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Isolated stenosis of left anterior descending or right coronary artery: Relation between site of stenosis and ventricular dysfunction and therapeutic implications

Indications for coronary arterial bypass surgery in single vessel coronary artery disease are unresolved. To determine the extent of myocardium at risk with stenosis (70 percent or more) of a single coronary artery, left ventricular angiograms of 200 patients with stenosis confined to either the left anterior descending or right coronary artery and of 15 normal control subjects were assessed. Among patients without myocardial infarction, ejection fraction was unchanged (p > 0.05 versus normal values) in (1) those with stenosis of the proximal (above first septal branch, n = 19), mid (between septal and first diagonal branches, n = 14) and distal (within 2 cm distal to diagonal branch, n = 15) left anterior descending coronary artery, and (2) those with stenosis of the proximal (above acute marginal branch, n = 16) and distal (between acute marginal and posterior descending branches, n = 16) right coronary artery. In contrast, ejection fraction was depressed (p < 0.001 versus normal values) In left anterior descending arterial stenosis with anterior myocardial Infarction: proximal (38 ± 10 percent, n = 33), mid (46 ± 12 percent, n = 24; p < 0.01 versus proximal), and distal (56 ± 9 percent, n = 15; p < 0.01 versus mid). Ejection fraction was similar with proximal and distal stenosis of the right coronary artery and inferior Infarction: 54 ± 11 percent versus 55 ± 9 percent, p > 0.05; both p < 0.05 versus normal value. Shortening velocity was assessed in three anterior (I to III, base to apex) and three inferior (IV to VI, apex to base) equidistant hemichords perpendicular to the long axis, 30 ° right anterior oblique view. With anterior Infarction and left anterior descending stenosis, shortening of hemichords I to V, I to IV and II to III with proximal, mid and distal stenosis, respectively, was depressed (p < 0.05 versus normal value). Septal excursion and thickening on M mode echocardiography with proximal left anterior descending stenosis and infarction were depressed (p < 0.05 versus mid and distal stenosis with infarcts). Hemichordal shortening with Inferior infarction was similarly depressed (p > 0.05) with proximal and distal stenoses.In conclusion, stenosis of the left anterior descending coronary artery is a heterogenous disease, the extent of jeopardized myocardium is highly dependent on the site of stenosis, and the criteria for surgery cannot be applied uniformly. When the surgical goal is myocardial preservation, these data provide an objective rationale for bypass of stenosis of the proximal left anterior descending coronary artery. In stenosis confined to the right coronary artery, left ventricular preservation alone should not be considered an indication for coronary bypass grafting.     

M mode echocardiography in hypertrophic cardiomyopathy: Diagnostic criteria and prediction of obstruction

To assess the reliability of the classic echocardiographic features in the heart with hypertrophic cardiomyopathy as criteria that differentiate it from normal heart and as predictors of outflow tract obstruction versus nonobstruction, 70 patients with clinical and angiographic evidence of hypertrophic cardiomyopathy were studied with M mode echocardiography. The diagnostic sensitivity and specificity of the classic features were assessed: ventricular septal thickness, 83 and 94 percent (sensitivity and specificity, respectively); ventricular septal amplitude of movement, 71 and 89 percent; ventricular septal thickness to left ventricular posterior wall ratio, 79 and 94 percent; left ventricular end-systolic dimension, 54 and 86 percent; septal-mitral valve distance at the onset of systole, 29 and 100 percent; systolic anterior motion of the mitral valve, 61 and 100 percent; and mid systolic closure of the aortic valve, 61 and 100 percent.No single M mode echocardiographic feature was consistently abnormal in hypertrophic cardiomyopathy. In nonobstructive hypertrophic cardiomyopathy, ventricular septal thickness greater than or equal to 13 mm (sensitivity 68 percent and specificity 94 percent) and ventricular septal thickness to posterior wall ratio greater than or equal to 1.5 (sensitivity 82 percent and specificity 94 percent) were the individual features with the greatest diagnostic value from the norm. Patients with obstruction at rest and labile obstruction (gradient only on provocation) had echocardiographically identical features. Ventricular septal thickness greater than or equal to 13 mm plus systolic anterior motion of the mitral valve or mid systolic closure of the aortic valve were the features that in combination best differentiated obstructive (resting and labile) from nonobstructive hypertrophic cardiomyopathy (sensitivity 82 percent and specificity 68 percent) and the heart with obstructive hypertrophic cardiomyopathy from the normal heart (sensitivity 82 percent and specificity 100 percent).     

Ventricular long-axis contraction as an earlier predictor of outcome in asymptomatic aortic regurgitation

The long-term prognostic significance of left ventricular (LV) long-axis contraction was investigated prospectively in 65 consecutive patients aged 58+/-15 years with asymptomatic aortic regurgitation, normal LV ejection fraction at rest, and no coronary artery or aortic root disease. A complete transthoracic echocardiographic study was performed at baseline and 12 months later. In 24 of 65 patients with peak systolic wave velocity at the lateral mitral annulus (LatS)<9 cm/s, LV diameter (p<0.01), volume (por=9 cm/s, none of these parameters was significantly affected during follow-up. Aortic valve replacement was performed in 6 of 24 patients (25%) with peak systolic wave velocity at the lateral mitral annulus<9 cm/s and none with peak systolic wave velocity at the lateral mitral annulus>or=9 cm/s. In patients with peak systolic wave velocity at the lateral mitral annulus<9 cm/s, a cut-off value of 6.25 cm/s predicted aortic valve replacement within the next year with 97% sensitivity and 83% specificity. In conclusion, ventricular long-axis contraction seems to be a reliable indicator for outcome prediction in patients with asymptomatic aortic regurgitation.     

Valve repair in rheumatic heart disease in pediatric age group

Valve repair in children is technically demanding but more desirable than valve replacement. From April 2004 to September 2005, 1 boy and 8 girls with rheumatic heart disease, aged 2-13 years (median, 9 years), underwent valve repair for isolated mitral regurgitation in 5, combined mitral and aortic regurgitation in 2, mitral stenosis in 1, and mitral regurgitation associated with atrial septal defect in 1. Chordal shortening in 7, annular plication in 6, commissurotomy in 1, reconstruction of commissural leaflets in 7 were performed for mitral valve disease. Plication and reattachment of the aortic cusps was carried out in 2 patients. Annuloplasty rings were not used. All patients survived the operation, 8 had trivial or mild residual mitral regurgitation, and 1 had trivial aortic regurgitation. Mean left atrial pressure decreased from 14 to 7 mm Hg postoperatively. During follow-up of 3-18 months, all children were asymptomatic and enjoyed normal activity. None required reoperation. In addition to chordal shortening and annular plication, reconstruction of the commissural leaflets is considered the most important aspect of valve repair. It can be achieved without annuloplasty rings, giving good early and midterm results.     

Systolic and diastolic properties of the human left ventricle during valve replacement for chronic mitral regurgitation

M mode and two dimensional echocardiography were combined with pressure-flow data to analyze systolic mechanics and diastolic compliance in nine patients during valve replacement for chronic mitral regurgitation. Both M mode (six patients) and two dimensional (four patients) echographic analyses revealed large decreases in early postoperative shortening fraction (?24 ± 17 [standard deviation]percent M mode study, p < 0.01; ?30 ± 12 percent two dimensional study, p < 0.02), which were significantly different from small changes observed in control subjects (M mode study, + 7 ± 10 percent, 25 subjects and two dimensional study, ?7 ± 14 percent, 8 subjects). Additional data suggest that left ventricular compliance is increased in chronic mitral regurgitation and that elimination of the low impedance left atrial pathway by valve replacement is associated with a significant increase in wall stress (five patients, p < 0.02) that appears to be responsible for the decreased ejection fraction postoperatively. Analysis of hemodynamic variables other than ejection fraction and rate of circumferential shortening revealed no difference between five postoperative patients with chronic mitral regurgitation and five with coronary artery disease. These results in human subjects confirm predictions from studies in animal models and suggest that unique properties of chronic mitral regurgitation demand special attention when patients with this condition are being evaluated for surgery.     

Aortic and mitral valve bioprostheses. Normal and pathological M mode echocardiographic aspects

The M mode echocardiographic recordings of 52 normal mitral bioprostheses (NMB), 7 pathological mitral bioprostheses (PMB), 30 normal aortic bioprostheses (NAB) and 10 pathological aortic bioprostheses (PAB) were reviewed. In normal bioprostheses a significant correlation was observed between the echocardiographic and the "specified" diameters, the diastolic and systolic slopes and the amplitude of anterior motion of the support. In NMB, the end-systolic diameter of the left ventricular outflow tract depended on the "specified" diameter of the bioprosthesis. Paradoxical septal motion was observed in 78 p. 100 of cases. In PMB, the velocity of anterior leaflet opening was significantly increased (p less than 0.001). The end-diastolic internal left ventricular dimension was also increased (p less than 0.01). A significant correlation was found between left ventricular fractional shortening and maximal leaflet separation (p less than 0.05). Normal septal motion was more common (p less than 0.05). In 5 cases of prosthetic valve dysfunction with mitral regurgitation the maximal leaflet separation was greater than normal (p less than 0.001), the diastolic slope of the support was increased (p less than 0.05) and diastolic vibrations of thickened irregular leaflets were observed. Systolo-diastolic vibrations with chaotic leaflet motion were characteristic of cusp tear and/or eversion. Stratified echos behind a support with reduced leaflet excursion was observed in one case of partial thrombosis: a thickened systolic echo with reduced diastolic excursion was observed in a case of degenerative stenosis. The review of 10 PAB showed a reduced amplitude of systolic excursion of the anterior support in cases of aortic regurgitation (p less than 0.05). Systolic vibrations of the cusp were not specific and were observed in normal cases. In severe valvular regurgitation mitral and/or septal diastolic fluttering was observed. Systolic excursion of the cusps was reduced in cases of relative stenosis due to an inappropriately small sized bioprosthesis. Thickening of the diastolic cusp echos was observed in cases of degenerative stenosis. Ventricular dilatation and reduced septal and free wall motion were dysfunction.     

Noninvasive assessment of load reduction in patients with asymptomatic aortic regurgitation

Afterload reduction in chronic asymptomatic aortic regurgitation might retard left ventricular enlargement and hypertrophy and, consequently, delay the onset of myocardial dysfunction and the need for surgical intervention. Since afterload is best expressed as wall stress, the effect of nitroglycerin on wall stress was determined in 10 normal subjects and in eight asymptomatic subjects with aortic regurgitation and normal left ventricular and circulatory function. Peak and end-systolic wall stress were estimated using a noninvasive echocardiographic technique. At rest, despite significantly larger left ventricular dimensions in the subjects with aortic regurgitation, peak systolic wall stress in this group (134 ± 29 × 10³ dynes/cm²) was similar to that in normal subects (134 ± 26 × 10³ dynes/cm²). In contrast, end-systolic wall stress was higher in aortic regurgitation (84 ± 12 versus 59 ± 15 × 10³ dynes/cm²) (P < 0.01). Following the administration of nitroglycerin, the subjects with aortic regurgitation had larger reductions in left ventricular end-diastolic (3.5 mm) and end-systolic (3.1 mm) dimensions than did the normal subjects (0.6 and 1.1 mm, respectively), despite similar changes in blood pressure. This resulted in normalization of end-systolic wall stress and in reduction of peak systolic wall stress below normal in aortic regurgitation. We conclude that (1) nitroglycerin offers a simple and effective means of acutely reducing afterload in asymptomatic aortic regurgitation; (2) left ventricular dimensional changes after the administration of nitroglycerin are larger in subjects with aortic regurgitation than in normal subjects. Consequently, unloading therapy may be effective in protecting the left ventricle in this disorder.     

Quantitative radionuclide angiography in the right anterior oblique view: Comparison with contrast ventriculography

Because the right anterior oblique view is widely accepted as the best “single” projection for assessing wall motion, the utility of this view during first pass radionuclide angiography was studied in 44 patients who also underwent contrast ventriculography and coronary arteriography. Of the 44 patients, 8 had a normal heart and 14 had coronary artery disease with normal wall motion on contrast ventriculography. All also had normal contraction on radionuclide angiography. On contrast ventriculography, 22 patients had coronary artery disease and asynergy involving 34 left ventricular segments. Of 17 segments localized to the anterior and apical asynergic areas on contrast ventriculography, 16 were accurately localized with radionuclide angiography. Similarly, of 17 inferior asynergic areas, 13 were also shown to be inferior on radionuclide angiography. In addition, quantitative assessment of the severity of asynergy using the hemiaxis method demonstrated a good correlation between asynergic severity as defined with radionuclide angiography and contrast ventriculography. Of 11 anterior areas, 7 defined as hypokinetic with contrast ventriculography demonstrated chordal shortening of 20.1 ± 5.2 percent (mean ± standard error of the mean) (P < 0.005 compared with normal) on radionuclide angiography. Similarly, four akinetic or dyskinetic segments on contrast ventriculography demonstrated a greater reduction (4.0 ± 4.0 percent) in chordal shortening on radionuclide angiography (P < 0.05 compared with hypokinetic segments). Akinetic apical and inferior segments as defined with contrast ventriculography also showed a marked reduction in wall motion to 10.4 ± 7.3 percent and 7.5 ± 4.1 percent, respectively.After appropriate background subtraction, determination of ejection fraction using radionuclide angiography showed a correlation of 0.839 between the left anterior oblique and right anterior oblique projections independent of the sequence of injection. In addition, ejection fraction determined with radionuclide angiography in the left (r = 0.824) and right (r = 0.801) anterior oblique views correlated well with ejection fraction assessed from contrast ventriculography. Thus, first pass radionuclide angiography performed in the right anterior oblique view is a sensitive noninvasive means of assessing the location and severity of asynergy as well as global left ventricular performance in patients with coronary artery disease.