MioAtlas
G5: Cardiomyopathies

Dilated cardiomyopathy

Intrinsic myocardial cardiomyopathy characterized by left ventricular (or biventricular) dilation and global systolic dysfunction with depressed ejection fraction (LVEF < 50%).

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Definition

Intrinsic myocardial cardiomyopathy characterized by left ventricular (or biventricular) dilation and global systolic dysfunction with depressed ejection fraction (LVEF < 50%), not secondary to obstructive coronary artery disease or abnormal pressure/volume loading conditions (such as primary valvular disease or severe hypertension) [C1] [G5-02] [G5-12].

Severity criteria

  • Mild (L): Left ventricular ejection fraction 45–49% (mild systolic dysfunction / early hypokinetic phenotype; end-diastolic diameter > 58 mm or indexed end-diastolic volume > 2 SD) [C1] [G5-02] [G5-12].
  • Moderate (M): Left ventricular ejection fraction 30–44% (moderate systolic dysfunction, overt ventricular dilation, and moderate elevation of pulmonary capillary wedge pressures) [C1] [G5-02] [G5-12].
  • Severe (G): Left ventricular ejection fraction < 30% (severe systolic dysfunction with extreme spherical remodeling, markedly depressed cardiac output, and severe PCWP elevation > 20 mmHg) [C1] [G5-02] [G5-12].

Findings by layer

Hemodynamics

  • LV ejection fraction (left ventricular ejection fraction): L 45–49%, M 30–44%, G < 30% [C1] [G5-02] [G5-12].
  • LV end-diastolic volume: Marked elevation (> 150–220 mL) with increased sphericity [G5-12].
  • Mean pulmonary capillary wedge pressure and right atrial pressure: Elevated in grades M and G (> 15–20 mmHg and > 10–12 mmHg respectively) [G5-02].
  • Pulse pressure: Narrow in severe stages due to reduced stroke volume [B4] [G5-02].

Rhythm

  • Normal sinus rhythm [C1] [G5-02].
  • Complete left bundle branch block and atrial fibrillation as cardinal rhythms or conduction disturbances due to myocardial fibrosis and dilation [E2] [C1] [G5-02].

ECG

  • Left bundle branch block (lbbb / wide QRS ≥ 120 ms with notched R wave in I, aVL, V5–V6) or non-specific intraventricular conduction delay [E2] [C1] [G5-02].
  • Diffuse ventricular repolarization abnormalities (non-specific flattening or T-wave inversion), possible limb lead low voltage, and poor precordial R-wave progression [E1] [E2] [G5-02].

Heart sounds and murmurs

  • Third heart sound (S3): Low-frequency early diastolic ventricular gallop auscultated with bell at apex in moderate and severe stages, caused by sudden deceleration of transmitral flow entering a dilated, poorly compliant ventricle with elevated residual volume [G1-12] [G5-02].
  • First heart sound (S1): Soft or muffled due to reduced ventricular systolic dP/dt and incomplete valve closure [G1-10] [G5-02].
  • Functional mitral regurgitation murmur: Soft to moderate apical holosystolic murmur (grade 1–3/6) originating from secondary mitral incompetence (annular dilation and apical tethering of leaflets due to papillary muscle displacement) [G1-14] [G5-02].

Arterial pulse

  • Low-amplitude pulse (pulsus parvus) and reduced pulse pressure [B4] [G5-02].
  • In severe forms with advanced myocardial dysfunction: Pulsus alternans (regular beat-to-beat alternation in peripheral pulse amplitude with regular rhythm) [B4] [G5-02].

Jugular venous pulse

  • Elevated jugular venous pressure with prominent 'v' wave and rapid 'y' descent when functional tricuspid regurgitation and secondary right ventricular failure develop [B3] [G5-02].

Maneuvers

  • Valsalva maneuver: Shows square wave hemodynamic response pattern (square wave response: continuous, sustained pressure elevation without normal drop during phase II of expiratory effort, due to baseline congestion and overfilling) [B1] [G5-02].

Simulator severity grades

Simulator severity grades: Mild, Moderate, Severe
Baseline rhythm: Normal Sinus Rhythm

Also known as: Idiopathic dilated cardiomyopathy · Dilated cardiomyopathy · Congestive cardiomyopathy · Non-ischemic dilated cardiomyopathy · DCM

Other pathologies in this group

Sources

  1. [B1] Bedside diagnosis of systolic murmurs . N Engl J Med (1988) . DOI: 10.1056/NEJM198806163182404 PubMed: 2897627
  2. [B3] The jugular venous pressure revisited . Cleve Clin J Med (2013) . DOI: 10.3949/ccjm.80a.13039 PubMed: 24085809
  3. [B4] The Carotid Pulse . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250154
  4. [C1] 2023 ESC Guidelines for the management of cardiomyopathies . Eur Heart J (2023) . DOI: 10.1093/eurheartj/ehad194 PubMed: 37622657
  5. [E1] AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part V: electrocardiogram changes associated with cardiac chamber hypertrophy: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: endorsed by the International Society for Computerized Electrocardiology . Circulation (2009) . DOI: 10.1161/CIRCULATIONAHA.108.191097 PubMed: 19228820
  6. [E2] AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part III: intraventricular conduction disturbances: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: endorsed by the International Society for Computerized Electrocardiology . Circulation (2009) . DOI: 10.1161/CIRCULATIONAHA.108.191095 PubMed: 19228822
  7. [G1-10] The First Heart Sound . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250175
  8. [G1-12] The Third Heart Sound . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250184
  9. [G1-14] Systolic Murmurs . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250186
  10. [G5-02] 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure . Eur Heart J (2021) . DOI: 10.1093/eurheartj/ehab368 PubMed: 34447992
  11. [G5-12] Proposal for a revised definition of dilated cardiomyopathy, hypokinetic non-dilated cardiomyopathy, and its implications for clinical practice: a position statement of the ESC working group on myocardial and pericardial diseases . Eur Heart J (2016) . DOI: 10.1093/eurheartj/ehv727 PubMed: 26792875