Posibleng Mga Sanhi para sa Normal na Electrocardiogram Esophagitis Malalang Coronary Syndrome Pulmonary Embolism Patent Ductus Arteriosus Mitral Valve Prolapse Ventricular Septal Defect Conduction Disorder sa Puso Pheochromocytoma noong Kabataan Kaliwang Atrial Hypertrophy