A patient monitoring system for monitoring cardiac arrhythmias includes an ECG monitor configured to monitor cardiac potentials during cardiac cycles and an arterial blood flow monitor configured to monitor arterial blood flow and generate pulse waveform. The system further includes an arrhythmia detection module that detects the presence of an arrhythmia based on the cardiac potentials and generates an arrhythmia indicator, and an arrhythmia analysis module that assesses the severity of the detected arrhythmia. The arrhythmia analysis module calculates average sinus pulse information based on the pulse waveform data for two or more cardiac cycles occurring when no arrhythmia is detected, and then calculates average arrhythmia pulse information based on pulse waveform data for two or more cardiac cycles occurring after detection of the arrhythmia. The average arrhythmia pulse information is then compared to the average sinus pulse information and an arrhythmia severity indicator is generated based on the comparison.
