We suggested the use of a cardioid aperture in the processing of cardiac images via confocal laser scanning microscopy (CSLM). We calculated the point spread function (PSF) corresponding to the cardioid aperture and the cardiac images by using the FFT algorithm. Then, we studied the effect of image rotation on the PSF. In addition, we computed the autocorrelation corresponding to the cardiac images and cardiac aperture and compared them with the autocorrelation of the uniform circular aperture. Additionally, we computed the cross-correlation of the aligned and rotated cardiac images. Finally, we obtained cardiac images using a confocal scanning microscope with circular and cardioid apertures. The MATLAB code was used for all images and plots.