Recognition of regional hypertrophy in hypertrophic cardiomyopathy using thallium-201 emission-computed tomography: Comparison with two-dimensional echocardiography

The configuration of the hypertrophied myocardium was evaluated by thallium-201 emission-computed tomography and 2-dimensional (2-D) sector scan in 10 patients with obstructive hypertrophic cardiomyopathy (HC), 10 with nonobstructive HC with giant negative T waves and 10 with concentric left ventricular (LV) hypertrophy. Thallium-201 myocardial imaging was reconstructed into multiple 12-mm-thick slices in 3 planes. The thickness ratio of the ventricular septum and the LV posterior wall in the short-axis plane and the ratio of the ventricular septum and the apical wall in the long-axis plane were analyzed. In the patients with obstructive HC the ventricular septal wall thickness index was increased, and the ratio of septal to posterior wall thickness index (1.45 ± 0.23) was greater than that in the patients with nonobstructive HC with giant negative T waves or in those with concentric LV hypertrophy (1.03 ± 0.20 and 0.98 ± 0.11, respectively; p <0.01 for each). In the patients with nonobstructive HC with giant negative T waves, increased apical wall thickness with apical cavity obliteration was characteristic, and the ratio of ventricular septal to apical wall thickness index (0.66 ± 0.14) was less than that in the patients with obstructive HC or in those with concentric LV hypertrophy (1.46 ± 0.38 and 1.04 ± 0.09, respectively; p <0.001 for each). In contrast, technically satisfactory 2-D sector scanning (83%) demonstrated various configurations of the hypertrophied ventricularseptum, but could not detect apical hypertrophy in 4 of the 10 patients with nonobstructive HC with giant negative T waves whose LV cineangiograms demonstrated apical hypertrophy. Thus, thallium-201 emission-computed tomography is useful in evaluating the characteristics of LV hypertrophy and assists 2-D sector scan, especially in patients with apical hypertrophy in HC.     

A case of asymmetrical apical hypertrophy which is a form of hypertrophic nonobstructive cardiomyopathy with giant negative T-waves

Clinical, hemodynamic, electrocardiographic (ECG), echocardiographic, left ventricular (LV), and coronary angiographic (CA) findings are reported in a case with apical hypertrophy (AH), a form of hypertrophic nonobstructive cardiomyopathy (HNCM). The most striking symptom was chest pain and the most conspicuous electrocardiographic finding consisted of giant negative T waves, reaching an amplitude of 4.0 mV. Echocardiography revealed an apical thickness of the septum and posterior wall of 40 mm; this was significantly greater than septal and posterior free wall thickening in the LV outflow area. The anterior motion (SAM) of the anterior mitral leaflet, was present, and, in hemodymic investigation, the isoproterenol test was negative. The left ventricular end-diastolic pressure (LVEDP) and the EF were elevated. In the LV angiogram from the right anterior oblique position (RAO), the LV free wall thickness at the apex was significantly thicker than at the outflow tract level. The patient had dilated coronary arteries. We conclude that these findings are typical for AH (HNCM) and it seems that hypertrophic obstructive cardiomyopathy (IHSS, MO), and hypertrophic non-obstructive cardiomyopathy (ASH, AH) are different manifestations of a wide spectrum of hypertrophic cardiomyopathy.     

Interpretation of electrocardiographic abnormalities in hypertrophic cardiomyopathy with cardiac magnetic resonance.

AIMS: To clarify the mechanisms of electrocardiographic abnormalities in hypertrophic cardiomyopathy, 102 patients were examined with cardiac magnetic resonance. Distribution and magnitude of hypertrophy and late-enhancement were correlated with electrocardiographic abnormalities. METHODS AND RESULTS: Abnormal Q waves were associated with greater upper anterior septal thickness (22+/-7 mm vs. 18+/-5 mm, P=0.001) and increased ratios of upper anterior septum to mean inferolateral (P=0.01), anterolateral (P=0.002), apical (P=0.001), and right ventricular (P=0.001) wall thickness. There was no relation between abnormal Q waves and late-enhancement, except for Q waves >/=40 ms (P=0.02). Conduction disturbances and absent septal Q waves were associated with late-enhancement (89 vs. 45%, P=0.01 and 75 vs. 39%, P=0.002, respectively). The depth of negative T waves was related to an increased ratio of the mean thickness between apical and basal level (P=0.01), and to the presence of apical late-enhancement (P=0.03). CONCLUSION: Abnormal Q waves reflect the interrelation between upper anterior septal thickness and other regions of the left and right ventricles, and wider Q waves are associated with late-enhancement. Conduction disturbances and absent septal Q waves are associated with late-enhancement. The depth of negative T waves is related to craniocaudal asymmetry and apical late-enhancement.     

Cardiac characteristics and postoperative courses in Cushing's syndrome.

To assess the cardiac characteristics and postoperative courses in patients with Cushing's syndrome, electrocardiography and echocardiography were performed to study 12 consecutive, unselected patients, and results were compared with those of essential hypertension and primary aldosteronism. Eleven patients had hypertension and 7 had diabetes mellitus. Before adrenalectomy, common electrocardiographic abnormalities consisted of high-voltage QRS complexes (10 patients) and negative T waves (7 patients). Echocardiograms showed left ventricular hypertrophy in 9 patients, and all the patients had evidence of asymmetric septal hypertrophy. In patients with left ventricular hypertrophy, the thickness of the interventricular septum ranged from 16 to 32 mm, whereas the ratio of the thickness of interventricular septum to that of the posterior wall ranged from 1.33 to 2.67. The interventricular septum in Cushing's syndrome was extremely thicker and asymmetric septal hypertrophy occurred more often than essential hypertension and primary aldosteronism. Nine patients could be followed up after operation. In these patients abnormal electrocardiographic findings had normalized, the thickness of interventricular septum had decreased and asymmetric septal hypertrophy had disappeared except in 1 patient. The reason why left ventricular hypertrophy in Cushing's syndrome is severe is still unknown. Because left ventricular hypertrophy is more severe and the frequency of asymmetric septal hypertrophy much greater in Cushing's syndrome than in essential and other secondary hypertension, it is thought that not only increased aortic pressure but excessive plasma cortisol may be etiologic factors in the progression of left ventricular hypertrophy in Cushing's syndrome.     

Apical hypertrophic cardiomyopathy: clinical and two-dimensional echocardiographic assessment

Of 965 patients with hypertrophic cardiomyopathy evaluated by echocardiography at the National Institutes of Health during a 7-year period, 23 (2%) had a nonobstructive morphologic form, in which wall thickening occurred predominantly in the apical (distal) portion of the left ventricle. The patients ranged in age from 15 to 69 years (mean, 37) and were predominantly male (14 patients) and white (only 1 was of oriental descent). Fifteen patients had significant functional limitation, which was usually caused by exertional dyspnea and fatigue. Several electrocardiographic patterns were identified in the study group, but only 4 of these patients showed "giant" negative T waves. Only 3 patients had a morphologic expression of apical hypertrophy that closely resembled that described in Japanese patients--that is, hypertrophy that was particularly localized and confined to the true left ventricular apex (2 of these patients had giant negative T waves). Hence, hypertrophy located predominantly in the distal left ventricle was uncommon in our primarily North American patient population with hypertrophic cardiomyopathy. Most of our patients showed morphologic and clinical features that were dissimilar to those found previously in Japanese patients with apical hypertrophy.     

Distribution patterns of hypertrophy at the apical level in patients with giant negative T waves: identification by magnetic resonance imaging

To clarify the distribution patterns of hypertrophy at the apical level in patients with giant negative T waves (GNT), ECG-gated magnetic resonance imaging (MRI) was performed in 10 patients with GNT and in five normal controls. End-diastolic left ventricular short-axis images at the basal and apical levels were obtained in all subjects. Thicknesses of the septal, anterior, lateral and posterior walls at these two levels were measured and distribution of hypertrophied myocardium (more than or equal to 15 mm) at the apical level was examined. The ratio (R) of the maximal thickness at the apical level over that at the basal level was calculated. In normal subjects, the mean apical wall thickness was 8.7 +/- 1.9 mm. In the GNT group, the wall thickness was always greater than the mean value +3 SD of the normal control, and there were no differences among the four segmental walls. The hypertrophic portions at the apex were circumferential in three, septal-anterior-lateral in two, septal-anterior in two, septal in one, anterior in one and lateral in one. In patients with GNT, the average maximal thickness at the apical level was 19.3 +/- 3.2 mm; by location, four cases in the septum, four in the anterior wall and two in the lateral wall, and the average minimum thickness was 11.7 +/- 3.7 mm; all in the posterior wall. The R was more than 1.3 in nine patients with GNT and less than 1.0 in all normal subjects. In conclusion, there was a variety of patterns of apical hypertrophy, and the R greater than or equal to 1.3 was characteristic in patients with GNT.     

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.     

A case of heterozygous Fabry''s disease with a short PR interval and giant negative T waves.

A 55 year old woman with heterozygous Fabry's disease presented with cardiac symptoms. The electrocardiogram showed a PR interval of 0.12 s and giant negative T waves, suggesting apical hypertrophic cardiomyopathy. Endomyocardial biopsy, however, revealed myelin like substances characteristic of Fabry's disease. Increasing thickness of the left ventricular wall was seen by echocardiography over a period of five years. A deficiency of alpha galactosidase activity in the leucocytes confirmed the diagnosis of Fabry's disease, although this patient had neither angiokeratoma or proteinuria. The possibility of Fabry's disease should be considered in patients with cardiomegaly of unknown cause and the following electrocardiographic abnormalities: a PR interval less than or equal to 0.12 s, high voltage QRS complexes in the left precordial leads, and giant negative T waves.     

Nuclear magnetic resonance in hypertrophic cardiomyopathy.

The large differences in the spin lattice relaxation times (T1) of blood and myocardium (measured by nuclear magnetic resonance) allow the heart to be visualised without the use of contrast media. The findings using nuclear magnetic resonance in 11 unselected patients with hypertrophic cardiomyopathy were compared with those in equal numbers of normal subjects and patients with electrocardiographic features of left ventricular hypertrophy. In patients with hypertrophic cardiomyopathy characteristic septal hypertrophy was noted together with variable and sometimes pronounced hypertrophy of the left ventricular free wall, which is consistent with the heterogeneous nature of this disease. The mean (SD) ratio of septal to free wall thickness was 1.5(0.8) for patients with hypertrophic cardiomyopathy, 0.8(0.2) for those with left ventricular hypertrophy, and 0.9(0.2) for normal subjects. Although septal measurements by nuclear magnetic resonance were greater than those obtained by echocardiography there was a significant correlation between the two. Septal and free wall area were significantly smaller in normal subjects. There were no differences in septal or free wall T1 values between the three groups. Non-gated nuclear magnetic resonance can detect septal and free wall hypertrophy. With the addition of multiple slice acquisition, rapid estimation of myocardial mass will be possible allowing the potentially important assessment of progression or regression of myocardial hypertrophy.     

Nuclear magnetic resonance in hypertrophic cardiomyopathy

The large differences in the spin lattice relaxation times (T1) of blood and myocardium (measured by nuclear magnetic resonance) allow the heart to be visualised without the use of contrast media. The findings using nuclear magnetic resonance in 11 unselected patients with hypertrophic cardiomyopathy were compared with those in equal numbers of normal subjects and patients with electrocardiographic features of left ventricular hypertrophy. In patients with hypertrophic cardiomyopathy characteristic septal hypertrophy was noted together with variable and sometimes pronounced hypertrophy of the left ventricular free wall, which is consistent with the heterogeneous nature of this disease. The mean (SD) ratio of septal to free wall thickness was 1.5(0.8) for patients with hypertrophic cardiomyopathy, 0.8(0.2) for those with left ventricular hypertrophy, and 0.9(0.2) for normal subjects. Although septal measurements by nuclear magnetic resonance were greater than those obtained by echocardiography there was a significant correlation between the two. Septal and free wall area were significantly smaller in normal subjects. There were no differences in septal or free wall T1 values between the three groups. Non-gated nuclear magnetic resonance can detect septal and free wall hypertrophy. With the addition of multiple slice acquisition, rapid estimation of myocardial mass will be possible allowing the potentially important assessment of progression or regression of myocardial hypertrophy.     

Left ventricular outflow tract obstruction due to systolic anterior motion of the anterior mitral leaflet in patients with concentric left ventricular hypertrophy

Patients with hypertrophic cardiomyopathy (i.e., asymmetric septal hypertrophy) may show obstruction to left ventricular outflow under basal conditions or with provocative maneuvers. The presence of dynamic left ventricular outflow tract obstruction in patients with concentric ventricular wall thickening (but without abnormalities of the aortic valve) has been less well appreciated. Clinical and morphologic features of five patients with nondilated left ventricles and with left ventricular outflow obstruction are presented. In each patient peak systolic pressure gradients between left ventricle and systematic artery were measured at cardiac catheterization and ranged from 60-140 mm Hg under basal conditions or with provocation. Each patient had echocardiographically documented systolic anterior motion of the anterior mitral leaflet, which was apparently responsible for the outflow obstruction, and concentric left ventricular wall thickening (septal-free wall thickness ratio of less than 1.3). Two of the five patients had evidence of genetically transmitted hypertrophic cardiomyopathy, as evidenced by disorganized muscle cells in the ventricular septum or asymmetric septal hypertrophy in first degree relatives. Hence, left ventricular outflow tract obstruction associated with systolic anterior motion of the anterior mitral leaflet may occur in some patients with concentric left ventricular hypertrophy who do not have typical hypertrophic cardiomyopathy.     

Left ventricular ejection dynamics in apical hypertrophy, a form of hypertrophic nonobstructive cardiomyopathy

The left ventricular (LV) cineangiograms of ten patients with apical hypertrophy (AH, group I) as a form of hypertrophic nonobstructive cardiomyopathy (HNCM) were analyzed. The left ventricular ejection dynamics, the extent and pattern of left ventricular contraction were compared with eight patients with secondary myocardial hypertrophy due to arterial hypertension (group II) and eight normal subjects (group III). End-diastolic, end-systolic and stroke volumes were significantly lower in group I. The analysis of left ventricular ejection dynamics with frame-by-frame-analysis revealed the typical ejection pattern of hypertrophic nonobstructive cardiomyopathy: Left ventricular ejection was completed within two thirds of the systolic ejection period. This ejection pattern is of diagnostic value when compared with the dynamics in group II. Although the apical segment in group I shows a good fiber shortening, the overall contribution to systolic performance is low; systolic function in apical hypertrophy is maintained by a compensatory increase in regional wall motion of the basal and midzonal part of the left ventricular free wall. There is no striking difference between apical hypertrophy with and without giant negative T waves with respect to the ejection pattern. Within these subgroups, the only difference was the greater left ventricular mass in patients with giant T wave inversion. Thus, the ejection dynamics in apical hypertrophy is typical of hypertrophic nonobstructive cardiomyopathy. Global parameters of systolic left ventricular performance revealed supernormal values even though systolic function is impaired. Segmental analysis of ejection phase was most sensitive in establishing the diagnosis.     

Contribution of electrovectorcardiography in the diagnosis of hypertrophic cardiomyopathy. Comparative study with an echocardiographic score

The object of the study was to define spreading and quantitative criteria of left ventricular hypertrophy in echocardiography by using a "score"--for this, the left ventricle has been divided into 11 regions and a "score" attributed to each one of them--and to find the correlation with the vectocardiogram (VCG) in 42 patients with hypertrophic myocardiopathy (HM). The results obtained show the following: 1) the left ventricular hypertrophy aspect on the ECG and the VCG is very sensitive for the identification of a diffuse HM; 2) the necrosis, hemiblock or septal hypertrophy indicate a hypertrophy located in the forepart septum or the whole of the septum; 3) the giant T waves indicate a hypertrophy of the apex; 4) a left ventricular hypertrophy associated with a necrosis or a hemiblock indicate a global myocardiopathy, with the basal region of the septum largely affected.     

Hypertrophic myocardiopathy (I). The clinical and echocardiographic characteristics of a population of 72 patients

The results of the echocardiographic evaluation of 72 patients with hypertrophic cardiomyopathy are presented. We have measured left ventricular wall thickness in 8 different segments and classified our patients in 6 types according to the hypertrophy extent. Moreover, we have evaluated by Doppler ultrasound the presence and severity of mitral regurgitation and the left ventricular inflow and outflow. The hypertrophy cardiomyopathy pattern was symmetric in 8 patients, apical in five, and asymmetric in 31. According to Maron classification, asymmetric cardiomyopathy was I type: 4 patients, II type: 16, III type: 11, and IV type: 0 patients. There were left ventricular outflow obstruction (greater than 25 mmHg) in 26 patients (36.1%). This obstruction was more frequent in II and III type hypertrophic cardiomyopathy and we found significative relationship between septal posterior segment hypertrophy and left ventricular outflow obstruction. Ventricular inflow showed bad distensibility pattern in 45 patients (62.5%). Mitral regurgitation was mild, moderate and severe in 25, 15, and 4 patients. Left ventricular outflow obstruction, bad distensibility pattern and mitral regurgitation were independent each other.     

Giant T wave inversion as a manifestation of asymmetrical apical hypertrophy (AAH) of the left ventricle. Echocardiographic and ultrasono-cardiotomographic study.

Left ventricular scanning by echocardiography and ultrasono-cardiotomography was performed to search the possible muscular abnormality in 9 cases with giant T wave inversion without documented cause. The deeply inverted T wave was more than 1.2 mV (average was 1.63 mV) in the left precordial leads. All the cases had electrocardiographic left ventricular hypertrophy of obscure origin and ischemic episode was absent. Conventional echo beam direction to measure the short axis of the left ventricle disclosed almost normal thickness and movement of both interventricular septum (IVS) and the posterior wasll (PW), so that the report of these cases is frequently within normal limits. However, ultrasono-cardiotomography (sector B scan) disclosed the fairly localized hypertrophy near the left ventricular apex, and conventional echocardiography also revealed the same area of either IVS or PW or both below the insertion of the papillary muscles, when the scanning towards the apex was performed (asymmetrical apical hypertrophy: AAH). Control study of 9 cases with IHSS showed asymmetrical septal hypertrophy (ASH) with almost equally hypertrophied IVS from base to apex. All cases had inverted T waves, but these were of lesser degree. Three cases had relatively deep T wave compatible with those of AAH, and these cases also had the apical hypertrophy of considerable degree (unusual type of IHSS, i.e., intermediate type between AAH and ASH). The close relationship between the depth of the inverted T waves and the Apex/Mid wall thickness ratios suggests that the altered recovery process of the hypertrophied apical musculature is responsible for the giant T wave inversion of heretofore unsolved origin. Until the connective link of AAH to the other forms of hypertrophic cardiomyopathy is disclosed, the cases with such a T wave and the apical hypertrophy may be designated as asymmetrical apical hypertrophy (AAH).     

Value of Electro‐Vectorcardiogram in Hypertrophic Cardiomyopathy

The electrocardiogram is an important tool for the initial diagnostic suspicion of hypertrophic cardiomyopathy in any of its forms, both in symptomatic and in asymptomatic patients because it is altered in more than 90 percent of the cases. Electrocardiographic anomalies are more common in patients carriers of manifest hypertrophic cardiomyopathy and the electrocardiogram alterations are earlier and more sensitive than the increase in left ventricular wall thickness detected by the echocardiogram. Nevertheless, despite being the leading cause of sudden death among young competitive athletes there is no consensus over the need to include the method in the pre‐participation screening. In apical hypertrophic cardiomyopathy the electrocardiographic hallmarks are the giant negative T waves in anterior precordial leads. In the vectorcardiogram, the QRS loop is located predominantly in the left anterior quadrant and T loop in the opposite right posterior quadrant, which justifies the deeply negative T waves recorded. The method allows estimating the left ventricular mass because it relates to the maximal spatial vector voltage of the left ventricle in the QRS loop. The recording on electrocardiogram or Holter monitoring of nonsustained monomorphic ventricular tachycardia in patients with syncope, recurrent syncope in young patient, hypotension induced by strain, bradyarrhythmia, or concealed conduction are markers of poor prognosis. The presence of rare sustained ventricular tachycardia is observed in mid‐septal obstructive HCM with apical aneurysm. The presence of complete right bundle branch block pattern is frequent after the percutaneous treatment and complete left bundle branch block is the rule after myectomy.     

Anterior QRS loop in hypertrophic cardiomyopathy.

Frank vectorcardiograms (VCGs) were reviewed in 45 patients with hypertrophic cardiomyopathy (HCM), 26 with obstruction and 19 without obstruction. Twelve of the 19 patients without obstruction and five of the 26 patients with obstruction were found to have predominantly anterior QRS loops. Fourteen patients had a large left anterior QRS loop with increased anterior and leftward force; the posterior and terminal rightward force were within the normal range, and the T loops were displaced posteriorly and to the right opposite to the QRS loop. Asymmetric septal and apical hypertrophy were noted echocardiographically and/or angiographically. Increased electrical force from the asymmetric hypertrophy of the septal and apical area is proposed to explain this large left anterior loop. Three patients had a QRS loop located anteriorly and to the right with electrocardiograms (ECGs) resembling those of posterolateral myocardial infarction or right ventricular hypertrophy. These finding suggest that (1) hypertrophic cardiomyopathy may be another cause of an anterior QRS loop; (2) the recognition of the large left anterior loop in the VCG in patients with a left ventricular hypertrophy pattern in the ECG is helpful in the diagnosis of HCM, especially the nonobstructive form; and (3) hypertrophic cardiomyopathy should be considered in the differential diagnosis of myocardial infarction or right ventricular hypertrophy.     

Patterns of left ventricular adaptation in borderline and mild essential hypertension. Echocardiographic findings

To assess patterns of left ventricular adaptation, 38 patients with borderline and 38 with sustained mild essential hypertension, all lacking electrocardiographic and roentgenographic criteria for left ventricular hypertrophy, were compared using systemic hemodynamic values and M-mode echocardiograms. All patients had normal left ventricular function and measurements of wall thickness. Those with borderline hypertension showed no asymmetric increase in the ratio of septal to posterior wall thickness. The ratio of the left ventricular radius to wall thickness remained normal in both groups, indicating no disproportionate hypertrophy or dilatation of chambers during the phase of normal left ventricular function. Neither finding substantiates asymmetric septal hypertrophy in early hypertension. Those with mild essential hypertension demonstrated an augmented mean circumferential fiber shortening rate compared to those with borderline hypertension (P less than 0.005), suggesting an early stage of left ventricular hyperfunction in the development and elaboration of hypertensive heart disease.     

Abnormal septal Q waves in sickle cell disease. Prevalence and causative factors

Electrocardiograms and M-mode echocardiograms were obtained prospectively from 72 patients with hemoglobin SS (n = 55) or SC (n = 17) disease to assess the prevalence of abnormal Q waves in sickle cell disease and to determine if such Q waves could be explained by, or related to, echocardiographically determined anatomic or functional abnormalities. The mean age (+/- SD) of the population under study was 28 +/- 9 years, and the mean hematocrit reading was 28 +/- 5 percent; 43 male and 29 female patients were evaluated. No patient had a history of systemic arterial hypertension, valvular heart disease, or congestive heart failure. Abnormal septal Q waves (amplitude greater than or equal to 0.30 mV; duration less than or equal to 29 msec) were noted in leads V4, V5, or V6 in 15 of 72 patients, and 50 percent (36) of the population under study demonstrated electrocardiographic voltage changes consistent with left ventricular hypertrophy. M-mode echocardiography showed that 29 of 72 patients had a thickened interventricular septum (greater than or equal to 1.2 cm), 16 of 72 had an abnormally thickened left ventricular posterior wall (greater than or equal to 1.2 cm), and 31 of 72 had increased left ventricular mass (greater than 215 g). The prevalence of electrocardiographic and echocardiographic abnormalities was not significantly different between patients with hemoglobin SS and SC disease. Septal excursion was decreased in 11 of the patients, and global left ventricular function (percent fractional shortening) was slightly decreased in three patients. Regional wall motion was normal in all 72 patients. Six percent (four) of the patients met echocardiographic criteria for asymmetric septal hypertrophy. Linear regression analysis yielded significant positive correlations between septal dimension (r = 0.38; p less than 0.001) and left ventricular mass (r = 0.37; p less than 0.005) when each was compared with Q-wave amplitude. A significant negative correlation (r = 0.40; p less than 0.001) was noted between hematocrit reading and Q-wave amplitude. We conclude that abnormal septal Q waves are common in sickle cell disease and are related, in part, to septal thickness, as well as left ventricular mass and degree of anemia.     

Echocardiographic characterization of the reversible cardiomyopathy of hypothyroidism

Nineteen patients with untreated hypothyroidism were evaluated by M-mode echocardiography. Asymmetric septal hypertrophy (ASH), defined as a ratio of interventricular septal thickness to left ventricular posterior wall thickness (IVS/LVPW) equal to or greater than 1.3, was identified in 17 cases. Additional abnormalities recognized by echocardiography included reduced amplitude of systolic septal excursion (SSex) [13 patients], reduced per cent of systolic septal thickening (%SST)[19 patients], reduced left ventricular outflow tract dimension (LVOT)[five patients] and systolic anterior motion of the mitral valve (SAM)[five patients]. These findings are similar to some of the echocardiographic features of idiopathic hypertrophic subaortic stenosis (IHSS). In 10 patients who returned to euthyroid state with L-thyroxine therapy, these abnormalities resolved. We conclude that long-standing hypothyroidism leads to a reversible cardiomyopathy, manifested by asymmetric septal hypertrophy with or without other echocardiographic features of a hypertrophic obstructive cardiomyopathy. This previously unrecognized features of hypothyroidism has important diagnostic and therapeutic implications.