Combined evaluation of bedside clinical variables and the electrocardiogram for the differential diagnosis of paroxysmal atrioventricular reciprocating tachycardias in patients without pre-excitation.

OBJECTIVES

The aim of this study was to assess the independent predictive contribution to the electrocardiogram (ECG) of bedside clinical variables to distinguish the major forms of paroxysmal supraventricular tachycardias.

BACKGROUND

Atrioventricular nodal re-entrant tachycardias (AVNRTs) and orthodromic reciprocating tachycardias (ORTs), through concealed accessory pathways, are major mechanisms of paroxysmal atrioventricular re-entrant tachycardias.

METHODS

We prospectively included 370 consecutive patients undergoing an electrophysiologic study for paroxysmal, regular, narrow-QRS complex tachycardias without pre-excitation in sinus rhythm. A diagnostic interpretation of ECG recordings was performed by 2 observers blinded to invasive diagnosis used as gold standard. The independent diagnostic contribution of basic clinical variables from a 7-item questionnaire was analyzed alone and in combination with the ECG interpretation by stepwise logistic regression.

RESULTS

AVNRTs and ORTs were demonstrated in 262 and 108 patients, respectively. Age at symptom onset (odds ratio [OR]: 1.27), presence of palpitations in the neck (OR: 3.54), and female sex (OR: 2.96) (all p = 0.0001) were the clinical variables with significant diagnostic power for AVNRT diagnosis. These variables were selected by the logistic model as predictors of the tachycardia diagnosis when the ECG interpretation was included in the analysis (C statistic = 0.81 vs. 0.75 with clinical variables alone; p = 0.003). Neck palpitation was the only predictor of AVNRT when positive ECG findings were lacking.

CONCLUSIONS

Age at the onset of symptoms, sensation of rapid regular pounding in the neck during tachycardia, and female sex are the only significant clinical variables in the differential diagnosis of paroxysmal atrioventricular reciprocating tachycardias in patients without pre-excitation in sinus rhythm. Their consideration adds significant diagnostic information to the ECG.