Background: The total atrial conduction time (TACT) is an independent predictor of atrial fibrillation (AF). A new transthoracic echocardiographic tool to determine TACT by tissue Doppler imaging (PA-TDI (the time from the initiation of the P wave on the ECG (lead II) to the A' wave on the lateral left atrial tissue Doppler tracing)) has been developed recently.
Objective: To test the hypothesis that measurement of PA-TDI enables prediction of new-onset AF.
Methods: 249 Patients without a history of AF were studied. All patients underwent an echocardiogram and the PA-TDI interval was measured. Patient characteristics and rhythm at follow-up were recorded.
Results: During a mean (SD) follow-up of 680 (290) days, 15 patients (6%) developed new-onset AF. These patients had a longer PA-TDI interval than patients who remained in sinus rhythm (172 (25) ms vs 150 (20) ms, p = 0.001). Furthermore, the patients developing AF were older, more often had a history of heart failure or chronic obstructive pulmonary disease, more often used alpha blockers, had enlarged left atria and more frequently mitral incompetence on the echocardiogram. After adjusting for potential confounders, Cox regression showed that PA-TDI was independently associated with new-onset AF (OR = 1.375; 95% CI 1.037 to 1.823; p = 0.027). The 2-year incidence of AF was 33% in patients with a PA-TDI interval >190 ms versus 0% in patients with a PA-TDI interval <130 ms (p = 0.002).
Conclusions: A prolonged PA-TDI interval may predict the development of new-onset AF. This measure may be used to identify patients at risk in future strategies to prevent the development or complications of AF.