Speckle tracking echocardiography to assess regional ventricular function in patients with apical hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy and left ventricular non-compaction: Distinct diseases or variant phenotypes of a single condition?

Hypertrophic cardiomyopathy (HCM) is a genetically determined myocardial disease characterized by an increased thickness of the left ventricle (LV) wall that cannot be solely attributed to abnormal loading conditions. HCM may present with an intraventricular or LV outflow tract obstruction, diastolic dysfunction, myocardial fibrosis and/or ventricular arrhythmias. Differentiating HCM from other diseases associated with LV hypertrophy, such as hypertension, aortic stenosis, or LV non-compaction (LVNC), can at times be challenging. LVNC is defined by excessive LV trabeculation and deep recesses between trabeculae, often accompanied by increased LV myocardial mass. Previous studies indicate that the LVNC phenotype may be observed in up to 5% of the general population; however, in most cases, it is a benign finding with no impact on clinical outcomes. Nevertheless, LVNC can occasionally lead to LV systolic dysfunction, manifesting as a phenotype of dilated or non-dilated left ventricular cardiomyopathy, with an increased risk of thrombus formation and arterial embolism. In extreme cases, where LVNC is associated with a very thickened LV wall, it can even mimic HCM. There is growing evidence of an overlap between HCM and LVNC, including similar genetic mutations and clinical presentations. This raises the question of whether HCM and LVNC represent different phenotypes of the same disease or are, in fact, two distinct entities.

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.

Left Ventricular Segmental Strain Identifies Unique Myocardial Deformation Patterns After Intrinsic and Extrinsic Stressors in Mice

We used segmental strain analysis to evaluate whether intrinsic (diet-induced obesity [DIO]) and extrinsic (unpredictable chronic mild stress [UCMS]) stressors can alter deformational patterns of the left ventricle. Six-week-old male C57BL/6J mice were randomized into the lean or obese group (n = 24/group). Mice underwent 12 wk of DIO with a high-fat diet (HFD). At 18 wk, lean and obese mice were further randomized into UCMS and non-UCMS groups (UCMS, 7 h/d, 5 d/wk, for 8 wk). Echocardiography was performed at baseline (6 wk), post-HFD (18 wk) and post-UCMS (26 wk). Machine learning was applied to the DIO and UCMS groups. There was robust predictive accuracy (area under the receiver operating characteristic curve [AUC] = 0.921) when comparing obese with lean mice, with radial strain changes in the lateral (-64%, p ≤ 0.001) and anterior free (-53%, p < 0.001) walls being most informative. The ability to predict mice that underwent UCMS, irrespective of diet, was assessed (AUC = 0.886), revealing longitudinal strain rate of the anterior midwall and radial strain of the posterior septal wall as the top features. The wall segments indicate a predilection for changes in deformation patterns to the free wall (DIO) and septal wall (UCMS), indicating disease-specific alterations to the myocardium.

Apical variant hypertrophic cardiomyopathy "multimodality imaging evaluation"

Apical variant hypertrophic cardiomyopathy (AHCM) is characterized by asymmetric hypertrophy of the left ventricular (LV) apex. T wave inversions of variable degree, particularly in the left precordial leads, and left ventricular hypertrophy (LVH) are common EKG findings in AHCM. Echocardiography is typically the initial imaging modality used in the diagnosis and evaluation of AHCM. The diagnosis is made when the LV apex has apical wall thickness of ≥ 15 mm or a ratio of apical to basal LV wall thickness of ≥ 1.3 at end-diastole. The use of microbubble contrast agents with echocardiography is helpful for visualization of the apex. Cardiac magnetic resonance (CMR) has the advantage of a large field of view and the ability to perform tissue characterization. Late gadolinium enhancement (LGE) sequences are essential in the assessment of potential areas of myocardial scarring. Cardiac computed tomography (CCT) has the advantage of being able to evaluate coronary arteries in addition to assessing cardiac anatomy and function. A "Solar Polar" map pattern is the characteristic feature of AHCM on myocardial perfusion imaging (MPI) in cases not associated with apical aneurysm (APA). Recognition of typical perfusion patterns in AHCM patients is not only important in the diagnostic evaluation of this disease process, but also for avoiding unnecessary and costly tests. The purpose of this article is to review the imaging features of AHCM from different imaging modalities and assess the value added of each modality in the diagnosis of AHCM.

Development and validation of a new method to diagnose apical hypertrophic cardiomyopathy by gated single-photon emission computed tomography myocardial perfusion imaging

AIM

The aim of this study is to develop and validate a new method to diagnose apical hypertrophic cardiomyopathy (AHCM) by the integral quantitative analysis of myocardial perfusion and wall thickening from gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI).

PATIENTS AND METHODS

Twenty-two consecutive patients, who showed T wave inversion of at least 3 mm in precordial leads and sinus rhythm in ECG, were enrolled. All the patients underwent cardiac magnetic resonance (CMR), gated rest SPECT MPI and echocardiography. According to CMR diagnostic results, 13 patients were categorized as in the AHCM group and the remaining nine patients were categorized as in the non-AHCM group. Operators who were blinded to the CMR diagnosis independently performed the diagnosis by gated SPECT MPI. The regions of interest inside the apical hotspots on the perfusion polar map were drawn and the mean values of wall thickening in the drawn region of interests were calculated. Using MRI diagnosis as the gold standard, AHCM was diagnosed based on receiver operating characteristic analysis of the mean wall thickening in the apical perfusion hotspot. The area under curve, sensitivity, specificity, and accuracy of our method were 0.97, 100%, 89%, and 95%, respectively.

CONCLUSION

Our new method has high sensitivity, specificity, and accuracy against CMR diagnosis. It has great promise to become a clinical tool in the diagnosis of AHCM.