OBJECTIVES: The objective of this study was to compare survival outcomes and intra-arrest arterial blood pressures between children receiving cardiopulmonary resuscitation for bradycardia and poor perfusion and those with pulseless cardiac arrests. DESIGN: Prospective, multicenter observational study. SETTING: PICUs and cardiac ICUs of the Collaborative Pediatric Critical Care Research Network. PATIENTS: Children (< 19 yr old) who received greater than or equal to 1 minute of cardiopulmonary resuscitation with invasive arterial blood pressure monitoring in place. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 164 patients, 96 (59%) had bradycardia and poor perfusion as the initial cardiopulmonary resuscitation rhythm. Compared to those with initial pulseless rhythms, these children were younger (0.4 vs 1.4 yr; p = 0.005) and more likely to have a respiratory etiology of arrest (p < 0.001). Children with bradycardia and poor perfusion were more likely to survive to hospital discharge (adjusted odds ratio, 2.31; 95% CI, 1.10-4.83; p = 0.025) and survive with favorable neurologic outcome (adjusted odds ratio, 2.21; 95% CI, 1.04-4.67; p = 0.036). There were no differences in diastolic or systolic blood pressures or event survival (return of spontaneous circulation or return of circulation via extracorporeal cardiopulmonary resuscitation). Among patients with bradycardia and poor perfusion, 49 of 96 (51%) had subsequent pulselessness during the cardiopulmonary resuscitation event. During cardiopulmonary resuscitation, these patients had lower diastolic blood pressure (point estimate, -6.68 mm Hg [-10.92 to -2.44 mm Hg]; p = 0.003) and systolic blood pressure (point estimate, -12.36 mm Hg [-23.52 to -1.21 mm Hg]; p = 0.032) and lower rates of return of spontaneous circulation (26/49 vs 42/47; p < 0.001) than those who were never pulseless. CONCLUSIONS: Most children receiving cardiopulmonary resuscitation in ICUs had an initial rhythm of bradycardia and poor perfusion. They were more likely to survive to hospital discharge and survive with favorable neurologic outcomes than patients with pulseless arrests, although there were no differences in immediate event outcomes or intra-arrest hemodynamics. Patients who progressed to pulselessness after cardiopulmonary resuscitation initiation had lower intra-arrest hemodynamics and worse event outcomes than those who were never pulseless.