PMC8305644_01
Fluoroscopic and Echocardiographic Imaging to Guide Catheter Positioning. (A) The 7-F conductance catheter is a pig-tail catheter with a single pressure sensor and multiple electrodes situated at the terminal portion of the catheter that facilitate volumetric measurements. Reproduced with permission from CD Leycom. (B and C) Still-frame fluoroscopic views illustrating antegrade positioning of the conductance catheter:placed from a femoral vein, coursing from the RA to LA via transseptal puncture and into the LV:immediately after transcatheter valve deployment. 1 = conductance catheter; 2 = Agilis steering sheath; 3 = pulmonary arterial catheter; 4 = temporary transvenous pacemaker; 5 = transcatheter aortic valve delivery sheath; and 6 = pig-tail catheter in the aorta. (D) Intraprocedural echocardiographic confirmation of the conductance catheter in the RV apex from the apical 4-chamber view. Ao = aorta; LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.
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This novel technique overcame previous challenges guiding the stiff conductance catheter and minimized artifact associated with suboptimal catheter positioning (Figure 1).
4-Chamber PV Analysis Before, During, and After TAVR. Pressure-volume (PV) loops before transcatheter aortic valve replacement (TAVR) in the RA, RV, LA, and LV are displayed in the blue box at the top of the figure. Key hemodynamic parameters in the RV and LV before TAVR are presented in the table below the PV loops. The gray box focuses on LV hemodynamics during valve deployment (n.b. that these loops reflect LV hemodynamics after deployment of a 26-mm S3 prosthesis, which had to be retracted due to significant paravalvular regurgitation). The top panel highlights PV loops in the LV; the blue PV loops are captured immediately before the 29-mm S3 prosthesis being deployed, the gray PV loops represent the LV during rapid ventricular pacing; and the loops represented by the gradient of colors from yellow to red were captured immediately after valve deployment. The dashed line connecting the vertical axis with the point of end-systole represents the end-systolic PV relationship (ESPVR), which serves as a surrogate of ventricular contractility. The pressure-time tracing in the gray box below the PV loops illustrates how LV pressure changes in each of the perivalve deployment phases. An intracardiac electrogram from the conductance catheter (labeled as ECG) during the pressure-time tracing is provided for reference in the bottom panel. Post-TAVR PV loops in all 4 cardiac chambers are displayed in the red box, and accompanied by notable RV and LV hemodynamic parameters in the table below. Pre-TAVR deployment loops are presented in light blue for comparison. All ventricular PV loops feature the ESPVR and end-diastolic PV relationship (EDPVR) as dashed lines. Vascular resistance (VR) in the tables is presented as pulmonary VR for the RV, and systemic VR for the LV. Ea = effective arterial elastance; EDP = end-diastolic pressure; EDV = end-diastolic volume; Ees = end-systolic elastance; ESP = end-systolic pressure; ESV = end-systolic volume; HR = heart rate; SW = stroke work; V0 = volume-axis intercept; other abbreviations as in Figure 1.
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Baseline PV loops are highlighted in Figure 2. Rapid ventricular pacing (RVP) during valve deployment (Figure 2) induces a significant decline in LV contractility and pressure (see the gray PV loops and pressure-time tracing in the middle panel), and LV size and function do not return to baseline after RVP termination. LV function improved by the time PV loops were repeated at the end of the procedure (Figure 2), but the slope of the end-systolic PV relationship suggests only a partial recovery.