Value of Index Beat in Evaluating Left Ventricular Systolic and Diastolic Function in Patients with Atrial...

Area of Science:

• Cardiology
• Echocardiography
• Cardiac Physiology

Background:

• Atrial fibrillation (AF) complicates echocardiographic assessment of left ventricular (LV) function.
• Traditional methods for LV function evaluation may be less reliable in the presence of irregular heart rhythms like AF.
• The index beat method offers a potential alternative for assessing cardiac function during AF.

Purpose of the Study:

• To evaluate the utility of the index beat method for assessing LV function in patients with AF.
• To compare the accuracy of the index beat method with established averaging techniques.
• To determine the optimal Doppler-derived parameters for LV function assessment during AF.

Main Methods:

• Utilized dual pulsed wave Doppler to simultaneously measure peak early diastolic mitral inflow velocity (E) and mitral annular velocities (diastolic e', systolic s') beat-to-beat.
• Assessed patients diagnosed with atrial fibrillation.
• Compared index beat measurements of s' and E/e' ratios against mean values obtained through averaging methods.

Main Results:

• The index beat systolic mitral annular velocity (s') demonstrated strong correlation with mean values (r=0.96 for septal, r=0.92 for lateral wall).
• The E/e' ratio calculated at the pre-index beat showed superior correlation with mean values (r=0.88 for septal, r=0.97 for lateral wall) compared to the index beat cycle.
• Both parameters showed statistically significant correlations (p<0.000).

Conclusions:

• The index beat method, particularly for s', is a valuable tool for assessing LV systolic function in AF.
• The E/e' ratio derived from the pre-index beat is a reliable indicator of LV diastolic function in AF patients.
• These findings support the use of specific index beat and pre-index beat Doppler parameters for accurate LV function assessment in AF.