Electrophysiological examination of the heart - Causes, Symptoms and Treatment .MF .
Indications Contraindications EFI
Preparing to study
Explanation of results and possible complications
among multiple cardiac arrhythmias and conduction are such diseases, which are sometimes very difficult to identify and define a strategy for their further treatment.These diseases are not always safe, as they can cause serious cardiac activity followed by circulatory disorders.Therefore, the diagnosis of arrhythmias is given special attention, and scientists are continually expanding the possibility of using additional methods of research in arrhythmology.Since 60 's, last century, the practice of cardiologists and aritmologov were gradually introduced methods of electrophysiological studies of the heart.
The general principle of these methods is to ensure that if the doctor can not "catch" a violation of rhythm during a single ECG or daily ECG monitoring, it is necessary to stimulate the heart in such a way as to provoke a particular type of arrhythmia with the ability to fix it in a
By electrophysiological methods of investigation of the heart (EPS) are non-invasive (transesophageal) and invasive test. Invasive divided into endocardial and epicardial study.
endocardial EFI carried out by introducing the electrode through the femoral vein to the ventricle or atrium, and epicardial stimulation performed open-heart during cardiac surgery with dissection of the anterior chest wall.Thus, in the study of endocardial heart is stimulated by the "inside", while epicardial - with the "outer" surface of the heart, and at Transesophageal - from the esophagus (the electrode is in close proximity to the left atrium).Invasive investigation can be self-diagnostic procedure or be stage surgical treatment of arrhythmias (ablation - the destruction of pathological pathways in heart muscle).
Transesophageal EPS is conducted more frequently than endocardial, as the latter method requires a more powerful technical equipment and expensive equipment, which entails a significant increase in costs.Additionally, when the risk of complications of non-invasive interventions are always lower than during the introduction into the organism of different probes.But studies invasive diagnostic capabilities wider as the part of the esophagus can only stimulate the left atrium (due to anatomical features), while the introduction of the electrode into the heart chambers and possible provocation of ventricular arrhythmias as well.
Indications for the electrophysiological study
transesophageal electrophysiological examination of the heart may be appointed for the following diseases:
- bradyarrhythmia caused by a dysfunction of the sinus node,
- paroxysmal supraventricular tachyarrhythmias,
- tachycardia syndrome - bradycardia caused by sinus syndrome (mainly atrial fibrillation),
- monitoring the effectiveness of antiarrhythmic drug therapy,
- identification of arrhythmogenic action (provoking arrhythmia occurrence) of medications,
- definition of indications to install a pacemaker with the ineffectiveness of drug therapy.
Invasive electrophysiological examination is appointed in cases where the patient has complex rhythm disturbances, or arrhythmias, accompanied by severe clinical symptoms and can cause death:
- bradyarrhythmias, accompanied by loss of consciousness (attacks MES - Morgagni-Edemsa-Stokes),
-supraventricular tachycardia (atrial fibrillation, ERW - syndrome (Wolff-Parkinson-White syndrome), tachycardia from atrial - ventricular connection - AV - connection),
- paroxysmal ventricular tachycardia of various forms (can lead to spontaneous development of ventricular fibrillation, which is equivalent to sudden cardiacdeath),
- AV block of various degrees,
- bundle branch block (especially bifastsikulyarnaya - the defeat of the two branches of the three, because it can lead to the rapid development trifastsikulyarnoy blockade, and this condition is life-threatening and can cause sudden cardiac death),
- determination of the indications for cardioversion (restoring sinus rhythm using cardioverter - apparatus capable of changing the heart rate by means of electrical impulses of a certain power), to the implantation of an artificial pacemaker or radiofrequency ablation of accessory pathways in the heart in the absence of the effect of drug therapy.
Contraindications for the electrophysiological study of the heart
such conditions relate to contraindications for invasive electrophysiology heart studies are:
- acute myocardial
infarction - acute coronary
syndrome - first revealed and progressive angina
- cardiac aneurysm or aortic
- heart disease,cardiomyopathy with severe blood circulation
- severe chronic heart failure
- acute heart failure
- embolism, ischemic or hemorrhagic stroke and other acute vascular events
contraindications for transesophageal study, in addition to the above, are lesions of the esophagus,such as diverticula, tumors, strictures (seam), acute and chronic phase in acute inflammation of the esophagus wall.
Preparing for EFI patient
patient may be directed to the study of the health center or from the profile of the hospital where he received treatment and diagnostic care physician cardiologist or cardiac surgeon arrhythmology.And Transesophageal and invasive study conducted strictly on an empty stomach.The day before the procedure should not abuse of coffee, cigarettes and alcohol, as well as the need to cancel all medicines that affect the heart and blood vessels, but only in consultation with your doctor.
Before sending the patient for the procedure, the attending physician must examine the patient thoroughly.The patient must be at the hands of the ECG results, daily (Holter) monitoring of ECG, Echo - CG (ultrasound of the heart), stress tests (treadmill or bicycle ergometer).Also, you may need to enter into an EEG (electroencephalogram), CT scan or MRI of the brain (on purpose neurologist to rule out neurological nature of syncope) and consulting other doctors (neurologist, endocrinologist, vascular surgeons and others).
How is the electrophysiological study of the heart?
transesophageal study conducted in the department of functional diagnostics.The patient comes in the morning in the office, he was invited to ChpEFI room and laid on the couch, where the measured blood pressure and a normal ECG is recorded.Next, the doctor who owns this technique, explains the procedure to the patient and begin to implement it.
through the nose or mouth (less often) is introduced into the esophagus probe, the tip of which is a tiny electrode that allows you to record electrogram.Also this sensor is carried out via the left atrium stimulation by transmitting short electrical pulses certain amperage (10 to 20 mA).After the successful introduction of the probe is attached to the unit in charge of the stimulation and analysis of the electrograms.
After stimulation produced record electrograms, which may cause the desired rhythm disorders.Next, the probe is removed, the doctor carried out an analysis of the data using a computer, and the result is handed to the patient or transferred to the department doctor.Induced tachyarrhythmia, in most cases, takes place independently or with the help of drugs.The general procedure is the duration of 30 to 60 minutes, causing the patient only a slight burning sensation behind the breastbone, which is not a pathology in the context of this methodology.
Invasive electrophysiological isssledovanie rentgenhirurgicheskih held in the department of diagnostic methods.
introduced into the cavity of the heart
performing procedures invasive EFI
patient transported on a gurney out of profile department to the office after sedation (intravenous anesthetic and sedative drug), is placed on the operating table, where measuredblood pressure and recorded a standard ECG.Next, the doctor performing research in the projection pierces the femoral skin (usually) or the subclavian vein (rarely) in order to make an injection of local anesthetic (eg, articaine) then performs puncture the vein itself.This is the only bad moment, able to cause a little discomfort in the patient, as the whole procedure is painless.
further through a puncture through a special wire (sheath) is injected into a vein thin, flexible catheter, under fluoroscopy to advance into the heart cavity.At the end of its range from three to five miniature electrodes that perform similar compared to ChpEFI function - electrograms recorded before and after electrical stimulation and itself.The data are processed by appropriate equipment, and displays the result.
procedure lasts more than an hour, and when it was decided to carry out radiofrequency ablation as the next phase of the operation, while lengthening procedure.After investigation, the catheters are removed, an area punctured vein compressive bandage is applied and the patient is delivered to the intensive care unit for a few hours or for a day under the supervision of doctors.After the specified time, he transferred to the department in which he was hospitalized before.
Decoding results EFI
Normally imprisoned electrophysiological study should be stated that all types of stimulation provoked arrhythmias have been identified.
In identifying violations of rhythm and conduction give a full description of each type of arrhythmia.Also parallel to the estimated ST segment of the electrogram (depression or rise) to obtain information about the presence of myocardial ischemia, tachycardia provoked.
The results must be carefully interpreted arrhythmology physician to determine the future tactics of the patient and correct treatment.
Complications during electrophysiological study
Complications during electrical stimulation are extremely rare, because during the years of studies in this area, achieved the most physiological stimulation protocols that do not lead to the development of life-threatening diseases.Still, the doctors conducting the study should be aware of the risk of critical care conditions, such as congestive heart failure, ventricular fibrillation, sudden cardiac death, and master the skills of first aid and cardio - pulmonary resuscitation.
therapists Sazykina OJ