All patients in this study will be subjected to the following (as detailed in the attached patient's data sheet).

1. Clinical History: focusing on:

   • Socio-demographic factors, especially age, gender, family history, and degree of consanguinity.
   • Cardiac symptoms, such as feeding difficulties in the infant, exercise intolerance in older children, fatigue, dyspnea on exertion, heart failure symptoms.

2. Thorough clinical examination: focusing on:

   • General condition.
   • Anthropometric measures (weight, height, and body mass index).
   • Vital signs (Including HR, BP, SO2, RR, Body temperature).
   • Cardiac examination (including any associated murmur, signs up heart failure).

3. Severity of heart failure in children with dilated cardiomyopathy For all patients, they were classified according to Children's Ross HF classification.

   Children's Ross HF classification is as follows[17]:

   Class I: asymptomatic cases.

   Class II: mild tachypnea or diaphoresis with feeding in infants, dyspnea on exertion in older children.

   Class III: marked tachypnea or diaphoresis with feeding in infants, marked dyspnea on exertion, and prolonged feeding times with growth failure.

   Class IV: tachypnea, retractions, grunting, or diaphoresis at rest are examples of symptoms.

4. Data collection: according to attached checklist for every patient involved in the study

Dilated cardiomyopathy is defined as "dilatation and impaired contraction of the left or both ventricles with normal wall thickness" . It is characterized by systolic dysfunction with reduced myocardial contractility . DCM is the third leading cause of heart failure in pediatrics 3. The exact etiology of DCM is unknown in more than half of the cases and the term idiopathic DCM is used after exclusion of all the well-known etiologies of DCM as viral infections, autoimmune, genetic, endocrinal, and metabolic diseases .

DCM is typically diagnosed when patients present with heart failure symptoms, typically related to left ventricle systolic dysfunction, but right systolic dysfunction may accompany left ventricle failure . About 8-15% of patients will present with cardiac arrest, or with near-arrest requiring emergent resuscitation. In the remainder of patients, the most common symptom is shortness of breath (50%), followed by gastrointestinal upset and fatigue that is reported in a third of patients. Symptoms of an upper respiratory tract infection are also common. Echocardiography is the gold standard for diagnosis of DCM .

Methods:

All patients in this study will be subjected to the following (as detailed in the attached patient's data sheet).

1. Clinical History: focusing on:

   • Socio-demographic factors, especially age, gender, family history, and degree of consanguinity.
   • Cardiac symptoms, such as feeding difficulties in the infant, exercise intolerance in older children, fatigue, dyspnea on exertion, heart failure symptoms.

2. Thorough clinical examination: focusing on:

   • General condition.
   • Anthropometric measures (weight, height, and body mass index).
   • Vital signs (Including HR, BP, SO2, RR, Body temperature).
   • Cardiac examination (including any associated murmur, signs up heart failure).

3. Severity of heart failure in children with dilated cardiomyopathy For all patients, they were classified according to Children's Ross HF classification.

   Children's Ross HF classification is as follows[17]:

   Class I: asymptomatic cases.

   Class II: mild tachypnea or diaphoresis with feeding in infants, dyspnea on exertion in older children.

   Class III: marked tachypnea or diaphoresis with feeding in infants, marked dyspnea on exertion, and prolonged feeding times with growth failure.

   Class IV: tachypnea, retractions, grunting, or diaphoresis at rest are examples of symptoms.

4. Data collection: according to attached checklist for every patient involved in the study

5. Investigations: focusing on

   • Laboratory investigations (IGF-1, free T3 and T4, TSH, morning serum cortisol and ACTH, 25 OH vit D, total and ionized calcium, serum parathyroid hormones levels, serum prolactin, serum electrolytes as Na, K). Samples to be withdrawn from cases and controls at 9:00 a.m. at the Pediatric Cardiology Unit, Sohag University Hospital.
   • Echocardiography assessment including:

   Ejection fraction

   Fractional shortening

   Left ventricular end systolic diameter

   Left ventricular end diastolic diameter

   Mitral valve closure to opening time

   Left ventricular ejection time

   Mitral valve ejection

   Mitral valve area

   E/A ratio Mitral valve

   Myocardial performance index of Left ventricular

6. Possible Therapeutic Modalities given to patients in the study Medical treatment (e.g .Anti-failure medications: Diuretics, ACE inhibitors,..etc.)

Inclusion Criteria:

• children aged 1 to 12 years diagnosed with dilated cardiomyopathy by Echocardiography.

Control: Age and sex match children attending Pediatric cardiology clinic with acute non serious illness to be included as Control

Exclusion Criteria:

• Other types of cardiomyopathy (As hypertrophic, restrictive cardiomyopathy and other types).

Dilatation of Left ventricle due to other congenital or rheumatic heart diseases