Pulsatile arterial blood pressure mimicking aortic valve opening during continuous-flow LVAD support: a case report

BACKGROUND: Left ventricular assist devices (LVAD) have become a common treatment option in advanced heart failure. Lack of aortic valve opening during left ventricular unloading is a common complication and associated with a worse outcome. Maintaining a minimum pulse pressure is an important goal during the early postoperative period after LVAD implantation since it is commonly seen as secure sign of aortic valve opening. AIMS/OBJECTIVE: We report a case of an LVAD-supported patient with early permanent closure of the aortic valve despite a pulse pressure > 15 mmHg at all times following LVAD implantation. We demonstrate how careful assessment of the invasive arterial blood pressure curve can indicate aortic valve closure irrespective of pulsatile blood flow. METHOD: A 69-year old male patient with terminal ischemic cardiomyopathy was referred for long-term mechanical circulatory support. Due to mild aortic regurgitation both an aortic bioprosthesis and a continuous-flow left ventricular assist device were implanted. Postoperative echocardiography documented a patent aortic bioprosthesis and an acceptable residual systolic left ventricular contractility. During invasive arterial blood pressure monitoring repetitive transient slight blood pressure decreases followed by slight blood pressure increases coincided with programmed LVAD flushing cycles. Permanent pulsatile flow with a pulse pressure of ≥15 mmHg conveyed systolic opening of the aortic valve. Echocardiography, however, proved early permanent aortic valve closure. In retrospect, transformation of the automated LVAD flushing cycles into visible changes of the arterial blood pressure curve during invasive blood pressure monitoring is indicative of ejection of the complete cardiac output through LVAD itself, and therefore an early clinical sign of aortic valve closure. DISCUSSION/CONCLUSION: We present this interesting didactic case to highlight caveats during the early postoperative period after LVAD implantation. Moreover, this case demonstrates that careful and differentiated observation of the arterial blood pressure waveform provides crucial information in this unique and growing patient population of continuous-flow LVAD support.