1. Cardiothoracic Department, Institut Jantung Negara, Kuala Lumpur, Malaysia
2. Internal Medicine/Respiratory and Sleep Study Department, UiTM Fakulti Perubatan, Sungai Buloh, Malaysia
3. Faculty of Medicine, UiTM Fakulti Perubatan, Sungai Buloh, Malaysia
4. Cardiovascular and Thoracic Surgery Department, UiTM Fakulti Perubatan, Sungai Buloh, Malaysia