Several works studied the elicitation of emotions through the exposure of individuals to relevant stimuli, using spectral analysis of Heart Rate Variability (HRV) when people are subject to emotional elicitation. If correlation exists between HRV and emotional responses, spectral analysis can be used to study emotion regulation under external stimuli. In this work, we studied the relationship between visual elicitation and emotion regulation, employing HRV. Images (with pleasant, unpleasant and neutral emotional content) were selected from the IAPS (International Affective Picture System) dataset. Ninety-eight participants were enrolled, and subject to view all images, displayed in random order for each participant. Heart rate was recorded during the experiment, and HRV analysis was performed. Spectral values were studied for the different images. The presentation order of images was relevant, mainly when unpleasant images were viewed in first place; this significantly affects HRV values. Spectral values were higher for men, being this difference stronger when pleasant pictures were displayed. Age and gender dependences of spectral indexes were found. The influence of visual elicitation, with different emotional contents, over HRV, was assessed. Results indicate that HRV parameters are affected when individuals are subject to external, emotional-based stimuli.