Value of the QRS complex in assessing left ventricular ejection fraction

Area of Science:

• Cardiology
• Medical Imaging
• Clinical Electrophysiology

Background:

• Assessing left ventricular function is crucial in managing chronic coronary artery disease (CAD).
• Current methods like echocardiography or cardiac catheterization can be invasive or less accessible.
• Electrocardiography (ECG) is a widely available, noninvasive tool.

Purpose of the Study:

• To investigate the relationship between specific electrocardiographic findings and left ventricular ejection fraction (EF) and augmented ejection fraction (EFa) in patients with CAD.
• To determine if ECG can serve as a noninvasive predictor of left ventricular function in this population.

Main Methods:

• Seventy-three patients with documented chronic CAD were analyzed.
• Patients were grouped based on the presence or absence of abnormal Q waves and myocardial infarction type.
• The sum of R waves (sigmaR) from specific ECG leads was calculated and correlated with angiographically determined EF and EFa.

Main Results:

• A significant positive correlation was found between sigmaR and EF (r=0.61) and between sigmaR and EFa (r=0.77).
• Patients with sigmaR ≥ 4.0 mV showed significantly higher EFa (>0.45 in 93%) compared to those with sigmaR < 4.0 mV (EFa <0.45 in 73%, P<0.001).
• No significant differences in cardiac index, LVEDP, or coronary narrowing were observed across patient groups.

Conclusions:

• The sum of R waves (sigmaR) on a standard ECG is a reliable, noninvasive indicator of left ventricular ejection fraction and augmented ejection fraction in patients with chronic CAD.
• ECG measurements can potentially guide the assessment of cardiac function, complementing traditional methods.