Electrocardiographic Changes in Intensive Care Unit Patients During Their Last Hours of Life: Can We Use These Parameters as Prognostic Indicators?

ABS TRACT Objective: QRS amplitude attenuation and prolonged QRS duration has been associated with increased mortality in various clinical conditions including critical care patients and general population. Relative bradycardia has been found to be associated with lower mortality in patients with septic shock, but there are no studies in literature evaluating the electrocardiographic (ECG) changes and changes in heart rate (HR) just before death. Our aim of this study is to calculate the gradual changes in these parameters in the last hours of life from II derivation telemetry records. Material and Methods: We included 30 patients who died in intensive care unit irrespective of their diagnosis during admission and follow up. HR, QRS amplitude and QRS duration were analysed from the telemetry recordings obtained from the last 10 hours of their life. Results: QRS duration prolongs and heart rate decreases during the last 10 hours of life and the changes in these parameters were more prominent in the last hours. QRS duration increased at rate of 5.43 ms per hour (p<0.001) and heart rate decreased at rate of 2.68/min each hour (p<0.001). QRS amplitude attenuation were more subtle (decreased by 0.23 mV per hour, p=0.02) compared to QRS duration and heart rate. Conclusion: During last 10 hours of life, there was widening of QRS complex, attenuation of QRS voltage and decrease in heart rate. Automated softwares could present these findings in graphics and can be used as a prognostic indicators to recognize a dying patient. This information could be used in certain acute reversible critical conditions such as fulminant myocarditis, anaphylactic shock, trauma patients as a sign of poor prognosis or on decision making regarding end-of-life in irreversible illness such as terminal cancer patients.