Asymmetric Septal Hypertrophic Cardiomyopathy Research Articles

Differences in clinical features of hypertrophic cardiomyopathy with or without left ventricular enlargement.

Few studies have focused on the clinical features of hypertrophic cardiomyopathy (HCM) with enlarged left ventricle (ELV). In this study, participants were patients with HCM (n=170), who were divided into two groups [ELV and normal left ventricle (NLV)] according to left ventricle size. Age at diagnosis, sex, complications, electrocardiogram (ECG), symptoms, drug treatment, and echocardiographic parameters were compared between the NLV (n=153) and ELV (n=17) groups. The incidence of end-stage HCM (ES-HCM) among all HCM patients was 5.29%, while that of ELV was 10.0%. For all patients with HCM and those with asymmetric septal HCM (ASHCM), there were more males with ELV than NLV. Of the patients with HCM and ASHCM, left ventricular ejection fraction (LVEF) was significantly lower in the ELV group than the NLV group; accordingly, the rates of diuretics use in the ELV group were higher than those in the NLV group. Among apical HCM (ApHCM) patients, the left atrial diameter (LAd), incidence of atrial fibrillation (Af) or ST-T change, and rate of angiotensin converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) use were all higher in the ELV group compared to the NLV group. These findings suggest that the prevalence of ES-HCM in HCM patients with ELV was higher than those with NLV. Additionally, ELV is more common in men than women and there are differences in the clinical features of different types of HCM with ELV.

Dimensional Assessment of the Heart in Hypertrophic Cardiomyopathy Patients in Tertiary Care Hospitals

Hypertrophic cardiomyopathy (HCM) is one of the most prevalent disorders responsible for sudden cardiac death. Presentation of the symptoms varies due to the degree of thickening, and functional ability of the cardiomyocytes. The aims of the current study were to assess the clinical features, and cardiac morphology. This was a descriptive study with some analytical components. Thirty-four adult HCM patients were included within a duration of four months by patient selection checklist. After informed written consent, relevant information was noted and analyzed. Frequency distribution of phenotypes were, 56% asymmetric septal hypertrophy, 29% concentric hypertrophy, and 15% apical hypertrophy. Breathlessness and chest discomfort were present in 56% and 62% patients respectively, and higher in asymmetric septal HCM. Palpitation was very frequent in concentric HCM (90%). ECG revealed left ventricular hypertrophy in 85% of patients, and 79% of them had ST change. The interventricular septal thickness was narrower in apical type (14.80mm). The posterior wall thickness was higher in concentric HCM (19.20mm). The left atrial size was smaller in Concentric type(34.60mm).

A chance encounter with a case of hypertrophic cardiomyopathy.

A chance encounter with a case of hypertrophic cardiomyopathy.

Comparison of Long-Term Outcome between Apical and Asymmetric Septal Hypertrophic Cardiomyopathy

Objectives: As reported, diagnostic age, gender and presence of outflow tract obstruction have an impact on prognosis in patients with hypertrophic cardiomyopathy. The aim of this study was to compare the long-term outcome between apical hypertrophic cardiomyopathy (ApHCM) and asymmetric septal hypertrophic cardiomyopathy (ASHCM) after the exclusion of these factors. Methods: A total of 540 patients (270 with ApHCM and 270 with ASHCM) identified in a consecutive single-center cohort were retrospectively studied. The two groups were matched by diagnostic age, gender and the presence of outflow tract obstruction. Clinical characteristics and long-term outcomes were compared. Results: The mean follow-up duration in ASHCM and ApHCM were 6.6 ± 5.5 and 7.6 ± 4.1 years, respectively. During follow-up, 16 patients experienced cardiovascular death in the ASHCM group, while 2 patients experienced cardiovascular death in the ApHCM group (6.3 vs. 0.7%, p < 0.01). Cardiovascular morbidity in the ASHCM and ApHCM groups were 39.9 and 18.5% (p < 0.01). In the multivariate Cox regression analysis late gadolinium enhancement (LGE; HR 4.81, 95% CI 1.28-78.0, p = 0.03) and unexplained syncope (HR 9.68, 95% CI 1.9-17.2, p < 0.01) were independent predictors for cardiovascular mortality. Unexplained syncope was independently associated with a higher risk for sudden cardiac death (HR 4.3, 95% CI 1.2-15.3, p = 0.02). Conclusions: After eliminating the interference of diagnostic age, gender and outflow tract obstruction, ASHCM represented a worse prognosis with a higher incidence of cardiovascular mortality and morbidity than ApHCM. LGE was a strong predictor for cardiovascular death.

Geometric Assessment of Asymmetric Septal Hypertrophic Cardiomyopathy by CMR

The aim of this study was to analyze the geometric pattern of hypertrophy (HT) in patients with asymmetrical septal hypertrophic cardiomyopathy (HCM) using cardiac magnetic resonance (CMR) and to test the hypothesis that at least in some patients, the HT follows a longitudinal spiral pattern. The highly heterogeneous phenotypic expression of HCM is a well-known phenomenon. CMR has emerged as a robust 3-dimensional (3D) tomographic imaging technique that is increasingly used to explore phenotypic expression. Short-axis cine CMR was used to study the 3D extent of HT (i.e., radial, circumferential, and longitudinal extent, as well as the relation between circumferential and longitudinal extent). Inclusion criteria were septal wall thickness (WT) ≥15 mm and septal to free wall WT ratio >1.3. CMR was performed in 132 patients. Maximal WT was 22 ± 5 mm, with a circumferential extent of 131 ± 51°, and a longitudinal extent of 64 ± 19%, resulting in a hypertrophied left ventricular (LV) surface of 26 ± 15%. Linear regression analysis showed in 86% of patients a consistent course of HT along the longitudinal direction. The HT invariably started at the basal anteroseptum and rotated, except in 2 patients, in a counterclockwise direction (CC-spiral patients) with a mean global rotation of 116 ± 68° (range 5° to 350°). After the CC-spiral patients were divided according to magnitude of rotation quartiles (Q1: 5° to 70°, Q2: 75° to 105°, Q3: 110° to 150°, and Q4: 155° to 350°), Q4 patients were significantly older and had more LV outflow tract obstruction and hypertension than patients without the spiraling pattern. In 11 patients, continuation of HT into an apical form of HCM was found. Using 3D analysis, we found that the majority of patients with asymmetrical septal HCM in fact showed a spiral pattern of HT following a counterclockwise (or "left-handed") spiral trajectory. The variation in magnitude of rotation among patients, however, was highly variable. Further research is warranted to better understand the significance of the current findings, in particular to relate them to the genetic and morphological substrate, hemodynamic consequences, and patient outcome.

MRI classification of asymmetric septal hypertrophic cardiomyopathy and its relation to the presence of risk factors

Asymmetric septal hypertrophic cardiomyopathy (ASH) is the common phenotype of hypertrophic cardiomyopathy (HCM). We sought to classify ASH using magnetic resonance imaging (MRI) and to determine whether the MRI classification of ASH is related to the presence of risk factors for HCM. Ninety-three patients with ASH underwent cine and delayed-enhancement MRI. The ASH was classified morphologically using cine MRI at end-diastole. We evaluated the association between the MRI findings and the presence of risk factors in the ASH. The ASH was classified into three subtypes by MRI: contiguous subtype showing various clinical and MRI features (57%), sigmoid subtype (29%) with fewer risk factors, and reverse-curve subtype (14%) in younger patients with the larger myocardial mass and delayed-enhancement, which were significantly related to the risk factors. MRI was used to classify ASH into three subtypes, which might be related to the presence of risk factors.

Quantitative of myocardial extracellular volume fraction improves characterization of fibrotic burden in patients with apical hypertrophic cardiomyopathy beyond visual assessment with late gadolinium enhancement

Summary Patients with apical hypertrophic cardiomyopathy (APH) have evidence of increased fibrotic burden, compared to normal controls, in myocardial segments without visible LGE. This finding may have diagnostic implication in patients with thickened apical segments of the LV and a clinical suspicion of APH. Background Apical hypertrophic cardiomyopathy (APH), a variant of hypertrophic cardiomyopathy, is generally considered to have a benign clinical course, with localized hypertrophy and evidence of myofibril disarray and fibrosis at the apex alone. However, traditional late gadolinium enhancement (LGE) techniques are not sensitive enough to detect subclinical apical fibrosis. Accordingly, we hypothesized that quantitative myocardial extracellular collagen volume fraction (MECVF) via T1 mapping techniques at the apex would differentiate patients with and without APH. Methods We performed 3T cardiac MRI in 35 subjects including 11 patients with APH including 3 patients without LGE and 8 with LGE (mean age 48 ± 7 years, all male, diagnosed via standard clinical and echocardiographic assessment), 13 patients with asymmetric septal hypertrophic cardiomyopathy (HCM) including 2 patients without LGE and 11 with LGE (mean age 41 ± 13 years, 62% male) and 11 normal control subjects (mean age 52 ± 12years, 36% male, without cardiac disease or hypertension). MRI included cine imaging, LGE imaging, and a validated Look-Locker gradient echo cine IR technique for quantification of R1 in parallel short-axis locations. The myocardial partition coefficient was estimated by least-squares linear regression of R1 in myocardium against R1 in blood. MECVF was obtained by adjusting the partition coefficient by the patient’s hematocrit. We used a 18-segment model to quantify regional diffuse fibrosis and excluded segments with visible LGE in fibrosis quantification. Results Patients with APH had a trend toward slightly higher MECVF as compared with normal controls at the base (0.30 vs. 0.27; Wilcoxon rank sum P = 0.09) and mid myocardial segments. In apical segments, there was a significant and substantial MECVF (0.38 vs. 0.29; P = 0.0002) in patients with APH compared to normal controls. There were no differences in MECVF between patients with APH and HCM in any segments. Conclusions In patients with APH, MECVF is significantly elevated in the regions of apical segments despite no visualized LGE. These results suggest that myocardial R1

210 An unusual case of Mahaim fibers in hypertrophic cardiomyopathy

The coexistence of Mahaim fibbers (MF) and hypertrophic cardiomyopathy (HCM) is exceptional. We report an unusual case of a young female patient presenting with HCM and MF. A 17 y/o woman was referred in 1998 for a familial HCM screening. She had no symptoms; her surface EKG revealed a preexcitation suggesting a right anteroseptal WPW syndrome. The transthoracic echocardiogram (TTE) demonstrated an asymmetric septal HCM without LV outflow tract (LVOT) obstruction. The electrophysiological study (EPS) demonstrated the presence of MF (normal AH interval, a short and fixed HV interval and atrial pacing produced AH prolongation without change of preexcitation degree, indicating fasciculo-ventricular MF). Eight years later (25 y/o) while the patient was doing well, the ECG was similar and TEE demonstrated the same aspect of asymmetric septal HCM without obstruction. Three months later the patient was pregnant and gave birth to a healthy baby. (During pregnancy: Delta wave was present and there was no LVOT obstruction). After delivery, Surprisingly there was no more preexcitation on her ECG and the TEE demonstrated now a significant LVOT obstruction with a systolic anterior motion of the mitral valve and an LVOT gradient of 36 mmHg. A second EPS was performed in 2008 and showed no more preexcitation. We speculate the hypothesis that FV fiber played in this case a similar pathogenic role as does the apical right ventricular pacing when it is used to decrease LVOT gradient in patients with HCM. This case deserves to be reported because the association of MF and HCM is rare (only 3 cases reported in english litterature), the disappearance of MF during pregnancy has never been reported and the hypothesis that the RV preexcitation via FV Mahaim fiber played a role in decreasing LVOT gradient in this patient with HCM.

Impaired Myocardial Function in Hypertrophic Cardiomyopathy

Tissue Doppler imaging (TDI) parameters of peak myocardial velocities (S', E', and A') has been employed to assess the regional left ventricular myocardial function. The global function index (GFI) derived from TDI has been recently employed to distinguish the different etiologies of left ventricular hypertrophy. To analyze whether the GFI or individual TDI parameters of peak myocardial velocities (S', E', and A') allows detecting different degrees of regional myocardial dysfunction in the most frequent forms of hypertrophic cardiomyopathy (HCM). GFI = (E/E')/S' (where E is the peak transmitral flow velocity, E' is the early diastolic myocardial velocity, and S' is the peak systolic myocardial velocity) and TDI peak myocardial velocities was measured in the septal and lateral mitral annulus in 101 patients with HCM (mean age 47.5 +/- 14 years, 58 women) and in age-matched group of 30 healthy controls (mean age 46 +/- 6 years, 16 women). Forty-five patients had nonobstructive asymmetric septal HCM, 20 patients had a subaortic gradient >or= 30 mm Hg, 21 p. had apical HCM, and 15 p. had other forms of HCM (midventricular, symmetric, and biventricular). All patients with HCM exhibited a decrease in early diastolic (E') and systolic (S') myocardial velocities, both in the lateral and septal-mitral annulus border, but more pronounced in septal-mitral annulus. Septal GFI was higher in HCM patients than in healthy subjects (1.8 (1.1-2.5) and (0.57 (0.31-0.92), respectively, P < 0.001), but no differences were seen when different forms of HCM were compared. In a selected population of patients with HCM and a preserved left ventricular(LV) systolic function, GFI and individual TDI parameters of peak velocity (S', E', and A') and E/E' ratio were similar in different forms of HCM, indicating that in all patients with HCM there is regional systolic and diastolic myocardial dysfunction, regardless of the location of hypertrophy.

Myocardial deformation abnormalities in paediatric hypertrophic cardiomyopathy: are all aetiologies identical?

Hypertrophic cardiomyopathy (HCM) is a disease with a heterogeneous clinical and morphological presentation. It can be secondary to mutations in genes encoding for sarcomeric and non-sarcomeric proteins. The pattern of ventricular hypertrophy can vary from isolated basal septal to concentric hypertrophy. We investigated if there are differences in regional myocardial function in different forms of HCM. We performed echocardiograms on children with (i) isolated asymmetric septal HCM, (ii) isolated concentric HCM, (iii) Friedreich's ataxia associated with concentric HCM, and (iv) healthy controls. Wall thickness, left ventricular dimensions, ejection fraction, and mitral inflow were measured. Peak early diastolic myocardial velocities, peak systolic myocardial velocities, peak systolic strain rate (SR), peak systolic strain (epsilon), post-systolic shortening and time to maximal epsilon were measured in the basal and mid-septum and basal lateral wall to evaluate longitudinal myocardial function. Similar data were acquired and analysed in the anterior septum and infero-lateral wall to evaluate the radial myocardial function. All three groups with HCM had had increased wall thickness, reduced left ventricular dimensions, and evidence of impaired diastolic filling compared to controls. All forms of HCM had reduced early diastolic and systolic myocardial velocities and peak systolic SR and peak systolic epsilon compared with controls in all myocardial segments investigated. Children with asymmetric septal HCM had reduced systolic deformation, increased post-systolic shortening, and prolonged time to maximal epsilon in the basal septum compared with the other two groups with HCM. There were no differences in any echocardiographic variable between patients with isolated concentric HCM and Friedreich's ataxia and resulting HCM. Myocardial deformation is abnormal in all forms of paediatric HCM. Myocardial deformation is more reduced and associated with post-systolic shortening in the more hypertrophied basal septum in patients with asymmetric septal HCM. In contrast, this reduction is uniformly distributed in all myocardial segments in patients with concentric HCM irrespective of whether HCM results from isolated or secondary HCM. Our findings suggest the pattern of hypertrophy influences myocardial deformation more than the underlying cause of HCM.

Understanding Left Ventricular Outflow Obstruction: Anatomoechocardiographic Correlation

Echocardiography is a valuable noninvasive technique for identifying the site and type of obstruction in the left ventricular outflow tract. Knowledge of the morphological details of each type of obstruction is the basis for correct interpretation of the diagnostic images and clinical decisions. This study was undertaken to provide improved understanding of the anatomy of left ventricular outflow obstruction with corresponding side-by-side echocardiographic images. Specimens were part of the collection of the Department of Embryology of the Instituto Nacional de Cardiología "Ignacio Chávez," Mexico City, Mexico. Twenty-eight patients were studied by echocardiography, and 22 specimens with different types of left ventricular outflow tract obstruction were analyzed. Echocardiographic characteristics: Eighteen (64.3%) patients were women and 10 (35.7%) men. Three had fibrous rings, 19 with obstructive asymmetric septal hypertrophic cardiomyopathy, 1 with posterior displacement of the infundibular septum, 2 with accessory mitral valve tissue, 2 with anomalous insertion of mitral valve chordae tendineae, and 1 with malposition of the mitral valve and papillary muscles. Anatomic characteristics: Twelve had fibrous ring, 2 asymmetric septal hypertrophic cardiomyopathy, 2 posterior displacement of the infundibular septum, 1 ectopic mitral tissue, 1 anomalous insertion of mitral valve chordae tendineae in the ventricular septum, 3 malposition of the mitral valve and papillary muscles, and 1 subaortic infundibulum. The anatomoechocardiographic correlation clearly demonstrates the mechanism of subaortic obstruction. The comparison with corresponding echocardiographic images of different subaortic obstruction types is potentially quite valuable in enhancing the echocardiographer's understanding especially of complex subaortic obstruction.

Impaired retention of technetium-99m tetrofosmin in hypertrophic cardiomyopathy

The purpose of this study was to determine whether myocardial imaging using technetium-99m tetrofosmin can noninvasively identify myocardial damage in hypertrophic cardiomyopathy (HC). The study consisted of 10 patients with apical HC, 10 with asymmetric septal HC (ASH) group, 5 with dilated cardiomyopathy (DC)-like group, and 20 healthy subjects. With use of a bull’s-eye map of single-photon emission computed tomographic imaging, the total defect score of tetrofosmin and the washout rate were assessed in 5 segments (septum, and anterior, lateral, and inferior walls, and apex) of the left ventricle. A localized increase in defect score and washout rate was observed in the hypertrophied region in the group with apical HC. An increased washout rate was observed in the ASH group regardless of hypertrophy, suggesting that tetrofosmin retention by the mitochondria was impaired in the entire left ventricular wall. The washout rate was further increased at all segments in the DC-like group versus the ASH group. Tetrofosmin retention by mitochondria was impaired in the entire left ventricular wall in the ASH group and was increased further in the DC-like group. The dysfunction of myocardial cells was limited to the hypertrophied region in the apical HC group.

Assessment of Left Ventricular Systolic Wall Motion Velocity with Pulsed Tissue Doppler Imaging: Comparison with Peak dP/dt of the Left Ventricular Pressure Curve

To assess the usefulness of the tissue Doppler imaging variables for the evaluation of left ventricular (LV) systolic function, we compared variables obtained by the pulsed Doppler method with the LV ejection fraction (%EF) and the maximum value for the first derivative of LV pressure (peak dP/dt). We examined 65 patients, including 15 patients with noncardiac chest pain, 15 with ischemic heart disease, 15 with dilated cardiomyopathy, 10 with hypertensive heart disease, and 10 with asymmetric septal hypertrophic cardiomyopathy. The subendocardial systolic wall motion velocity patterns were recorded for LV posterior wall and ventricular septum in the parasternal LV long-axis view. The peak dP/dt was significantly lower in the hypertensive heart disease, hypertrophic cardiomyopathy, and dilated cardiomyopathy groups. The peak systolic velocity was lower and the time from the electrocardiographic Q wave to the peak of the systolic wave for the posterior wall was longer in the hypertensive heart disease (5.9 ± 0.5 cm/sec and 215 ± 21 msec, respectively), hypertrophic cardiomyopathy (6.2 ± 0.9 cm/sec and 217 ± 17 msec, respectively), and dilated cardiomyopathy (5.2 ± 0.8 cm/sec and 235 ± 26 msec, respectively) groups than in the noncardiac chest pain (7.7 ± 0.9 cm/sec and 187 ± 24 msec, respectively) and the ischemic heart disease (7.6 ± 0.8 cm/sec and 184 ± 22 msec, respectively) groups. In all groups, the peak systolic velocity and the time from the electrocardiographic Q wave to the peak of the systolic wave for the posterior wall correlated directly and inversely, respectively, with the %EF ( r = 0.59, p < 0.0001; r = –0.59, p < 0.0001) and the peak dP/dt ( r = 0.75, p < 0.0001; r = –0.68, p < 0.0001). Both tissue Doppler variables for the ventricular septum did not correlate with the %EF but roughly correlated with peak dP/dt. We conclude that the systolic LV wall motion velocity parameters obtained by pulsed tissue Doppler imaging may be useful for noninvasive evaluation of global LV systolic function in patients with no regional asynergy. (J Am Soc Echocardiogr 1998;11:442-9.)

MRI and cine MRI of asymmetric septal hypertrophic cardiomyopathy.

This study was designed to determine MR and cine MR characteristics of asymmetric septal hypertrophic cardiomyopathy and to correlate MR and cine MR features with the severity of left ventricular outflow tract obstruction. Ten consecutive patients with asymmetric septal hypertrophic cardiomyopathy [resting obstructive (n = 3), latent obstructive (n = 4), nonobstructive hypertrophic (n = 3)] and five healthy volunteers underwent MRI and cine MRI. Oblique two chamber and four chamber views were obtained in all cases. In the 10 patients, the mean +/- SD end-diastolic myocardial thickness was 22.7 +/- 6.3 mm in the basal septum and 13 +/- 3.9 mm in the posterolateral wall with a ratio of 1.76 +/- 0.30; the corresponding values were 10.6 +/- 1.1, 10.4 +/- 1.1, and 1.02 +/- 0.08 mm, respectively, in five healthy volunteers. The mean systolic thickening of the basal septum was 22 +/- 12%. This value was 49 +/- 4% in the five healthy volunteers. In resting obstructive hypertrophic cardiomyopathy, septal wall thickness was > or = 25 mm with a systolic thickening of 10%. A systolic anterior motion of the mitral valve was demonstrated in four patients with resting subaortic pressure gradients ranging from 28 to 120 mm Hg. A signal void area was demonstrated within the left ventricular outflow tract during systole in the seven patients with obstructive cardiomyopathy. This signal void area reached its maximum during early systole in the most severe obstructions and during midsystole in the less severe obstructions. In patients with asymmetric septal hypertrophic cardiomyopathy, gross correlation was demonstrated between severity of obstruction and several MR and cine MR features including increased end-diastolic thickness of the septal wall, decreased systolic thickening of the septal wall, systolic anterior motion of the mitral valve, and signal void area within the left ventricular outflow tract during systole.