Principles of heart rhythm analysis – diagnosis of arrhythmias
Effective treatment of cardiac arrhythmias and conduction disorders requires the accurate diagnosis of specific rhythm disturbances, an analysis of the clinical situation in which they occur, and the definition of a safe and effective goal of therapy. Recognition and subsequent correction of any hemodynamic, electrolyte, metabolic and respiratory disorders that aggravate the condition are extremely important for the treatment of arrhythmias.
Rhythm disorders may be primary or secondary. Primary disorders are the result of electrophysiological disorders caused by the pathological process; they are causally not associated with significant changes in the circulatory system.
In contrast, when the pathological process leads to hemodynamic disturbances, which in turn trigger or contribute to the occurrence of electrophysiological disorders, the arrhythmia is called secondary. Prevention or control of secondary arrhythmias is carried out using monotherapy with hemodynamically active agents or their combination with antiarrhythmic drugs.
A standard electrocardiographic study using 12 leads and analysis of longer fragments, taken specifically for rhythm assessment, are the most readily available means of diagnosing cardiac rhythm disorders. The study of the P wave, the morphology of the QRS complex and their relative position may be sufficient for accurate diagnosis of arrhythmia.
If a standard electrocardiogram (ECG) is not sufficiently informative, special lead systems (bipolar esophageal – for recording activity of the left atrium) or an intraatrial catheter with an electrode – for recording right atrial activity can be used to identify the P teeth and obtain additional information.
Constant monitoring of the cardiac rhythm in the inpatient or use of recording devices with simultaneous recording of indicators from two leads (usually II and MCL-1 in the midclavicular line in the outpatient) expands diagnostic capabilities. When rhythm disturbances occurring in this patient only occasionally, the use of recording devices is included, which are switched on as needed by him or by others. This will allow the device to start working during an attack of arrhythmia and will subsequently enable the doctor to process the data obtained.