Class iv Versus Class Iiib Laser Therapy on Median Sternotomy Healing After Coronary Artery Bybass Graft

Inclusion Criteria: * aged between 45 and 65 years * male gender; haemodynamic stability * body mass index (BMI) from 18.5 to 29.9 kg/m2 * Non-infected sternotomy site * Normal ejection fraction to ensure normal vascularity. Exclusion Criteria: * included previous thoracic surgery * emergency or urgent coronary artery bypass surgery * respiratory insufficiency after surgery, manifesting hypoxemia with partial oxygen pressure in arterial blood \< 60 mmHg; Ejection fraction \< 50% * Paramedian sternotomy which may cut wire causing sternal mobilization which is the start of deep wound infection * Bilateral mammary harvesting which decrease blood flow to sternum; low cardiac output syndrome with ST segment elevation in multiple electrocardiogram leads, cardiac arrhythmias or hypotension, according to the American College of Cardiology Foundation and American Heart Association * other medical conditions, such as diabetes, uncontrolled hypertension and obesity.