Echocardiographic Features of Cardiomyopathies: A Comprehensive Review

Authors: Ghassan Hamdan Al‐Naami

Abstract

Cardiomyopathies represent a heterogeneous group of myocardial diseases characterized by structural and functional abnormalities that can lead to heart failure, arrhythmias, and sudden cardiac death. Echocardiography remains the first‐line, non‐invasive imaging modality for the evaluation of cardiomyopathies, owing to its broad availability, safety profile, and diagnostic versatility. This review comprehensively outlines the echocardiographic features associated with the major morphofunctional subtypes of dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), restrictive cardiomyopathy (RCM), arrhythmogenic right ventricular cardiomyopathy (ARVC), and left ventricular non‐compaction cardiomyopathy (LVNC). Emphasis is placed on both adult and pediatric populations, with attention to age‐specific diagnostic criteria and measurement standards. The article also includes structured tabular summaries to facilitate clinical interpretation and application across diverse patient settings. Through an integrated and standardized echocardiographic approach, this review aims to support accurate diagnosis, effective monitoring, and informed therapeutic decision‐making in the management of cardiomyopathies.

Introduction

Cardiomyopathies represent a heterogeneous group of myocardial disorders that are classified based on morphofunctional characteristics into five major dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), restrictive cardiomyopathy (RCM), arrhythmogenic cardiomyopathy (ACM), and left ventricular non‐compaction (LVNC). Figure 1 shows echocardiographic images for these types of cardiomyopathies. These conditions may be idiopathic or secondary to genetic, metabolic, infectious, or systemic causes, and they often lead to significant morbidity and mortality due to heart failure, arrhythmias, thromboembolic events, and sudden cardiac death. Early and accurate diagnosis is therefore paramount to optimizing patient outcomes and guiding appropriate therapeutic interventions.

Echocardiography remains the cornerstone of cardiomyopathy assessment due to its non‐invasive nature, widespread availability, and ability to provide real‐time structural, functional, and hemodynamic information (Table 1). It is indispensable in the initial diagnostic evaluation, risk stratification, serial monitoring, and follow‐up of both adult and pediatric patients with suspected or confirmed cardiomyopathies. Advanced echocardiographic modalities—including tissue Doppler imaging (TDI), speckle‐tracking echocardiography (STE), three‐dimensional (3D) echocardiography, and contrast‐enhanced studies—have further enhanced the precision of myocardial characterization and the detection of early or subtle phenotypic expressions.

Among these, global longitudinal strain (GLS) has emerged as a highly sensitive and reproducible echocardiographic parameter for the early detection of myocardial dysfunction, often preceding changes in left ventricular ejection fraction (LVEF). Unlike traditional volumetric indices, GLS assesses myocardial deformation by quantifying the percentage of longitudinal fiber shortening, particularly in the subendocardial layer, which is most vulnerable to early damage across cardiomyopathies [1, 2, 3, 4]. In dilated cardiomyopathy (DCM), reduced GLS can identify subclinical systolic dysfunction before overt decline in LVEF, aiding in early diagnosis and monitoring therapeutic response. In hypertrophic cardiomyopathy (HCM), GLS is typically reduced in hypertrophied myocardial segments despite preserved or hyperdynamic LVEF, and global impairment correlates with increased risk of heart failure and arrhythmias. In restrictive cardiomyopathy (RCM), GLS may reveal global or regional dysfunction not apparent on conventional imaging, and in cardiac amyloidosis, the hallmark finding of apical sparing (“cherry‐on‐top” pattern) provides diagnostic specificity. In arrhythmogenic right ventricular cardiomyopathy (ARVC), reduced longitudinal strain in the RV free wall may offer additional diagnostic value, especially when traditional measures are equivocal. For left ventricular non‐compaction (LVNC), GLS abnormalities reflect impaired contractile function in non‐compacted segments and may predict clinical deterioration. The routine incorporation of GLS into echocardiographic assessment improves diagnostic precision, supports early risk stratification, and enhances prognostic evaluation across a broad spectrum of cardiomyopathies.

In parallel, the application of artificial intelligence (AI) and machine learning (ML) in cardiovascular imaging is rapidly expanding, offering promising new tools for the detection, classification, and risk stratification of cardiomyopathies. These technologies enable automated analysis of complex echocardiographic data, including feature extraction from strain patterns, myocardial texture, and motion dynamics, with the potential to reduce interobserver variability and improve diagnostic consistency. Additionally, multimodal imaging fusion—which integrates echocardiographic, cardiac MRI, CT, and even genetic or electrocardiographic data—enhances the ability to comprehensively characterize myocardial structure and function. In particular, AI‐assisted platforms may assist in distinguishing phenotypically overlapping conditions, such as differentiating hypertrophic cardiomyopathy from athlete's heart or early ARVC from normal variants. While these innovations hold considerable promise for improving diagnostic accuracy and workflow efficiency, they are currently in various stages of clinical validation. Rigorous prospective studies, regulatory approval, and integration into standardized imaging protocols are needed before widespread adoption in routine cardiomyopathy assessment.

Despite the widespread use of echocardiography, the interpretation of findings can vary significantly depending on patient age, body habitus, and institutional practices. As such, the application of standardized measurement protocols and age‐ and size‐specific normative data is critical to ensure diagnostic consistency and clinical reliability across different populations. In pediatric cardiology, where normal cardiac dimensions vary considerably with growth and development, the role of normative z‐scores and reference values becomes particularly important.

This review aims to synthesize key echocardiographic findings, measurement techniques, and diagnostic thresholds associated with each cardiomyopathy subtype. It emphasizes the role of standardized imaging approaches, highlights the nuances in pediatric versus adult assessments, and underscores the importance of integrating echocardiographic parameters into comprehensive clinical decision‐making frameworks.

Pediatric considerations: Pediatric measurements rely on z‐scores for any volumetric measurements. This supports the diagnosis of various cardiac disorders especially cardiomyopathies which relies much on accurate measurements.

Here are several reliable and commonly used online z‐score calculators for pediatric echocardiography (Table 2). These tools are based on validated datasets and are widely used in clinical practice to assess cardiac chamber size, wall thickness, and function in children [4, 5, 6, 7]: Boston Children's Hospital Z‐Score Calculator

Website: https://zscore.chboston.org

Features: Calculates z‐scores for multiple cardiac structures including LVEDD, LV mass, RV dimensions, aorta, and valves.Based on Pettersen et al. (2008) [5] normative data.Easy BSA calculation using height and weight.Printable results and graphical output. Source Reference: Pettersen et al. JASE 2008. Pediatric Z‐Score Calculator (ParameterZ)

Website: https://parameterz.blogspot.com

Features: Covers LV and RV size, wall thickness, and valve annuli.Indexed to BSA, with multiple reference datasets.Includes tools for both 2D and M‐mode parameters. Note: Developed by a pediatric cardiologist; often used in academic settings.

Z‐Score Calculator by Children's Heart Center—Nevada

Website: https://www.pedz.de

Features: Supports a wide range of z‐score calculations for pediatric echo.Provides tables and percentile curves.Includes calculators for both dimensions and functional parameters. Congenital Heart Disease Z‐Scores—University of Michigan

Website: https://med.umich.edu/mott/pdf/zscore.pdf (PDF) Features: Manual z‐score lookup tables for a variety of cardiac measurements.Good for reference or use in offline settings.

Key Tips for Use: Always input accurate height and weight to compute BSA reliably.Ensure the measurement method (e.g., PLAX vs. apical view) matches the dataset used by the calculator.Use consistent reference datasets when comparing values over time (e.g., for serial studies).Be aware of the growth charts and percentiles used in your local population, as some norms may differ slightly based on geography.

Echocardiographic Overview of Cardiomyopathy Subtypes

Dilated Cardiomyopathy (DCM)

Echocardiography plays a pivotal role in the diagnosis, evaluation, and management of dilated cardiomyopathy (DCM), a condition characterized by ventricular chamber enlargement and systolic dysfunction in the absence of abnormal loading conditions or significant coronary artery disease. In DCM, echocardiography typically reveals a dilated left ventricle with globular geometry, thinned walls, and reduced left ventricular ejection fraction (LVEF)—often below 40%. The mitral valve may exhibit functional regurgitation due to annular dilation and papillary muscle displacement. Left atrial enlargement is common due to chronic volume overload. M‐mode and 2D imaging confirm chamber dilation and wall motion abnormalities, while Doppler techniques assess diastolic filling patterns, which may range from impaired relaxation to restrictive physiology in advanced disease. Tissue Doppler imaging (TDI) and strain imaging offer insights into subtle myocardial dysfunction and can detect early myocardial impairment even when ejection fraction is preserved. Right ventricular involvement, frequently seen in advanced cases, is assessed by TAPSE (tricuspid annular plane systolic excursion) and RV fractional area change. Echocardiography also evaluates for complications such as intracavitary thrombus, especially in the apex, which poses a risk for systemic embolism. Serial echocardiograms are essential in monitoring disease progression, response to therapy (e.g., with beta‐blockers, ACE inhibitors, or CRT), and candidacy for advanced interventions like implantable defibrillators or cardiac transplantation. Overall, echocardiography remains an indispensable, non‐invasive, and repeatable tool in the comprehensive care of patients with dilated cardiomyopathy [8, 9, 10, 11, 12].

DCM is characterized by ventricular chamber enlargement with impaired systolic function.

Quantitative Assessment of LV Enlargement in Adults:

LV End‐Diastolic Diameter (LVEDD): >58 mm (men), >52 mm (women)LVEDD is a key echocardiographic measurement used to assess left ventricular size and function. It represents the internal diameter of the left ventricle at the end of diastole, when the chamber is at its maximum filling. LVEDD is a critical parameter in evaluating volume status, ventricular remodeling, and early signs of dilated cardiomyopathy. It can be measured using 2D image or M‐mode of the left ventricle in parasternal long or short axis views (Figure 2). Normal reference values vary with age, sex, and body size, and deviations from these ranges can indicate pathological dilation or hypertrophy (Table 3). Accurate assessment of LVEDD is essential for diagnosing and monitoring various cardiac conditions especially in pediatric and adult populations with suspected myocardial disease like DCM (Table 4). LV End‐Diastolic Volume Index (LVEDVi): >74 mL/m^2^ (men), >61 mL/m^2^ (women)LVEDVi is a measurement of the volume of blood in the left ventricle at the end of diastole, indexed to body surface area (BSA), and is typically expressed in **mL/m^2^ **. It is a crucial echocardiographic and MRI parameter used to assess left ventricular dilation and remodeling, especially in the context of Dilated Cardiomyopathy (DCM).

In DCM, the left ventricle becomes enlarged and weakened, leading to a significantly elevated LVEDVi. This reflects increased preload and poor systolic function due to ventricular dilatation.

It can be measured

Cardiac MRI is the gold standard for LV volume measurement.

Or simply, 2D or 3D echocardiography can estimate LVEDVi using Simpson's biplane method, though less precise. LV Mass Index: >115 g/m^2^ (men), >95 g/m^2^ (women) LV Mass Index (LVMI) quantifies the mass of the left ventricle (LV) relative to body surface area (BSA), expressed in **g/m^2^ **. It reflects myocardial hypertrophy or remodeling and is an essential echocardiographic marker in many forms of cardiomyopathy, including DCM.The LV chamber is dilated and the wall may be thinned, but in many cases the total LV mass increases due to eccentric hypertrophy (myocyte elongation and fibrosis).LVMI is often elevated, especially in moderate to advanced stages of disease, reflecting eccentric hypertrophy (dilation + increased mass).Elevated LVMI is associated Higher risk of arrhythmiasProgressive systolic dysfunctionPoorer prognosis in DCM patients

Relative Wall Thickness (RWT): <0.42 suggests eccentric remodelingIt evaluates left ventricular geometry. It is calculated as twice the posterior wall thickness divided by the left ventricular end‐diastolic diameter (2 × PWT/LVEDD). RWT helps differentiate patterns of left ventricular remodeling, distinguishing between concentric and eccentric hypertrophy. An increased RWT suggests concentric remodeling or hypertrophy, often seen in pressure overload conditions such as hypertension, while a normal or reduced RWT may indicate volume overload or dilated cardiomyopathy.

Quantitative Assessment of RV Enlargement in Adults:

RV Basal Diameter (RVD1): >41 mmThe Right Ventricular Basal Diameter (RVD1) is an essential echocardiographic measurement that reflects the transverse dimension of the right ventricle at its widest point near the base, typically measured in the apical four‐chamber view. It provides a reliable estimate of right ventricular size and is commonly used in the assessment of right ventricular dilation. An increased RVD1 may indicate conditions such as pulmonary hypertension, right heart failure, or congenital heart disease. RV Mid‐Cavity Diameter (RVD2): >35 mmIt is measured at the mid‐level of the right ventricle, approximately halfway between the base and the apex, in the apical four‐chamber view. It provides valuable information about the mid‐portion of the right ventricular chamber and is used to assess right ventricular size and remodeling. Enlargement of RVD2 may indicate right ventricular dilation due to pressure or volume overload, as seen in pulmonary hypertension, congenital heart disease, or cardiomyopathies. RV Length (RVD3): >86 mmAlso known as the longitudinal dimension, is measured from the tricuspid annulus to the apex of the right ventricle in the apical four‐chamber view. It reflects the longitudinal size of the right ventricle and complements other measurements such as RVD1 and RVD2 in assessing overall right ventricular dimensions. An increased RVD3 may indicate right ventricular dilation due to conditions like pulmonary hypertension, right‐sided volume overload, or cardiomyopathy.Figure 3 demonstrates these three diameters. RVEDA Index: >20 cm^2^/m^2^ The Right Ventricular End‐Diastolic Area (RVEDA) Index is an echocardiographic parameter that represents the area of the right ventricle at end‐diastole, indexed to body surface area to allow for size‐related comparisons across individuals. Measured in the apical four‐chamber view, the RVEDA Index is used to assess right ventricular size and enlargement. An increased RVEDA Index is indicative of right ventricular dilation, commonly associated with pulmonary hypertension, right heart failure, or congenital heart defects. It is a valuable tool for evaluating right ventricular remodeling and guiding clinical management in both pediatric and adult patients. RV FAC: <35% indicates systolic dysfunctionRight Ventricular Fractional Area Change (RV FAC) is a widely used echocardiographic parameter that quantifies right ventricular systolic function. It is calculated as the percentage change in the right ventricular area from end‐diastole to end‐systole using the [(RVEDA—RVESA)/RVEDA] × 100, where RVEDA is the end‐diastolic area and RVESA is the end‐systolic area. Measured in the apical four‐chamber view, RV FAC reflects global right ventricular contractility. A reduced RV FAC (<35%) suggests impaired systolic function and may be seen in conditions such as pulmonary hypertension, right heart failure, or cardiomyopathies.

Hypertrophic Cardiomyopathy (HCM)

Echocardiography is the cornerstone imaging modality in the diagnosis, phenotypic assessment, and management of hypertrophic cardiomyopathy (HCM), a genetically determined myocardial disease characterized by left ventricular hypertrophy (LVH) in the absence of abnormal loading conditions such as hypertension or aortic stenosis. Conventional two‐dimensional transthoracic echocardiography allows for the assessment of asymmetric septal hypertrophy, which is the most common morphological variant, as well as other patterns including concentric, apical, or mid‐ventricular hypertrophy (Figure 4). Left ventricular wall thickness exceeding 15 mm in one or more segments is diagnostic, with the interventricular septum typically being most affected. M‐mode imaging may demonstrate systolic anterior motion (SAM) of the mitral valve, which contributes to left ventricular outflow tract (LVOT) obstruction—a dynamic feature present in approximately 70% of patients either at rest or with provocation (Figure 5). Doppler echocardiography quantifies the LVOT gradient, which is a critical determinant of symptoms and treatment decisions; a resting or provocable gradient ≥30 mmHg is considered significant, while ≥50 mmHg often warrants septal reduction therapy (Figure 6). Color Doppler also aids in assessing mitral regurgitation secondary to SAM. Advanced echocardiographic techniques such as tissue Doppler imaging (TDI) and speckle‐tracking echocardiography (STE) can detect subclinical myocardial dysfunction, even when ejection fraction appears preserved, and may provide prognostic information. Left atrial enlargement, reduced left ventricular cavity size, and abnormal diastolic filling patterns are also common findings. Transesophageal echocardiography (TEE) and contrast echocardiography may be used in specific clinical scenarios, especially when image quality is suboptimal. Furthermore, serial echocardiographic assessments are crucial for risk stratification, particularly in evaluating the evolution of hypertrophy, obstruction, and detection of apical aneurysms or thrombi. In patients with ambiguous morphology or discordant findings, cardiac magnetic resonance imaging (CMR) serves as a valuable adjunct. Nonetheless, echocardiography remains the first‐line, accessible, and dynamic tool for diagnosing HCM, guiding clinical decisions, and monitoring therapy effectiveness, including the impact of pharmacologic agents and the need for surgical or interventional approaches [13, 14, 15, 16, 17, 18].

HCM is defined by LV wall thickness ≥15 mm in adults (or z >2 in children), not explained by loading conditions.

**Key Features (**Table 5): Asymmetric septal hypertrophy (septal/posterior wall ratio >1.3).Systolic anterior motion (SAM) of the mitral valve.LVOT obstruction (provokable gradient ≥50 mmHg).MR due to SAM: Mitral regurgitation (MR) in hypertrophic cardiomyopathy (HCM) is often caused by systolic anterior motion (SAM) of the mitral valve. During systole, the hypertrophied septum and altered mitral valve geometry cause the anterior leaflet to be drawn toward the outflow tract, resulting in dynamic left ventricular outflow tract (LVOT) obstruction. This abnormal motion leads to incomplete coaptation of the mitral leaflets and posteriorly directed MR. The severity of MR correlates with the degree of SAM and LVOT gradient, contributing to symptoms such as dyspnea and fatigue in affected patients.Hyperdynamic LV The left ventricular (LV) function often appears hyperdynamic due to the reduced end‐systolic volume and preserved or even enhanced contractility. Despite the presence of diastolic dysfunction and impaired filling, the thickened myocardium generates vigorous systolic contraction, leading to a reduced LV cavity and an ejection fraction that is typically normal or supranormal.Diastolic Diastolic dysfunction is a hallmark of hypertrophic cardiomyopathy (HCM) and plays a central role in the pathophysiology of the disease. The hypertrophied, stiff left ventricular (LV) myocardium impairs relaxation and reduces ventricular compliance, leading to elevated filling pressures and impaired ventricular filling during diastole.

Restrictive Cardiomyopathy (RCM)

Echocardiography is a fundamental diagnostic modality in the evaluation of restrictive cardiomyopathy (RCM), a rare but severe myocardial disorder characterized by impaired ventricular filling due to increased myocardial stiffness, with preserved or near‐normal systolic function, particularly in the early stages. The hallmark echocardiographic feature of RCM is biatrial enlargement resulting from chronically elevated filling pressures, often out of proportion to the degree of ventricular hypertrophy or dysfunction. The ventricular walls are typically non‐dilated and non‐hypertrophied, distinguishing RCM from hypertrophic and dilated cardiomyopathies, although wall thickening may occur in infiltrative forms such as amyloidosis. Doppler echocardiography plays a crucial role in identifying abnormal diastolic filling patterns, including a restrictive transmitral inflow pattern—marked by a tall E wave (Figure 7), diminished A wave, shortened deceleration time, and reduced E/A variability with respiration—indicative of elevated left ventricular end‐diastolic pressures. Tissue Doppler imaging (TDI) further refines diastolic assessment by showing reduced mitral annular e′ velocities and **elevated E/e′ ratios (**Figure 8), correlating with elevated left atrial pressure. Infiltrative etiologies like amyloidosis may exhibit characteristic findings such as increased myocardial echogenicity, thickened valves, and a “sparkling” or “granular” appearance of the myocardium. Strain imaging, especially global longitudinal strain (GLS), may reveal apical sparing, a finding highly suggestive of cardiac amyloidosis. Echocardiography is also essential in ruling out constrictive pericarditis, which can mimic RCM clinically and hemodynamically. Key differentiating features include ventricular interdependence, a septal bounce, annulus reversus (reversal of the normal pattern of early diastolic (e′) tissue Doppler velocities between the lateral and medial (septal) mitral annulus), and respiratory variation in mitral inflow velocities in constrictive pericarditis, all of which are typically absent in RCM (Table 6). In advanced cases of RCM, right ventricular involvement may occur, often demonstrated by reduced tricuspid annular plane systolic excursion (TAPSE) and elevated right atrial pressures. Echocardiography, supplemented by contrast studies or transesophageal echocardiography, when necessary, is indispensable for serial monitoring of disease progression and for assessing the response to treatment, particularly in patients being evaluated for advanced therapies such as heart transplantation [19, 20, 21, 22, 23].

Defined by impaired diastolic filling and preserved or mildly reduced systolic function.

**Echocardiographic Findings (**Table 7): Biatrial enlargementNormal wall thicknessHigh E/A ratio (>2), short deceleration time (<160 ms)Reduced e′ velocity, elevated E/e′ (>15)Dilated IVC with reduced respiratory variation (Figure 9)

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC)

Echocardiography is an essential imaging modality in the initial evaluation and longitudinal monitoring of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), a genetically mediated myocardial disease characterized by fibrofatty replacement of the right ventricular (RV) myocardium, leading to ventricular arrhythmias and an increased risk of sudden cardiac death, especially in young individuals and athletes. Although echocardiography may lack sensitivity in detecting early or localized disease compared to cardiac MRI, it remains a widely accessible and non‐invasive tool that contributes critical diagnostic and prognostic information. Classic echocardiographic features of ARVC include RV dilation, reduced RV systolic function, regional wall motion abnormalities (such as hypokinesia, akinesia, or dyskinesia), and focal aneurysms, particularly of the **RV outflow tract (RVOT), apex, and inferior wall (**Figure 10). M‐mode and 2D imaging can reveal RV wall thinning and aneurysmal bulging, while Doppler echocardiography may assess tricuspid regurgitation and estimate pulmonary pressures. RV fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), and tissue Doppler imaging (TDI) of the tricuspid annulus are often employed to quantify RV systolic function, though their sensitivity may be limited in early disease stages. The 2010 Task Force Criteria for the diagnosis of ARVC include specific echocardiographic parameters, such as RV end‐diastolic diameter and regional motion abnormalities, which must be interpreted in the context of other clinical, electrocardiographic, and genetic findings. In addition to evaluating the RV, echocardiography may detect left ventricular (LV) involvement, which is now recognized in advanced disease and in certain genetic variants (e.g., desmoplakin mutations), manifesting as subepicardial or midmyocardial fibrosis, wall motion abnormalities, or LV systolic dysfunction. Contrast echocardiography can enhance visualization of endocardial borders in technically difficult cases, while three‐dimensional echocardiography may improve assessment of RV volume and function. Though cardiac MRI remains the gold standard for tissue characterization and detailed RV evaluation, echocardiography continues to be indispensable in screening at‐risk relatives, guiding follow‐up, and monitoring for progressive structural changes in established ARVC [24, 25, 26, 27, 28, 29].

Characterized by Fibrofatty RV Replacement and Arrhythmias.

**Key Features (**Table 8): RV dilation, wall motion abnormalitiesRV aneurysm, FAC <33%, TAPSE <17 mmRVOT dilation (>32 mm PLAX, >36 mm PSAX)Trabecular pattern changes, hyperechogenicity

LV Involvement: Seen in advanced stages; includes wall motion abnormalities and strain reduction.

Left Ventricular Non‐Compaction (LVNC)

Echocardiography is a primary imaging modality for the diagnosis and assessment of left ventricular non‐compaction cardiomyopathy (LVNC), a rare myocardial disorder characterized by prominent trabeculations and deep intertrabecular recesses resulting from an arrest in normal embryonic endomyocardial compaction. The condition most commonly affects the apical and mid‐ventricular segments of the left ventricle, although biventricular or isolated right ventricular involvement can also occur. On two‐dimensional transthoracic echocardiography, key diagnostic features include a two‐layered myocardial structure with a thin, compacted epicardial layer and a markedly thicker non‐compacted endocardial layer. The Jenni criteria, widely used in echocardiographic diagnosis, define LVNC based on a non‐compacted to compacted (NC/C) myocardial ratio greater than **2:1 during systole (**Figure 11), most notably in the parasternal short‐axis or apical views. Color Doppler imaging further supports the diagnosis by demonstrating blood flow within the deep intertrabecular recesses, confirming their communication with the ventricular cavity. Three‐dimensional echocardiography and contrast‐enhanced studies can enhance the delineation of the trabecular architecture and improve diagnostic accuracy, particularly in technically challenging cases. Functional assessment typically reveals left ventricular systolic dysfunction, although diastolic dysfunction and regional wall motion abnormalities may also be present. Importantly, the degree of non‐compaction does not always correlate with functional impairment, and some individuals may remain asymptomatic. Tissue Doppler imaging and speckle‐tracking echocardiography may reveal subclinical myocardial dysfunction, even when the global ejection fraction is preserved. LVNC is often associated with arrhythmias, thromboembolic events, and progressive heart failure, making risk stratification crucial; echocardiography aids in the identification of intracavitary thrombi and provides a basis for therapy decisions, including anticoagulation, implantable cardioverter‐defibrillators, or advanced heart failure therapies. While cardiac magnetic resonance imaging (CMR) offers superior tissue characterization and more sensitive quantification of trabeculation, echocardiography remains a vital, first‐line, and widely available tool in the diagnosis and longitudinal monitoring of LVNC, particularly in resource‐limited settings or as a screening modality for affected family members [30, 31, 32, 33, 34, 35].

Defined by Prominent Trabeculations and Intertrabecular Recesses

**Diagnostic Criteria (**Table 9): NC/C ratio >2:1 in end‐systoleApical/mid‐ventricular involvementColor Doppler showing flow in recessesPossible systolic dysfunction

Major LVNC diagnostic criteria used in practice are summarized in Table 10.

Prognostic and Therapeutic Implications

Understanding the prognostic indicators and therapeutic implications of various cardiomyopathies is essential for risk stratification, clinical decision‐making, and individualized patient management. Echocardiography not only aids in diagnosis but also plays a pivotal role in monitoring disease progression and guiding treatment strategies. Table 11 below summarizes key echocardiographic parameters associated with adverse outcomes in each cardiomyopathy subtype and outlines their relevance to current therapeutic approaches.

Limitations of Echocardiography in Cardiomyopathy Diagnosis

Despite its widespread use and diagnostic utility, echocardiography has several inherent limitations in the evaluation of cardiomyopathies. Image acquisition and interpretation are highly operator‐dependent, and the diagnostic accuracy can be significantly affected by patient body habitus, acoustic window quality, and sonographer experience. In early or segmental disease—such as arrhythmogenic right ventricular cardiomyopathy (ARVC) or infiltrative forms like cardiac amyloidosis—structural changes may be subtle or focal and therefore difficult to detect with conventional echocardiography. Additionally, echocardiography lacks the ability to directly characterize myocardial tissue, limiting its sensitivity in differentiating between fibrotic, fatty, or infiltrative pathologies. These constraints underscore the importance of multimodal imaging approaches and highlight the complementary role of cardiac magnetic resonance imaging (CMR) or computed tomography (CT) in select cases, particularly when echocardiographic findings are inconclusive or discordant with clinical suspicion.

Conclusion

Echocardiography remains an essential and first‐line imaging modality in the comprehensive evaluation and management of cardiomyopathies. Table 12 summarizes the key echocardiographic features that distinguish the five major cardiomyopathy subtypes, including chamber morphology, functional impairments, valve abnormalities, and advanced diagnostic criteria such as strain analysis and Doppler patterns. A systematic approach that integrates quantitative chamber measurements, functional assessment, and age‐ or size‐specific normative data—particularly in both adult and pediatric populations—significantly enhances diagnostic accuracy and supports informed clinical decision‐making. Advanced echocardiographic techniques, including tissue Doppler imaging, speckle‐tracking strain analysis, and contrast‐enhanced imaging, further improve sensitivity for detecting early or subtle myocardial dysfunction and allow for a more nuanced understanding of cardiac mechanics.

However, in cases where echocardiographic findings are limited by poor acoustic windows or lack specificity—such as in infiltrative, arrhythmogenic, or apical pathologies—additional modalities such as cardiac magnetic resonance (CMR) and cardiac computed tomography (CT) play a complementary role. These techniques offer superior tissue characterization, scar detection, and detailed anatomical visualization. As imaging technology continues to evolve, a multimodal approach incorporating echocardiography, CMR, and CT will remain central to the personalized, evidence‐based care of patients with cardiomyopathy.