Background <p>Cardiovascular hemodynamics, electrophysiological characteristics, and heart anatomy are all negatively impacted by obesity. The aim of this study is to compare the impact of sleeve gastrectomy versus single anastomosis sleeve ileal bypass on cardiac functions and rhythm disturbance.</p> Methods <p>The current study included 78 patients who were allocated into two equal groups. Group A (<i>n</i> = 39) underwent laparoscopic sleeve gastrectomy (LSG), while group B (<i>n</i> = 39) underwent single anastomosis sleeve ileal bypass (SASI). Follow-up was designed for 6 and 12 months for cardiac functions and rhythm disturbance.</p> Results <p>The patients’ mean age in the current study was 41.6 ± 6.88 and 43.2 ± 7.54 in groups A and B, respectively. There was a statistically significant longer operative time in patients who underwent SASI in comparison with those who underwent LSG (<i>P</i> &lt; 0.001*). The %EWL was significantly higher in the SASI group at 6 and 12 months follow-up (<i>P</i> &lt; 0.001*) QTC m sec and QT dispersion were significantly decreased within and between both groups after 6 and 12 months. There was a statistically significant improvement in the rhythm disturbance in both groups, mainly in group B, reported as a decrease in the overall AF with its subtypes in both groups. There was a statistically significant increase in the E/A ratio in both groups after 6 and 12 months follow-up, with no significant difference between both groups. There was an increase in LVEF in both groups, but it did not reach a significant value.</p> Conclusions <p>LSG and SASI seem to be effective techniques in improving cardiac functions and overall AF in obese patients.</p>