Ventricular Tachycardia (Vtach) and Ventricular Fibrillation (Vfib) are both medical conditions, especially the ones associated with irregular electrical impulses of the heart and the abnormal rhythm of the heartbeats. People with certain heart diseases like valvular heart disease usually experience ventricular tachycardia, which usually causes a heart attack that involves a heightened heart rate in a ventricle of the heart.
On the other hand, ventricular fibrillation is a condition of the heart usually associated with an abnormal rhythm of the heartbeats. This condition causes the heart not to pump blood as it should, thereby leading to cardiac arrest. Ventricular tachycardia is caused by a lot of medical conditions such as Congestive heart failure, Ischemic heart condition, structural heart disorder, etc.
On the other hand, ventricular fibrillation is caused by some medical conditions such as Aortic stenosis, Cardiomyopathies, heart failure, electrical shock, Coronary artery disorder, etc. Ventricular tachycardia can be diagnosed by using Electrocardiogram, Transoesophageal echocardiography, while ventricular fibrillation can be diagnosed by using Chest X-ray, Echocardiogram, Electrocardiogram (ECG), etc.