Clinical and Electrophysiological Predictors of Ventriculoatrial Conduction in Patients under Evaluation for Ventricular Tachyarrhythmia

BACKGROUND: Ventriculoatrial (VA) conduction has an important role in the initiation and maintenance of some arrhythmias. The aim of this study was to evaluate whether clinical and electrophysiological parameters of atrioventricular (AV) conduction can predict VA conduction. METHODS: Detailed demographic, electrocardiographic, and echocardiographic data were recorded in 54 consecutive patients undergoing electrophysiological study for the evaluation of ventricular tachyarrhythmia. The basic parameters including atrial-His (AH) and His-ventricular (HV) intervals, atrioventricular Wenckebach point (AVWP), ventriculoatrial Wenckebach point (VAWP), anterograde effective refractory period of atrioventricular node(AERP-AVN), retrograde effective refractory period of atrioventricular node (RERP-AVN) and effective refractory period of ventricle (VERP) were measured based on standard protocol. RESULTS: Mean age of the patients was 59.4 (± 13.9) years. Forty-three (79.6%) patients were male and 39 (72.2%) had a history of ischemic heart disease. Ventriculoatrial (VA) conduction was recorded in 21 (38.9%) patients; it was slightly more prevalent in the men (44.2% vs. 18.2%; p value = 0.114). In the patients without VA conduction, the means of AVWP, AERP-AVN, and PR intervals were significantly more prolonged (p value = 0.007, 0.030, and 0.045, respectively), and a trend toward more prolonged AH, HV, and QRS interval was seen in them (p value = 0.078, 0.124, and 0.159, respectively). AVWP was the best predictor for the absence of Ventriculoatrial (VA) conduction. Fifty (92.5%) patients had a better AV than VA conduction. Age, presence of ischemic heart disease, left ventricular ejection fraction, and diastolic function could not predict VA conduction. A significant direct relationship was found between left ventricular ejection fraction and VAWP (p value = 0.036, r = 0.4; the Pearson correlation test). CONCLUSION: Prediction of VA conduction based on clinical and echocardiographic characteristics is not possible. Impairment of AV conduction was the best predictor for the impairment of VA conduction, and most patients had a better AV than VA conduction. In this study, the men had a slightly higher prevalence of VA conduction.