New insights into resting and exertional right ventricular performance in the healthy heart through real‐time pressure‐volume analysis

Abstract

Key points Despite growing interest in right ventricular form and function in diseased states, there is a paucity of data regarding characteristics of right ventricular function – namely contractile and lusitropic reserve, as well as ventricular‐arterial coupling, in the healthy heart during rest, as well as submaximal and peak exercise. Pressure‐volume analysis of the right ventricle, during invasive cardiopulmonary exercise testing, demonstrates that that the right heart has enormous contractile reserve, with a three‐ or fourfold increase in all metrics of contractility, as well as myocardial energy production and utilization. The healthy right ventricle also demonstrates marked augmentation in lusitropy, indicating that diastolic filling of the right heart is not passive. Rather, the right ventricle actively contributes to venous return during exercise, along with the muscle pump. Ventricular‐arterial coupling is preserved during submaximal and peak exercise in the healthy heart.AbstractKnowledge of right ventricular (RV) function has lagged behind that of the left ventricle and historically, the RV has even been referred to as a ‘passive conduit’ of lesser importance than its left‐sided counterpart. Pressure‐volume (PV) analysis is the gold standard metric of assessing ventricular performance. We recruited nine healthy sedentary individuals free of any cardiopulmonary disease (42 ± 12 years, 78 ± 11 kg), who completed invasive cardiopulmonary exercise testing during upright ergometry, while using conductance catheters inserted into the RV to generate real‐time PV loops. Data were obtained at rest, two submaximal levels of exercise below ventilatory threshold, to simulate real‐world scenarios/activities of daily living, and maximal effort. Breath‐by‐breath oxygen uptake was determined by indirect calorimetry. During submaximal and peak exercise, there were significant increases in all metrics of systolic function by three‐ to fourfold, including cardiac output, preload recruitable stroke work, and maximum rate of pressure change in the ventricle (dP/dtmax), as well as energy utilization as determined by stroke work and pressure‐volume area. Similarly, the RV demonstrated a significant, threefold increase in lusitropic reserve throughout exercise. Ventricular‐arterial coupling, defined by the quotient of end‐systolic elastance and effective arterial elastance, was preserved throughout all stages of exercise. Maximal pressures increased significantly during exercise, while end‐diastolic volumes were essentially unchanged. Overall, these findings demonstrate that the healthy RV is not merely a passive conduit, but actively participates in cardiopulmonary performance during exercise by accessing an enormous amount of contractile and lusitropic reserve, ensuring that VA coupling is preserved throughout all stages of exercise.

A step in the right direction: pressure‐volume relationships provide insight into right ventricular performance during exercise in healthy adults

“…Cornwell et al . (2020) have demonstrated that systolic RV performance in healthy volunteers can augment up to 3‐fold, which advances observations from patient controls (Spruijt et al . 2015).…”

“…Cornwell et al . (2020) have contributed to filling these knowledge gaps in a recent article in The Journal of Physiology . The study aimed to comprehensively describe systolic and diastolic RV performance and reserve in healthy individuals using pressure‐volume relationships at rest and during exercise.…”

Physiology of the Right Ventricle Across the Lifespan

“…The RV can quickly adapt to increases in O 2 demand by increasing coronary blood flow and increasing O 2 extraction. Clinically, this has recently been elegantly demonstrated in healthy adults using RV conductance catheters to collect real-time pressurevolumes loops (Cornwell et al, 2020). The authors found that resting RV energy expenditure was markedly lower than that of the resting LV and that RV energy expenditure increased dramatically with exercise to levels comparable with the resting LV.…”

Impact of Altitude on Cardiopulmonary and Right Ventricular Hemodynamics During Exercise

“…29 Hypoxia-mediated augmentations in PAP lead to an increase in RV afterload. 6,[34][35][36][37][38][39][40] In a study of healthy individuals, RV end-diastolic volume increased from 52 ± 12 to 61 ± 25 mL at SL to 5085 m, respectively, which coincided with increases in systolic PAP (13.1 ± 5.9 versus 26.6 ± 10.8 mm Hg). 37 In another study, TAPSE declined from 2.9 ± 0.3 to 2.3 ± 0.3 from SL to 5050 m. 29 Finally, pharmacologic reductions of PAP by administration of sildenafil led to an increase in LV SV.…”

“…39 In total, these data suggest that, as PAP (and hence, RV afterload) rises, RV contractility declines over time, and this reduction in RV function compromises LV SV. Further research incorporating invasive and comprehensive assessments of RV function-such as has recently been performed in patients with pulmonary arterial hypertension, 41 heart failure with preserved ejection fraction, 42 heart failure patients supported by LV assist devices, 43 and even healthy individuals exercising at SL 40 -is necessary to characterize the effects of acute and chronic altitude exposure on resting and exertional RV performance and how decrements in RV function may influence LV SV, Qc, and exercise capacity overall.…”