Right ventricular functional recovery assessment with stress echocardiography and cardiopulmonary exercise testing after pulmonary embolism: a pilot prospective multicentre study.

BACKGROUND: Data on right ventricular (RV) exercise adaptation following acute intermediate and high-risk pulmonary embolism (PE) remain limited. This study aimed to evaluate the symptom burden, RV functional recovery during exercise and cardiopulmonary exercise parameters in survivors of intermediate and high-risk acute PE. METHODS: We prospectively recruited patients following acute intermediate and high-risk PE at four sites in Australia and UK. Study assessments included stress echocardiography, cardiopulmonary exercise testing (CPET) and ventilation-perfusion (VQ) scan at 3 months follow-up. RESULTS: Thirty patients were recruited and 24 (median age: 55 years, IQR: 22) completed follow-up. Reduced peak oxygen consumption (VO2) and workload was seen in 75.0% (n=18), with a persistent high symptom burden (mean PEmb-QoL Questionnaire 48.4±21.5 and emPHasis-10 score 22.4±8.8) reported at follow-up. All had improvement in RV-focused resting echocardiographic parameters. RV systolic dysfunction and RV to pulmonary artery (PA) uncoupling assessed by stress echocardiography was seen in 29.2% (n=7) patients and associated with increased ventilatory inefficiency (V̇E/V̇CO2 slope 47.6 vs 32.4, p=0.03), peak exercise oxygen desaturation (93.2% vs 98.4%, p=0.01) and reduced peak oxygen pulse (p=0.036) compared with controls. Five out of seven patients with RV-PA uncoupling demonstrated persistent bilateral perfusion defects on VQ scintigraphy consistent with chronic thromboembolic pulmonary vascular disease. CONCLUSION: In our cohort, impaired RV adaptation on exercise was seen in almost one-third of patients. Combined stress echocardiography and CPET may enable more accurate phenotyping of patients with persistent symptoms following acute PE to allow timely detection of long-term complications.

Right heart strain assessment on CTPA following acute pulmonary embolism: Interobserver variability between expert radiologists and physicians.

BACKGROUND: Accuracy of right heart strain (RHS) measured on computed tomography pulmonary angiogram (CTPA) scans by non-radiologists is unknown. We assessed inter-observer variability of four RHS features and determined the accuracy of measurements by respiratory physicians. METHOD: 1560 consecutive patients with acute PE were identified, and those who had a CTPA and an echocardiogram within 24-h included. CTPAs were independently scored prospectively by two radiologists, two thoracic physicians and a specialist registrar. Inter-observer variability was assessed, and diagnostic accuracy compared to echocardiography. RESULTS: 182 patients (median age 62.8 years, IQR 49.8-71.5) with acute PE (7.7% high-risk, 40.7% intermediate high-risk, 31.3% intermediate low-risk and 20.3% low-risk) were included. Right ventricle to left ventricle diameter ratio (RV:LV) measurement had low inter-observer variability among the radiologists and non-radiologists with interclass correlation coefficient (ICC) of 0.95 (95%CI 0.92-0.97) and 0.96 (95%CI 0.94-0.97) respectively. RV:LV ratio had high diagnostic accuracy compared to RV dilatation on echocardiography (AUC 0.89, 95%CI 0.84-0.94 for radiologists and AUC 0.84, 95%CI 0.77-0.90 for non-radiologists). Main pulmonary artery to ascending aorta diameter ratio (MPA:Ao) measurement also had excellent agreement amongst the radiologists and non-radiologists (ICC 0.93 (95%CI 0.88-0.96) and 0.92 (95%CI 0.81-0.96) respectively). Significant variability was seen in the assessment of subjective features of RHS (leftward bowing of interventricular septum and contrast reflux into inferior vena cava) amongst the non-radiologists. CONCLUSION: RV:LV and MPA:Ao diameter ratios on CTPA measured by non-radiologists have low inter-observer variability and good agreement with radiologists, and can be reliably used where an expert report is unavailable.

Physiological demands of singing for lung health compared with treadmill walking.

INTRODUCTION: Participating in singing is considered to have a range of social and psychological benefits. However, the physiological demands of singing and its intensity as a physical activity are not well understood. METHODS: We compared cardiorespiratory parameters while completing components of Singing for Lung Health sessions, with treadmill walking at differing speeds (2, 4 and 6 km/hour). RESULTS: Eight healthy adults were included, none of whom reported regular participation in formal singing activities. Singing induced acute physiological responses that were consistent with moderate intensity activity (metabolic equivalents: median 4.12, IQR 2.72-4.78), with oxygen consumption, heart rate and volume per breath above those seen walking at 4 km/hour. Minute ventilation was higher during singing (median 22.42 L/min, IQR 16.83-30.54) than at rest (11 L/min, 9-13), lower than 6 km/hour walking (30.35 L/min, 26.94-41.11), but not statistically different from 2 km/hour (18.77 L/min, 16.89-21.35) or 4 km/hour (23.27 L/min, 20.09-26.37) walking. CONCLUSIONS: Our findings suggest the acute metabolic demands of singing are comparable with walking at a moderately brisk pace, hence, physical effects may contribute to the health and well-being benefits attributed to singing participation. However, if physical training benefits result remains uncertain. Further research including different singing styles, singers and physical performance impacts when used as a training modality is encouraged. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov registry (NCT04121351).

Right ventricle functional assessment: have new techniques supplanted the old faithful conductance catheter?

This review explores the historical development of conductance catheterization of the human right ventricle (RV) and its current diagnostic role in assessing RV function in an era of contemporary noninvasive imaging. Significant advances in echocardiography, cardiothoracic computed tomography, and cardiac magnetic resonance in the last decade have led a paradigm shift away from invasive hemodynamic assessment toward noninvasive measurement of RV function. However, imaging modalities are not without some disadvantages. For example, they do not provide the beat-to-beat pressure-volume assessment that is obtained by conductance catheterization, which is still arguably the gold standard for measuring cardiac performance. Right heart catheterization remains an integral part of the assessment of patients with RV dysfunction, and a burgeoning interest in early RV insufficiency in a range of cardiopulmonary diseases has brought the detailed interrogation of RV function back into focus. Although conductance volume assessment of the RV is more limited than the left ventricle, the scope for improving the understanding of RV adaptation to pulmonary and valvular pathologies and RV myocardial disease by using a conductance catheter still exists. We review the up-to-date functional applications of echocardiography and computed tomography/cardiac magnetic resonance to assess the RV and illustrate the potential of contemporary conductance catheter techniques to complement noninvasive imaging in the assessment of RV function.