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BACKGROUND: Interventricular interactions may be responsible for the decline in ventricular performance observed in various disease states that primarily affect the contralateral ventricle. OBJECTIVES: This study sought to quantify the impact of such interactions on right ventricular (RV) size and function using clinically stable individuals with left ventricular assist devices (LVADs) as a model for assessing RV hemodynamics while LV loading conditions were acutely manipulated by changing device speed during hemodynamic optimization studies (ie, ramp tests). METHODS: The investigators recorded RV pressure-volume loops with a conductance catheter at various speeds during ramp tests in 20 clinically stable HeartMate3 recipients. RESULTS: With faster LVAD speeds and greater LV unloading, indexed RV end-diastolic volume increased (72.28 ± 15.07 mL at low speed vs 75.95 ± 16.90 at high speed; P = 0.04) whereas indexed end-systolic volumes remained neutral. This resulted in larger RV stroke volumes and shallower end-diastolic pressure-volume relationships. Concurrently, RV end-systolic pressure decreased (31.58 ± 9.75 mL at low speed vs 29.58 ± 9.41 mL at high speed; P = 0.02), but contractility, as measured by end-systolic elastance, did not change significantly. The reduction in RV end-systolic pressure was associated with a reduction in effective arterial elastance from 0.65 ± 0.43 mm Hg/mL at low speed to 0.54 ± 0.33 mm Hg/mL at high speed (P = 0.02). CONCLUSIONS: Interventricular interactions resulted in improved RV compliance, diminished afterload, and did not reduce RV contractility. These data challenge the prevailing view that interventricular interactions compromise RV function, which has important implications for the understanding of RV-LV interactions in various disease states, including post-LVAD RV dysfunction.
Assuntos
Insuficiência Cardíaca , Coração Auxiliar , Volume Sistólico , Função Ventricular Direita , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Função Ventricular Direita/fisiologia , Volume Sistólico/fisiologia , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Ventrículos do Coração/fisiopatologia , Disfunção Ventricular Direita/fisiopatologia , Pressão Ventricular/fisiologia , Idoso , Adulto , Hemodinâmica/fisiologiaRESUMO
INTRODUCTION: ST-elevation myocardial infarction (STEMI) remains a leading cause of death despite advances in revascularization and post-STEMI care. Especially for patients with a poor prognosis, there is increasing emphasis on comfort-focused care. METHODS: We conducted a single-center retrospective cohort study of patients with STEMI at a large tertiary care academic medical center, abstracting patient-level data, causes of death, and use of palliative care consultation from the medical records. We sought to investigate the frequency of comfort-focused approaches and palliative care consultation after STEMI. RESULTS: A total of 536 patients presented with or were transferred with STEMI from January 2010 to July 2018, of whom 61/536 (11.4%) died during index hospitalization. Among those who underwent percutaneous intervention (PCI), the in-hospital mortality rate was 6.8%. Median (IQR) and time to death was two (0-6) days. Among those who died, 25/61 (41%) were treated with mechanical circulatory support (MCS). A total of 25/61 (41%) patients died following transition to a comfort-focused approach. Rate of MCS utilization during hospitalization was higher in the group that was ultimately transitioned to comfort-focused measures than the group who received full treatment measures. Palliative care was consulted in the case of 6/61 (9.8%) patients. Median time to consultation was 5 (1-7) days and time to death was 6.5 (2-28) days. DISCUSSION: Transition to comfort-focused care before death after STEMI is common, particularly in those with cardiogenic shock and/or treated with MCS, highlighting the critical status of such patients. Although increasingly employed in recent years, palliative care consults remain rare and are often employed late in the hospitalization.
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Chronic heart failure (HF) is a clinical syndrome of myocardial dysfunction characterized by inadequate cardiac output or preserved output that can only be achieved by sustaining abnormal loading conditions. Morphologically, HF with reduced left ventricular function results in progressive chamber remodeling, meaning the ventricle dilates, operating at larger end-diastolic and end-systolic volumes, and takes on an abnormal, spherical shape that increases wall stress. Reverse remodeling is the goal of HF-directed therapies and can be achieved by biological means, ie, altering the loading conditions that, at a cellular level, promote myocardial dysfunction, or physical means, ie, directly altering myocardial mass or shape. In this review, we highlight the existing and emerging device-based mechanisms for biologically and physically reverse remodeling the left ventricle in chronic HF.
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Ventricular pressure-volume (PV) loops offer unique insights into cardiovascular mechanics. PV loops can be instrumental in improving our understanding of various congenital heart diseases, including single ventricular physiology, heart failure, and pulmonary hypertension, as well as guiding therapeutic interventions. This review focuses on the theoretical and practical foundations for the acquisition and interpretation of PV loops in congenital heart disease and discusses their clinical applications.