Heart rate variability

Over the last few decades, considerable evolutions were made in the diagnosis of cardiovascular diseases. Interpretive electrocardiography is one of the areas where the progress has been significant. This involves digital recording of cardiac signals at the body surface and subsequent computerized analysis. An important outcome of such analysis is heart rate variability (HRV), which is widely accepted to have prognostic significance in patients with cardiovascular diseases especially after acute myocardial infarction. This is because HRV represents one of the most helpful markers of autonomic balance and hence can predict the tendency to develop fatal arrhythmias. Recently, interest has grown in relating some diseases to abnormal autonomic nervous system (ANS) activity based on HRV studies, for example: hypertension, bronchial asthma, diabetes mellitus, irritable bowel syndrome, anxiety and so many other diseases. This actually reflects the vital role of the autonomic nervous system in maintaining health. Unfortunately, HRV is of little practice, if ever, by Sudanese doctors. Therefore, this review is intended to update the physiological basis, determinants, common ways of measurements and some important clinical uses of HRV.