Homozygous mutation in cardiac troponin T: implications for hypertrophic cardiomyopathy.

BACKGROUND: Mutations in the gene that encode cardiac troponin T (cTnT) account for approximately 15% of cases of familial hypertrophic cardiomyopathy (HCM). These mutations are associated with a particularly severe form of HCM characterized by a high incidence of sudden death and a poor overall prognosis, despite subclinical or mild left ventricular hypertrophy. METHODS AND RESULTS: We evaluated a family with HCM and multiple occurrences of sudden death in children. DNA samples were isolated from peripheral blood or paraffin-embedded tissue, and all protein-encoding exons of the cTnT gene were sequenced. A mutation was identified in exon 11 and is predicted to substitute a phenylalanine-for-serine mutation at residue 179 (Ser(179)Phe) in cTnT. Both parents and 3 of 4 surviving and clinically unaffected children were heterozygous for this mutation; another clinically unaffected child did not carry the mutation. Genetic analysis of DNA from a child who died suddenly at age 17 years demonstrated he was homozygous for this mutation. A review of his echocardiogram revealed profound left and right ventricular hypertrophy. CONCLUSIONS: An homozygous Ser(179)Phe mutation in cTnT causes a severe form of HCM characterized by striking morphological abnormalities and juvenile lethality. In contrast, the natural history of the heterozygous mutation is benign. These studies emphasize the relevance of genetic diagnosis in hypertrophic cardiomyopathy and provide a new perspective on the clinical consequences of troponin T mutations.

Hypertensive hypertrophic cardiomyopathy or hypertrophic cardiomyopathy with hypertension? A study of 78 patients.

Hypertensive hypertrophic cardiomyopathy may be a distinctive cardiac condition resulting from hypertension. Alternatively, this disease may represent the coincidence of a common disease, hypertension, with a relatively rare cardiomyopathy. A consecutive series of patients with hypertrophic cardiomyopathy and hypertension were studied and compared with age- and gender-matched patients with cardiomyopathy alone. Thirty-nine patients were identified as having hypertension; they ranged in age from 31 to 84 years (average 60 +/- 13); 82% were greater than 50 years old; 18 (46%) were women. When these patients were compared with the age-matched group with hypertrophic cardiomyopathy alone, there were no clinical or electrocardiographic differences between the two groups. By echocardiography, the hypertensive and nonhypertensive groups had a similar incidence of systolic anterior motion (77 versus 64%, respectively), mitral annular calcification (31 versus 31%), septal thickness greater than 20 mm (56 versus 46%) and outflow tract gradient greater than 20 mm (59 versus 67%). A posterior wall thickness greater than 13 mm was more frequent in the hypertensive group (54%) compared with the nonhypertensive group (31%) (p = 0.02). The findings show that hypertrophic cardiomyopathy with associated hypertension is a disease of the elderly. But, with the exception of thicker walls, the clinical and echocardiographic features of the patients with hypertension were indistinguishable from those of the age-matched and, hence, elderly group of patients with cardiomyopathy without hypertension. These findings suggest that hypertension may make hypertrophy worse, but that it is not the primary cause of the cardiomyopathy. Thus, the condition might be better termed "hypertrophic cardiomyopathy with hypertension."

Echocardiographic findings in 25 patients with left atrial myxoma.

The echocardiographic findings were studied in 25 patients with pathologically proved left atrial myxoma. All patients had M-mode echocardiograms and 14 had two-dimensional studies. Seventeen patients had pre- and postoperative echocardiograms. Clinical, hemodynamic, angiographic and pathologic correlations were made. The diagnosis of left atrial myxoma was suspected clinically in only three patients before the echocardiographic study. The correct echocardiographic diagnosis was made in 24 patients; in one patient it was missed with an M-mode study. In addition to the usual "mass" of extraneous echoes seen behind the mitral valve in the left atrium, the only other consistent abnormality on M-mode study was a decreased EF slope of the mitral valve (3.9 +/- 3.5 cm/s). The following dimensions were usually normal: left atrium, 4.0 +/- 0.7 cm; right ventricle, 2 +/- 0.7 cm; left ventricular end-diastolic diameter, 4.8 +/- 0.6 cm and end-systolic diameter, 2.9 +/- 0.5 cm. The mean percent of shortening was 37 +/- 5%. Two-dimensional echocardiography correctly identified the presence of a left atrial myxoma in all 14 patients studied. It provided additional information regarding size, shape, mobility, surface characteristics and site of insertion of the tumor. Eighteen patients had hemodynamic and angiographic studies. Coronary artery disease was found in one patient with typical angina. Echocardiography is an excellent technique for visualizing atrial myxoma. Cardiac catheterization is probably not needed before excision of a myxoma.

Intraoperative Doppler echocardiography in hypertrophic cardiomyopathy: correlations with the obstructive gradient.

Although significant pressure gradients can be recorded across the left ventricular outflow tract in patients with hypertrophic cardiomyopathy, controversy exists regarding the presence or absence of true obstruction. Ten patients with hypertrophic cardiomyopathy were studied at the time of septal myectomy. A sterile continuous wave Doppler transducer was placed on the ascending aorta and directed toward the left ventricular outflow tract to measure velocity simultaneously with invasive gradient measured using solid-state hub transducers by direct puncture of the left ventricle and aorta. Simultaneous Doppler velocity and invasive gradient measurements (n = 33) were made at rest, before and after myectomy and during interventions with isoproterenol, volume loading and phenylephrine. High velocity flow with a characteristic contour was recorded in patients with a significant gradient. Using the modified Bernoulli equation (gradient = 4 X velocity), a good correlation was found between the Doppler-derived gradient and the peak instantaneous gradient measured invasively (r = 0.93, y = 0.89X + 12, p = 0.0001). Changes in gradient and velocity due to interventions also correlated well (r = 0.96, y = 0.91X - 3, p = 0.0001). Continuous wave Doppler echocardiography can accurately estimate the outflow tract gradient. The magnitude, timing and contour of these high velocity flow signals support the hypothesis that true obstruction is present in patients with hypertrophic cardiomyopathy who have a significant gradient.

Benefits of intraoperative echocardiography in the surgical management of hypertrophic cardiomyopathy.

OBJECTIVES: The purpose of this study was to determine the role of intraoperative echocardiography in planning the site and extent of myectomy and in ensuring adequate control of the left ventricular outflow tract gradient. BACKGROUND: Although intraoperative echocardiography has been found to be beneficial in patients undergoing valve repair, its impact on surgical decisions in patients undergoing septal myectomy for hypertrophic cardiomyopathy has not been described. METHODS: In 50 patients undergoing septal myectomy over a 5-year period, epicardial echocardiography was performed before cardiopulmonary bypass to establish the extent of outflow tract obstruction, locate its site and plan the myectomy. In 30 patients, transesophageal echocardiography was also used to corroborate data on outflow tract anatomy and examine the mitral valve. RESULTS: In 40 patients (80%) the initial myectomy resulted in a reduction of the maximal outflow tract gradient from 88 +/- 45 to 24 +/- 11 mm Hg, measured by epicardial continuous wave Doppler echocardiography. Ten patients (20%) were shown by postbypass intraoperative echocardiography to have an unsatisfactory result, based on a persistent gradient > 50 mm Hg (n = 7) or persistent mitral regurgitation of greater than moderate severity (n = 3). The postbypass two-dimensional echocardiogram was then used to direct the surgeon toward the most likely site of continued obstruction, and cardiopulmonary bypass was reinstituted to permit further myectomy (n = 9) or mitral valve repair (n = 1). After the second or subsequent period of cardiopulmonary bypass, the outflow tract gradient (26 +/- 14 mm Hg) was substantially reduced and was not significantly different from the postbypass gradient (24 +/- 11 mm Hg) in the group with initial surgical success. At postoperative follow-up (20 +/- 37 weeks), the maximal measured outflow tract gradient (22 +/- 21 mm Hg) showed no difference between patients with immediate surgical success and those requiring a second period of cardiopulmonary bypass for further resection. CONCLUSIONS: Intraoperative echocardiography proved a useful tool to guide the site and extent of septal myectomy, leading to more adequate surgical resection and to persistence of satisfactory control of the outflow tract obstruction into the early follow-up period.

Outcome of patients with hypertrophic obstructive cardiomyopathy after percutaneous transluminal septal myocardial ablation and septal myectomy surgery.

OBJECTIVES: This study was conducted to evaluate follow-up results in patients with hypertrophic obstructive cardiomyopathy (HOCM) who underwent either percutaneous transluminal septal myocardial ablation (PTSMA) or septal myectomy. BACKGROUND: Controversy exists with regard to these two forms of treatment for patients with HOCM. METHODS: Of 51 patients with HOCM treated, 25 were treated by PTSMA and 26 patients via myectomy. Two-dimensional echocardiograms were performed before both procedures, immediately afterwards and at a three-month follow-up. The New York Heart Association (NYHA) functional class was obtained before the procedures and at follow-up. RESULTS: Interventricular septal thickness was significantly reduced at follow-up in both groups (2.3 +/- 0.4 cm vs. 1.9 +/- 0.4 cm for septal ablation and 2.4 +/- 0.6 cm vs. 1.7 +/- 0.2 cm for myectomy, both p < 0.001). Estimated by continuous-wave Doppler, the resting pressure gradient (PG) across the left ventricular outflow tract (LVOT) significantly decreased immediately after the procedures in both groups (64 +/- 39 mm Hg vs. 28 +/- 29 mm Hg for PTSMA, 62 +/- 43 mm Hg vs. 7 +/- 7 mm Hg for myectomy, both p < 0.0001). At three-month follow-up, the resting PG remained lower in the PTSMA and myectomy groups (24 +/- 19 mm Hg and 11 +/- 6 mm Hg, respectively, vs. those before procedures, both p < 0.0001). The NYHA functional class was also significantly improved in both groups (3.5 +/- 0.5 vs. 1.9 +/- 0.7 for PTSMA, 3.3 +/- 0.5 vs. 1.5 +/- 0.7 for myectomy, both p < 0.0001). CONCLUSIONS: Both myectomy and PTSMA reduce LVOT obstruction and significantly improve NYHA functional class in patients with HOCM. However, there are benefits and drawbacks for each therapeutic method that must be counterbalanced when deciding on treatment for LVOT obstruction.

Systolic anterior motion of the mitral valve after Carpentier ring valvuloplasty for mitral valve prolapse.

Between July 1983 and March 1985, 45 patients with severe mitral regurgitation underwent mitral valvuloplasty with insertion of a semirigid Carpentier ring. No patient had echocardiographic evidence of systolic anterior motion (SAM) preoperatively, whereas 5 patients had this echocardiographic finding postoperatively. All 5 had mitral valve prolapse as their underlying disease process and SAM developed at varying intervals after valvuloplasty. The development of SAM is related to insertion of the semirigid ring, persistence of a redundant anterior mitral leaflet, narrowing of the left ventricular (LV) outflow tract and the Venturi effect. LV and aortic pressure measurements with simultaneous Doppler echocardiography have confirmed the presence of a significant LV outflow tract gradient in these patients. Although all 5 patients are functionally improved after mitral valvuloplasty, the long-term implications of SAM after valvuloplasty are unknown.

Resting echocardiographic features of latent left ventricular outflow obstruction in hypertrophic cardiomyopathy.

We determined resting echocardiographic features predictive of latent left ventricular (LV) outflow obstruction in 50 consecutive patients with nonobstructive hypertrophic cardiomyopathy (26 provocable, 24 nonprovocable with amyl nitrite inhalation) to have a better understanding of the pathophysiology of this condition and to identify such patients without pharmacologic provocation. Measurements included wall thickness, type of hypertrophy, LV outflow tract diameter, degree of mitral systolic anterior motion, outflow pressure gradient, and ventricular volume. The direction of the ejection streamline was measured to assess the magnitude of the drag force acting on the mitral valve. Thirteen of 16 patients (81%) with proximal septal bulge were provocable, whereas only 3 of 8 patients (38%) with asymmetric septal hypertrophy and 10 of 26 (38%) with concentric hypertrophy were provocable (p < 0.05). LV outflow tract was significantly narrower and the angle between the ejection flow and the mitral valve was larger in provocable patients. The sensitivity for predicting provocable patients by a combination of a narrow outflow tract (< or = 2 cm) and a large angle (> or = 35 degrees) was 65%, with a specificity of 80% and a positive predictive value of 79%. When these criteria were combined with the presence of septal bulge, the sensitivity was 35%, but the specificity and the positive predictive value were both 100%. Patients with nonobstructive hypertrophic cardiomyopathy with proximal septal bulge, a narrow LV outflow tract, and an oblique angle between the ejection flow and the mitral valve appeared to be predisposed for latent outflow obstruction. These features are consistent with the presence of the large Venturi and drag forces. Thus, the left ventricle, which is capable of increasing both the Venturi and the drog forces on the basis of the morphologic change, contributes to the development of outflow obstruction with amyl nitrite inhalation.

Left ventricular hypertrophy in persons age 90 years and older.

Clinical, electrocardiographic and echocardiographic findings of 32 patients age 90 years or older were analyzed to assess the prevalence, characteristics and correlates of left ventricular (LV) hypertrophy. All patients (mean age 92 years, range 90 to 98; 21 women and 11 men) were referred to the echocardiography laboratory with a definite or suspected cardiovascular diagnosis. LV hypertrophy, echocardiographically diagnosed by high LV mass index, was present in 28 patients. The LV mass index ranged from 105 to 215 g/m2 in men and 140 to 262 g/m2 in women. Electrocardiographic evaluation showed LV hypertrophy in only 5 patients. Five patients had low voltage on the electrocardiogram. There was no correlation between the LV mass index and presence of electrocardiographic LV hypertrophy or presence of low voltage on the electrocardiogram. LV hypertrophy was concentric in 19 and eccentric in 9. There was no correlation between types of LV hypertrophy and underlying cardiovascular disease or presence of electrocardiographic LV hypertrophy. It is concluded that LV hypertrophy is frequently present and has a wide range and heterogeneous character in very elderly patients with cardiovascular disease. In the tenth decade of life, echocardiography is a sensitive method for detecting, characterizing and classifying LV hypertrophy, whereas electrocardiography lacks sensitivity in detecting it.

Provocation of latent left ventricular outflow tract gradients with amyl nitrite and exercise in hypertrophic cardiomyopathy.

Amyl nitrite may be used to provoke latent gradients in patients with hypertrophic cardiomyopathy (HC) without significant resting outflow tract gradients, but afterload reduction may not be comparable to a more physiologic stressor such as symptom-limited exercise testing. This study compared the ability of amyl nitrite and exercise testing to provoke outflow tract gradients in 57 patients (40 men and 17 women, mean age +/- SD 49 +/- 16 years) with HC (septal thickness 19 +/- 5 mm, average resting gradient 13 +/- 10 mm Hg) who underwent echocardiography at rest, after amyl nitrite inhalation, and after maximal exercise. No significant gradient (< 50 mm Hg) was induced after either provocation in 26 patients (46%); in 15 patients (26%), inducibility was achieved after both stressors, in 6 (11%) after exercise only, and in 10 (18%) after amyl only. Patients with amyl-induced gradients differed from those in whom gradients were noninducible on the basis of smaller outflow tract dimensions (p < 0.001), larger resting gradients (p < 0.001), and a greater prevalence of "septal bulge" morphology (p = 0.02). Those with exercise-induced gradients were able to attain a greater workload (p = 0.07), have larger resting gradients (p = 0.02), and also tended to have a septal bulge morphology (p < or = 0.01). Although outflow tract obstruction increased to similar levels after amyl nitrite (49 +/- 39 mm Hg) and symptom-limited exercise (47 +/- 39 mm Hg), gradients induced by exercise and amyl correlated poorly (r = 0.54).(ABSTRACT TRUNCATED AT 250 WORDS)

Dynamic magnetic resonance imaging assessment of the effect of ventricular wall curvature on regional function in hypertrophic cardiomyopathy.

We hypothesized that contraction within the ventricular septum in hypertrophic cardiomyopathy (HC) may be related to its abnormal morphology because ventricular wall stress is related to wall curvature by the Laplace equation. To test this, we studied 17 HC patients with various septal morphologies using dynamic magnetic resonance imaging techniques. Short- and long-axis curvatures of the basal septal and basal lateral walls were determined on cine images as the reciprocal of the radius of the arc best fit to the endocardial contour, which was negative if the wall was convex to the cavity of the left ventricle. Endocardial and epicardial intramyocardial circumferential shortening (% circumferential shortening) was measured in the septal and lateral walls on basal short-axis myocardial tagging images. Septal walls were flatter in the short-axis plane and more convex toward the left ventricular cavity in the long-axis plane than lateral walls, as indicated by smaller short- and long-axis curvatures. Septal percent circumferential shortening was significantly lower than the lateral percent circumferential shortening, suggesting reduced septal contraction. Endocardial and epicardial percent circumferential shortening showed significant positive correlations with wall curvatures. Multiple stepwise linear regression analysis revealed that both short- and long-axis curvatures significantly contributed to percent circumferential shortening (r=0.87 for endocardial and r=0.70 for epicardial, both p<0.0001). In conclusion, wall curvature is related to wall function in HC; the more convex toward the left ventricular cavity the wall is, the less it contracts. Reduced contraction of the septum in HC may be partly due to its abnormal curvature.

Surgical management of hypertrophic obstructive cardiomyopathy. Early and late results.

From 1975 through 1993, 178 patients underwent surgical management of hypertrophic obstructive cardiomyopathy. Operations included isolated septal myectomy (n = 95), septal myectomy and coronary artery bypass grafting (n = 41), septal myectomy plus a valve procedure (n = 25), septal myectomy, valve procedure, and coronary artery bypass grafting (n = 14), and mitral valve replacement without septal myectomy (n = 3). Recent myectomy results were monitored with transesophageal echocardiography. After initial myectomy, 32 patients (20%) underwent a second pump run for more extensive myectomy only (n = 22), mitral valve replacement only (n = 5), or both (n = 2). In-hospital mortality was 6% (n = 11) and 4% (n = 6) for patients undergoing septal myectomy or septal myectomy plus coronary artery bypass grafting, respectively. Heart block occurred in 17 patients (10%). Left ventricular outflow tract systolic gradients decreased from a mean of 93 mm Hg to 21 mm Hg after myectomy. Late survival was 86% and 70% at 5 and 10 postoperative years, respectively, and 93% and 79% for patients undergoing septal myectomy alone or septal myectomy plus coronary artery bypass grafting, respectively. Only 3 of 131 in-hospital survivors of septal myectomy or septal myectomy plus coronary artery bypass grafting died late cardiac deaths, for a yearly mortality of 0.6%. However, the 5-year late survival of patients undergoing valve operation plus septal myectomy was 51%, and multivariate testing confirmed the adverse influence on late survival (p = 0.008), as well as adverse influences of increasing age (p = 0.016) and return to cardiopulmonary bypass for mitral valve replacement (p = 0.038). At follow-up 136 patients (94%) had New York Heart Association class I or II symptoms. For patients with hypertrophic obstructive cardiomyopathy, septal myectomy alone or in combination with coronary artery bypass grafting produces effective symptom relief, excellent long-term survival, and a low risk of late cardiac death.

Treatment of hypertrophic cardiomyopathy by mitral valve repair and septal myectomy.

This report describes surgical treatment consisting of mitral valve repair and septal myectomy in a young patient with a combination of hypertrophic cardiomyopathy and intrinsic mitral valve disease. The posterior mitral valve leaflet was elongated and was subject to systolic anterior motion, creating left ventricular outflow tract obstruction. With the described treatment, it was possible to avoid mitral valve replacement in this patient.

Aortoseptal angulation and left ventricular hypertrophy pattern: an echocardiographic study in patients with aortic valvular stenosis.

We studied 15 patients with valvular aortic stenosis (mean age 63 +/- 14 [SD] years) with M-mode, two-dimensional, and Doppler echocardiography to evaluate the influence of aortoseptal angulation on left ventricular changes. The diastolic aortoseptal angle averaged 118 degrees +/- 4 degrees in 10 patients (group I) and 96 degrees +/- 17 degrees in five patients (group II) (p less than 0.05). Left ventricular outflow tract diameter was significantly narrower in group II versus group I (1.5 +/- 0.5 cm versus 2.1 +/- 0.2 cm, p less than 0.01), and severe left ventricular outflow tract obstruction developed in two patients in group II after surgery. Moreover, diastolic aortoseptal angulation did not correlate with any of left ventricular indexes in group I but correlated significantly with left ventricular diastolic posterior wall thickness in group II (r = -0.975, p = 0.025). We conclude that aortoseptal angulation in aortic stenosis may alter left ventricular geometry, and its clinical significance may be related to its effects on postoperative accentuation of left ventricular outflow tract obstruction.

Hypertension and left ventricular hypertrophy in black vs white heart transplant patients 1 year after surgery.

To evaluate the impact of race on the prevalence of systemic hypertension and its effects on left ventricular function, structure, and allograft survival after cardiac transplantation, 31 heart transplant recipients (7 blacks and 24 whites) were studied at 1 year after surgery. Echocardiographic and hemodynamic evaluation of the allografts was performed in addition to clinical follow-up and estimation of patients' survival. There was no difference in the demographic and clinical data between black and white patients. No differences between black and white cardiac transplant recipients were detected with regard to the prevalence of systemic hypertension, left ventricular hypertrophy, left ventricular function, renal function, or patients' survival. Moreover, racial mismatch did not predispose to allograft rejection. However, black patients had significantly higher resting systolic blood pressure and lower heart rates. We conclude that the race of heart recipients is not a detrimental factor in the early outcome after cardiac transplantation. The long-term cardiovascular consequences of these findings should be explored.

Determinants of left ventricular hypertrophy in patients with aortic stenosis.

The determinants of left ventricular (LV) mass were evaluated in 150 patients with aortic stenosis. All patients underwent M-mode, two-dimensional, and Doppler echocardiography. Peak aortic gradients ranged from 9 mmHg to 144 mmHg (mean 52.3 mmHg). The degree of left ventricular hypertrophy, as determined by LV mass index, was compared to several variables, including age, systolic blood pressure, left ventricular function, peak and mean pressure gradients, relative wall thickness, estimated LV systolic pressure, and aortic valve area. The LV mass index varied from 114.1 to 547.2 g/m2 (mean, 159.4 g/m2). Multiple regression analysis revealed that both age and LV function were highly significant predictors of LV mass index. Moreover, LV mass index and systolic blood pressure were significantly greater in patients older than 65 years (P less than .01; P less than .0001, respectively). These results suggest that the severity of left ventricular hypertrophy in the presence of aortic stenosis is multifactorial and not affected only by the hemodynamic severity of aortic stenosis as assessed by aortic valve area or pressure gradient estimation. Patient age, systolic blood pressure, and ventricular function should all be considered when evaluating the degree of left ventricular hypertrophy in patients with aortic stenosis.

Steep left ventricle to aortic root angle and hypertrophic obstructive cardiomyopathy: study of a novel association using three-dimensional multimodality imaging.

BACKGROUND: Patients with hypertrophic cardiomyopathy (HCM) exhibit a difference in left ventricular outflow tract (LVOT) obstruction, independently of basal septal thickness (BST). Some patients with HCM have a steeper left ventricle to aortic root angle than controls. OBJECTIVE: To test the predictors of the LV-aortic root angle and the association between LV-aortic root angle and LVOT obstruction using three-dimensional imaging. PATIENTS: 153 consecutive patients with HCM (mean (SD) age 46 (14) years, 68% men) and 62 patients with hypertensive heart disease of the elderly (all >65 years of age, 73 (6) years, 34% men) who underwent whole-heart three-dimensional cardiac magnetic resonance (CMR) angiography (1.5 T) and Doppler echocardiography. Forty-two controls (age 43 (11) years, 38% men) who underwent contrast-enhanced multidetector computed tomography and were free of cardiovascular pathology were also studied. MAIN OUTCOMES: LV-aortic root angle, BST and maximal non-exercise LVOT gradient were measured in patients with HCM and in hypertensive-elderly patients. Additionally, LV-aortic root angle and BST were measured in controls. RESULTS: The mean (SD) LV-aortic root angle was significantly different (p<0.001) in the three groups: HCM (134 (10) degrees ), hypertensive-elderly (128 (10) degrees ), control (140 (7) degrees ). There was an inverse correlation between age and LV-aortic root angle in the three groups (all p<0.001): HCM (r = -0.56), hypertensive-elderly (r = -0.35), control (r = -0.48). On univariate analysis, in the HCM group, LV-aortic root angle (beta = -0.34, p<0.001), age (beta = 0.23, p = 0.01) and end-systolic volume index (beta = -0.20, p = 0.02), but not BST (beta = 0.02, p = 0.8), were associated with LVOT gradient. On multivariate analysis, only LV-aortic root angle was associated with LVOT gradient. CONCLUSIONS: Patients with HCM have a steeper LV-aortic root angle than controls. In patients with HCM, a steeper LV-aortic root angle predicts dynamic LVOT obstruction, independently of BST.

Abnormal papillary muscle morphology is independently associated with increased left ventricular outflow tract obstruction in hypertrophic cardiomyopathy.

BACKGROUND: Abnormal papillary muscles (PM) are often found in hypertrophic cardiomyopathy (HCM). OBJECTIVE: To assess the relationship between morphological alterations of PM in patients with HCM and left ventricular outflow tract (LVOT) obstruction, using magnetic resonance imaging (MRI) and echocardiography. METHODS: Fifty-six patients with HCM (mean age 42 years (interquartile range 27, 51), 70% male) and 30 controls (mean age (42 (30, 53) years, 80% male) underwent MRI on a 1.5 T scanner (Siemens, Erlangen, Germany). Standard cine images were obtained in short-axis (base to apex), along with two-, three- and four-chamber views. The presence of bifid PM (none, one or both) and anteroapical displacement of anterolateral PM was recorded by MRI and correlated with resting LVOT gradients obtained by echocardiography. RESULTS: Double bifid PM (70% vs 17%) and anteroapical displacement of anterolateral PM (77% vs 17%) were more prevalent in patients with HCM than in controls (p<0.001). Subjects with anteroapically displaced PM and double bifid PM had higher resting LVOT gradients than controls (45 (6, 81) vs 12 (0, 12) mm Hg (p<0.01) and 42 (6, 64) vs 11 (0, 17) mm Hg (p = 0.02), respectively. In patients with HCM, the odds ratio of having significant (>or=30 mm Hg) peak resting gradient was 7.1 (95% CI 1.4 to 36.7) for anteroapically displaced anterolateral PM and 10.4 (95% CI 1.2 to 91.2) for double bifid PM (both p = 0.005), independent of septal thickness, use of beta-blockers and/or calcium blockers and resting heart rate. CONCLUSIONS: Patients with HCM with abnormal PM have a higher degree of resting LVOT gradient, which is independent of septal thickness.

The role of echocardiography in assessing the morphological response of left ventricular thrombus to anticoagulation.

We present a patient with idiopathic dilated cardiomyopathy and a large left ventricular apical thrombus in which serial echocardiography over a 1-month period documented progressive enlargement of this mural thrombus. This case illustrates the dramatic progression of left ventricular thrombus size despite aggressive anticoagulation. In addition, the critical role of echocardiography in the diagnosis and follow-up of patients with left ventricular thrombus is emphasized.