ABSTRACT
BACKGROUND: The relationship between speckle tracking assessed global longitudinal strain (GLS) and Doppler-based echocardiography with basic physiological markers of cardiac function derived from pressure-volume loops is poorly elucidated. OBJECTIVE: We aimed to describe the association between LS and Doppler-based echocardiography and direct measurements of central haemodynamic parameters from conductance catheter-based pressure-volume loops in an animal model with increasing left ventricular (LV) dysfunction. METHODS: 12 Danish landrace female pigs (75-80 kg) were used. All instrumentations were performed percutaneously, including the conductance catheter in the LV. Progressive LV dysfunction was induced by embolisation through the left main coronary artery with microspheres every 3 min until a >50% reduction in cardiac output (CO) or mixed venous saturation (SvO2), compared with baseline, or SvO2 <30%. Echocardiography was performed at baseline and 90 s after each injection. RESULTS: With progressive LV dysfunction, mean CO decreased from 5.6±0.9 L/min to 2.1±0.9 L/min, and mean SvO2 deteriorated from 61.1±7.9% to 35.3±6.1%. Mean LS and LV outflow tract velocity time integral (LVOT VTI) declined from -13.8±3.0% to -6.1±2.0% and 16.9±2.6 cm to 7.8±1.8 cm, respectively. LS and LVOT VTI showed the strongest correlation to stroke work in unadjusted linear regression (r2=0.53 and r2=0.49, respectively). LS correlated significantly with stroke volume, end-systolic elastance, systolic blood pressure, ventriculo-arterial coupling and arterial elastance. CONCLUSION: In an animal model of acute progressive LV dysfunction, echocardiographic and conductance catheter-based measurements changed significantly. LS and LVOT VTI displayed the earliest and the largest alterations with increased myocardial damage and both correlated strongest with stroke work.
Subject(s)
Disease Models, Animal , Shock, Cardiogenic , Ventricular Dysfunction, Left , Ventricular Function, Left , Animals , Female , Ventricular Function, Left/physiology , Ventricular Dysfunction, Left/physiopathology , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Left/diagnostic imaging , Shock, Cardiogenic/physiopathology , Shock, Cardiogenic/etiology , Echocardiography, Doppler/methods , Swine , Predictive Value of TestsABSTRACT
AIMS: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) with profound left ventricular (LV) failure is associated with inadequate LV emptying. To unload the LV, VA-ECMO can be combined with Impella CP (ECMELLA). We hypothesized that ECMELLA improves cardiac energetics compared with VA-ECMO in a porcine model of cardiogenic shock (CS). METHODS AND RESULTS: Land-race pigs (weight 70 kg) were instrumented, including a LV conductance catheter and a carotid artery Doppler flow probe. CS was induced with embolization in the left main coronary artery. CS was defined as reduction of ≥50% in cardiac output or mixed oxygen saturation (SvO2) or a SvO2 < 30%. At CS VA-ECMO was initiated and embolization was continued until arterial pulse pressure was <10 mmHg. At this point, Impella CP was placed in the ECMELLA arm. Support was maintained for 4 h. CS was induced in 15 pigs (VA-ECMO n = 7, ECMELLA n = 8). At time of CS MAP was <45 mmHg in both groups, with no difference at 4 h (VA-ECMO 64 mmHg ± 11 vs. ECMELLA 55 mmHg ± 21, P = 0.08). Carotid blood flow and arterial lactate increased from CS and was similar in VA-ECMO and ECMELLA [239 mL/min ± 97 vs. 213 mL/min ± 133 (P = 0.6) and 5.2 ± 3.3 vs. 4.2 ± 2.9 mmol/ (P = 0.5)]. Pressure-volume area (PVA) was significantly higher with VA-ECMO compared with ECMELLA (9567 ± 1733 vs. 6921 ± 5036 mmHg × mL/min × 10-3, P = 0.014). Total diureses was found to be lower in VA-ECMO compared with ECMELLA [248 mL (179-930) vs. 506 mL (418-2190); P = 0.005]. CONCLUSIONS: In a porcine model of CS, we found lower PVA, with the ECMELLA configuration compared with VA-ECMO, indicating better cardiac energetics without compromising systemic perfusion.
ABSTRACT
BACKGROUND: In selected cases of cardiogenic shock, veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is combined with trans valvular micro axial flow pumps (ECMELLA). Observational studies indicate that ECMELLA may reduce mortality but exposing the patient to two advanced mechanical support devices may affect the early inflammatory response. We aimed to explore inflammatory biomarkers in a porcine cardiogenic shock model managed with V-A ECMO or ECMELLA. METHODS: Fourteen landrace pigs had acute myocardial infarction-induced cardiogenic shock with minimal arterial pulsatility by microsphere embolization and were afterwards managed 1:1 with either V-A ECMO or ECMELLA for 4 h. Serial blood samples were drawn hourly and analyzed for serum concentrations of interleukin 6 (IL-6), IL-8, tumor necrosis factor alpha, and serum amyloid A (SAA). RESULTS: An increase in IL-6, IL-8, and SAA levels was observed during the experiment for both groups. At 2-4 h of support, IL-6 levels were higher in ECMELLA compared to V-A ECMO animals (difference: 1416 pg/ml, 1278 pg/ml, and 1030 pg/ml). SAA levels were higher in ECMELLA animals after 3 and 4 h of support (difference: 401 ng/ml and 524 ng/ml) and a significant treatment-by-time effect of ECMELLA on SAA was identified (p = 0.04). No statistical significant between-group differences were observed in carotid artery blood flow, urine output, and lactate levels. CONCLUSIONS: Left ventricular unloading with Impella during V-A ECMO resulted in a more extensive inflammatory reaction despite similar end-organ perfusion.
