Right Ventricular Stroke Work Research Articles

RV stroke work in children with pulmonary arterial hypertension: estimation based on invasive haemodynamic assessment and correlation with outcomes

BackgroundRV performance is an important determinant of outcomes in children with pulmonary arterial hypertension (PAH). RV stroke work (RVSW), the product of mean pulmonary artery pressure and stroke volume, integrates...

Progressive right ventricular functional and structural changes in a mouse model of pulmonary arterial hypertension.

Right ventricle (RV) dysfunction occurs with progression of pulmonary arterial hypertension (PAH) due to persistently elevated ventricular afterload. A critical knowledge gap is the molecular mechanisms that govern the transition from RV adaptation to RV maladaptation, which leads to failure. Here, we hypothesize that the recently established mouse model of PAH, via hypoxia and SU5416 treatment (HySu), captures that transition from adaptive to maladaptive RV remodeling including impairments in RV function and decreases in the efficiency of RV interactions with the pulmonary vasculature. To test this hypothesis, we exposed C57BL6 male mice to 0 (control), 14, 21, and 28 days of HySu and then obtained synchronized RV pressure and volume measurements in vivo. With increasing HySu exposure duration, arterial afterload increased monotonically, leading to a continuous increase in RV stroke work, RV fibrosis, and RV wall stiffening (P < 0.05). RV contractility increased at 14 days of HySu exposure and then plateaued (P < 0.05). As a result, ventricular–vascular coupling efficiency tended to increase at 14 days and then decrease. Our results suggest that RV remodeling may begin to shift from adaptive to maladaptive with increasing duration of HySu exposure, which would mimic changes in RV function with PAH progression found clinically. However, for the duration of HySu exposure used here, no drop in cardiac output was found. We conclude that the establishment of a mouse model for overt RV failure due to PAH remains an important task.

A porcine model for acute ischaemic right ventricular dysfunction

To establish an experimental model for acute ischaemic isolated right ventricular dysfunction and the subsequent haemodynamic changes. An open-chest porcine model with ischaemic dysfunction of the right ventricle induced by ligation of the three main branches supporting the right ventricular free wall. Invasive monitoring of mean arterial blood pressure (MAP), central venous pressure (CVP), left atrial pressure (LAP) and right ventricular pressure (RVP); ultrasonic measurement of cardiac output (CO) and calculation of haemodynamic parameters such as stroke volume (SV), systemic vascular resistance (SVR), pulmonary vascular resistance (PVR) and right ventricular stroke work (RVSW) using standard formulae. The ischaemic challenge to the right ventricle resulted in a significant (≥30%) reduction in RVSW associated with an increase (6-25%) in CVP and reduction (8-18%) in pulmonary artery pressure (PAP) despite unchanged PVR, all reflecting the failing right ventricle. There was also a significant drop in CO (14-22%) despite unchanged LAP indicating lessened transpulmonary delivery of left ventricular preload due to the failing right ventricle causing the haemodynamic compromise rather than left ventricular failure. Supraventricular and ventricular arrhythmias occurred in three and two out of seven pigs, respectively-all of which except one were successfully resuscitated with cardioversion and/or defibrillation. This novel open-chest porcine model of induced ischaemia of the right ventricular free wall resulted in significant haemodynamic compromise confirmed using standard haemodynamic measurements making it useful for further research on acute, ischaemic isolated right ventricular failure.

Shorter Survival in Familial versus Idiopathic Pulmonary Arterial Hypertension is Associated with Hemodynamic Markers of Impaired Right Ventricular Function

Abstract Although individuals with familial pulmonary arterial hypertension (FPAH) have more severe hemodynamics, compared to individuals with idiopathic PAH (IPAH), it is unclear whether this translates into a survival difference. The influence of right ventricular (RV) function on survival in these groups is also unknown. We reviewed hemodynamic data and health information from a prospective institutional database of 57 FPAH and 66 IPAH patients registered with the Vanderbilt Pulmonary Hypertension Research Cohort. We compared hemodynamics at the time of diagnosis between the two groups and calculated pulmonary arteriolar capacitance (PC) and RV stroke work index (RVSWI). Using survival analysis, we compared freedom from a 5-year composite of death or lung transplantation in FPAH and IPAH patients. The composite outcome of death or transplant at 5 years from diagnosis was significantly increased in FPAH (log rank [Formula: see text]). PC and RVSWI were significantly decreased in FPAH, compared to IPAH ([Formula: see text] for both). In univariate analysis, PC (odds ratio [OR]: 0.17 [95% confidence interval (95% CI): 0.03-0.83]) and RVSWI (OR: 0.86 [95% CI: 0.77-0.95]) were predictors of mortality, as were cardiac index (OR: 0.17 [95% CI: 0.06-0.51]) and PVR (OR: 1.1 [95% CI: 1.01-1.12]). Among FPAH patients, RVSWI was lower in those who died or received a transplant than in survivors ([Formula: see text]), while PC was not ([Formula: see text]). We found significantly worse event-free survival and significantly lower PC and RVSWI in FPAH than in IPAH. In FPAH patients who died or underwent transplantation, RVSWI was lower than that in survivors, suggesting disproportionate RV dysfunction.

The Impact of Right Ventricular Stroke Work on B‐Type Natriuretic Peptide Levels in Patients With Mitral Stenosis Undergoing Percutaneous Mitral Valvuloplasty

We aimed to explore the relationship between brain natriuretic peptide (BNP) levels and right ventricular (RV) function in patients with mitral stenosis (MS), and to investigate the hemodynamic parameters that predict reduction of BNP levels after percutaneous mitral valvuloplasty (PMV). Few studies have evaluated BNP in the context of MS, specifically the impact of the RV stroke work (RVSW) on serum BNP levels has not been defined. Thirty patients with symptomatic rheumatic MS in sinus rhythm who were referred for a PMV were enrolled. Right and left heart pressures were obtained before and after valvuloplasty. RVSW index (RVSWI) was calculated by cardiac catheterization. Basal BNP levels were elevated in MS patients and correlated with several hemodynamic parameters including pulmonary pressure, pulmonary vascular resistance index, cardiac index (CI), and RVSWI. In multivariate analysis, CI and RVSWI were independent predictors of raised basal BNP levels. PMV resulted in a significant decrease in the RVSWI with a concurrent increase in CI (2.4 ± 0.43 to 2.9 ± 0.8 L/min/m(2), P = 0.010). Overall, plasma BNP levels significantly decreased from 124 (63/234) to 73 (48/148) pg/ml postvalvuloplasty. Multivariate analysis revealed that the reduction of left atrial (LA) pressure post-PMV was an independent predictor of change in BNP levels. Elevated baseline BNP level in MS patients was independently associated with CI and RVSWI. Plasma BNP levels were reduced after successful PMV, which was associated with the reduction of the LA pressure.

Estimating Right Ventricular Stroke Work and the Pulsatile Work Fraction in Pulmonary Hypertension

The mean pulmonary artery pressure (mPAP) replaces mean systolic ejection pressure (msePAP) in the classic formula of right ventricular stroke work (RVSW) = (mPAP - RAP) × stroke volume, where RAP is mean right atrial pressure. Only the steady work is thus taken into account, not the pulsatile work, whereas pulmonary circulation is highly pulsatile. Our retrospective, high-fidelity pressure study tested the hypothesis that msePAP was proportional to mPAP, and looked at the implications for RVSW. Eleven patients with severe, precapillary pulmonary hypertension (PH) (six patients with idiopathic pulmonary arterial hypertension and five with chronic thromboembolic PH; mPAP = 57 ± 10 mm Hg) were studied at rest and during mild to moderate exercise. Eight non-PH control subjects were also studied at rest (mPAP = 16 ± 2 mm Hg). The msePAP was averaged from end diastole to dicrotic notch. In the full data set (53 pressure-flow points), mPAP ranged from 14 to 99.5 mm Hg, cardiac output from 2.38 to 11.1 L/min, and heart rate from 53 to 163 beats/min. There was a linear relationship between msePAP and mPAP (r² = 0.99). The msePAP matched 1.25 mPAP (bias, -0.5 ± 2.6 mm Hg). Results were similar in the resting non-PH group and in resting and the exercising PH group. This implies that the classic formula markedly underestimates RVSW and that the pulsatile work may be a variable 20% to 55% fraction of RVSW, depending on RAP and mPAP. At rest, RVSW in patients with PH was twice as high as that of the non-PH group (P < .05), but pulsatile work fraction was similar between the two groups (26 ± 4% vs 24 ± 1%) because of the counterbalancing effects of high RAP (11 ± 5 mm Hg vs 4 ± 2 mm Hg), which increases the fraction, and high mPAP, which decreases the fraction. Our study favored the use of an improved formula that takes into account the variable pulsatile work fraction: RVSW = (1.25 mPAP - RAP) × stroke volume. Increased RAP and increased mPAP have opposite effects on the pulsatile work fraction.

Right ventricular stroke work index as a negative predictor of mortality and initial hospital stay after lung transplantation

Studies have shown that patients with poor pre-lung transplant (LTx) right ventricular (RV) function have prolonged post-operative ventilation time and intensive care stay as well as a higher risk of in-hospital death. RV stroke work index (RVSWI) calculates RV workload and contractility. We hypothesized that patients with higher RV workload capacity, indicated by higher RVSWI, would have better outcomes after LTx. A retrospective record review was performed on all LTx patients between 2005 and 2011 who had right heart catheterizations (RHC) 1-year before LTx. In addition, results for echocardiograms and cardiopulmonary exercise testing within 1-year of RHCs were gathered. Mean RVSWI was 9.36 ± 3.59 for 115 patients. There was a significant relation between mean pulmonary artery pressure (mPAP), RVSWI, RV end-diastolic diameter (RVEDd), left atrial dimension (LAD), peak and resting pressure of end-tidal carbon dioxide, minute ventilation /volume of carbon dioxide production, and 1-year mortality after LTx. Contrary to our hypothesis, those who survived had lower RVSWI than those who died within 1 year (8.99 ± 3.38 vs 11.6 ± 4.1, p = 0.026). Hospital length of stay significantly correlated with mPAP, RVSWI, left ventricular ejection fraction, percentage of fractional shortening, RVEDd, RV fractional area change, LAD, and RV wall thickness in diastole. Intensive care length of stay also significantly correlated with these variables and with body mass index. RVSWI was significantly different between groups of different RV function, indicating that increased RVSWI is associated with impairment of RV structure and function in patients undergoing LTx evaluation. This study demonstrates an association between 1-year mortality, initial hospital and intensive care length of stay, and pre-LTx RVSWI. Increased mPAP is a known risk for outcomes in LTx patients. Our findings support this fact and also show increased mortality with elevation of RVSWI, demonstrating the value of RV function in the assessment of risk for pre-LTx patients.

Role of Angiogenesis in the Right Ventricle Remodeling in Response to Pulmonary Hypertension

Purpose Right ventricular (RV) remodeling consisting of RV hypertrophy and increase in contractility occurs in response to pulmonary hypertension (PH) In congenital heart disease (CHD), the right ventricle remains compensated longer than in other types of PH. We hypothesized that better matched myocardial angiogenesis contributes to delay the transition to RV failure in CHD. Methods and Materials We induced chronic PH over a 20 weeks period in a Shunt group (n=5) by creating an aorto to pulmonary shunt and in an chronic thromboembolic PH (CTEPH group, n=5) by ligating the left pulmonary artery (PA) followed by weekly embolizations of the right lower lobe for weekly. In the Sham group (n=5), the pigs were studied 20 weeks after a left PA dissection. We assessed hemodynamics using right heart catherterization and RV structural and functional remodeling using echocardiography and pressure-volume loops measurement. Myocaridal angiogenesis of the RV was studied by measuring capillary density. Results At 20 weeks, mean PA pressure (26.8 ± 1.4 mm Hg vs 22.8 ±0.9 mm Hg, p=NS) and RV stroke work (SW) (2192± 255 mmHg/ml vs 2110 ±211 mmHg/ml, p=NS) were not significantly different in the CTEPH and Shunt groups but significantly more elevated when compared to the Sham group (14.8 ± 0.8 mm Hg and 1124±44 mmHg/ml, respectively; p Conclusions In PH induced by systemic to pulmonary shunt, the transition from RV compensated hypertrophy to RV failure is delayed compared to similar PH in a CTEPH model. Myocardial capillary density appears to be preserved in the right ventricle of shunt models.

Quantitative Three Dimensional Echocardiographic Assessment of the Right Ventricle Can Identify Risk of Right Ventricular Failure in Patients Undergoing Left Ventricular Assist Device Surgery

Purpose Right ventricular failure (RVF) is associated with significant morbidity following left ventricular assist device (LVAD) surgery. Hemodynamic, clinical, and 2-dimensional echocardiographic variables poorly discriminate patients at risk of RVF. We examined the utility of 3-dimensional echocardiography (3DE) right ventricular (RV) volumetric assessment to identify patients at risk of RVF. Methods and Materials RVF was defined as need for inotropic infusion for >14 days following LVAD surgery or RV assist device (RVAD) placement. Preoperative RV volumes and ejection fraction (RVEF) were measured, blinded to clinical data, from transthoracic 3DE full volume data sets in 29 patients. Univariate analyses were used to compare baseline variables and 3DE RV indices among patients with and without RVF. Multivariate logistic regression was used to adjust for baseline covariates. Results 25 patients (86%) received continuous flow LVADs. 13 patients (45%) had RVF 2 required RVAD support and 11 required prolonged inotropes. Cardiac index (CI), RV stroke work index (RVSWI), indexed RV end diastolic and systolic volumes (RVEDVI & RVESVI) and RVEF were associated with RVF. RVEDVI (OR 1.082 (1.00, 1.17), p=0.049) and RVESVI (OR 1.117 (1.00, 1.25), p=0.049) remained associated with RVF after adjusting for RVSWI. Conclusions Quantitative 3DE is a promising method for pre-LVAD RV assessment. RV volumes assessed by 3DE are predictive of RVF in LVAD recipients, independent of RVSWI. Comparison of 3DE and baseline variables among patients with and without RVF. No RVF (mean±SD) RVF (mean±SD) P-value RVEDVI (ml/m2) 46 ± 13 65 ± 21 0.008 RVESVI (ml/m2) 30 ± 9 53 ± 22 0.0095 RVEF (%) 33 ± 9 23 ± 12 0.014 RVSWI (mmHg ml/m2) 644 ± 267 400 ± 175 0.0092 CI (l/min/m2) 2.3 ± 0.6 1.9 ± 0.3 0.047 Total Bilirubin (mg/dL) 1.4 ± 0.8 1.6 ± 0.9 0.68 BUN (mg/dL) 24 ± 13 17 ± 8 0.06 Right atrial pressure/PCWP ratio 0.4 ± 0.1 0.6 ± 0.2 0.09 Right atrial pressure (mmHg) 10 ± 4 14 ± 7 0.17

Left Ventricular Assist Device in Right Ventricular Failure

Purpose Left ventricular (LV) assist device (AD) placement for end-stage LV failure (F) is contraindicated with co-existing right ventricular (RV) F. We propose a strategic pre-op management (“HF tune up”) prior to LVAD allowing safe LVAD implant despite RVF. Methods and Materials This single center study identified 47 patients (pts) who underwent Heart Mate II implant from 2009 to 2011. Pre-op hemodynamics were analyzed at three time points: presentation (T0), 1 day pre-op (T1) and 3 days post-op (T2). Pre-op RVF was defined visually by 2D-echocardiography &/or by RV Stroke Work Index (RVSWI 14 days &/or RVAD placement. All pts underwent escalating pre-op “HF tune up” (diuresis, vasodilators, inotropes). Results Mean INTERMACS score for all HF pts who underwent HMII LVAD insertion was 1.7 ±0.6. Mean age was 61±16 yrs. 62% (n=29) of pts had preexisting RVF by echocardiography (51% moderate, 11% severe) with markedly elevated CVP at T0 compared to non-RVF. Of those, 24% (n=7) pts had RVF by RVSWI criteria. HF tune up significantly improved CVP and PCWP (T1) without change in RVSWI (T0: 0.6 ±0.5 vs T1: 0.3±0.3; p=ns). Despite marked pre-op RVF, post-op RVF rate were markedly low with 2% (n=1) suggesting that under ideal hemodynamics (Fontan physiology) the LVAD can support both, LV & RV. 1-year morbidity and mortality was excellent and not different between RVF vs non-RVF. Conclusions Effective pre-op HF tune up targeting CVP ≤ 8, PCWP ≤18, and PVR≤1.2 in end-stage HF pts with refractory pre-op RVF can greatly reduce post-op RVF. In this setting, LVAD placement appears to be safe and supports both ventricles via a “Fontan” circuit. LVAD and Hemodynamics at different time points Variables No RVF(n=18) RVF(n=29) CVP (mmHg) T0 13.8 ± 4.5 17.7 ± 4.1 0.004 T1 8.6 ± 3.9 9.1 ± 2.1 NS NS T2 12.4±4.9 11.5±4.2 NS PCWP(mmHg) T0 23.2±4.3 22.9±5.0 NS T1 17.6±5.6 15.43±3.7 NS NS NS T2 19.3±5.6 14±5.6 0.02 PVR (WU) T1 3.1±2.0 2.53±1.7 NS NS T2 1.95±4.2 1.14±1.8 NS

Right Atrial to Pulmonary Capillary Wedge Pressure Ratio Is Not Associated with Failure of Optimal Medical Management in the INTERMACS 4-5 Population

Purpose Intracardiac filling pressures play an important role in in risk stratification of patients with advanced systolic heart failure (HF) undergoing cardiac transplantation (OHT) and left ventricular assist device (LVAD) placement. The right atrial (RA) pressure to pulmonary capillary wedge pressure (PCWP) ratio has been shown to have important prognostic significance. Less is known about the prognostic impact of cardiac filling pressures in patients with ambulatory advanced HF (INTERMACS profiles 4-5). Methods and Materials We retrospectively evaluated 187 patients referred for consideration of advanced HF therapies at our center from January 2005 to July 2010. The endpoint of failure of optimal medical management (OMM) was defined as death, OHT or LVAD implantation. Tertiles of RA:PCWP ratio were defined as 0.583(tertile 3). Median PCWP in each cohort was 16, 25, and 20 mmHg respectively (p Results Patients in tertile 3 had lower PA oxygen saturation(p= 0.006), RV stroke work index (p 20mmHg, p=0.146). However, when evaluating each RA and PCWP independently, only increasing PCWP was associated with failure of OMM [HR 1.046 (1.020-1.073), p Conclusions In a cohort of patients with advanced ambulatory HF (INTERMACS 4-5), increasing RA:PCWP was associated with worsening RV function and decreased exercise capacity but not with failure of OMM. PCWP varied across tertiles of RA:PCWP ratio and was independently associated with failure of OMM. Our study suggests that left and right-sided filling pressures may need to be interpreted independently in advanced ambulatory heart failure.

Assessment of Right Ventricle before the Implantation of Left Ventricular Assist Device by Echocardiographic Parameters (ARVADE)

Purpose The aim of the study is to identify preoperative echocardiographic predictors of post-LVAD Right ventricular failure (RVF). Methods and Materials Data were collected on 42 patients undergoing LVAD implantation in the heart and diabetes center in Germany. Echocardiographic measurements were supplemented by strain of RV. Data were compared between patients with and without RVF. A score was established with independent predictors of RVF by rounding the exponentiated regression model coefficients to the nearest 0.5. Results RVF occurred in 24 of 42 patients. The INTERMACS levels were lower in RVF patients. Basal end-diastolic RV diameter, right-to-left ventricular end-diastolic diameters and mitral E wave were higher in RVF patients whereas RVSWI was decreased.Em > 105 cm/s (RR 2.48, IC [1.40-4.38], p = 0.003), basal RVEDD (RR 1.74, IC [1.04-2.91], p = 0.037) and INTERMACS 1 level (RR1.70, IC [1.00 – 2.90], p = 0.049) were independent predictor of RVF. An ARVADE score > 2 can predict the occurrence of RVF with sensibility 92% and specificity 67%. Conclusions The ARVADE score can help to device selection. RVF patients n = 24 No RVF patients n = 18 P value FAC, % 12.5 [9.0-18.8] 13.8 [6.8-22.8] 0.30 Basal RVEDD, mm 50 [43-56] 42 [37-48] 0.016 Svd, cm/s 10.1 [7.8-12.5] 11.5 [9.6-13.5] 0.059 TAPSE, mm 15 [12-19] 17 [15-20] 0.16 Strain, % 8.9 [6.9-10. 3] 9.4 [8.6-11.5] 0.70 sPAP, mmHg 32 [24-43] 35 [32-43] 0.40 RVSWI, mmHg/m2/L 7.8 [5.3-12.5] 11.6 [6.1-18.7] 0.04 RVEDD-to-LVEDD ratio 0.65 [0.60-0.72] 0.58 [0.45-0.66] 0.02 LVEDD, mm 77 [67-84] 72 [70-76] 0.76 LVEF, % 18.4 [10.6-25.1] 17.2 [12.3-23.8] 0.56 Em, cm/s 106 [86-134] 85 [65-91] 0.008 Values are median (interquartile range) or n/N (%). FAC right ventricular fractional area change; Basal RVEDD basal RV end-diastolic diameter; TAPSE maximal systolic excursion of the tricuspid annulus, SRV RV tissue doppler systolic velocities; SPAP systolic pulmonary arterial pressure; RVSWI RV stroke work index; LVEDD LV end-diastolic diameter, LVEF LV ejection fraction; Em mitral E wave.

Relationship of Right- to Left-Sided Ventricular Filling Pressures in Advanced Heart Failure

Background— Although right atrial pressure (RAP) and pulmonary capillary wedge pressure (PCWP) are correlated in heart failure, in a sizeable minority of patients, the RAP and PCWP are not tightly coupled. The basis of this variability in the RAP/PCWP ratio, and whether it conveys prognostic value, is not known. Methods and Results— We analyzed the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial database. Baseline characteristics, including echocardiographic assessment of right ventricular (RV) structure and function, and invasively measured hemodynamic parameters, were compared among tertiles of the RAP/PCWP ratio. Multivariable Cox proportional hazard models assessed the association of RAP/PCWP ratio with the primary ESCAPE outcome (6-month death or hospitalization [days]) adjusting for systolic blood pressure, blood urea nitrogen, 6-minute walk distance, and PCWP. The RAP/PCWP tertiles were 0.27 to 0.4 (tertile 1); 0.41 to 0.615 (tertile 2), and 0.62 to 1.21 (tertile 3). Increasing RAP/PCWP was associated with increasing median right atrial area (23, 26, 29 cm 2 , respectively; P &lt;0.005), RV area in diastole (21, 27, 27 cm 2 , respectively; P &lt;0.005), and pulmonary vascular resistance (2.4, 2.9, 3.6 woods units, respectively; P =0.003), and lower RV stroke work index (8.6, 8.4, 5.5 g·m/m 2 per beat, respectively; P &lt;0.001). RAP/PCWP ratio was associated with death or hospitalization within 6 months (hazard ratio, 1.16 [1, 1.4]; P &lt;0.05). Conclusions— Increased RAP/PCWP ratio was associated with higher pulmonary vascular resistance, reduced RV function (manifest as a larger right atrium and ventricle and lower RV stroke work index), and an increased risk of adverse outcomes in patients with advanced heart failure.

Impact of continuous-flow left ventricular assist device support on right ventricular function

Continuous-flow (CF) pumps have yielded improvements in short- and long-term survival and quality of life, and have reduced the number of left ventricular assist device (LVAD)-related complications. However, their ability to unload the right ventricle (RV) and improve RV function has not been as clearly defined. We evaluated the short- and mid-term effects of CF-LVADs on central venous pressure (CVP), pulmonary artery pressures (PAP), pulmonary capillary wedge pressure (PCWP), cardiac index (CI), RV ejection fraction (RVEF), RV end-diastolic dimension (RVEDD), RV stroke work index (RVSWI), tricuspid annular plane systolic excursion (TAPSE) and severity of tricuspid regurgitation (TR). From March 2006 through June 2012, 130 patients with chronic heart failure underwent implantation of a CF-LVAD (122 HeartMate II and 8 HeartWare devices) as a bridge to transplant (n = 76) or as destination therapy (n = 54). Patients with pre-operative long-term LVADs (n = 4) and patients who underwent concomitant tricuspid valve repairs during their LVAD implant (n = 21) were excluded from the analysis. Echocardiograms and right heart catheterizations of the remaining 105 patients were reviewed pre-operatively and at 1 and 6 months post-LVAD implantation. At 1 month post-LVAD implantation, CVP decreased from 12.4 ± 5.9 mm Hg to 8.7 ± 4.5 mm Hg (p < 0.001), systolic PAP decreased from 52.3 ± 14.1 mm Hg to 36.8 ± 11.3 mm Hg (p < 0.001), PCWP decreased from 23.0 ± 9.4 mm Hg to 12.9 ± 8.0 mm Hg (p < 0.001), CI index increased from 1.8 ± 0.5 liters/min m2 to 2.4 ± 0.5 liters/min m2 (p < 0.001), RVEF increased from 33.1 ± 4.9% to 40.4 ± 6.2% (p < 0.001), RVEDD decreased from 36 mm to 31 mm (p = 0.020), RVSWI improved from 408.6 ± 144.6 mm Hg ml m2 to 614.4 ± 196.2 mm Hg ml m2 (p < 0.001), and mean TAPSE increased from 1.1 ± 0.4 cm to 1.9 ± 0.4 cm (p = 0.004). Similarly, qualitative RV function on echocardiography improved from 57.1% moderately or severely reduced pre-operatively to 38.1% at 1 month (p = 0.008). Severity of TR decreased from 11.4% moderate or severe pre-operatively to 4.8% at 1 month (p < 0.001). These improvements were maintained at 6 months post-LVAD. CF-LVAD support significantly decreased CVP and RVEDD, with concomitant improvement in RV function, as measured by increases in RVEF, RVSWI and TAPSE, as well as improvements in the qualitative echocardiographic appearance of RV contractility and a reduction in TR.

Energy Transfer Ratio as a Metric of Right Ventricular Efficiency in Repaired Congenital Heart Disease

With the success of early repair, continued functional assessment of repaired congenital heart disease is critical for improved long-term outcome. Pulmonary regurgitation, which is one of the main postoperative sequelae of congenital heart disease involved with the right ventricle (RV) such as tetralogy of Fallot and transposition of the great arteries, results in progressive RV dilatation coupled with pulmonary artery (PA) obstruction causing elevated RV pressures. The appropriate timing of intervention to correct these postoperative lesions remains largely subjective. In the present study, we evaluated an energy-based end point, namely energy transfer ratio (eMPA ), to assess the degree of RV and PA inefficiency in a group of congenital heart disease patients with abnormal RV-PA physiology. Eight patients with abnormal RV-PA physiology and six controls with normal RV-PA physiology were investigated using a previously validated technique that couples cardiac magnetic resonance imaging and invasive pressure measurements. The mean eMPA of the patient group (0.56 ± 0.33) was significantly lower (P <.04) than that of the control group (1.56 ± 0.85), despite the fact that the patient group had a significantly higher RV stroke work indexed to body surface area (RV SWI ) than the control group (0.205 ± 0.095 J/m(2) vs. 0.090 ± 0.038 J/m(2) ; P <.02). We determined that the patients had inefficient RV-PA physiology due to a combination of RV dilatation with pulmonary regurgitation and RV outflow obstruction leading to an elevated end-systolic pressure. Using coupled magnetic resonance imaging and invasive pressure measurements, eMPA is determined to be a sensitive energy-based end point for measuring RV-PA efficiency. It may serve as a diagnostic end point to optimize timing of intervention.

A Clinical Phenotype of Adverse Response to Biventricular Pacing: A Case Series

Biventricular pacing is an established therapy for patients with heart failure with reduced left ventricular ejection fraction and prolonged QRS duration. However, there are few reports on the adverse effects of biventricular pacing. Three patients who deteriorated rapidly following biventricular pacing (heart transplantation/ventricular assist device within 3 months of device implantation) were identified. The clinical, echocardiographic, and functional characteristics before and after device implantation were evaluated. The acute hemodynamic effects of biventricular pacing were assessed by cardiac catheterization. Preimplant assessment showed biventricular dysfunction, pulmonary hypertension, and relatively narrow QRS duration. The time from device implantation to assessment was 62, 58, and 42 days. All three patients developed right bundle branch block (RBBB)-type QRS morphology, deterioration in right ventricular (RV) function, and functional capacity in association with rapid clinical decline. Acutely, biventricular pacing resulted in higher right atrial pressure, pulmonary wedge pressure, lower cardiac output, and RV stroke work in all three patients. A phenotype of adverse response to biventricular pacing is characterized by relatively narrow QRS duration, RV dysfunction, and pulmonary hypertension. Clinical decline is rapid and associated with the development of RBBB-type morphology, worsening of pulmonary hemodynamics, and RV dysfunction with biventricular pacing.

Echocardiographic Evaluation of Right Ventricular Stroke Work Index in Advanced Heart Failure: A New Index?

BackgroundRight ventricular (RV) function plays a pivotal role in advanced heart failure patients, especially for screening those who may benefit from left ventricular assist device (LVAD) implantation. We introduce RV contraction pressure index (RVCPI) as a new echo-Doppler parameter of RV function. The accuracy of RVCPI in detecting RV failure was compared with the criterion standard, the RV stroke work index (RVSWI) obtained through right heart catheterization in advanced heart failure patients referred for heart transplantation or LVAD implantation. Methods and ResultsRight heart catheterization and echo-Doppler were simultaneously performed in 94 consecutive patients referred to our center for advanced heart failure (ejection fraction (EF) 24 ± 8.8%, 40% NYHA functional class IV). RV stroke volume and invasive pulmonary pressures were used to obtain RVSWI. Simplified RVCPI (sRVCPI) was derived as TAPSE × (RV − right atrial pressure gradient). Close positive correlation between sRVCPI and RVSWI was found (r = 0.68; P < .001). With logistic regression, we found that increased sRVCPI showed an independent reduced risk (odds ratio 0.98, 95% confidence interval [CI] 0.97–0.99; P = .016) for patients to present a depressed RVSWI (<0.25 mm Hg/L·m2). Simplified RVCPI showed high diagnostic accuracy (area under the receiver operating characteristic curve 0.94, 95% CI 0.89–0.99) and good sensitivity and specificity (92% and 85%, respectively) to predict depressed RVSWI with the use of a cutoff value of <400 mm·mm Hg. ConclusionsIn patients with advanced heart failure, the new simple bedside sRVCPI closely correlated with RVSWI, providing an independent, noninvasive, and easy tool for the evaluation of RV function.

Right Ventricular Longitudinal Strain and Right Ventricular Stroke Work Index in Patients With Severe Heart Failure: Left Ventricular Assist Device Suitability for Transplant Candidates

BackgroundRight ventricular (RV) systolic function has a critical role in determining the clinical outcome and the success of using left ventricular assist devices in patients with refractory heart failure. RV deformation analysis by speckle tracking echocardiography (STE) has recently allowed the analysis of RV longitudinal function. Using cardiac catheterization as the reference standard, this study aimed to explore the correlation between RV longitudinal function by STE and RV stroke work index (RVSWI) among patients referred for cardiac transplantation. MethodsRight heart catheterization and transthoracic echo-Doppler were simultaneously performed in 47 patients referred for cardiac transplant assessment due to refractory heart failure (ejection fraction 25.1 ± 4.5%). Thermodilution RV stroke volume and invasive pulmonary pressures were used to obtain RVSWI. RV longitudinal strain (RVLS) by STE was assessed averaging RV free-wall segments (free-wall RVLS). We also calculated. Tricuspid S' and tricuspid annular plane systolic excursion (TAPSE). ResultsNo significant correlation was observed for TAPSE on tricuspid S' with RV stroke volume (r = 0.14 and r = 0.06, respectively). A close negative correlation between free-wall RVLS and RVSWI was found (r = −0.82; P < .0001). Furthermore, free-wall RVLS showed the highest diagnostic accuracy (area under the curve of 0.90) with good sensitivity and specificity of 95% and 91%, respectively, to predict depressed RVSWI using a cutoff value less than −11.8%. ConclusionsAmong patients referred for heart transplantation, TAPSE and tricuspid S' did not correlate with invasively obtained RVSWI. RV longitudinal deformation analysis by STE correlated with RVSWI, providing a better estimate of RV systolic performance.

The Impact of Portopulmonary Hypertension on Intraoperative Right Ventricular Function of Living Donor Liver Transplant Recipients

Portopulmonary hypertension (PPH) burdens a right ventricle (RV) already exposed to physiologic stress during liver transplantation. The magnitude of the impact of PPH on RV function, especially early reperfusion, has not been evaluated adequately by prospective controlled trials. In this study, we prospectively quantified the impact of PPH on the RV function in living donor liver transplant recipients. Twenty patients undergoing living donor liver transplant were stratified based on mean pulmonary artery pressure (mPAP) into a control group (mPAP <25 mm Hg) and a PPH group (mPAP ≥25 mm Hg). Standard anesthetic technique and monitoring were used. Fiberoptic pulmonary artery catheters enabled to measure RV ejection fraction (RVEF) were used. Hemodynamics were recorded after induction of anesthesia, the end of hepatectomy, before portal unclamping, 5 and 30 minutes after reperfusion, and at skin closure. The PPH group had significantly lower RVEF, stroke volume, and higher central venous pressure and RV end-diastolic volume index after portal unclamping versus the controls. Pulmonary vascular resistance index and mPAP were significantly higher throughout the operation in the PPH group, but RV stroke work index did not differ significantly between groups. RVEF was significantly reduced in the PPH group after reperfusion compared with baseline, but the control group did not experience such a reduction. Mild to moderate PPH was associated with reduced RVEF during liver transplantation, especially after reperfusion, likely because of a reduced RV contractile reserve in PPH patients. This reduction in RVEF was clinically well tolerated by patients with mild to moderate PPH.

Calpain Inhibition Preserves Talin and Attenuates Right Heart Failure in Acute Pulmonary Hypertension

Right heart failure from right ventricular (RV) pressure overload is a major cause of morbidity and mortality, but its mechanism is incompletely understood. We tested the hypothesis that right heart failure during 4 hours of RV pressure overload is associated with alterations of the focal adhesion protein talin, and that the inhibition of calpain attenuates RV dysfunction and preserves RV talin. Anesthetized open-chest pigs treated with the calpain inhibitor MDL-28170 (n = 20) or inactive vehicle (n = 23) underwent 4 hours of RV pressure overload by pulmonary artery constriction (initial RV systolic pressure, 64 ± 1 and 66 ± 1 mm Hg in MDL-28170 and vehicle-treated pigs, respectively). Progressive RV contractile dysfunction was attenuated by MDL-28170: after 4 hours of RV pressure overload, RV systolic pressure was 44 ± 4 mm Hg versus 49 ± 6 mm Hg (P = 0.011), and RV stroke work was 72 ± 5% of baseline versus 90 ± 5% of baseline, (P = 0.027), in vehicle-treated versus MDL-28170-treated pigs, respectively. MDL-28170 reduced the incidence of hemodynamic instability (death or systolic blood pressure of < 85 mm Hg) by 46% (P = 0.013). RV pressure overload disrupted talin organization. MDL-28170 preserved talin abundance in the RV free wall (P = 0.039), and talin abundance correlated with the maintenance of RV free wall stroke work (r = 0.58, P = 0.0039). α-actinin and vinculin showed similar changes according to immunohistology. Right heart failure from acute RV pressure overload is associated with reduced talin abundance and disrupted talin organization. Calpain inhibition preserves the abundance and organization of talin and RV function. Calpain inhibition may offer clinical utility in treating acute cor pulmonale.