Definition

  Dilated cardiomyopathy (DCM) is a disease of the heart muscle with impaired systolic function

      (impaired contractility) which involves one or both ventricles.

  By definition, the coronary arteries are normal in DCM.

  DCM has NO diagnostic ECG finding.

  However, the ECG is frequently abnormal in DCM.




The ECG abnormalities that are frequently seen in patients with DCM are

  Left ventricular hypertrophy pattern: even if the wall thickness is not increased,

      the LVH pattern may be seen due to increased left ventricular mass of the dilated heart.

  Left bundle branch block (LBBB) (more frequent),

      intraventricular conduction disturbance (IVCD) (IVCD),

      right bundle branch block (RBBB) (less frequent).

  Left atrial abnormality, biatrial abnormality: due to increased ventricular end-diastolic pressure

      and the resultant atrial dilatation.

  Abnormal Q waves (
pseudoinfarction pattern): due to myocardial fibrosis.

 
Poor R wave progression in chest leads.

  Nonspecific ST segment depression.

 
Widespread T wave negativity

  Sinus tachycardia: due to increased sympathetic activity in heart failure.

  Supraventricular arrhythmias (atrial fibrillation, etc.)

  Ventricular arrhythmias

  First degree atrioventricular (AV) block





ECG 1. The ECG above belongs to a patient with normal coronay arteries and dilated cardiomyopathy (DCM), and shows

biatrial abnormality
and intraventricular conduction defect .

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ECG 2.
Biatrial abnormality , intraventricular conduction defect and VPC in another patient with DCM.

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ECG 3. Atrial fibrillation, left ventricular hypertrophy pattern, and nonspecific
ST segment depression and T wave negativity in
a patient with DCM (and normal coronary arteries).

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ECG 4. Left ventricular hypertrophy pattern, and nonspecific
ST segment depression and T wave negativity in another patient
with DCM (and normal coronary arteries).

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ECG 5. The ECG above belongs to a patient with dilated cardiomyopathy and normal coronary arteries.
Intraventricular conduction disturbance, left axis deviation and negative T waves in the anterolateral leads are seen.

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