Left Atrial Dysfunction in Apical Hypertrophic Cardiomyopathy: Assessed by Cardiovascular Magnetic Resonance Feature-tracking

PURPOSE

To evaluate the left atrial (LA) function in participants with apical hypertrophic cardiomyopathy (AHCM) by cardiovascular magnetic resonance feature tracking (CMR-FT).

MATERIALS AND METHODS

Thirty typical AHCM (TAHCM) patients, 23 subclinical AHCM (SAHCM) patients and 32 normal healthy volunteers who underwent CMR exam were retrospectively analyzed. LA reservoir, conduit, and contractile function were quantified by volumetric and CMR-FT derived strain and strain rate (SR) parameters from 2-chamber and 4-chamber cine imaging.

RESULTS

Compared with healthy participants, both TAHCM and SAHCM patients had impaired LA reservoir function (total strain [%]: TAHCM 31.3±12.2, SAHCM 31.8±12.3, controls 40.4±10.7, P <0.01; total SR [/s]: TAHCM 1.1±0.4, SAHCM 1.1±0.5, controls 1.4 ± 0.4, P <0.01) and conduit function (passive strain [%]: TAHCM 14.4±7.6, SAHCM 16.4±8.8, controls 23.3±8.1, P <0.01; passive SR [/s]: TAHCM -0.5±0.3, SAHCM -0.6±0.3, controls -1.0±0.4, P <0.01). Regarding contraction function, although TAHCM and SAHCM patients had preserved active emptying fraction and strain (all P >0.05), patients with TAHCM had the lowest active SR value among the 3 groups ( P= 0.03). LA reservoir and conduit strain were both significantly associated with left ventricular mass index and maximal wall thickness (all P <0.05). A moderate correlation between LA passive SR and left ventricular cardiac index ( P <0.01).

CONCLUSIONS

The LA reservoir and conduit function are predominately impaired and appeared in both SAHCM and TAHCM patients.

Apical hypertrophic cardiomyopathy: pathophysiology, diagnosis and management

Since the first description of apical hypertrophic cardiomyopathy (ApHCM) in 1976, contrasting information from all over the world has emerged regarding the natural history of the disease. However, the recommended guidelines on hypertrophic cardiomyopathy (HCM) pay a cursory reference to ApHCM, without ApHCM-specific recommendations to guide the diagnosis and management. In addition, cardiologists may not be aware of certain aspects that are specific to this disease subtype, and a robust understanding of specific disease features can facilitate recognition and timely diagnosis. Therefore, the review covers the incidence, pathogenesis, and characteristics of ApHCM and imaging methods. Echocardiography and cardiovascular magnetic resonance imaging (CMR) are the most commonly used imaging methods. Moreover, this review presents the management strategies of this heterogeneous clinical entity. In this review, we introduce a novel transapical beating-heart septal myectomy procedure for ApHCM patients with a promising short-time result.

Accurate diagnosis of apical hypertrophic cardiomyopathy using explainable advanced electrocardiogram analysis

AIMS

Typical electrocardiogram (ECG) features of apical hypertrophic cardiomyopathy (ApHCM) include tall R waves and deep or giant T-wave inversion in the precordial leads, but these features are not always present. The ECG is used as the gatekeeper to cardiac imaging for diagnosis. We tested whether explainable advanced ECG (A-ECG) could accurately diagnose ApHCM.

METHODS AND RESULTS

Advanced ECG analysis was performed on standard resting 12-lead ECGs in patients with ApHCM [n = 75 overt, n = 32 relative (<15 mm hypertrophy); a subgroup of which underwent cardiovascular magnetic resonance (n = 92)], and comparator subjects (n = 2449), including healthy volunteers (n = 1672), patients with coronary artery disease (n = 372), left ventricular electrical remodelling (n = 108), ischaemic (n = 114) or non-ischaemic cardiomyopathy (n = 57), and asymmetrical septal hypertrophy HCM (n = 126). Multivariable logistic regression identified four A-ECG measures that together discriminated ApHCM from other diseases with high accuracy [area under the receiver operating characteristic (AUC) curve (bootstrapped 95% confidence interval) 0.982 (0.965-0.993)]. Linear discriminant analysis also diagnosed ApHCM with high accuracy [AUC 0.989 (0.986-0.991)].

CONCLUSION

Explainable A-ECG has excellent diagnostic accuracy for ApHCM, even when the hypertrophy is relative, with A-ECG analysis providing incremental diagnostic value over imaging alone. The electrical (ECG) and anatomical (wall thickness) disease features do not completely align, suggesting that future diagnostic and management strategies may incorporate both features.

Ethnic and sex-related differences at presentation in apical hypertrophic cardiomyopathy: An observational cross-sectional study

BACKGROUND

We investigated whether ethnicity and sex are associated with different clinical presentations and cardiovascular magnetic resonance (CMR) findings in individuals with apical hypertrophic cardiomyopathy (ApHCM).

METHODS

A retrospective observational cohort study of consecutive ApHCM patients from a large tertiary referral center in the United Kingdom (UK). Demographic, clinical, 12‑lead electrocardiogram (ECG) and CMR findings were collected. Participants presented in our clinics between 2010 and 2020. 'Pure' ApHCM was defined as isolated apical hypertrophy and 'mixed' with both apical and septal hypertrophy but with the apical segments of a greater wall thickness. Deep T-wave inversion was defined as ≥5 mm in any electrocardiogram lead.

RESULTS

A total of 150 consecutive ApHCM patients (75% men, 25% women; 37% White, 25% Black, 24% Asian and 15% of Mixed/Other ethnicity) were included. Females were diagnosed at an older age compared to men, had less prominent ECG changes, had higher left atrial area index, and were more hypertensive. Black patients had higher left ventricular mass index, more hypertension, and more of the 'mixed' type of ApHCM. The majority of hypertensive male patients showed the 'mixed' phenotype.

CONCLUSIONS

Individuals of Black ethnicity and hypertensive male patients are more likely to present with mixed apical and basal hypertrophy, whereas White, Asian and non-hypertensive male patients tend to have hypertrophy limited to the apex. Females present at an older age and are less likely to have deep T wave inversion on ECG.

Endomyocardial fibrosis and apical calcification: A case report with unusual presentations of apical hypertrophic cardiomyopathy

RATIONALE

Apical hypertrophic cardiomyopathy (ApHCM) is a phenotypic variant of hypertrophic cardiomyopathy. Endomyocardial fibrosis and endocardial calcification are especially rare in ApHCM.

PATIENT CONCERNS

The main symptoms was chest tightness, palpitation, shortness of breath, and fatigue. Echocardiography and imaging examinations found apical hypertrophy along with endocardial calcification and endomyocardial fibrosis. Abnormal structural changes led to thrombosis and made the left ventricle a flat shape resembling an "apple."

DIAGNOSES

The typical presentations, hypertrophic apex on echocardiography and an elevated N-terminal pro-brain natriuretic peptide level indicated the diagnosis of ApHCM and heart failure with preserved ejection fraction.

INTERVENTIONS

Optimal medical therapy including the administration of ApHCM, heart failure and atrial fibrillation to improve symptoms and life quality.

OUTCOMES

Since discharge, the patient could perform normal daily activities and had no discomfort based on the optimal medical therapy.

LESSONS

We report a ApHCM patients with unusual presentations of endomyocardial fibrosis and apical calcification. This case highlights the importance of understanding the specific pathological changes of ApHCM for treatment and prognosis.

[Analysis of conventional echocardiographic features in apical hypertrophic cardiomyopathy patients complicated with left ventricular apical aneurysm]

Objective: To explore the basic characteristics of conventional echocardiography of apical hypertrophic cardiomyopathy (ApHCM) patients complicating with left ventricular apical aneurysm (LVAA). Methods: This is a retrospective study. Patients who underwent echocardiography and cardiac magnetic resonance (CMR) and were diagnosed with ApHCM complicated with LVAA by CMR at Fuwai Hospital, Chinese Academy of Medical Sciences from August 2012 to July 2017 were enrolled. According to whether LVAA was detected by echocardiography, the enrolled patients were divided into two groups: LVAA detected by echocardiography group and LVAA not detected by echocardiography group. Clinical data of the two groups were compared to analyze the causes of missed diagnosis by echocardiography. Results: A total of 21 patients were included, of whom 67.0% (14/21) were males, aged (56.1±16.5) years. Patients with chest discomfort accounted for 81.0% (17/21), palpitation 38.1% (8/21), syncope 14.3% (3/21). ECG showed that 21 (100%) patients had ST-T changes and 18 (85.7%) had deep T-wave invertion. Echocardiography revealed ApHCM in 17 cases (81.0%) and LVAA in 7 cases (33.3%). The mean left ventricular apical aneurysm diameter was 33.0 (18.0, 37.0) mm, and left ventricular ejection fraction was (66.5±6.6) %, and left ventricular apex thickness was (21.0±6.3) mm. Left ventricular outflow tract obstruction was presented in 4 cases and middle left ventricular obstruction in 10 cases. The mean left ventricular apical aneurysm diameter of LVAA detected by echocardiography was greater than that of LVAA not detected by echocardiography (25.0 (18.0, 28.0) mm vs. 16.0 (12.3, 21.0) mm, P=0.006). Conclusions: Conventional echocardiography examination has certain limitations in the diagnosis of ApHCM. Smaller LVAA complicated with ApHCM is likely to be unrecognized by echocardiography. Clinicians should improve their understanding of this disease.

Prevalence, characteristics, and natural history of apical phenotype in a large cohort of patients with hypertrophic cardiomyopathy

BACKGROUND

Apical hypertrophic cardiomyopathy (ApHCM) is a variant of hypertrophic cardiomyopathy (HCM) with distinct imaging and clinical characteristics. Data on the prognosis of this HCM subgroup appear conflicting. Our study aims to clarify the natural history of ApHCM and identify predictors of outcomes.

MATERIALS AND METHODS

A total of 856 patients with HCM were retrospectively examined. ApHCM was defined as asymmetric left ventricular hypertrophy confined predominantly at the apex, either isolated (pure ApHCM type) or with co-existent hypertrophy of the interventricular septum (mixed ApHCM). Echocardiographic, clinical, and survival data were compared between individuals with ApHCM and non-ApHCM.

RESULTS

A total of 143 (16.7%) patients were diagnosed with ApHCM. Compared with non-ApHCM, subjects with apical HCM were diagnosed at an older age and had better echocardiographic indices and more comorbidities at baseline. Apical aneurysms were more prevalent among the ApHCM phenotype (6.3% vs. 1.7%, p = 0.003). During a mean follow-up of 6 ± 3 years, ApHCM was characterized by lower all-cause, cardiovascular, heart failure-related mortality, and ventricular arrhythmic events compared with non-ApHCM. Multivariate analysis identified atrial fibrillation and HCM risk-sudden cardiac death (SCD) as independent predictors of the composite outcome of overall mortality and hospitalizations for cardiovascular reasons (hazard ratio [HR] 4.3, 95% confidence interval [CI] 1.9-9.5 for atrial fibrillation and HR 1.2, 95% CI 1.02-1.3 for HCM risk-SCD) in ApHCM.

CONCLUSIONS

ApHCM exhibited a lower rate of all-cause mortality and arrhythmic events in the middle-aged population of patients with HCM. Atrial fibrillation and HCM risk-sudden cardiac death were independent predictors of a composite of overall mortality and cardiovascular hospitalizations among those with ApHCM.

Left ventricular apical hypertrophy emerged from the fourth-year post heart transplantation: Case report and literature review

Apical hypertrophic cardiomyopathy (AHCM) is a relatively rare phenotype of hypertrophic cardiomyopathy, which is characterized by focal thickening of the left ventricular (LV) apical myocardium, showing a spade-shaped shadow on the left ventricle. We present the case of a 59-year-old man who was found to have AHCM, is an asymptomatic orthotopic heart transplantation (HTx) patient. This rare and progressive case of LV apical hypertrophy emerged from the fourth year post surgery. We analyzed the etiology of this case and summarized the clinical manifestations and prognosis of AHCM following HTx by reviewing our case and the literature.

Apical papillary muscle displacement is a prevalent feature and a phenotypic precursor of apical hypertrophic cardiomyopathy

AIMS

Papillary muscle (PM) abnormalities are considered part of the phenotypic spectrum of hypertrophic cardiomyopathy (HCM). The aim of this study was to evaluate the presence and frequency of PM displacement in different HCM phenotypes.

METHODS AND RESULTS

We retrospectively analysed cardiovascular magnetic resonance (CMR) findings in 156 patients (25% females, median age 57 years). Patients were divided into three groups: septal hypertrophy (Sep-HCM, n = 70, 45%), mixed hypertrophy (Mixed-HCM, n = 48, 31%), and apical hypertrophy (Ap-HCM, n = 38, 24%). Fifty-five healthy subjects were enrolled as controls. Apical PM displacement was observed in 13% of controls and 55% of patients, which was most common in the Ap-HCM group, followed by the Mixed-HCM and Sep-HCM groups (respectively: inferomedial PM 92 vs. 65 vs. 13%, P < 0.001; anterolateral PM 61 vs. 40 vs. 9%, P < 0.001). Significant differences in PM displacement were found when comparing healthy controls with patients with Ap- and Mixed-HCM subtypes but not when comparing them with patients with the Sep-HCM subtype. T-wave inversion in the inferior and lateral leads was more frequent in patients with Ap-HCM (100 and 65%, respectively) when compared with Mixed-HCM (89 and 29%, respectively) and Sep-HCM (57 and 17%, respectively; P < 0.001 for both). Eight patients with Ap-HCM had prior CMR examinations because of T-wave inversion [median interval 7 (3-8) years], and in the first CMR study, none showed apical hypertrophy [median apical wall thickness 8 (7-9) mm], while all of them presented with apical PM displacement.

CONCLUSION

Apical PM displacement is part of the phenotypic Ap-HCM spectrum and may precede the development of hypertrophy. These observations suggest a potential pathogenetic, mechanical link between apical PM displacement and Ap-HCM.

Yamaguchi syndrome - An updated review article of electrocardiographic and echocardiographic findings

Apical hypertrophic cardiomyopathy (ApHCM) is thought to be an uncommon variant of hypertrophic cardiomyopathy (HCM). This article is a literature review focusing on the characteristic electrocardiogram (EKG) and 2D echocardiogram findings as currently there are no specific ACC/AHA/ESC guidelines set as diagnostic criteria for ApHCM.

Apical Ischemia Is a Universal Feature of Apical Hypertrophic Cardiomyopathy

BACKGROUND

Apical hypertrophic cardiomyopathy (ApHCM) accounts for ≈10% of hypertrophic cardiomyopathy cases and is characterized by apical hypertrophy, apical cavity obliteration, and tall ECG R waves with ischemic-looking deep T-wave inversion. These may be present even with <15 mm apical hypertrophy (relative ApHCM). Microvascular dysfunction is well described in hypertrophic cardiomyopathy. We hypothesized that apical perfusion defects would be common in ApHCM.

METHODS

A 2-center study using cardiovascular magnetic resonance short- and long-axis quantitative adenosine vasodilator stress perfusion mapping. One hundred patients with ApHCM (68 overt hypertrophy [≥15 mm] and 32 relative ApHCM) were compared with 50 patients with asymmetrical septal hypertrophy hypertrophic cardiomyopathy and 40 healthy volunteer controls. Perfusion was assessed visually and quantitatively as myocardial blood flow and myocardial perfusion reserve.

RESULTS

Apical perfusion defects were present in all overt ApHCM patients (100%), all relative ApHCM patients (100%), 36% of asymmetrical septal hypertrophy hypertrophic cardiomyopathy, and 0% of healthy volunteers (P<0.001). In 10% of patients with ApHCM, perfusion defects were sufficiently apical that conventional short-axis views missed them. In 29%, stress myocardial blood flow fell below rest values. Stress myocardial blood flow was most impaired subendocardially, with greater hypertrophy or scar, and with apical aneurysms. Impaired apical myocardial blood flow was most strongly predicted by thicker apical segments (β-coefficient, -0.031 mL/g per min [CI, -0.06 to -0.01]; P=0.013), higher ejection fraction (-0.025 mL/g per min [CI, -0.04 to -0.01]; P<0.005), and ECG maximum R-wave height (-0.023 mL/g per min [CI, -0.04 to -0.01]; P<0.005).

CONCLUSIONS

Apical perfusion defects are universally present in ApHCM at all stages. Its ubiquitous presence along with characteristic ECG suggests ischemia may play a disease-defining role in ApHCM.

Prognosis for patients with apical hypertrophic cardiomyopathy: A multicenter cohort study based on propensity score matching

BACKGROUND

Apical hypertrophic cardiomyopathy (AHCM) is a subtype of HCM, and few studies on the prognosis in AHCM are available.

AIMS

This study aimed to explore the clinical prognosis for AHCM and non-AHCM patients through clinical data based on propensity score matching (PSM) in a large cohort of Chinese HCM patients.

METHODS

The cohort study included 2268 HCM patients, 226 AHCM and 2042 non-AHCM patients from 13 tertiary hospitals, who were treated between 1996 and 2021. Fifteen demographic and clinical variables of 226 AHCM patients and 2042 non-AHCM patients were matched using 1:2 PSM. A Cox proportional hazard regression model was constructed to assess the effect of AHCM on mortality.

RESULTS

During a median follow-up of 5.1 (2.4-8.4) years, 353 (15.6%) of the 2268 HCM patients died, of whom 205 died due to cardiovascular mortality/cardiac transplantation and 94 experienced sudden cardiac death (SCD). In the matched cohort, the ACHM patients had lower rates of all-cause mortality (P = 0.003), cardiovascular mortality/cardiac transplantation (P = 0.03), and SCD (P = 0.02) than the non-AHCM patients. Furthermore, the Cox proportional hazard regression model showed that AHCM was an independent prognostic predictor of all-cause HCM mortality (P = 0.004) and a univariable prognostic predictor of cardiovascular mortality/cardiac transplantation (P = 0.03) and for SCD (P = 0.03). However, AHCM was not significant in multivariable Cox regression models in relation to cardiovascular mortality/cardiac transplantation and SCD.

CONCLUSION

AHCM had a favorable prognosis both before and after matching, with lower all-cause mortality, cardiovascular mortality/cardiac transplantation, and SCD than non-AHCM.