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.     

Electrocardiographic changes can precede the development of myocardial hypertrophy in the setting of hypertrophic cardiomyopathy

A comparison was made of electrocardiographic findings in 107 first-degree relatives of patients with hypertrophic cardiomyopathy without any clinical and echocardiographic signs of the disease and 188 healthy persons with a negative family history. A significantly larger number of electrocardiographic signs of left ventricular hypertrophy (P less than 0.05) and abnormal Q wave (P less than 0.005) was shown in the group of the relatives. Abnormalities of the R wave in V1-3 and of the ST-T segment were also more frequent in this group, but the difference is not statistically significant. In all, electrocardiographic abnormalities were found in 13 of 107 asymptomatic relatives of the patients with hypertrophic cardiomyopathy. These relatives had normal clinical and echocardiographic findings. These 13 patients underwent long-term follow-up (4.5-8 years). Typical hypertrophic cardiomyopathy developed in two patients (an increase in the myocardial thickness from 6 to 15 m in six years and from 8 to 13 mm in 4.5 years, respectively) which was accompanied by progression of the electrocardiographic findings. Electrocardiography is the only commonly available method which may reveal the latent forms of hypertrophic cardiomyopathy at the stage when neither myocardial hypertrophy nor other signs of the disease are expressed. Longitudinal follow-up is necessary for all the relatives of the patients with hypertrophic cardiomyopathy who have abnormal or borderline electrocardiographic findings. A normal echocardiogram cannot exclude the disease at this stage.     

Mode of inheritance of hypertrophic cardiomyopathy in Iceland. Echocardiographic study.

We used an abnormally thick interventricular septum (greater than or equal to 1.3 cm) as an echocardiographic marker to find the inheritance pattern of hypertrophic cardiomyopathy among relatives of eight patients who had that disease at necropsy. Forty normal subjects served as a control group. Fifty-eight family members were examined and 18 (41%) of the 44 first degree relatives had hypertrophic cardiomyopathy. The overall inheritance pattern was consistent with an autosomal dominant genetic disorder and in one family a recessive trait could be excluded. The diagnosis of hypertrophic cardiomyopathy can be difficult clinically as only 13% of our patients had serious symptoms and only 30% had abnormal auscultatory findings. The electrocardiogram is a useful screening test among relatives as it was abnormal in 20 (87%) of those who had an abnormally thick septum. Symmetric septal hypertrophy was found in 30% of patients with cardiomyopathy in this study and only 17% had clinical evidence of obstruction.     

Familial hypertrophic cardiomyopathy: vectorcardiographic findings in echocardiographically unaffected relative.

The electrocardiographic and vectorcardiographic (Frank system) features of the first degree relatives of subjects with documented familial hypertrophic cardiomyopathy were analysed. A total of nine affected members and 29 relatives were examined in four families. THe subjects were considered to be affected when the septal to free posterior wall thickness ratio exceeded 1.3 at M-mode echocardiography. Four relatives had asymmetric septal hypertrophy. Among 25 relatives without evidence of asymmetric septal hypertrophy, two over 20 years and 10 under 20 years of age showed increased voltage of QRS anterior forces (Qz amplitude greater than 0.80 mV) on the orthogonal electrocardiogram. The vectorcardiographic data of the relatives under 20 years of age without evidence of asymmetric septal hypertrophy (18 subjects) were compared with those of 38 normal control subjects of comparable age range. The young relatives without disproportionate septal hypertrophy had significantly greater Qz amplitude and Q/Rz ratio than the normal control subjects. In contrast, the echocardiographic data were not significantly different. We suggest that the electrocardiographic finding of abnormal anterior forces in one or more first degree relatives of subjects with documented hypertrophic cardiomyopathy may constitute a valuable aid in ascertaining the genetic transmission of the disease and in recognising affected members without echocardiographic evidence of hypertrophic cardiomyopathy.     

Relation of electrocardiographic abnormalities and patterns of left ventricular hypertrophy identified by 2-dimensional echocardiography in patients with hypertrophic cardiomyopathy

Distribution of left ventricular (LV) hypertrophy was assessed by wide-angle, 2-dimensional (2-D) echocardiography in 153 patients with hypertrophic cardiomyopathy and compared with the scalar electrocardiogram in the same patients. The most common electrocardiographic alterations were S-T segment changes and T-wave inversion (61%), LV hypertrophy (47%), abnormal Q waves (25%), and left atrial enlargement (24%). LV hypertrophy on the electrocardiogram was significantly more common in patients with the most extensive distribution of LV hypertrophy on 2-D echocardiogram involving substantial portions of both the ventricular septum and LV free wall (type III; 51 of 69, 74%) than in those with more limited distribution of LV hypertrophy (21 of 84, 25%; p less than 0.001). Most patients with hypertrophic cardiomyopathy and normal electrocardiograms (13 of 23) had localized (type I) hypertrophy, but only 4 had the extensive type III pattern of hypertrophy. Abnormal Q waves were significantly more common in those patients without hypertrophy of the anterior, basal septum (type IV; 15 of 27, 56%) than in those with basal septal hypertrophy (23 of 126, 18%; p less than 0.001); abnormal Q waves were uncommon in extensive type III distribution of hypertrophy (13 of 69, 19%). Thus, although no single electrocardiographic abnormality is characteristic of hypertrophic cardiomyopathy, 2-D echocardiography clarifies the significance of certain electrocardiographic patterns: (1) LV hypertrophy on the electrocardiogram, although present in only about half of the study group, was a relatively sensitive (74%) marker for extensive (type III) LV hypertrophy; (2) abnormal Q waves cannot be explained by ventricular septal hypertrophy alone; and (3) a normal electrocardiogram was most commonly a manifestation of localized LV hypertrophy.     

Electrocardiographic changes associated with training and discontinuation of training in an athlete with hypertrophic cardiomyopathy

The 12-lead electrocardiogram of a 17-year-old African professional soccer player had signs of left ventricular (LV) hypertrophy and deeply inverted T waves in the inferior and precordial leads. Two-dimensional echocardiography showed mild LV hypertrophy with normal cavity size consistent with nonobstructive hypertrophic cardiomyopathy. After 5 months of complete discontinuation of training, the electrocardiogram normalized; however, the echocardiogram was unchanged. Subsequently, and contrary to our advice, the athlete resumed training and professional soccer. One year later the electrocardiogram again showed a similar and markedly abnormal pattern without cardiac dimensional changes.     

Equivocal and borderline myocardial hypertrophy in relatives of patients with hypertrophic cardiomyopathy: possible implications in genetics of the disease

To determine the occurrence of familial and sporadic forms of hypertrophic cardiomyopathy (HC) 74 first-degree relatives of 21 patients with proven HC were studied by M-mode and two-dimensional echocardiography. A diagnosis of HC was made in 11 relatives (15%) while it was excluded in 61 of them (82%); 2 subjects (3%) were considered neither affected nor unaffected (borderline left ventricular hypertrophy suggestive of HC). Inspection of pedigrees revealed 38% of familial forms of HC with an autosomal dominant pattern of inheritance in 5/8 families (62%). Furthermore, among those relatives judged unaffected by means of full echocardiographic criteria for HC, an attempt was made to find out whether minor changes of left ventricular geometry were present for their possible implications in genetics of HC (latent or potential forms, low phenotypic expression of the disease). Eleven out of 61 unaffected relatives had a left ventricular wall thickness radius ratio greater than 0.50 (equivocal hypertrophy), a value that was higher than two standard deviations of the control group. Assessment of clinical significance of borderline and equivocal hypertrophy in relatives of patients with HC is required for a better understanding of genetic transmission of this disease. In this view the occurrence of sporadic and familial forms of HC might be revisited.     

Familial aggregation of idiopathic dilated cardiomyopathy: clinical features and pedigree analysis in 14 families.

OBJECTIVE--A recent prospective study in patients with dilated cardiomyopathy has reported that the disease is familial in at least 20% of cases, but the pattern of inheritance could not be ascertained. The presence of an autosomal dominant pattern, such as seen in hypertrophic cardiomyopathy, could make it possible to search for single gene defects with linkage analysis, whereas polygenic inheritance would be consistent with the autoimmune hypothesis. To assess the pattern of inheritance, we retrospectively identified patients with familial disease and assessed their first degree relatives (parents, siblings and children) for dilated cardiomyopathy. DESIGN AND PATIENTS--The family history of 105 consecutive patients with dilated cardiomyopathy was reviewed and 14 who had at least one first degree relative with documented disease were identified as probands. Their healthy relatives (109) were studied by physical examination, electrocardiography, M mode and cross sectional echocardiography, and were classified as unequivocally normal or as potential carriers. The potential carriers had abnormal electrocardiography with either at least one echocardiographic measurement of left ventricular cavity dimension or percentage fractional shortening outside 2 SDs of normal values (based on age and body surface area). The potential carriers underwent 24 hour Holter monitoring and maximal treadmill exercise. RESULTS AND CONCLUSION--Twenty three relatives (21%) were classified as potential carriers: 12 had an increased left ventricular end diastolic dimension, with reduced percentage fractional shortening in three; 11 had an abnormal electrocardiogram and increased end diastolic dimension, with reduced percentage fractional shortening in five. Such abnormalities were very mild and follow up is necessary to find whether such changes represent early disease. Pedigree analysis was most consistent with polygenic inheritance.     

Hypertrophic cardiomyopathy manifesting different modes of illness: report of three cases

Three cases of hypertrophic cardiomyopathy (HCM) which presented with different modes of appearance of left ventricular hypertrophy are reported. Case 1: A 24-year-old man had three relatives with HCM. At 13 years of age, he showed no electrocardiographic or echocardiographic abnormalities characteristic of HCM. During the ensuing 11 years, he developed asymmetric septal hypertrophy (ASH) and systolic anterior motion of the mitral valve (SAM), with right bundle branch block and T-wave inversion. Cardiac catheterization confirmed the diagnosis of hypertrophic obstructive cardiomyopathy by demonstrating an intraventricular pressure gradient of 25 mmHg. These observations indicate that this case developed abnormal hypertrophy during adolescence on the basis of genetic predisposition of an autosomal dominant trait. Case 2: A 51-year-old woman had three proven and three possibly affected relatives. At 35 years of age, she had a normal electrocardiogram, although the echocardiogram was not available. Now, 16 years later, she had developed ASH with abnormal Q-waves and was diagnosed as having non-obstructive HCM. These suggest that ASH can be manifested as late as during middle-age, even in those with genetic predisposition. Case 3: A 47-year-old woman was diagnosed as having hypertension and her blood pressure was 190/100 mmHg at 40 years of age, though she had no abnormal electrocardiographic findings and heart murmurs. Now, at 47 years of age, she had developed T-wave inversion, ASH, SAM, and an intraventricular pressure gradient of 50 mmHg. Thus, her ASH appeared during middle-age, and was probably provoked by hypertension, though a complete family survey could not be conducted. These three patients' findings indicate that there may be various modes of appearance of left ventricular hypertrophy in HCM. In the majority of patients with genetic predisposition, abnormal hypertrophy may develop during adolescence as in Case 1. In others, it may develop in middle-age, as it did in Case 2. The disease spectrum of HCM may additionally include those who develop abnormal hypertrophy during middle-age, following provocation by hypertension, as in Case 3.     

HLA-DR3 antigen linkage in patients with hypertrophic obstructive cardiomyopathy

In order to investigate if genetic factors could be involved in the pathogenesis of hypertrophic obstructive cardiomyopathy, we determined HLA-A, HLA-B, HLA-C, and HLA-DR specificities in 12 Italian patients affected with the disease and in healthy family members of one of them. HLA-DR3 was found in 50% of patients as compared to 17.1% of normal control subjects (p = 0.023, relative risk = 4.82). The two relatives also had HLA-DR3 antigen and, in addition, showed equivocal signs of hypertrophy at echocardiographic examination. Thus hypertrophic obstructive cardiomyopathy is associated with genes in the HLA-DR region, and immunogenetic factors could be involved in the pathogenesis of the disease. Furthermore, the minimal target organ abnormalities in "healthy" relatives could represent a subclinical stage of the disease.     

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.     

Quantitative assessment of ultrasonic myocardial reflectivity in hypertrophic cardiomyopathy

The purpose of this study was to investigate the relation between acoustic properties of the myocardium and magnitude of left ventricular hypertrophy in patients with hypertrophic cardiomyopathy. An on-line radio frequency analysis system was used to obtain quantitative operator-independent measurements of the integrated backscatter signal of the ventricular septum and posterior free wall in 25 patients with hypertrophic cardiomyopathy and 25 normal age-matched control subjects. The integrated values of the radio frequency signal were normalized for the pericardial interface and expressed in percent. Tissue reflectivity was significantly increased in the hypertrophied ventricular septum, as well as in the nonhypertrophied posterior free wall, in patients with hypertrophic cardiomyopathy (58 +/- 15% and 37 +/- 12%, respectively) compared with values in normal subjects (33 +/- 10% and 18 +/- 5%, respectively; p less than 0.001). Furthermore, measurements of reflectivity of the septum or posterior free wall, or both, were beyond 2 SD of normal values in greater than 90% of the patients and were also abnormal in each of the five study patients who had only mild and localized left ventricular hypertrophy. No correlation was identified between myocardial tissue reflectivity and left ventricular wall thickness in the patients with hypertrophic cardiomyopathy (correlation coefficient r = 0.4; p = NS). These findings demonstrate that myocardial reflectivity is abnormal in most patients with hypertrophic cardiomyopathy and is largely independent of the magnitude of left ventricular hypertrophy. Moreover, quantitative analysis of ultrasonic reflectivity can differentiate patients with hypertrophic cardiomyopathy from normal subjects independently of clinical features and conventional echocardiographic measurements.     

Intraventricular Systolic Flow Mapping in Hypertrophic Cardiomyopathy

Ninety-two consecutive patients with hypertrophic cardiomyopathy were studied with pulsed and continuous-wave Doppler and color flow imaging to assess the intraventricular systolic flow profile from apex to base and compare it with that obtained in normals and in patients with aortic stenosis and systemic hypertension. Hypertrophic cardiomyopathy patients had higher intraventricular blood flow velocities (cm/sec) from apex to base compared with normals and aortic stenosis and systemic hypertension patients (apex: 41.5 ± 17.3 vs 24 ± 1.9,26.1 ± 2.9, and 26.4 ± 3.3; papillary muscles: 95.4 ± 66.5 vs 41.9 ± 4.9, 46.2 ± 3.4, and 46.4 ± 5.7; outflow tract: 249.3 ± 176.2 vs 66.9 ± 8.4, 64.1 ± 10.8, and 66 ± 9.5, respectively) (P < 0.001). Eighty-six (93%) hypertrophic cardiomyopathy patients showed an abnormal intraventricular systolic color flow pattern at one or more sites but none of the patients with aortic stenosis or systemic hypertension or normal controls. Of those, 65 (71%) showed one or more variant (mosaic) flow, all of whom had intraventricular gradients, while 75 showed abnormal aliased flow at a site other than the subaortic area. It is concluded that patients with hypertrophic cardiomyopathy often exhibit an abnormal spatial distribution of the intraventricular systolic flow velocity profile compared with normals and patients with secondary forms of ventricular hypertrophy that can readily be recognized with color flow imaging. This could improve the sometimes difficult separation of hypertrophic cardiomyopathy patients from secondary hypertrophy.     

Hypertrophic cardiomyopathy with ventricular septal hypertrophy localized to the apical region of the left ventricle (apical hypertrophic cardiomyopathy)

Clinical and morphologic features are described in a unique subgroup of seven patients with hypertrophic cardiomyopathy. Five patients either died suddenly or are alive but severely symptomatic. In each patient ventricular septal hypertrophy was demonstrated on two dimensional echocardiography or at necropsy to be virtually confined to its apical one-half. However, conventional M mode echocardiography was unreliable in identifying this site of hypertrophy because It was often inaccessible to the path of the M mode beam. Apical distribution of septal hypertrophy does not constitute a separate disease entity, but rather appears to be part of the morphologic spectrum of hypertrophic cardiomyopathy, as judged from two findings: (1) genetic transmission of hypertrophic cardiomyopathy in relatives of each study patient; and (2) marked disorganization of cardiac muscle cells in the left ventricular wall of the two patients studied at necropsy.

Apical distribution of septal hypertrophy in these patients was associated with relatively mild T wave inversion in the electrocardiogram and characteristic angiographic appearance of the left ventricle with mid ventricular constriction and a small, often poorly contractile apical segment. These electrocardiographic and angiographic features differ from those previously described in Japanese patients with “apical hypertrophic cardiomyopathy” in whom “giant” T wave inversion and a “spade-like” appearance of the left ventricle were characteristic.     

Non-obstructive apical hypertrophic cardiomyopathy—Emergence of clinical features within three years in a Chinese

A Chinese engineer presented with non-specific palpitation, atypical chest pain and normal electrocardiogram both at rest and during exercise, was documented to develop electrocardiographic evidence of left ventricular hypertrophy and abnormal isotopic cardiac scintigraphy during stress test within a period of three years. His echocardiogram remained unremarkable. Cardiac catheterisation and cineventriculogram confirmed the presence of apical hypertrophic cardiomyopathy, without any outflow tract obstruction or coronary artery disease. This case, together with 14 others detected recently in Hong Kong, will arouse the existence of this form of hypertrophic cardiomyopathy in the Chinese. The emergence of all diagnostic features in this patient within a short time will support an aetiological hypothesis that apical hypertrophic cardiomyopathy can be acquired in patients with genetic predisposition.     

The electrocardiogram is a more sensitive indicator than echocardiography of hypertrophic cardiomyopathy in families with a mutation in the MYH7 gene.

BACKGROUND--Mutations in the cardiac beta myosin heavy chain gene causing hypertrophic cardiomyopathy have been identified, and to assist both diagnosis and prediction of outcome attempts have been made to correlate phenotype and genotype. Two new mutations in codon 403 of the gene in three unrelated families are described and attention drawn to variable or even absent phenotypic expression in different family members. METHODS AND RESULTS--The polymerase chain reaction and heteroduplex analysis on Mutation Detection Enhancement gels were used to search for mutations in the globular head of the beta myosin heavy chain gene in families with hypertrophic cardiomyopathy. Two mutations were found in exon 13 (codon 403) of the gene. In two unrelated Polish families the mutation resulted in the conversion of arginine to tryptophan (CGG-->TGG). A second mutation, found in a British family, converted the same arginine to leucine (CGG-->CTG). These mutations were detected in family members who had electrocardiographic and echocardiographic features typical of hypertrophic cardiomyopathy; however, they were also detected in 7 other adult relatives with an abnormal electrocardiogram but a normal echocardiogram. Two unrelated adult relatives had completely normal clinical findings but carried the gene mutation. CONCLUSIONS--Identification of a specific mutation gives no guide to the clinical phenotype. There is considerable variability in the phenotypic expression of hypertrophic cardiomyopathy. Mutations were detected in adults previously regarded as normal or in whom the diagnosis was questionable. The fact that the clinical significance of the mutation in these people is still unknown emphasises the dilemma facing screening programmes. Isolated, unexplained electrocardiographic abnormalities in first degree relatives in a family with a definitive diagnosis of hypertrophic cardiomyopathy should be regarded as evidence of a carrier state.     

Apical segmental dysfunction in hypertrophic cardiomyopathy: subgroup with unique clinical features

A segmental wall motion abnormality is an unusual finding in patients with hypertrophic cardiomyopathy. To clarify its clinical significance, 48 patients with hypertrophic cardiomyopathy were analyzed. Eight patients (Group A) had apical segmental dysfunction; 40 (Group B) had normal wall motion. No patient in either group had coronary artery stenosis on selective coronary arteriography. In all patients in Group A, apical segmental dysfunction was revealed by left ventriculography; however, it could be detected by echocardiography in only two patients in Group A. Left ventricular hypertrophy by electrocardiogram (ECG) was more common in Group B (p less than 0.05). Abnormal Q waves were more frequently discovered in Group A (p less than 0.005) and were recognized predominantly in the lateral leads. On serial ECGs, a gradual development of abnormal Q waves was noted in six of eight patients in Group A. Malignant arrhythmias were more common in Group A (p less than 0.001). In two patients in Group A, left ventricular dilation and congestive heart failure developed during the follow-up period. Thus, the presence of a Q wave in the lateral leads on an ECG in patients with hypertrophic cardiomyopathy may indicate the presence of apical segmental dysfunction. Left ventriculography should be performed to examine the presence of this abnormality and 24 h ambulatory ECG monitoring should be done to detect malignant arrhythmias in patients who have abnormal Q waves in the lateral leads. Patients with this unique type of hypertrophic cardiomyopathy need careful follow-up evaluation.     

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.     

Development of severe left ventricular outflow tract obstruction over the course of 14 years: an unusual natural history of hypertrophic obstructive cardiomyopathy

A patient with hypertrophic obstructive cardiomyopathy who when first seen had a normal physial examination, chest x-ray, and electrocardiogram, and no provokable gradient with isoproterenol at cardiac catheterization, was re-evaluated after 14 years. At the time of re-evaluation, she was found to have a typical systolic ejection murmur, cardiomegaly, left ventricular hypertrophy, a pseudoinfarction pattern on electrocardiography, and a significant subaortic gradient both by catheterization and by doppler. This case demonstrates that hypertrophic obstructive cardiomyopathy can be a progressive disease and that patients with this condition warrant careful follow-up. Echocardiography with doppler may provide an excellent noninvasive method of following these patients.     

Morphologic classification of hypertrophic cardiomyopathy with myocardial single photon emission tomography. Comparison with echocardiographic classification

INTRODUCTION AND OBJECTIVES: The aim of this study was to compare different morphologic types of hypertrophic cardiomyopathy obtained by single photon emission tomography to those obtained by echocardiogram. MATERIALS AND METHODS: In 76 (64%) out of 119 patients with hypertrophic cardiomyopathy the echocardiogram permitted an optimal visualization of all left ventricular segments in the short axis view and consequent classification to one of the six morphological types: type I (septal anterior hypertrophy), type II (septal anterior and septal posterior hypertrophy), type III (septal and antero-lateral hypertrophy), type IV (antero-lateral and/or septal posterior hypertrophy), type V (concentric hypertrophy) and type VI (apical hypertrophy). Without knowledge of echo data, two experienced observers included the short axis of single photon emission tomography images at rest (99mTc-tetrofosmin) to one of those types. RESULTS: Global concordance between echocardiogram and single photon emission tomography was 75%. Type III was the most frequent both in echo (76%) and in single photon emission tomography (74%) and type III produced the majority of discrepancies. SPET identified 4 patients with a predominant septal and inferior hypertrophy, that did not correspond to any of the 6 types of echocardiographic classification and had been previously classified as type III by echo in 3 cases and as type V in 1 case. CONCLUSIONS: There was agreement between echo and single photon emission tomography in the morphological classification of most of the patients (75%) with hypertrophic cardiomyopathy. Nevertheless, some discrepancies were observed for the type III echocardiogram.