Cardiovascular diseases (CVD) are associated with high healthcare costs, as well as are a leading cause of mortality and hospitalizations. The main challenge for today's researchers is to develop new technologies, which may help to improve diagnosis of CVD, thereby reducing healthcare costs and quality of patients' lives. Non-invasive wearable electronics offer new capabilities for the diagnosis and management of patients with CVD. Several reports with wearable electronics have been published, in which achieved very positive results with high accuracy. Aim of our study is to show utility of biomedical shirt-based ECG monitoring of patients with CVD in different clinical situations using Nuubo® ECG (nECG) system.

The study is an investigator-initiated, multicentre, prospective observational trial. The study will be carried out in 2 tertiary university hospitals on cardiology wards (adult and pediatric). The study will consist of four independent groups of patients whose ECG will be monitored using the biomedical shirt. The study groups will be as follows: patients after pulmonary veins isolation (PVI), cardiac resynchronization therapy (CRT) recipients, patients during cardiac rehabilitation after myocardial infarction, and pediatric patients with supraventricular tachycardia (SVT) before electrophysiology study (EPS). Approval for all study groups was obtained from institutional review board.

ECG platform The system consists of biomedical shirt, electronic device and ECG software. The biomedical shirt captures the electrocardiographic signal via the textile electrodes integrated into the garment. The biomedical shirt enable non-invasive reception of a medical-quality ECG signal through adherence of textile electrodes to the skin. The biomedical shirt-ECG monitoring is based on BlendFix® sensor electrode technology that is capable of being used in real-time and for continuous recording. To the shirt is attached the electronic device that transmits the ECG signal (as well as other signals including accelerometer and GPS) via bluetooth to a computer and stores the information in memory cards. The software allows the visualisation and analysis of data such as ECG, heart rate, activity index and relative position of the body captured by the electronic device. The platform is a medical device certified in the European Union that has been tested in patients who underwent an exercise echocardiography test.

Patients after PVI

Inclusion Criteria:

• PVI in a patient with paroxysmal AF
• 18 - 70 years old
• Signed written informed consent Exclusion criteria
• BMI ≥35 kg/m2
• Chronic inflammatory disease, severe chronic kidney disease,
• Active cancer, and a period of 5 years from the end of treatment
• Use of antiarrhythmic agents after PVI
• Persistent AF
• Previous PVI
• The size of the chest that prevents wearing biomedical shirt
• Contraindications to wear biomedical shirt (structural disease of the chest, skin diseases, allergy for materials used in ECG shirts)

CRT recipients

Inclusion criteria:

• > 18 years old
• Meeting the current European Society of Cardiology Guidelines indications for CRT implantation (including upgrades)
• Signed written informed consent Exclusion criteria
• Chest size which make impossible to wear nECG shirt
• Contraindications to wear biomedical shirt (structural disease of the chest, skin diseases, allergy for materials used in ECG shirts)

Patients during cardiac rehabilitation after myocardial infarction

Inclusion criteria:

• Patients within 3 months after myocardial infarction, after completed early post-infarction ambulatory cardiac rehabilitation
• Signed written informed consent
• 18 - 80 years old

Exclusion criteria:

• Dysfunction of the lower limbs or other walking impairments,
• Age below 18 or over 80 years old.
• Unstable angina pectoris.
• Life-threatening arrhythmias.
• Decompensated congestive heart failure.
• Left ventricular ejection fraction <35%.
• Dissecting aneurysm of the aorta.
• Acute myocardial infarction.
• Vein thrombophlebitis.
• Pulmonary or peripheral embolism.
• Uncontrolled hypertension.
• Active inflammation.
• Other contraindication to physical activity.
• The state after the pacemaker or implantable cardioverter-defibrillator implantation (contraindication to bioelectrical impedance measurement).
• Persistent AF
• Previous PVI

Pediatric patients with SVT

Inclusion criteria:

• 5-18 years old
• Patients with diagnosed SVT qualified to EPS
• Signed written informed consent

Exclusion criteria:

• BMI ≥35 kg/m2
• Chronic inflammatory disease, severe chronic kidney disease,
• Active cancer, and a period of 5 years from the end of treatment
• The size of the chest that prevents wearing biomedical shirt
• Contraindications to wear biomedical shirt (structural disease of the chest, skin diseases, allergy for materials used in ECG shirts)

The study will be consisted of four independent patient groups: 30 patients with paroxysmal AF treated with PVI; 30 patients scheduled for CRT implantation; 120 patients after early post-infarction ambulatory cardiac rehabilitation; 40 patients, between 5 to 18 years old, with diagnosed SVT and who are qualified for electrophysiological study (EPS).

Data will be available for meta-analysis