Hypertrophic cardiomyopathy with left ventricular dilatation

There is increasing interest in the notion that some patients with hypertrophic cardiomyopathy (HCM) progress to morphological and functional manifestations similar to those of dilated cardiomyopathy (DCM). From 165 consecutive patients with HCM, 20 patients with left ventricular dilatation (left ventricular end-diastolic diameter greater than or equal to 50 mm) were selected and designated as dilated HCM. The diagnosis of HCM was established in these patients either by detection of the classical form of HCM in family members, with 2-dimensional echocardiographic evidence of asymmetric septal hypertrophy (ASH; septal thickness greater than or equal to 15 mm and a ratio of septal to posterior wall thickness greater than or equal to 1.3); or by demonstrating myocardial fiber disarray in autopsy or biopsy samples. The clinical manifestations of these patients with dilated HCM were then compared with those of other forms of HCM without left ventricular dilatation; 1) 40 patients with hypertrophic obstructive cardiomyopathy (HOCM) who had resting intraventricular pressure gradients of 20 mmHg or more, 2) 80 patients with non-obstructive HCM, each of whom had ASH of the entire ventricular septum (typical ASH), and 3) 25 non-obstructive patients whose hypertrophy was localized to the apical region of the ventricular septum (apical ASH). Patients having apical hypertrophy with a spade-like configuration on the left ventriculogram were excluded from the study. Compared with HOCM and typical ASH groups, the patients with dilated HCM had family histories of significantly more frequent HCM and less frequent hypertension. The patients with dilated HCM also had significantly less fractional shortening (FS), decreased interventricular septal thickness, greater left ventricular end-diastolic pressure (LVEDP), and left ventricular dilatation. During the follow-up period (average: 3.5 years), seven patients (35%) with dilated HCM died; five from congestive heart failure (CHF), one suddenly, and one three days following mitral valve replacement. The other five patients had CHF at the time of their follow-up examination. The patients with apical ASH had clinical features similar to those of dilated HCM; a higher familial frequency, less marked septal hypertrophy, and higher LVEDP. They tended to develop left ventricular dilatation, associated with reduced fractional shortening, although left ventricular diameter at end-diastole did not exceed 50 mm. These findings suggested that dilated HCM is not a rare condition. It is observed in 12% of consecutive patients with HCM.(ABSTRACT TRUNCATED AT 400 WORDS)     

Coronary Flow Reserve Impairment in Apical vs Asymmetrical Septal Hypertrophic Cardiomyopathy

Background

Mechanisms underlying a reduction in coronary flow reserve (CFR) in hypertrophic cardiomyopathy (HCM), especially apical HCM (ApHCM), are elusive. This study set out to evaluate mechanisms underlying a reduction in CFR in 2 HCM subtypes.

Hypothesis

Mechanisms for CFR reduction in HCM are different between the 2 subtypes of HCM.

Methods

Thirty‐one patients with asymmetrical septal hypertrophy (ASH), 43 with ApHCM, and 27 healthy volunteers were recruited. Mean diastolic coronary flow velocity (CFmv) was monitored before and after adenosine infusion by transthoracic echocardiography in the mid‐to‐distal left anterior descending coronary artery. Coronary flow reserve was defined as the ratio between CFmv before and after adenosine infusion. Left ventricular mass index and stress myocardial perfusion were assessed by cardiac magnetic resonance imaging.

Results

Although basal CFmv was higher in ASH patients than in healthy controls (P < 0.05), it was similar in ApHCM patients and controls (P = 0.85). Poststress CFmv was significantly lower in both HCM subtypes than in controls (P < 0.05). Consequently, CFR was higher in controls than in ASH or ApHCM patients (P < 0.05). When HCM patients were stratified into 2 groups based on the presence of CFR impairment, no difference was observed between these 2 groups in terms of left ventricular mass index by cardiac magnetic resonance imaging. Multivariate logistic regression analysis identified basal CFmv as the only independent variable associated with CFR reduction in HCM (r² = 0.49, P < 0.001).

Conclusions

Whereas the inability to augment coronary flow to its maximal level during stress was found to underlie CFR impairment in both HCM subtypes, the recruitment of vasodilatory capacity at baseline was more prominent in ASH than in ApHCM patients. This study was presented in the Annual Scientific Meeting of the American Society of Echocardiography, June 30–July 3, 2012, National Harbor, Maryland. This research was supported by Handok Research Fund 2012 and by the Leading Foreign Research Institute Recruitment Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (0640‐20100001). The authors have no other funding, financial relationships, or conflicts of interest to disclose.     

Substrate Characterization and Catheter Ablation for Monomorphic Ventricular Tachycardia in Patients With Apical Hypertrophic Cardiomyopathy

VT Ablation in Apical Hypertrophic Cardiomyopathy . Introduction: Monomorphic ventricular tachycardia (VT) is uncommon in apical hypertrophic cardiomyopathy (HCM). The purpose of this study was to define the substrate and role of catheter ablation for VT in apical HCM. Methods: Four patients with apical HCM and frequent, drug refractory VT (mean age of 46 ± 10 years, left ventricular [LV] ejection fraction; 54 ± 14%) underwent catheter ablation with the use of electroanatomic mapping. Endocardial mapping was performed in 4 patients and 3 patients underwent epicardial mapping. Results: In 3 patients, VT was related to areas of scar in the apical LV where maximal apical wall thickness ranged from 14.5 to 17.8 mm, and 2 patients had apical aneurysms. Endocardial and epicardial substrate mapping revealed low voltage (<1.5 mV) scar in both endocardial and epicardial LV in 2 and only in the epicardium in 1 patient. Inducible VT was abolished with a combination of endocardial and epicardial ablation in 2 patients, but was ineffective in the third patient who had intramural reentry that required transcoronary ethanol ablation of an obtuse marginal vessel for abolition. The fourth patient had focal nonsustained repetitive VT from right ventricular outflow tract (RVOT), consistent with idiopathic RVOT‐VT, that was successfully ablated. During follow‐ups of 3‐9 months, all patients remained free from VT. Conclusion: Monomorphic VT in apical HCM can be due to endocardial, epicardial or intramural reentry in areas of apical scar. Epicardial ablation or transcoronary alcohol ablation is required in some cases. (J Cardiovasc Electrophysiol, Vol. 22, pp. 41‐48, January 2011)     

Cardiac muscle cell disorganization in apical hypertrophic cardiomyopathy: a cardiac biopsy study

Apical hypertrophic cardiomyopathy has been divided into two entities: apical asymmetric septal hypertrophy (apical ASH) and apical symmetric hypertrophy (AH). The latter differs clinically from hypertrophic cardiomyopathy (HCM) with ASH, and it is unclear whether AH represents a distinct subtype of HCM. In the present study, the presence or absence and the extent of cardiac muscle cell disorganization, a histologic characteristic of HCM, were compared in patients with AH (n = 10) and ASH (n = 29) in whom cardiac biopsy specimens were obtained from the left ventricular apex and interventricular septum. Disorganization was graded as (1+) in only 1 patient in the AH group and (-) in the remaining 9. In contrast, in the ASH group disorganization was graded as (1+) in 15 patients, (2+) in 7, (3+) in 3, and (-) in only 4 (P < 0.0001). Thus, it was observed that in AH disorganization is virtually absent or at most limited to a very narrow area. It is concluded from a histological stand point as well that the type of apical hypertrophic cardiomyopathy showing apical symmetric hypertrophy differs from usual HCM.     

Mid‐ventricular obstruction is associated with non‐sustained ventricular tachycardia in patients with hypertrophic obstructive cardiomyopathy

BackgroundMid‐ventricular obstruction (MVO) is a rare subtype of hypertrophic cardiomyopathy (HCM) but it is associated with ventricular arrhythmia. The relationship between MVO and non‐sustained ventricular tachycardia (NSVT) in HCM patients is unknown.HypothesisThe severity of MVO increases the incidence of NSVT in patients with hypertrophic obstructive cardiomyopathy (HOCM).MethodsFive hundred and seventy‐two consecutive patients diagnosed with HOCM in Fuwai Hospital between January 2015 and December 2017 were enrolled in this study. Holter electrocardiographic and clinical parameters were compared between HOCM patients with and without MVO.ResultsSeventy‐six (13.3%) of 572 patients were diagnosed with MVO. Compared to patients without MVO, those with MVO were much younger, and had a higher incidence of syncope, greater left ventricular (LV) posterior wall thickness, a higher percentage of LV late gadolinium enhancement, and higher prevalence of NSVT. Furthermore, the prevalence of NSVT increased with the severity of MVO (without, mild, moderate or severe: 11.1%, 18.2%, 25.6%, respectively, p for trend < .01). Similarly, the prevalence of NSVT differed among patients with isolated LV outflow tract (LVOTO), both MVO and LVOTO, and isolated MVO (11.1%, 21.3%, 26.6%, respectively, p for trend = .018). In addition to age, diabetes, left atrial diameter, and maximal wall thickness, multivariate analysis revealed the presence of MVO as an independent risk factor for NSVT (Odds ratio 2.69; 95% confidence interval 1.41 to 5.13, p = .003).ConclusionsThe presence and severity of MVO was associated with higher incidence of NSVT in HOCM patients.     

Ventricular flutter induced during electrophysiologic studies in patients with old myocardial infarction: clinical and electrophysiologic predictors,and prognostic significance

INTRODUCTION: Induction of ventricular flutter during electrophysiologic (EP) studies (similar to that of ventricular fibrillation [VF]) often is viewed as a nonspecific response with limited prognostic significance. However, data supporting this dogma originate from patients without previously documented ventricular tachyarrhythmias. We examined the significance of ventricular flutter in patients with and without spontaneous ventricular arrhythmias. METHODS AND RESULTS: We conducted a cohort study of all patients with myocardial infarction (MI) undergoing EP studies at our institution. Of 344 consecutive patients, 181 had previously documented spontaneous sustained ventricular arrhythmias, 61 had suspected ventricular arrhythmias, and 102 had neither. Ventricular flutter was induced in 65 (19%) of the patients. Left ventricular ejection fraction was highest among patients with inducible VF (35 +/- 13), lowest for patients with inducible sustained monomorphic ventricular tachycardia (SMVT; 27 +/- 9), and intermediate for patients with inducible ventricular flutter (30 +/- 10). Similarly, the coupling intervals needed to induce the arrhythmia were shortest for VF (200 +/- 28 msec), intermediate for ventricular flutter (209 +/- 27 msec), and longest for SMVT (230 +/- 35 msec). During 5 +/- 8 years of follow-up, the risk for ventricular tachycardia/VF was high for patients with SMVT and ventricular flutter and low for patients with inducible VF and noninducible patients (46%, 34%, 17%, and 14%, P < 0.005).CONCLUSION: Patients with inducible ventricular flutter appear to be "intermediate" between patients with inducible VF and patients with SMVT in terms of clinical and electrophysiologic correlates. However, the prognostic value of inducible ventricular flutter is comparable to that of SMVT.     

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.     

Mid‐ventricular Obstructive Hypertrophic Cardiomyopathy during Pregnancy Complicated by Preeclampsia and Acute Myocardial Infarction: A Case Report

Hypertrophic cardiomyopathy (HCM) with mid‐ventricular obstruction (MVO) is a rare condition occurring in 1% of HCM patients. It is characterized by asymmetric left ventricular hypertrophy with MVO and elevated intraventricular pressure gradients. Myocardial infarction has been associated with mid‐ventricular obstructive HCM. Briefly, this case presents an unusual clinical scenario where a young pregnant woman complicated by preeclampsia presents with myocardial injury and hemodynamic compromise related to undiagnosed HCM with MVO illustrating hemodynamic challenges created by pregnancy and surgery.     

Regional myocardial coronary blood flow reserve in hypertrophic cardiomyopathy assessed by digital subtraction coronary angiography]

Using digital subtraction coronary angiography (DSA), we evaluated the regional myocardial coronary blood flow reserve (rMFR) in 18 patients with hypertrophic cardiomyopathy (HCM). There were 13 patients with asymmetrical septal hypertrophy (ASH), and 5 with asymmetrical apical hypertrophy (AAH). Eight subjects without apparent cardiac abnormality served as controls. Relations between the rMFR and regional wall thickness as determined by echocardiography were also investigated. Peak contrast density (Cm) and time to Cm (Tm) were measured from digital angiograms at the middle and distal ventricular septum (VS) and at the apical and left ventricular posterior wall (PW). The rMFR of each region of interest was expressed as the ratio of Cm/Tm at the baseline and at peak hyperemic response induced by intracoronary administration of papaverine. The rMFR was significantly lower at the VS and apex in HCM than in controls: middle VS, 1.9 +/- 0.5 vs 3.9 +/- 0.5, p < 0.001; distal VS, 2.0 +/- 0.5 vs 4.4 +/- 0.9, p < 0.001; and the apex, 2.0 +/- 0.7 vs 4.5 +/- 1.6, p < 0.01. However, it did not differ at the PW; 2.6 +/- 0.9 vs 3.0 +/- 0.9 between the 3 groups. The middle VS and apex, where the wall was the thickest, had the lowest rMFR in ASH and AAH. Furthermore, at the VS and apex, a curvilinear relationship was observed between the rMFR and wall thickness (rMFR = -0.88 in WT + 2.39, r = -0.57, p < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)     

Arrhythmic risk stratification in ischemic,non-ischemic and hypertrophic cardiomyopathy: A two-step multifactorial,electrophysiology study inclusive approach

Annual arrhythmic sudden cardiac death ranges from 0.6% to 4% in ischemic cardiomyopathy (ICM), 1% to 2% in non-ischemic cardiomyopathy (NICM), and 1% in hypertrophic cardiomyopathy (HCM). Towards a more effective arrhythmic risk stratification (ARS) we hereby present a two-step ARS with the usage of seven non-invasive risk factors: Late potentials presence (≥ 2/3 positive criteria), premature ventricular contractions (≥ 30/h), non-sustained ventricular tachycardia (≥ 1episode/24 h), abnormal heart rate turbulence (onset ≥ 0% and slope ≤ 2.5 ms) and reduced deceleration capacity (≤ 4.5 ms), abnormal T wave alternans (≥ 65μV), decreased heart rate variability (SDNN < 70ms), and prolonged QT_c interval (> 440 ms in males and > 450 ms in females) which reflect the arrhythmogenic mechanisms for the selection of the intermediate arrhythmic risk patients in the first step. In the second step, these intermediate-risk patients undergo a programmed ventricular stimulation (PVS) for the detection of inducible, truly high-risk ICM and NICM patients, who will benefit from an implantable cardioverter defibrillator. For HCM patients, we also suggest the incorporation of the PVS either for the low HCM Risk-score patients or for the patients with one traditional risk factor in order to improve the inadequate sensitivity of the former and the low specificity of the latter.     

Correlation of Electrocardiographic Changes and Myocardial Fibrosis in Patients With Hypertrophic Cardiomyopathy Detected by Cardiac Magnetic Resonance Imaging

Background:

Despite several electrophysiologic and pathologic studies, the cause of electrocardiographic (ECG) changes in patients with hypertrophic cardiomyopathy (HCM) remains unclear. Late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging can detect myocardial fibrosis. We aimed to assess the relationship between ECG findings and LGE in such patients.

Hypothesis:

Myocardial LGE may be associated with ECG changes in HCM.

Methods:

Seventy consecutive patients with HCM (mean age, 55.5 ± 10.7 years; 47 males) underwent CMR and 12‐lead ECG. The subjects were divided into 3 groups according to the type of hypertrophy: the asymmetric septal hypertrophy group (ASH group, n = 31), the apical hypertrophy group (AP group, n = 22), and concentric hypertrophy group (CH group, n = 17). The transmural and segmental extent, pattern, and location of myocardial LGE were assessed and analyzed in relation to ECG changes.

Results:

All of the subjects showed some degree of LGE on CMR. The AP group showed significantly higher prevalence of negative T‐wave (P = 0.028) and deep negative T‐wave inversion (P = 0.001) than the ASH and CH groups. The total volume of LGE did not show any significant association with ECG changes. LGE detected at the interventricular septum was associated with increased QRS duration (P = 0.009) and was found in 94% of the ASH group, 59% of the AP group, and 77% of the CH group. LGE at the apex of the heart was present in 32% of the ASH group, 73% of the AP group, and 35% of the CH group and was also associated with negative T‐wave (P = 0.006) and deep negative T‐wave inversion (P = 0.018). Multifocal LGE lesions were associated with increased QRS duration (P = 0.039) as opposed to single nodular or patchy pattern of presence.

Conclusions:

The location of myocardial LGE in HCM shows significant association with various ECG changes. This may be useful information for initially evaluating subjects with HCM and adds pathophysiological insight into understanding ECG changes in myocardial diseases that cannot be explained otherwise. Clin. Cardiol. 2011 DOI: 10.1002/clc.22062 The authors have no funding, financial relationships, or conflicts of interest to disclose.     

Impaired myocardial perfusion in patients with hypertrophic cardiomyopathy: Assessment with digital subtraction coronary arteriography

Summary To study the clinical significance of abnormal myocardial perfusion in patients with hypertrophic cardiomyopathy (HCM), we performed a computerized washout analysis of digital subtraction coronary arteriograms in 28 patients with HCM and 16 control subjects. The contrast disappearance half-life (T 1/2) was calculated from a time-density curve generated in the four sectors of the myocardium perfused by the left anterior descending coronary artery and the mean T 1/2 was calculated by averaging T 1/2 values for these four sectors. Patients with HCM demonstrated longer T 1/2 in the ventricular septal region than control subjects. Thirteen (46%) of the patients with HCM presented abnormally longer mean T 1/2 values, suggesting impaired myocardial perfusion. Family histories of HCM were more frequent in patients with abnormal mean T 1/2 values (92% vs 47%;p<0.05). On the exercise stress test, patients with abnormal T 1/2 values presented significantly lower exercise tolerance with more frequent exercise-induced ST segment depression (62% vs 13%;p<0.05). However, there were no significant differences between the two groups with regard to ventricular wall thickness, left ventricular end-diastolic pressure, or the severity of systolic narrowing of the coronary arteries.These findings suggest that 13 (46%) of the patients with HCM have impaired myocardial perfusion, which may be a manifestation of intramural coronary artery disease in addition to left ventricular hypertrophy, elevated left ventricular end-diastolic pressure, or systolic narrowing of the coronary arteries. Additionally, significant association of the prolonged T 1/2 with a familial occurrence of HCM and depressed exercise tolerance with ST segment depression imply that impaired myocardial perfusion could be an important inherent pathophysiological state leading to myocardial ischemia during exercise.This study was supported in part by a Research Grant for Intractable Diseases from the Ministry of Health and Welfare of Japan.     

Correlations between electrocardiographic findings and echocardiographic patterns in 116 patients with hypertrophic cardiomyopathy

To evaluate the correlation between electrocardiographic and echocardiographic m-mode (E-TM) and two-dimensional (E-2D) patterns, 116 patients with hypertrophic cardiomyopathy (HCM) were studied by these two methods. Patients were classified into four types, according to Maron et al's E-2D classification of HCM. In addition a subgroup (IIIb) of 15 patients in types III, had typical left ventricular concentric hypertrophy. Twelve per cent of the study patients had a normal ECG, and most often those patients showed types I-II and IIIb. Left ventricular hypertrophy by ECG was most frequent (46%) and was found mostly in type III (P less than 0.02). Abnormal Q waves, suggestive but not diagnostic of HCM, were found in 22 of 116 (18%) patients, and were present in equal proportion in each morphologic type. Isolated ST-T changes were found in the same percentage of patients. Six of 7 patients with giant negative T waves had apical left ventricular hypertrophy, but 4 other patients with apical hypertrophy had no such ECG findings. Mean left atrial dimensions at E-TM, although larger in patients with atrial fibrillation, with statistical significance (P less than 0.001), were not predictive of this arrhythmia. ECG is still useful in the diagnosis of HCM, although there is no abnormal pattern specific for the disease, and even a normal ECG can be found in these patients.     

Association of ST elevation with apical aneurysm in hypertrophic cardiomyopathy

Objectives

Apical aneurysms in patients with hypertrophic cardiomyopathy (HCM) represent an underrecognized but clinically important subset of HCM patients. However it may be frequently missed by echocardiography because of poor image quality of left ventricular apex. We aimed to compare electrocardiographic STE in HCM patients with and without apical aneurysm.

Methods

We developed this clinical review using an extensive MEDLINE review of the literature and data from our laboratories; and some electrocardiographic parameters including STE were analysed in HCM patients with and without apical aneurysm.

Results

There were 29 HCM patients without apical aneurysm (Group 1; 52.6 ± 17.7years, 69% male) and 28 HCM patients with apical aneurysm (Group 2; 59.6 ± 13.2years, 57% male). The STE in V4-6 derivations were statistically more frequent in patients with apical aneurysm compared to those without aneurysm (93% vs 7%, p < 0.001). There was a positive correlation between the presence of the STE in V4-6 derivations and the presence of the apical aneurysm (Spearman''s ρ = 0.895, p < 0.001).

Conclusions

Clinicians and specifically echocardiographers must pay special attention on the electrocardiography to correctly detect the frequently overlooked apical aneurysm in HCM patients, and should be careful for apical aneurysm particularly in the presence of STE in V4-6 derivations.     

Atypische hypertrophe Kardiomyopathie mit verkalktem, linksventrikul?rem Spitzenthrombus

A case of atypical hypertrophic cardiomyopathy (HCM) with a calcified apical thrombus is presented. A 42 year old asymptomatic patient was admitted for evaluation of an abnormal electrocardiogram (ECG) which was recorded when the patient suffered from a bronchitis. The ECG showed giant negative T-waves in leads II, III, aVF, V3 to V6 associated with high QRS voltages in the precordial leads. The chest X-ray and fluoroscopy demonstrated a calcification in projection to the apical region of the heart. Echocardiography and the left ventricular (LV) cineangiography showed hypertrophy of the apical LV myocardium and an obliteration of the apical LV cavity. Magnetic resonance imaging identified a calcified thrombus in the apical cavity of the LV in the setting of an atypical HCM.     

Impaired Myocardial Function in Hypertrophic Cardiomyopathy

Background: 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. Objective: 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). Methods: 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). Results: Forty‐five patients had nonobstructive asymmetric septal HCM, 20 patients had a subaortic gradient ≥ 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. Conclusions: 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. (ECHOCARDIOGRAPHY, Volume 26, July 2009)     

Difference in the response to isoproterenol between asymmetric septal hypertrophy and symmetric hypertrophy in patients with hypertrophic cardiomyopathy

The response to isoproterenol was studied in 9 patients with hypertrophic cardiomyopathy (HCM) and asymmetric septal hypertrophy (ASH), 9 patients with HCM and symmetric hypertrophy (SH), and 9 normal controls (NC), using digitized M-mode echocardiography. There was no significant difference in fractional shortening (FS) between ASH and SH, nor between SH and NC before isoproterenol infusion. During isoproterenol infusion, however, FS was significantly greater in ASH (60 +/- 6%) than in SH (53 +/- 7%) and NC (49 +/- 5%) (p less than 0.05, p less than 0.01, respectively), and normalized peak rate of change of left ventricular dimension during systole (pVs) was greater in ASH (7.7 +/- 1.5/s) than in SH (5.2 +/- 0.8/s) and in NC (4.9 +/- 0.8/s) (p less than 0.001, p less than 0.001, respectively). This study shows that the response to isoproterenol of ASH differs from those of SH and of NC and suggests hypersensitivity of the beta-adrenergic receptor system in ASH and the possibility that ASH is a different clinical entity than SH.     

Magnetic resonance imaging for assessment of apical hypertrophy in hypertrophic cardiomyopathy

The purpose of the study was to evaluate the value of magnetic resonance imaging as compared with two-dimensional echocardiography for a reliable assessment of the degree and distribution of apical hypertrophy in hypertrophic cardiomyopathy (HCM). The study includes 10 HCM patients (8 males and 2 females, mean age: 42±7 years). Two-dimensional echocardiography was not definitive in assessing the abnormal thickening of the apical myocardium in two patients. Two other patients had inadequate echocardiographic visualization of the lower left ventricle due to technical reasons. At magnetic resonance imaging, 3 patients showed localized hypertrophy at the left ventricular apex only. Three other patients had evidence of hypertrophy at the apex as well as at the left ventricular free wall. In four patients, the hypertrophy was detected at either the apex or the lower interventricular septum. It is concluded that magnetic resonance imaging might provide an accurate assessment of myocardial hypertrophy in HCM patients. This technique appears to be of major value in those with wall thickening localized to (or predominant in) the apical portion of the ventricle.     

Sotalol in patients with life-threatening ventricular tachyarrhythmias

Summary To assess the antiarrhythmic efficacy of oral d,l-sotalol, 68 patients with sustained monomorphic ventricular tachycardia (SMVT) (n=62) or ventricular fibrillation (VF) (n=6) were studied by programmed ventricular stimulation (PVS). Fifty-one patients had coronary artery disease with a previous myocardial infarction and there were 17 patients without coronary disease: 11 patients had right and/or left ventricular dysplasia, one patient an aortic-valve replacement, and five patients had no visible heart disease. Prior to sotalol patients were treated with a mean of 3.6±1.3 antiarrhythmic class I drugs. None of these drugs prevented SMVT or VF. During control PVS (PVS 1), VF was induced in 8 patients (12%), SMVT in 47 patients (69%), and nonsustained ventricular tachycardia (NSVT) in 13 patients (19%). After loading with oral d,l-sotalol (320 mg/day), PVS (PVS 2) was repeated 4.2±3.3 weeks after PVS 1. In one of the patients (1%) VF was inducible, in 15 patients (22%) SMVT was induced, and in 18 patients (26%) NSVT was induced. In 34 patients (50%) either no or a short ventricular response was inducible. Our data show that oral d,l-sotalol is an effective antiarrhythmic agent in patients with SMVT or VF.     

Assessment of pathophysiology based on the left ventricular shape in five patients with midventricular obstructive hypertrophic cardiomyopathy

OBJECTIVES: The pathophysiology of midventricular obstructive hypertrophic cardiomyopathy (MVO) is unknown. Patients with MVO and MVO-like cardiomyopathy were classified into three groups based on the cardioimaging morphological characteristics of the left ventricle to investigate their complications and treatment. METHODS: Four patients with MVO and one patient with disease-like MVO were admitted in our hospital from 1999 to 2005. Group A consisted of one patient with indications of pressure gradient at mid-ventricle without apical aneurysm, Group B consisted of three patients with indications of pressure gradient and apical aneurysm, and Group C consisted of one patient with hour-glass appearance with apical aneurysm and decreased left ventricular systolic function without pressure gradient. RESULTS: The diagnosis was established during examination for sustained ventricular tachycardia (SVT, three patients), paroxysmal atrial fibrillation (one patient), and coronary artery disease (one patient). Cardiogenic embolization was observed in all cases which originated from atrial fibrillation (one case) and apical aneurysm (two cases). No embolic event occurred in any patient after warfarin therapy. SVT occurred in patients in Groups B and C. SVT refractory to beta-blocker and mexiletine was treated by amiodarone. Apical aneurysmectomy and cryoablation could prevent recurrent SVT with drug resistance. CONCLUSIONS: Four of the five patients with MVO had arrhythmia (atrial fibrillation, SVT) and three had cardiogenic embolization. MVO could be classified into three groups depending on the morphological characteristics and complications. Treatment of MVO should be based on these characteristics.