Electrocardiogram and cardiac electrophysiology characteristics of the premature ventricular contractions originating from right ventricular outflow tract

Abstract

Premature ventricular contractions (PVCs) are a common type of irregular heartbeat (arrhythmia). PVCs often cause of symptoms that reduced quality of life such as: palpitation, pounding or jumping, chest pain, fatigue, blank beats or missed beats… Besides that, PVCs can produce ventricular tachycardia, which can lead to life-threatening hemodynamic instability.[1]
 Research objectives: Evalute the electrocardiogram and electrophysiology charaterics of the PVCs from right ventricular outflow tract. 
 Objects and research methods: Cross-sectional descriptive study of 145 patients.
 Research results: all patients had R waveform in: D2, D3, aVF and S wave dominant in: aVR, aVL; Transitional lead from V3-V5, in which transition in V4 accounts for the highest rate of 60.7%. The average QRS time is 136.3 ± 14.4 ms, almost all PVCs have time index of R < 0.5 and amplitude index of R < 0.3… There are 48.3% of patients with only negative component in lead D1; 40% of PVCs have notching at D2, D3, aVF. About cardiac electrophysiolpgy charateristics, for the origin of PVCs, he majority of PVCs in our study originated from the anterior wall of the right ventricular outflow tract with 64.8%; by superior-inferior position, mainly inferior region with 66.9%; according to septum - lateral position, mainly septal region with 72.4%. Most patients had PVCs originated from the inferior-anterior-septal region of the right ventricular outflow tract with 36.6%.