Tissue Doppler imaging for the evaluation of patients with hypertrophic cardiomyopathy

PURPOSE OF REVIEW: To discuss the role of tissue Doppler imaging for assessing regional myocardial function in patients with proven or suspected hypertrophic cardiomyopathy and review its application in clinical practice for diagnosis, estimation of filling pressures, and monitoring of treatment. RECENT FINDINGS: Patients with hypertrophic cardiomyopathy have very abnormal systolic and diastolic myocardial function, even if global systolic function of the left ventricle appears normal. Regional function is most abnormal in walls that are markedly hypertrophied, but it is also abnormal in segments that are not affected by hypertrophy, and it is depressed in patients who have a mutation for hypertrophic cardiomyopathy but have not yet developed clear phenotypic changes. Genetic diagnosis remains difficult especially in sporadic cases, due to the very large number of mutations that have been identified; the hypertrophy may represent a nonspecific compensatory response to any mutation that impairs myofibrillar function. Subclinical changes especially affect long-axis ventricular function, and tissue Doppler imaging is the most sensitive test to identify reduced velocities of long-axis shortening and early diastolic lengthening of the left ventricle, prolonged contraction and relaxation times, and reduced strain in affected segments, both in patients with hypertrophy and in asymptomatic subjects with mutations. It can also discriminate well between hypertrophic cardiomyopathy and athlete's heart, and can be used with standard echocardiographic measurements to estimate left ventricular filling pressure or to monitor treatment. SUMMARY: Tissue Doppler imaging can now be usefully incorporated into the routine echocardiographic study of patients with proven or suspected hypertrophic cardiomyopathy.     

Differentiation between pathologic and physiologic left ventricular hypertrophy by tissue Doppler assessment of long-axis function in patients with hypertrophic cardiomyopathy or systemic hypertension and in athletes.

To identify new echocardiographic indexes of long-axis function that might differentiate between pathologic and physiologic left ventricular (LV) hypertrophy, we compared 60 subjects with different types of LV hypertrophy (group I: 15 patients with hypertrophic cardiomyopathy, group II: 15 patients with systemic hypertension, and group III: 30 athletes) with 20 normal subjects (group IV). The peak velocities of mitral annular motion at 4 sites were measured from the apex by tissue Doppler echocardiography. There were no differences in mean age and global ejection fraction between groups. Groups I and II had lower long-axis systolic and early diastolic velocities than the athletes (p <0.01) for all 4 sites. The best differentiation of pathologic from physiologic hypertrophy was provided by a mean systolic annular velocity <9 cm/s (sensitivity 87%, specificity 97%). Heterogeneity of annular velocities discriminated between group I and group II. Thus, long-axis systolic and early diastolic velocities are decreased in patients with pathologic hypertrophy, but preserved in athletes. These simple new echocardiographic parameters can differentiate between pathologic and physiologic hypertrophy.     

Tissue Doppler imaging for predicting outcome in patients with cardiovascular disease

PURPOSE OF REVIEW: Tissue Doppler imaging is being increasingly used for assessing global ventricular function in systole and diastole, and for quantifying regional wall motion abnormalities both in systolic heart failure with mechanical dyssynchrony and ischemic heart disease. Its use as a predictive tool is recent and the authors review publications relating to this aspect. RECENT FINDINGS: Peak early diastolic mitral annular velocity is a powerful predictor of outcome in a variety of cardiovascular conditions and adds incremental value to clinical parameters and standard mitral Doppler inflow velocities. Tissue Doppler imaging can also predict the development of hypertrophic cardiomyopathy in asymptomatic individuals carrying the genetic mutation even before the onset of overt left ventricular hypertrophy. In addition, the standard deviation of the time to peak systolic velocity is a good marker of mechanical asynchrony and can predict reverse remodeling. It may also be useful in identifying individuals with ischemic heart disease and regional wall motion abnormalities who have an adverse outcome. SUMMARY: Tissue Doppler imaging is a powerful new echocardiographic tool that is now becoming the standard for assessing ventricular function in a variety of situations and diseases.     

Tissue Doppler imaging and long axis left ventricular function: hypertrophic cardiomyopathy versus athlete's heart.

BACKGROUND: The different diagnosis between hypertrophic cardiomyopathy and athlete's heart has important clinical implications. The assessment of long axis left ventricular function with tissue Doppler imaging in hypertrophic cardiomyopathy (showing systolic and diastolic dysfunction with heterogeneity and asynchrony), may be useful in the differentiation of these situations. AIM: To study, with tissue Doppler imaging, long axis left ventricular function in a population of athletes (rowers) and to compare it with a population of non-obstructive hypertrophic cardiomyopathy patients. METHODS: In 24 patients with non-obstructive hypertrophic cardiomyopathy and in 20 competitive rowers with similar age, blood pressure and heart rate, we analyzed mitral annulus motion with pulsed tissue Doppler imaging in the 4 sides of the annulus (septal, lateral, inferior, anterior), in apical views. In each wave (systolic, rapid filling and atrial contraction) we measured velocities, time intervals and velocity-time integrals, and calculated heterogeneity and asynchrony indices. Data were compared between the groups, between the different sides in each group ("parallel analysis") and with conventional indices of global function. RESULTS: Hypertrophic cardiomyopathy patients showed: systolic function: lower velocities and integrals, shorter ejection time and shorter systolic time. These abnormalities occurred even in annular sites contiguous to walls without hypertrophy. DIASTOLIC FUNCTION: Much lower rapid filling velocities and integrals, lower atrial contraction velocities and integrals, lower e/a, longer isovolumic relaxation time and time to peak rapid filling wave. These abnormalities occurred even in annular sites adjacent to walls without hypertrophy. In the athletes group, the e/a ratio was never < 1, in any annular site. In hypertrophic cardiomyopathy patients this ratio was < 1 in 27% of the sites. CONCLUSIONS: 1--Systolic and diastolic long axis left ventricular function is different in hypertrophic cardiomyopathy and in athletes, in all mitral annulus sides. 2--The presence of these abnormalities in annular sites contiguous to walls without hypertrophy suggests that this technique may be useful in the differential diagnosis between these groups, particularly in the "gray zone" of Maron.     

Usefulness of Doppler echocardiographic assessment of diastolic filling in distinguishing "athlete's heart" from hypertrophic cardiomyopathy.

OBJECTIVE--In some athletes with a substantial increase in left ventricular wall thickness, it may be difficult to distinguish with certainty physiological hypertrophy due to athletic training from hypertrophic cardiomyopathy. The purpose of the present investigation was to determine whether assessment of left ventricular filling could differentiate between these two conditions. DESIGN--Doppler echocardiography was used to obtain transmitral flow velocity waveforms from which indices of left ventricular diastolic filling were measured. Normal values were from 35 previously studied control subjects. SETTING--Athletes were selected mostly from the Institute of Sports Science (Rome, Italy), and patients with hypertrophic cardiomyopathy were studied at the National Institutes of Health (Bethesda, Maryland). PARTICIPANTS--The athlete group comprised 16 young competitive athletes with an increase in left ventricular wall thickness (range 13-16 mm; mean 14). For comparison, 12 symptom free patients with non-obstructive hypertrophic cardiomyopathy were selected because their ages and degree of hypertrophy were similar to those of the athletes. RESULTS--In the athlete group, values for deceleration of flow velocity in early diastole, peak early and late diastolic flow velocities, and their ratio were not significantly different from those obtained in untrained normal subjects; furthermore, Doppler diastolic indices were normal in each of the 16 athletes. Conversely, in patients with hypertrophic cardiomyopathy, mean values for Doppler diastolic indices were significantly different from both normal subjects and athletics (p = 0.01 to 0.003), and one or more indices were abnormal in 10 (83%) of the 12 patients. CONCLUSIONS--Doppler echocardiographic indices of left ventricular filling may aid in distinguishing between pronounced physiological hypertrophy due to athletic training and pathological hypertrophy associated with hypertrophic cardiomyopathy.     

Relationship between outflow obstruction and left ventricular functional impairment in hypertrophic cardiomyopathy: a Doppler echocardiographic study

Left ventricular outflow tract (LVOT) obstruction is predictive of a worse outcome in hypertrophic cardiomyopathy (HCM). In a detailed Doppler echocardiographic study of 178 selected HCM patients, the group of patients (n = 73) with the obstructive form (resting peak gradient > or = 30 mmHg) presented more hypertrophy and poorer systolic and diastolic left ventricular (LV) functions than the HCM group (n = 105) without obstruction. LVOT peak gradient was positively correlated with hypertrophy (P < 0.0001) and negatively to tissue Doppler mitral annulus systolic (P = 0.0001) and early diastolic (P < 0.0001) velocities. The gradient significantly correlated with E/Ea ratio (r = 0.67; P < 0.0001). By multiple regression, LVOT gradient was related to E/Ea, LV maximal thickness and left atrial size. In comparison with patients without obstruction, patients with obstruction presented greater hypertrophy (P < 0.0001), lower systolic and early diastolic mitral annulus velocities (both P < 0.0001), higher E/Ea ratio (P < 0.0001) and higher global function index (P < 0.0001). In HCM, beyond the effects on hypertrophy, LVOT obstruction is an independent determinant of LV functional abnormalities.     

Screening for pre-clinical hypertrophic cardiomyopathy by tissue Doppler imaging

BACKGROUND: Hypertrophic cardiomyopathy is an autosomal dominant inherited disorder. On a routine clinical basis, genetic analysis is both time consuming and impractical at present. Thus, use of tissue Doppler imaging as a surrogate for genetic screening is an attractive option. METHODS AND RESULTS: Fifty-five first-degree relatives of 15 patients with hypertrophic cardiomyopathy were screened. Of them, two were found to have hypertrophic cardiomyopathy and were included in Group 1, which hence had 17 patients with overt hypertrophic cardiomyopathy. Group 2 had 53 family members who did not manifest any overt echocardiographic abnormality. Twenty healthy volunteers comprised Group 3. Doppler tissue myocardial longitudinal velocities were measured in systole and early diastole and with atrial contraction at the medial mitral annulus, lateral mitral annulus, mid lateral wall and mid interventricular septum. The tissue Doppler characteristics were analyzed for the presence of abnormalities suggestive of subclinical myocardial involvement. Myocardial velocities were highest in the normal control group and lowest in the hypertrophic cardiomyopathy group. The velocities of the relatives without overt hypertrophy were intermediate in range. Of the 53 relatives screened, nine (17%) subjects showed tissue Doppler abnormality in the systolic and early diastolic velocities at the medial and lateral mitral annulus suggestive of a possibility of pre-clinical hypertrophic cardiomyopathy and a carrier state for a hypertrophic cardiomyopathy. Twenty-two of the 53 screened members had a mean early diastolic velocity less than 13.5 cm/s, among this group 9 had an ejection fraction more than 68%. These findings suggest that at least 16.7% of the screened population may carry beta-myosin heavy chain mutation. CONCLUSIONS: Screening for hypertrophic cardiomyopathy is feasible and tissue Doppler imaging is a sensitive and easy means to detect subclinical myocardial involvement in apparently normal family members without overt hypertrophy.     

Left ventricular filling in hypertrophic cardiomyopathy: a pulsed Doppler echocardiographic study

Abnormal left ventricular diastolic properties have been described in patients with hypertrophic cardiomyopathy. To evaluate the diastolic filling characteristics of the left ventricle in patients with this disease, pulsed Doppler echocardiography was used to study mitral flow velocity in 17 patients with hypertrophic cardiomyopathy (11 with and 6 without systolic anterior motion of the mitral valve) and 16 age-matched normal subjects. There were no statistically significant differences between patients with hypertrophic cardiomyopathy with and without systolic anterior motion with regard to ventricular septal thickness, left ventricular posterior wall thickness, left ventricular internal dimensions or the extent of hypertrophy evaluated by two-dimensional echocardiography. Mitral regurgitation was detected by Doppler echocardiography in all 11 patients with and in 2 (33%) of the 6 patients without systolic anterior motion of the mitral valve. Early and late diastolic peak flow velocity, the ratio of late to early diastolic peak flow velocity and deceleration of early diastolic flow were measured from Doppler mitral flow velocity recordings. There were no statistically significant differences in these four indexes between the patients with systolic anterior motion and normal subjects. In contrast, the patients with hypertrophic cardiomyopathy without systolic anterior motion showed lower early diastolic peak flow velocity, higher ratio of late to early diastolic peak flow velocity and lower deceleration of early diastolic flow compared with the patients with systolic anterior motion and normal subjects, suggesting impaired left ventricular diastolic filling.(ABSTRACT TRUNCATED AT 250 WORDS)     

Usefulness of Doppler myocardial imaging for identification of mutation carriers of familial hypertrophic cardiomyopathy

Because myocyte dysfunction and disarray are early abnormalities in hypertrophic cardiomyopathy (HC), we tested if Doppler myocardial imaging (DMI) could identify systolic and diastolic dysfunction in mutation carriers (MC) (genotype positive patients without hypertrophy, defined as phenotype negative after conventional screening tests). In a single family with a missense mutation in the myosin binding protein C gene (Arg 502 Gln) we identified 5 MCs; these subjects were asymptomatic and had normal physical examination, normal electrocardiogram, treadmill stress test, ambulatory Holter electrocardiogram, and normal conventional M-mode, 2-dimensional, and Doppler echocardiography. In each patient we performed a DMI study and measured the peak velocities of the systolic (S), rapid filling (E), and atrial contraction (A) waves in the 4 sides of the mitral annulus, in 8 left ventricular segments (apical views), in the tricuspid annulus, and in 2 right ventricular segments. These data were compared with those from 10 normal volunteers matched for sex, age, and body surface. Compared with the normal volunteers, the MCs had lower left ventricular systolic velocities and higher right ventricular systolic velocities; lower diastolic rapid filling velocities; higher or similar atrial contraction velocities; reduced E/A; lower percentage of annular sides and segments with E/A >1 and lower average number of sides and/or segments with E/A >1 per patient; similar right ventricular rapid filling velocities; and similar or higher atrial contraction wave velocities. Thus, DMI detects important left and right ventricular annular and regional myocardial contraction and relaxation abnormalities independently of the presence of hypertrophy, in HC. These results show that DMI is more sensitive than conventional echocardiography and establishes a new and highly accurate method for the noninvasive screening of MCs of the disease.     

Prevalence of dignostic abnormalities in patients with genetically transmitted asymmetric septal hypertrophy

Echocardiographic studies were performed in 100 patients from a general population with cardiac disease and in 33 patients with classic hypertrophic obstructive cardiomyopathy and 116 of their first degree relatives. The findings were compared with those in 35 normal persons. The prevalence rate of asymmetric septal hypertrophy (ventricular septal to free posterior wall ratio greater than 1.3) was 8 percent in the general population with heart disease. No further clinical or echocardiographic evidence was found for a familial disease. The ventricular septal to free posterior wall ratios for this group and the normal subjects had a unimodal distribution curve. All patients with hypertrophic obstructive cardiomyopathy demonstrated asymmetric septal hypertrophy, a decreased systolic septal thickening of less than 25 percent and a characteristic left ventricular shape in the cross-sectional echocardiogram. The ventricular septal to posterior wall ratios in their 116 relatives had a bimodal distribution curve; in 35 relatives the ratio indicated asymmetric septal hypertrophy and in 81 the ratio was normal. In addition, all 35 relatives with echocardiographic evidence of asymmetric septal hypertrophy had decreased systolic septal thickening (less than 25 percent) and in 17 the echocardiographic left ventricular shape was similar to that in patients with hypertrophic obstructive cardiomyopathy. In contrast, the 81 relatives who had no asymmetric septal hypertrophy had normal systolic septal thickening and a normal left ventricular shape. The clinical examination, electrocardiogram and chest X-ray film were less sensitive than the echocardiogram in detecting diagnostic abnormalities in the 35 relatives with asymmetric septal hypertrophy.It is concluded that echocardiographically assessed asymmetric septal hypertrophy can be considered the anatomic marker for hypertrophic cardiomyopathy only when, in addition, a decreased systolic septal thickening and, to a lesser degree, an abnormal left ventricular shape are present. The asymmetric septal hypertrophy in these cases probably represents the anatomic expression of a genetic defect that has an autosomal dominant pattern of inheritance. In so-called “borderline” cases with echocardiographic signs of an abnormal ventricular septal to posterior wall ratio, a definitive clinical diagnosis of hypertrophic cardiomyopathy could be made only after echocardiographic screening of family members for the presence of asymmetric septal hypertrophy.     

Relation between extent of left ventricular hypertrophy and diastolic filling abnormalities in hypertrophic cardiomyopathy

In hypertrophic cardiomyopathy, the relation between left ventricular diastolic impairment and magnitude of left ventricular hypertrophy has not been clearly defined. In the present study, Doppler echocardiographic indexes of left ventricular diastolic filling were compared in 78 patients with hypertrophic cardiomyopathy and in 72 normal control subjects of similar age, and the relation between abnormalities of diastolic filling and magnitude of left ventricular hypertrophy was assessed. In patients with hypertrophic cardiomyopathy, isovolumic relaxation was prolonged (94 +/- 25 ms); peak early diastolic flow velocity (53 +/- 18 cm/s), deceleration of flow velocity in early diastole (341 +/- 142 cm/s2) and the ratio between early and late peaks of flow velocity (1.6 +/- 0.9) were reduced; and peak late diastolic flow velocity was increased (38 +/- 15 cm/s) compared with values in control subjects (76 +/- 12 ms, 65 +/- 12 cm/s, 512 +/- 131 cm/s2, 2.3 +/- 0.8 and 30 +/- 7 cm/s, respectively; p less than 0.001). Individual patient analysis showed that diastolic filling was abnormal in 52 (67%) of the 78 patients with hypertrophic cardiomyopathy. However, within the patient group, none of the Doppler diastolic indexes showed a significant correlation with maximal left ventricular wall thickness or the wall thickness index (correlation coefficients ranged from -0.15 to 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)     

Involvement of right ventricle in left ventricular hypertrophic cardiomyopathy: analysis by pulsed Doppler tissue imaging.

AIMS: This study uses pulsed Doppler tissue imaging to analyse right ventricular myocardial function and its interaction with left ventricle in hypertrophic cardiomyopathy involving ventricular septum. METHODS AND RESULTS: Thirty-four patients with septal hypertrophic cardiomyopathy and 30 normal subjects, comparable for sex, age, body mass index and heart rate, underwent complete standard Doppler echocardiography and pulsed Doppler tissue imaging of both posterior septum and right ventricular free wall, calculating myocardial velocities and both systolic and diastolic time intervals. Except for peak velocity A, the other Doppler tricuspid inflow measurements were significantly impaired in hypertrophic cardiomyopathy, without changes of tricuspid annular systolic excursion. Right ventricular Doppler tissue imaging showed longer right ventricular myocardial relaxation time in hypertrophic cardiomyopathy than in controls (P<0.00001), without a significant difference from other myocardial diastolic and systolic measurements. In the overall population, Doppler measurements of right and left ventricular inflow were not significantly associated, while (with the exception of myocardial deceleration time) all the other myocardial systolic and diastolic measurements derived by tissue imaging were directly related to the homologous septal myocardial indexes. In addition, a significant inverse relation was found between septal wall thickness and myocardial relaxation index (right-left myocardial relaxation time/right ventricular relaxation time x 100). CONCLUSIONS: This study shows the usefulness of pulsed Doppler tissue imaging to detect impairment of right ventricular myocardial function and to provide evidence about ventricular interaction in forms of hypertrophic cardiomyopathy which involve interventricular septum.     

Tissue Doppler imaging in Fabry disease

PURPOSE OF REVIEW: The development of effective enzyme replacement/enhancement therapy makes of clinical relevance considering Fabry disease in the differential diagnosis of patients with hypertrophic cardiomyopathy. In particular the opportunity to significantly modify the clinical progression of the disease has reinforced the need for early diagnosis of Fabry cardiomyopathy. RECENT FINDINGS: The study with tissue Doppler of Fabry patients with endomyocardial biopsy-proven cardiac involvement showed a reduction of both diastolic and systolic myocardial velocities recorded at septal and lateral corners of mitral annulus. Tissue Doppler abnormalities were present not only in patients with left ventricular hypertrophy but also in younger patients with normal cardiac wall thickness and represent the first sign of myocardial damage. Furthermore tissue Doppler studies have been shown useful in detecting cardiac involvement in female carriers with no systemic manifestations of Fabry disease. In patients already submitted to enzyme-replacement therapy tissue Doppler and strain rate imaging represent useful noninvasive tools in assessing treatment efficacy. SUMMARY: Tissue Doppler imaging can provide early detection of cardiac involvement in Fabry disease and represents the most accurate and sensitive noninvasive tool for the diagnosis of myocardial dysfunction and for the assessment of cardiac improvement during enzyme replacement therapy. The detection of tissue Doppler abnormalities in female carriers may represent a hint for an invasive assessment of cardiac involvement.     

Left ventricular diastolic function in elite athletes with physiologic cardiac hypertrophy

Left ventricular hypertrophy due to aortic stenosis, hypertension and other forms of heart disease is associated with abnormalities of diastolic function. It is uncertain whether these changes are an inherent consequence of the hypertrophic process or represent additional pathologic factors. To investigate this issue, echocardiographic indexes of left ventricular early diastolic function in highly trained athletes were compared with those in age-matched normal control subjects. Athletes were equally classified into two groups: 11 swimmers who had a pattern of myocardial hypertrophy with normal wall thickness to dimension ratio and 11 power lifters whose wall thickness to dimension ratio was increased. The peak rates of left ventricular dimension increase and wall thinning in swimmers and power lifters were greater than in control subjects despite significantly higher left ventricular wall thickness and left ventricular mass index in the athletes. This increase in diastolic function indexes was associated with greater ventricular size and systolic performance. Normalization of the peak rate of dimension increase for end-diastolic dimension and adjustment of the peak rate of wall thinning for the fractional systolic thickening resolved any differences between groups. Thus, after the effects of ventricular size and systolic function were taken into consideration, diastolic function was normal in these subjects with considerable physiologic hypertrophy. This is in contrast to the findings in patients with hypertrophy associated with left ventricular pressure or volume overload, and suggests that abnormalities of diastolic function seen in pathologic hypertrophy are due to factors other than cardiac hypertrophy itself.     

Transthoracic Doppler echocardiographic analysis of phasic coronary blood flow velocity in hypertrophic cardiomyopathy.

OBJECTIVE: To use transthoracic Doppler echocardiography to assess coronary blood flow non-invasively in patients with hypertrophic cardiomyopathy. DESIGN: High frequency transthoracic Doppler echocardiography was used to assess resting phasic coronary velocity patterns in patients with hypertrophic cardiomyopathy and to define the relation between coronary flow patterns and clinical, echocardiographic, and haemodynamic manifestations of this condition. SETTING: A tertiary referral cardiothoracic centre. METHODS: Fifteen patients (10 men and five women, mean (SD) age 49 (10.3) years) with asymmetric hypertrophic cardiomyopathy underwent high frequency (5 MHz) transthoracic Doppler echocardiographic assessment of the left anterior descending coronary artery. In addition, standard two dimensional echocardiography was performed. The results were compared with 16 normal participants (nine men and seven women, mean age 61.2 (10.7) years) who had no evidence of cardiac disease. RESULTS: Biphasic diastolic predominant coronary artery blood velocity profiles were obtained in all patients and controls. Systolic peak blood velocity and velocity time integral were significantly reduced in the hypertrophic cardiomyopathy group compared with controls (11.3 (15.8) cm/s and 1.09 (1.78) cm v 20.5 (13.1) cm/s and 4.23 (2.80) cm, respectively, P < 0.05). A reversed pattern of systolic blood flow velocity was found in three patients with severe anterior wall and septal hypertrophy. During diastole there was prolongation of the diastolic acceleration (203 (53) ms v 110 (60) ms in controls, P < 0.05) and deceleration times (487 (200) ms v 210 (90) ms in controls, P < 0.05). There was no significant difference between those with and without symptoms or a left ventricular outflow tract gradient. CONCLUSIONS: Patients with hypertrophic cardiomyopathy have abnormal systolic and diastolic coronary flow profiles at rest when measured by transthoracic echocardiography.     

Asymmetric septal hypertrophy in patients on long-term hemodialysis.

Echocardiographic studies were performed in 23 hypertensive patients who were receiving therapy with long-term hemodialysis. Five patients (22 percent) had normal thickness of the left ventricular wall. Eleven (48 percent) had symmetric left ventricular hypertrophy, and seven (30 percent) showed asymmetric septal hypertrophy, with a ratio of septal to posterior wall thickness of 1.3 or greater. The latter group differed from patients with hypertrophic cardiomyopathy in that patients on long-term hemodialysis had a dilated left ventricular dimension, a relatively normal diastolic slope of the mitral valve, absence of systolic motion of the mitral valve, and a septal to posterior wall ratio of less than 1.5. A high incidence of asymmetric septal hypertrophy in this and other studies indicates that this condition is not specific for hypertrophic cardiomyopathy. We suggest that in addition to asymmetric septal hypertrophy, the diagnosis of hypertrophic cardiomyopathy should be made in the light of the clinical picture, as well as other echocardiographic features.     

Mid-Term Results of Dual-Chamber Pacing in Children with Hypertrophic Obstructive Cardiomyopathy

Background: Permanent dual-chambered pacing (DDD) is an alternative to surgical treatment in patients with severe hypertrophic obstructive cardiomyopathy (HOCM) who do not have a satisfactory response to medical treatment. Methods: Five children with severe HOCM still symptomatic despite medical treatment underwent permanent DDD pacing and were followed for 21 ± 9.7 months. Results: All patients improved their functional class. Doppler echocardiographic studies showed an early reduction of the left ventricular outflow tract gradient from 66 ± 40 to 40 ± 20 mmHg (P < 0.05) and to 30 ± 11 mmHg (P < 0.05 and NS for comparison with the baseline and the early post-DDD pacing gradients, respectively) at mid-term follow-up. There was no evidence of left ventricular systolic dysfunction, and the results of left ventricular filling studies ruled out deleterious effects on diastolic function. Doppler echocardiography played a key role in the initial and subsequent assessment of these patients. Conclusions: Permanent DDD pacing is a reasonable alternative to surgery in children with HOCM who are still symptomatic despite medical therapy.     

Tissue Doppler imaging assessment of long axis left ventricular function in hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy is classically defined as a diastolic disease with normal systolic function. Long axis left ventricular function is an important and sensitive determinant of global ventricular function but its assessment is often difficult and complex. Tissue Doppler imaging of the mitral annulus allows the study of long axis left ventricular function. METHODS: 47 patients with non-obstructive hypertrophic cardiomyopathy and 45 healthy volunteers, matched by age and sex, were studied with pulsed tissue Doppler imaging of the 4 sides of the mitral annulus (septal, lateral, inferior, anterior) in 4 and 2 chamber views. In each wave (systolic-s, rapid filling-e, atrial contraction-a) we analyzed velocities, time intervals and velocity-time integrals, as well as heterogeneity and asynchrony. Data were compared among the different sides in each group, between groups and with conventional Doppler data. RESULTS: In contrast to normal subjects, hypertrophic cardiomyopathy patients showed: 1--Systolic function: lower velocities, longer systolic time intervals (isovolumic relaxation time, time to peak s, ejection time), higher systolic asynchrony (time to peak s, ejection time, systolic time) and lower s/shortening fraction ratio. These changes occurred despite normal indices of global systolic function. 2--Diastolic function: lower velocities (much lower rapid filling velocity, lower atrial contraction velocity, lower septal e/a), higher e/a heterogeneity index, longer protodiastolic times (isovolumic relaxation time and time to peak e), higher diastolic asynchrony (time to peak e) and lower e wave integral. Hypertrophic cardiomyopathy patients also showed higher average number of annular sides with e/a < 1 per patient and higher percentage of e/a < 1, mainly on the septal side. CONCLUSIONS: This study shows that: 1--Tissue Doppler imaging allows the detailed analysis of long axis left ventricular function in hypertrophic cardiomyopathy patients. 2--Long axis systolic function is abnormal in this disease, even in the presence of normal indices of global systolic function. 3--Long axis diastolic function is deeply disturbed in hypertrophic cardiomyopathy, at ventricular and atrial levels. 4--Long axis dysfunction occurs in annular sides contiguous to hypertrophied and non-hypertrophied walls, highlighting the role of other factors in its pathophysiology.     

Experience from clinical genetics in hypertrophic cardiomyopathy: proposal for new diagnostic criteria in adult members of affected families.

The diagnosis of hypertrophic cardiomyopathy has relied on echocardiographic demonstration of unexplained left ventricular hypertrophy. The prevalence of hypertrophic cardiomyopathy defined in this way has been estimated to be 1:500 and experience indicates that these criteria are relatively specific when other causes of left ventricular hypertrophy are absent. In recent years, however, the systematic evaluation of pedigrees performed in the context of molecular genetic studies revealed that in some families with hypertrophic cardiomyopathy up to 20% of adults who carry a disease causing gene defect do not fulfil conventional echocardiographic criteria. None the less, most of these individuals show symptoms, electrocardiographic alterations, and/or minor echocardiographic abnormalities. Revised diagnostic criteria in members of families with hypertrophic cardiomyopathy are proposed, including major and minor criteria based on symptoms, and electrocardiographic and echocardiographic abnormalities. Given that the chance of inheriting the gene defect is 1:2, the likelihood that symptoms plus electrocardiographic or echocardiographic abnormalities are the expression of a disease causing gene is high.     

Usefulness of Doppler echocardiographic assessment of diastolic filling in distinguishing “athlete''s heart” from hypertrophic cardiomyopathy

Objective—In some athletes with a substantial increase in left ventricular wall thickness, it may be difficult to distinguish with certainty physiological hypertrophy due to athletic training from hypertrophic cardiomyopathy. The purpose of the present investigation was to determine whether assessment of left ventricular filling could differentiate between these two conditions.

Design—Doppler echocardiography was used to obtain transmitral flow velocity waveforms from which indices of left ventricular diastolic filling were measured. Normal values were from 35 previously studied control subjects.

Setting—Athletes were selected mostly from the Institute of Sports Science (Rome, Italy), and patients with hypertrophic cardiomyopathy were studied at the National Institutes of Health (Bethesda, Maryland).

Participants—The athlete group comprised 16 young competitive athletes with an increase in left ventricular wall thickness (range 13–16 mm; mean 14). For comparison, 12 symptom free patients with non-obstructive hypertrophic cardiomyopathy were selected because their ages and degree of hypertrophy were similar to those of the athletes.

Results—In the athlete group, values for deceleration of flow velocity in early diastole, peak early and late diastolic flow velocities, and their ratio were not significantly different from those obtained in untrained normal subjects; furthermore, Doppler diastolic indices were normal in each of the 16 athletes. Conversely, in patients with hypertrophic cardiomyopathy, mean values for Doppler diastolic indices were significantly different from both normal subjects and athletics (p = 0·01 to 0·003), and one or more indices were abnormal in 10 (83%) of the 12 patients.

Conclusions—Doppler echocardiographic indices of left ventricular filling may aid in distinguishing between pronounced physiological hypertrophy due to athletic training and pathological hypertrophy associated with hypertrophic cardiomyopathy.