Normalized first derivative ofthe left apex cardiogram in assessment of left ventricular function

Area of Science:

• Cardiology
• Biomedical Engineering
• Physiology

Background:

• Assessing left ventricular function is crucial in managing cardiac disease.
• Noninvasive methods are preferred for patient monitoring and diagnosis.

Purpose of the Study:

• To investigate the relationship between the left apex cardiogram and left ventricular pressure during isovolumic contraction.
• To determine if the normalized derivative of the apex cardiogram can serve as a noninvasive index of left ventricular function.

Main Methods:

• Studied 30 patients with cardiac disease.
• Obtained normalized derivatives (dD/dt/D and dP/dt/P) from left apex cardiogram and left ventricular pressure tracings.
• Correlated these normalized derivatives with each other and with various left ventricular function indexes.

Main Results:

• Normalized derivatives (dD/dt/D and dP/dt/P) showed similar magnitude and variation.
• A highly significant correlation was found between normalized displacement velocity and normalized pressure velocity (r=0.76, P<0.001).
• Significant correlations were observed with other left ventricular function indexes, including end-diastolic pressure and peak dP/dt.

Conclusions:

• The normalized derivative of the left apex cardiogram (dD/dt/D) is a valuable noninvasive tool.
• This index effectively assesses left ventricular function in humans.
• The findings support the use of apex cardiography in clinical cardiology.