If you wish to use this database in your research, you must cite these articles:
Diabetes mellitus is an illness characterized by the accumulation of glucose in the blood, nowadays it affects around 135 million people in the world. Diabetes is also one of the main causes of death worldwide.
According to numerous studies the number of diabetic people will rise 40% in developped countries and 170% in developping countries. These increments are due to the fact that there is no cure for diabetes, nevertheless it can be controled since the apperance of insuline in 1921.
Many research projects show the importance of some physiological parameters, signs and symptoms in the diagnostic of diabetes mellitus. Electrocardiographic changes have been reported in diabetic subjects, these changes could turn out to be indicators in the diagnostic of this illness.
It has been proved that diabetic complications start happening sooner in life than it was beleived, therefore the early diagnosticit is of vital importance if we want to treat and prevent serious complications. It is important to note that these complications can result in a serious cost to the patient and to the public healthcare system.
One of the most frequent, and at the same time more dangerous, alterations produced by diabetes is the cardiac autonomic neuropathy (CAN), which is a result of the deterioration of the autonomic nervous system's fibres which innervate the heart and the blood vessels' receptors. The direct consequence of the CAN is a disorder in the cardiac frequency control and in the vascular dynamic.
Certain works have revealed that patients suffering of CAN don't have a heart's physiological response to certain physical stress stimuli such as exercise. It has been proved that CAN may be diagnosed in the early stages of diabetes because there is a relation between the CAN and the cardiac frequency variability.
Even though the relation between CAN and the cardiovascular mortality is well known, we still don't fully understand this illness. It is therefore of great importance to dispose of a database of diabetic patients which present CAN, in order to study the different complications of this sickness.
It is so that the Biologic and Medical Computation Group (GCMB) and the Applied Biophysics and Bioengineering Group (GBBA) of the Simon Bolivar University (USB) along with collaborators from the Caracas University Hospital (HUC) formed , in 2007, the Group for Diabetic Cardiac Neuropathy Diagnostic and Modeling (DICARDIA). The objective of this group is to develop methods that help increment the diagnostic value of clinical tests in CAN. This project was divided in 3 stages. The first one was the design of a clinical protocol to collect and develop a database, the second stage is the extraction and processing of the collected data, the third stage is the presentation of the results. The database here presented is the result of the accomplishment first stage of this project.
The data source for this project were rutinary procedures that took place in the HUC. The main idea was to stablish a method to value the autonomous nervous system, the cardiovascular system and the glucose regulation system in the diabetic patient and hence contribute with the solution of a public health problem.
The collected data was introduced in a database called ecgML, which helps visualizing the demographic, clinical an signal characteristics with notes for each patient.
The clinical protocol was designed and applied in the cardiology service of the HUC, the study was composed by 65 subjects divided in three groups:
This is a method to describe a document by inserting tags in it specificaly designed for ECG data collection and analisis. The specifications are coded in XML language.
The ecgML structure allows to represent the data from the ECG following a hierarchical structure, taking into account the events, patient's data, diagnostic and other clinical data.
There are two main components for each file: i) The demographic data, containing information such as age, gender, etc; ii) the ECG registries with notations.
All the XML files downloaded from this database may be opened by using ecgML and following these simple instructions:
This MATLAB function reads an ECG record from the DICARDIA database: