It was later reported that the low flow alarms were caused by a globular left ventricle (lv) with a narrow vertical distance between the apex and the mitral valve (mv).It was reported that the low flow alarms resolved following the repositioning of the pump.As of (b)(6) 2020, the patient was asymptomatic, off inotropes, and on the step-down floor with no further low flow alarms.It was reported that the plan of care was standard post left ventricular assist device (lvad) recovery and monitoring.
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Manufacturer's investigation conclusion: the report of low flow alarms was confirmed through the analysis of the submitted log files.Although the cause of the reported low flow alarms cannot be conclusively determined through this evaluation, the account reported that the low flow alarms were caused by a globular left ventricle (lv) with a narrow vertical distance between the apex and the mitral valve (mv).It was reported that the low flow alarms resolved following repositioning of the pump.A direct correlation between the device and the reported events could not be conclusively determined.The system controller event log file captured 73 low flow hazard alarms throughout the log file, when the estimated flow dropped below the 2.5 lpm threshold.There were also several controller fault flags for low flow captured; however, these fault flags were not active long enough to trigger low flow hazard alarms.There were multiple pi events captured throughout the log file.No additional atypical alarms were captured.The pump appeared to function as intended.The patient remains ongoing on vad support.The device history records including the sterilization and packaging records, were reviewed and showed no deviations from manufacturing or qa specifications.The implant kit shipped on 01jun2020.The heartmate 3 left ventricular assist system (lvas) instructions for use (ifu) rev.C is currently available.The introduction of the heartmate 3 lvas ifu explains the pump parameters, including pump flow, pump speed, pulsatility index (pi), and pump power.Per design, when the estimated flow value is calculated at less than 2.5 lpm, a low flow status is posted to the log file.If the flow remains below 2.5 lpm for 10 seconds, a low flow hazard alarm is triggered.The hazard alarms sub-section of the ifu notes that ¿changes in patient conditions can result in low flow, such as hypertension.¿ the alarms and troubleshooting section explains all system alarms, including low flow alarms, and the recommended actions associated with them.The heartmate 3 lvas ifu states that if the system detects a pi event, the pump speed will automatically reduce to the low speed limit and slowly ramp back up.Pi events are assumed by the system during cases where there is a sudden and substantial change in pi.Some reasons for pi changes include sudden changes in the patient¿s volume status, arrhythmias, sudden changes in power, and sudden changes in pump speed.This ifu also explains that the magnitude of the pi value is related to the amount of assistance provided by the pump.Higher values indicate more ventricular filling and higher pulsatility (ie, the pump is providing less support to the left ventricle) while lower values indicate less ventricular filling and lower pulsatility (ie, the pump is providing greater support and further unloading the ventricle).Hypertension is listed in the ifu as an adverse event that may be associated with the use of the heartmate 3 lvas.The patient care and management section of the ifu includes subsections entitled ¿measuring blood pressure¿ and ¿blood pressure management.¿ no further information was provided.The manufacturer is closing the file on this event.
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