TEXT
Introduction: The ventricular fibrillation ECG is characterized by the presence of irregular QRS complexes, with variable morphology, amplitude and frequency. Therefore, it is quite difficult to interpret. However, numerous researchers have tried to recognize discrete elements. Provided that VF primarily consists of a few large wave fronts on the endocardium of humans, the interpretation of ECG of VF should be less difficult. Based on experimental studies and published cases of ablation of VF triggers1-10, we are aware of essential structures that participate in the fibrillation process. The activation of each can be seen in the electrocardiogram. It is evident that their simultaneous activation will lead to complicated electrocardiographic complexes, which is why there is talk of a disorganized signal in the VF.
Aims: Analyze the electrocardiographic characteristic of induced sustained and non-sustained VF in laboratory, and establish a method to manage ECG of VF.
Methods: The twelve lead ECG of induced VF has been analyzed . VF was induced through programmed electrical stimulation (PES) in 8 patients with coronary artery disease ( 4 anterior and 3 myocardial infarction) and 7 with Brugada Syndrome ; 14 males, aged 53 ±15 years. A programmed electric stimulation consisted of 3 drive cycle lengths (500, 430, and 330 ms) with 1 to 3 ventricular extrastimuli (≥200 ms) from 2 right ventricle sites and burst pacing (cycle length ≥200 ms). Indications for the electrophysiological study were ventricular arrhythmias , unexplained syncope or risk evaluation of sudden death in patients with ischemic cardiomyopathy and Brugada Syndrome. All patients provided written informed consent. For analysis. the ECG has been divided into triggers (first premature complex PVC 1 and the second PVC 2) and two tachysistolic and sinusoidal phases, based on Wiggers’ stages11. The tachysistolic phase comprises the trace after 1-2 first complex. The sinusoidal phase would correspond to the trace from which there are no defined QRS complexes and only sinusoidal waves can be distinguished.