Integrated Echo-Hemodynamic Framework for VA-ECMO in Right Ventricular Infarction

Figures

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  Figure 1. Clinical Decision Thresholds and Definitions Overview of the hemodynamic and echocardiographic parameters used in the proposed integrated framework. (Top) Definitions of key parameters: right ventricular (RV) contractility markers (TAPSE, s', and RVFAC), afterload-normalized RV-pulmonary artery coupling ratios (TAPSE/PASP and s'/PASP), and the hemodynamic pulsatility index (PAPI). (Bottom) Proposed clinical decision thresholds based on the integration of these parameters. A PAPI ≤ 1.0 suggests severe RV failure potentially requiring VA-ECMO. For successful weaning, a PAPI >1.5 combined with preserved coupling (s'/PASP >0.33 and/or TAPSE/PASP >0.41) is required to ensure intrinsic RV recovery. CVP = central venous pressure; PADP = pulmonary artery diastolic pressure; PAPI = pulmonary artery pulsatility index; PASP = pulmonary artery systolic pressure; RVFAC = right ventricular fractional area change; s' = tricuspid annular systolic velocity; TAPSE = tricuspid annular plane systolic excursion; VA-ECMO = venoarterial extracorporeal membrane oxygenation.

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  Figure 2. Comparison of Weaning Parameters in Case 1 Comparison of hemodynamic and echocardiographic parameters between failed weaning (day 6) and successful weaning (day 10) in case 1. Although right ventricular fractional area change (RVFAC), a load-dependent parameter, showed a minimal change (31.9% vs 32.6%), the pulmonary artery pulsatility index (PAPI) showed a significant improvement (1.05 vs 1.71), correctly predicting weaning success. This supports the utility of PAPI >1.5 as a weaning threshold. ECMO = extracorporeal membrane oxygenation.

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  Figure 3. Echocardiographic Assessment Methodology Standardized echocardiographic measurements for right ventricular-pulmonary artery coupling assessment. (A) Tricuspid annular plane systolic excursion (TAPSE) by M-mode imaging. (B) Tricuspid annular systolic velocity (s’) by tissue Doppler imaging. (C) Tricuspid regurgitation pressure gradient (TRPG) for pulmonary artery systolic pressure estimation; coupling ratios (s’/PASP, TAPSE/PASP) are derived from these measurements. (D) Right ventricular fractional area change (RVFAC) by end-diastolic and end-systolic area tracings. Panels (A-C) obtained from Case 3 (acute phase) demonstrate coupling ratio assessment from a consistent hemodynamic state; Panel D from Case 2 (recovery phase) illustrates RVFAC methodology. TRPG = tricuspid regurgitation pressure gradient; other abbreviations as in Figure 1.

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  Figure 4. Paired Echocardiographic Images Demonstrating iNO-Induced Left Ventricular Volume Shift (Case 3) Apical 2-chamber views from case 3 at (A) day 2 baseline and (B) day 3 after inhaled nitric oxide initiation. Note the small, underfilled left ventricular (LV) cavity at baseline (A), reflecting reduced LV preload due to right ventricular (RV) dysfunction. After inhaled nitric oxide (iNO) administration (B), the LV cavity appears more filled, visualizing the mechanism whereby iNO-induced pulmonary vasodilation increased RV forward flow and LV preload. In this patient with limited LV reserve (left ventricular ejection fraction 39%), this acute volume shift resulted in LV decompensation (pulmonary capillary wedge pressure rose from 12-14 to 24 mm Hg).

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  Figure 5. Physiological Mechanisms and Safety Criteria for iNO Therapy in Right Ventricular Myocardial Infarction Schematic illustration of the hemodynamic effects of inhaled nitric oxide (iNO) and safety considerations based on mechanical circulatory support status. Left panel: Key monitoring indices including the pulmonary artery pulsatility index (PAPI) for hemodynamic reserve assessment and coupling ratios (s'/PASP and TAPSE/PASP) for intrinsic right ventricular (RV) function evaluation. Center panel: Physiological mechanism of iNO—pulmonary vasodilation reduces RV afterload, increasing RV forward flow and left ventricular (LV) preload. Right panel: Safety criteria stratified by mechanical support status. Without mechanical support, iNO requires adequate LV reserve (left ventricular ejection fraction >40%-45%, pulmonary capillary wedge pressure <18 mm Hg) to tolerate increased preload; RV unloading with Impella or VA-ECMO permits safer iNO administration by managing the augmented venous return. Continuous monitoring of PAPI trend and coupling ratios guides therapy continuation or discontinuation. Ea = arterial elastance; Ees = end-systolic elastance; LA = left atrium; LVEF = left…

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  Visual Summary. Proposed Clinical Framework for Echo-Hemodynamic Guided Management of Right Ventricular Myocardial Infarction Integrated decision-making algorithm for mechanical circulatory support in right ventricular (RV) myocardial infarction with cardiogenic shock. Upper left (initial assessment): Postrevascularization evaluation using a PAPI threshold of ≤1.0 to identify patients requiring VA-ECMO vs medical management. Upper right (ECMO weaning criteria): Dual-parameter approach requiring both PAPI >1.5 and adequate coupling ratios (s'/PASP >0.33 and/or TAPSE/PASP >0.41) before weaning attempts; inhaled nitric oxide (iNO) may facilitate RV recovery during mechanical support. Lower left (iNO therapy prerequisites): Safety criteria for iNO administration without mechanical support, requiring preserved left ventricular function (left ventricular ejection fraction >40%-45%) and normal filling pressures (pulmonary capillary wedge pressure <18 mm Hg). Lower right (iNO monitoring): Real-time assessment of therapeutic response; PAPI decline or deteriorating coupling ratios mandate immediate iNO discontinuation. PAPI = pulmonary artery pulsatility index; PASP = pulmonary artery systolic pressure;…