Validation of Echocardiographic Left Atrial Parameters in Atrial Fibrillation Using the Index Beat of Preceding Cardiac Cycles of Equal Duration

Myocardial performance index derived from pre-ejection period as a novel and useful predictor of cardiovascular events in atrial fibrillation

“…In addition, it is timeconsuming and not realistic in the clinical scenario to analyze more than 10 beats for evaluating left ventricular performance. Prior studies have found that the left ventricular systolic and atrial parameters measured from index beat are reasonable estimates of the measured average values over all cardiac cycles [20][21][22]. In the present study, we also demonstrated that using the index beat to measure PEPa-derived MPI was as accurate as and less timeconsuming than the onerous method of averaging of multiple cardiac cycles.…”

“…Because their measurements using average method were time-consuming, many echocardiographic parameters including left ventricular dimensions, LVEF, LAVI, LVMI, PEPa, ETa, IVRTa, and PEPa-derived MPI were not obtained from the averaging multiple cardiac cycles, but measured from the index beat. However, several studies including the present one had proven use of the index beat to measure certain echocardiographic parameters including left ventricular systolic, diastolic, and left atrial parameters in patients with AF was as accurate as the time-consuming method of averaging multiple cardiac cycles [20][21][22]. The majority of our patients were treated chronically with antihypertensive or anti-thrombosis medications.…”

“…The preceding and pre-preceding intervals of the index beat must be >500 ms [23], and the difference between them must be <60 ms [22]. The cardiac cycle of the index beat was also >500 m [23].…”

“…Left ventricular dimensions, LVEF, LAVI, LVMI, PEPa, IVRTa, Eta, and PEPa-derived MPI were measured using the index beat method [20][21][22]. Because their measurements were easy and rapid, the transmitral E-wave velocity (E), E-wave deceleration time, Ea and Sa were obtained from five beats [4] and the data were averaged to give the mean value for later analysis.…”

The use of echocardiography in acute cardiovascular care: Recommendations of the European Association of Cardiovascular Imaging and the Acute Cardiovascular Care Association

“…58,94 The averaging remains crucial for systolic as for diastolic function parameters assessment; however, other approaches have been proposed. 95 The 'index beat' method uses the measurement performed on the cardiac cycle following a pair of equal preceding cardiac cycles. If atrial fibrillation duration is >48 h or there is doubt about its duration, TOE can be used to rule out intracardiac thrombus prior to cardioversion.…”