Cardiol Res

Cardiology Research, ISSN 1923-2829 print, 1923-2837 online, Open Access

Article copyright, the authors; Journal compilation copyright, Cardiol Res and Elmer Press Inc

Journal website https://www.cardiologyres.org

Review

Volume 15, Number 5, October 2024, pages 319-329

Diverse Concepts in Definitions of Dilated Cardiomyopathy: Theory and Practice

**Table 1.** Classification Schemes of Cardiomyopathies From AHA and ESC
ESC	AHA
AHA: American Heart Association; DCM: dilated cardiomyopathy; ESC: European Society of Cardiology.
Cardiomyopathies	Primary cardiomyopathies
Hypertrophic cardiomyopathy, DCM, arrhythmogenic right ventricular cardiomyopathy, restrictive cardiomyopathy, unclassified	Genetic	Mixed	Acquired
Familial/genetic	Non-familial/non-genetic	Hypertrophic cardiomyopathy	DCM	Inflammatory (myocarditis)
Disease subtype	Disease subtype	Arrhythmogenic right ventricular cardiomyopathy/dysplasia	Restrictive	Stress-provoked (“tako-tsubo”)
Unidentified gene defect	Idiopathic	Glycogen storage	-	Peripartum
		Conduction defects	-	Tachycardia induced
		Mitochondrial myopathies	-	Infants of insulin-dependent mothers
		Ion channel disorders	-

Table 1. Classification Schemes of Cardiomyopathies From AHA and ESC

ESC

AHA

AHA: American Heart Association; DCM: dilated cardiomyopathy; ESC: European Society of Cardiology.

Cardiomyopathies

Primary cardiomyopathies

Hypertrophic cardiomyopathy, DCM, arrhythmogenic right ventricular cardiomyopathy, restrictive cardiomyopathy, unclassified

Genetic

Mixed

Acquired

Familial/genetic

Non-familial/non-genetic

Hypertrophic cardiomyopathy

DCM

Inflammatory (myocarditis)

Disease subtype

Arrhythmogenic right ventricular cardiomyopathy/dysplasia

Restrictive

Stress-provoked (“tako-tsubo”)

Unidentified gene defect

Idiopathic

Glycogen storage

Peripartum

Conduction defects

Tachycardia induced

Mitochondrial myopathies

Infants of insulin-dependent mothers

Ion channel disorders

**Table 2.** Example Definitions of DCM in Clinical Studies
Reference	Definition of dilated cardiomyopathy
DCM: dilated cardiomyopathy; HT: hypertension; LV: left ventricular; LVEF: left ventricular ejection fraction; NICM: non-ischemic cardiomyopathy.
Calderon-Dominguez et al (2021) [34]	“… the presence of left ventricular dilatation and systolic dysfunction in the absence of abnormal loading conditions or coronary artery disease sufficient to cause global systolic impairment.”
Costa et al (2021) [36]	“DCM was defined as either LVEF levels below 50% and/or left ventricular end-diastolic diameter larger than 56 mm.”
Diez-Lopez et al (2022) [37]	“… left ventricular (LV) chamber enlargement and systolic dysfunction in the absence of coronary artery disease.”
Haas et al (2022) [42]	“Idiopathic DCM is defined as the presence of both left ventricular (LV) enlargement and systolic dysfunction but without evidence of ischemic or known causes. Specifically, diagnostic criteria for idiopathic DCM include the presence of (1) LVEF < 50% and (2) left ventricular enlargement defined by echo-derived left ventricular end-diastolic dimension (≥ 95th percentile for gender/height).”
Hamshere et al (2015) [45]	“… diagnosis of non-ischemic DCM with no secondary cause found, an LVEF of, 45% (assessed by echocardiography at referral), symptoms classed as New York Heart Association (NYHA) 2 or greater and on optimal medical treatment (established for at least 6 months).”
Kimura et al (2021) [46]	“DCM was defined by the presence of left ventricular dilation [left ventricular end-diastolic dimension (LVEDD) > 55 mm, or indexed LVEDD > 33 mm/m² (men) or 32 mm/m² (women)] and LVEF < 50%, in the absence of severe systemic arterial HT, coronary artery disease, primary valvular heart disease, or secondary cardiac muscle disease caused by any known systemic condition, as determined by endomyocardial biopsy.”
Merlo et al (2022) [49]	“NICM was defined as presence of LVEF < 50% in the absence of significant coronary artery disease, primary valve disease, congenital heart disease, tachy-induced cardiomyopathy or acute myocarditis.”

Table 2. Example Definitions of DCM in Clinical Studies

Reference

Definition of dilated cardiomyopathy

DCM: dilated cardiomyopathy; HT: hypertension; LV: left ventricular; LVEF: left ventricular ejection fraction; NICM: non-ischemic cardiomyopathy.

Calderon-Dominguez et al (2021) [34]

“… the presence of left ventricular dilatation and systolic dysfunction in the absence of abnormal loading conditions or coronary artery disease sufficient to cause global systolic impairment.”

Costa et al (2021) [36]

“DCM was defined as either LVEF levels below 50% and/or left ventricular end-diastolic diameter larger than 56 mm.”

Diez-Lopez et al (2022) [37]

“… left ventricular (LV) chamber enlargement and systolic dysfunction in the absence of coronary artery disease.”

Haas et al (2022) [42]

“Idiopathic DCM is defined as the presence of both left ventricular (LV) enlargement and systolic dysfunction but without evidence of ischemic or known causes. Specifically, diagnostic criteria for idiopathic DCM include the presence of (1) LVEF < 50% and (2) left ventricular enlargement defined by echo-derived left ventricular end-diastolic dimension (≥ 95th percentile for gender/height).”

Hamshere et al (2015) [45]

“… diagnosis of non-ischemic DCM with no secondary cause found, an LVEF of, 45% (assessed by echocardiography at referral), symptoms classed as New York Heart Association (NYHA) 2 or greater and on optimal medical treatment (established for at least 6 months).”

Kimura et al (2021) [46]

“DCM was defined by the presence of left ventricular dilation [left ventricular end-diastolic dimension (LVEDD) > 55 mm, or indexed LVEDD > 33 mm/m² (men) or 32 mm/m² (women)] and LVEF < 50%, in the absence of severe systemic arterial HT, coronary artery disease, primary valvular heart disease, or secondary cardiac muscle disease caused by any known systemic condition, as determined by endomyocardial biopsy.”

Merlo et al (2022) [49]

“NICM was defined as presence of LVEF < 50% in the absence of significant coronary artery disease, primary valve disease, congenital heart disease, tachy-induced cardiomyopathy or acute myocarditis.”