Noninvasive ventilation (NIV) is a positive pressure ventilation method that has many cardiac healing effects and is an adjunct to medical treatments in cardiac patients. NIV includes continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP). Whereas CPAP provides continuous positive pressure ventilation, BiPAP provides separately inspiratory positive airway pressure (IPAP) and expiratory positive airway pressure (EPAP) (which corresponds to PEEP in IMV). BiPAP can reduce the work of breathing by creating driving pressure through increasing TV more than CPAP, and improve ventilation in patients, especially those with hypercarbia. In cardiac disorders (if there is no need for additional ventilation—such as hypercarbia), CPAP is generally preferred to improve oxygenation, reduce lung load, and produce effective PEEP. The effects of NIV on cardiac arrhythmia are controversial, and studies on this issue are generally derived from the results of OSA patients. Obstructive sleep apnea (OSA) and atrial fibrillation (AF) are both highly prevalent conditions that are associated with adverse cardiovascular outcomes. There is a growing body of literature suggesting that treatment of OSA with positive airway pressure (CPAP) may decrease the risk of AF after direct current cardioversion, although not all studies are consistent. In some cases, especially when the patient cannot synchronize with the device, forcing the patient to use NIV can increase cardiac load and be prearrhythmogenic. In this section, the association of NIV applications with cardiac arrhythmias will be discussed.