INTRA-AORTIC BALLOON COUNTER PULSATION MONITORED VIA A WIRELESS, WEARABLE DOPPLER ULTRASOUND

SESSION TITLE: Critical Care Case Report Posters 33 SESSION TYPE: Case Report Posters PRESENTED ON: 10/09/2023 02:10 pm - 02:55 pm INTRODUCTION: An intra-aortic balloon pump (IABP) is a temporary mechanical circulatory support device placed in patients with cardiogenic shock. IABP is also commonly employed in patients undergoing high-risk cardiac interventions. The physiological rationale for intra-aortic balloon counter-pulsation is to both reduce myocardial oxygen consumption during systole and augment myocardial oxygen delivery during diastole; the ultimate goal is to improve tissue perfusion.Important aspects of IABP care include timing of balloon inflation and deflation, and hemodynamic changes, especially during the weaning process. We hypothesized that a novel, wearable, wireless Doppler ultrasound that measures stroke volume (SV) and central venous pressure surrogates would give unique insights during IABP weaning in a patient with cardiogenic shock. CASE PRESENTATION: A 49-year-old female presented with syncope and third-degree heart block. Her medical history included hypertension, hyperlipidemia and tobacco use. Transcutaneous pacing was immediately initiated, and she underwent emergent temporary transvenous pacemaker placement as well as coronary angiography. She had significant two vessel disease, including 100% right coronary artery occlusion and mild left anterior descending disease. As she was in respiratory distress, bilevel positive airway pressure was initiated, and an IABP was inserted, following which, she was transferred to the cardiovascular ICU. Transthoracic echocardiogram showed severe mitral valve regurgitation (MR) and a calculated stroke volume of 29 mL. Transesophageal echocardiogram performed the following day confirmed ischemic MR due to papillary muscle dysfunction, and the left ventricle's inferior, lateral and inferoseptal walls were mildly hypokinetic with an ejection fraction of 50-55%. Carotid and jugular Doppler were performed on day three of her ICU stay. DISCUSSION: In this report we make 3 clinically-relevant observations. 1.) corrected flow time of the carotid artery (ccFT), a stroke volume surrogate, increased with reduced IABP support. 2.) simultaneously-measured jugular venous Doppler became less pulsatile (i.e., consistent with a shrinking and collapsing jugular vein) with less IABP support. 3.) based on the absolute time of assisted and unassisted systoles and the period of retrograde flow at the beginning of systole, balloon deflation may have been early, resulting in proximal aortic steal.Timing of IABP inflation and deflation are important to optimize myocardial oxygen consumption and delivery. During IABP weaning, hemodynamic measures of interest include SV and central venous pressure (among others). We have previously observed a strong, linear correlation between ccFT and SV. Therefore, increasing ccFT in native systoles during 1:2 and 1:3 imply that SV improved with less support. Consistent with rising ccFT was the pattern of change of the jugular venous Doppler waveform, which illustrated falling jugular venous pressure (JVP) with reduced IABP support. Together, these observations imply improved cardiac efficiency with reduced IABP support. This effect may be due to early balloon deflation and aortic steal. CONCLUSIONS: A novel, wireless, wearable Doppler ultrasound that records both the common carotid artery and internal jugular vein may provide unique hemodynamic measures in patients with an IABP. These measures may inform on balloon timing, weaning success and jugular venous pressure. REFERENCE #1: Randhawa V, Al-Fares A, Tong M, et al. A Pragmatic Approach to Weaning Temporary Mechanical Circulatory Support. J Am Coll Cardiol HF. 2021 Sep, 9 (9) 664–673. REFERENCE #2: Kenny JS, Barjaktarevic I, Mackenzie DC, Elfarnawany M, Yang Z, Eibl AM, Eibl JK, Kim CH, Johnson BD. Carotid Doppler ultrasonography correlates with stroke volume in a human model of hypovolaemia and resuscitation: analysis of 48 570 cardiac cycles. Br J Anaesth. 2021 Aug;127(2):e60-e63. REFERENCE #3: Kenny JS, Munding CE, Eibl AM, Eibl JK. Wearable ultrasound and provocative hemodynamics: a view of the future. Crit Care. 2022 Oct 25;26(1):329. DISCLOSURES: Employee relationship with Flosonics Medical Please note: 2021-2023 Added 04/04/2023 by Geoff Clarke, source=Web Response, value=Salary No relevant relationships by Stanley Gibbs No relevant relationships by Delaney Johnston Owner/Founder relationship with Flosonics Medical Please note: 2018-present Added 02/07/2023 by Jon-Emile Kenny, source=Web Response, value=Ownership interest Employee relationship with Flosonics Medical Please note: September 2022-now Added 03/21/2023 by Meredith Knott, source=Web Response, value=Salary Employee relationship with Flosonics Medical Please note: June 2022 - present Added 03/31/2023 by Tracy Savery, source=Web Response, value=Salary No relevant relationships by Praveen Sudhindra