Effect of Patent Foramen Ovale in Patients With Pulmonary Hypertension

Not Just CTEPH: A Narrative Review on the Spectrum Approach to Postpulmonary Embolism Conditions

Three mutually exclusive entities can underlie a postpulmonary embolism syndrome (PPES): not obstructed postpulmonary embolism syndrome (post-PE dyspnea), chronic thromboembolic pulmonary disease (CTEPD), and chronic thromboembolic pulmonary hypertension (CTEPH). Cardiorespiratory impairment in CTEPH and CTEPD underlies respiratory and hemodynamic mechanisms, either at rest or at exercise. Gas exchange is affected by the space effect, the increased blood velocity, and, possibly, intracardiac right to left shunts. As for hemodynamic effects, after a period of compensation, the right ventricle dilates and fails, which results in retrograde and anterograde right heart failure. Little is known on the pathophysiology of post-PE dyspnea, which has been reported in highly comorbid with lung and heart diseases, so that a "two-hit" hypothesis can be put forward: it might be caused by the acute myocardial damage caused by pulmonary embolism in the context of preexisting cardiac and/or respiratory diseases. More than one-third of PE survivors develops PPES, with only a small fraction (3-4%) represented by CTEPH. A value of ≈3% is a plausible estimate for the incidence of CTEPD. Growing evidence supports the role of CTEPD as a hemodynamic phenotype intermediate between post-PE dyspnea and CTEPH, but it still remains to be ascertained whether it constantly underlies exercise-induced pulmonary hypertension and if it is a precursor of CTEPH. Further research is needed to improve the understanding and the management of CTEPD and post-PE dyspnea.

Morphological Features of Patent Foramen Ovale Compared Between Older and Young Patients With Cryptogenic Ischemic Stroke

BACKGROUND

The morphology of a patent foramen ovale (PFO) with a high-risk for cryptogenic ischemic stroke (CS) is an important factor in the selection of patients for transcatheter closure, but the morphological features of PFO in older patients with a history of CS are less known because the most data are obtained from younger patients.

METHODS AND RESULTS

The study included 169 patients who had a history of CS and PFO. The prevalence of high-risk morphologies of PFO assessed by transesophageal echocardiography was compared between patients aged ≥60 years and patients aged <60 years. We also assessed the presence of septal malalignment of PFO on the aortic wall. The probability of CS due to PFO was evaluated using the PFO-Associated Stroke Causal Likelihood classification system. Patients aged ≥60 years had a significantly higher prevalence of atrial septal aneurysm than patients aged <60 years. The prevalence of large right-to-left shunt, long-tunnel of PFO, or Eustachian valve or Chiari's network was similar between patients aged ≥60 years and <60 years. Septal malalignment was observed more frequently in patients aged ≥60 years than in those <60 years old. Nearly 90% of patients aged ≥60 years were classified as 'possible' in the PFO-Associated Stroke Causal Likelihood classification system.

CONCLUSIONS

High-risk morphologies of PFO are common in older patients with a history of CS, as well as in younger patients.

Severe cough and hemoptysis induced reopening of patent foramen ovale leading to significant decrease in pulmonary artery pressure in a patient with idiopathic pulmonary arterial hypertension： A case report

Pulmonary arterial hypertension (PAH) is a perilous disease that precipitates right ventricular hypertrophy, induces right heart failure, and exerts deleterious ramifications on prognostic outcomes. The establishment of atrial communication can create a right-to-left shunt, thereby ameliorating hemodynamic parameters. Previous reports suggested that opening of a patent foramen ovale (PFO) was common in patients with severe PAH, but exhibited no discernible impact on long-term survival. We reported the case of a 39-year-old man with severe idiopathic PAH, who underwent reopening of the PFO due to severe cough and hemoptysis, followed by a marked amelioration in symptoms and a substantial decrease in pulmonary arterial pressure. The patient has survived for more than 12 years, persisting in World Health Organization functional class Ⅱ with mild PAH.

Case report: Extracorporeal life support as a successful bridge to recovery in an incident case of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized by a progressive increase in pulmonary vascular resistance (PVR) due to vascular remodeling of the small pulmonary arteries. In advanced RV failure or severe hypoxemia, extra corporeal life support (ECLS) is now to be considered, with the objective to bridge patients back to their baseline clinical state while waiting or right after lung transplantation, or bridge to pharmacological optimization of PAH (i.e., bridge to recovery). We describe herein a case of a 30-year-old woman (gravida 6, para 6) with an incident case of heritable PAH revealed by refractory hypoxemia. Despite the use of mechanical ventilation and fluid optimization, the patient remained profoundly hypoxemic. ECLS was then initiated to avoid tissue hypoxia. The mechanical option chosen was peripheral femoro-femoral venoarterial extracorporeal membrane oxygen (VA-ECMO), percutaneously implanted. Due to the absence of evidence of chronic respiratory disease or chronic thromboembolic pulmonary hypertension, this severe pre-capillary pulmonary hypertension was attributed to PAH. Therefore, epoprostenol infusion and an association of oral treatments (bosentan and tadalafil) were administered. A dramatic improvement was observed, allowing decannulation 7 days after the initiation of pharmacological treatment. After 29 days, the patient was discharged from the hospital with epoprostenol, bosentan, and tadalafil. The assessment has been completed by positive research on mutations (c.741C > G, p.Tyr247) corresponding to a loss of function of the bone morphogenetic protein receptor 2 (BMPR2) gene. The final diagnosis was heritable PAH. The use of ECLS has been well demonstrated in patients with PAH complicated by acute RV failure or refractory hypoxemia in the "bridge-to-transplantation" strategy. Only a few reports have described the use of ECLS as a "bridge-to-recovery" with PAH drugs in untreated or undertreated PAH patients, but none has described such a rapid improvement with resolution of refractory hypoxemia. More studies are needed to assess the benefits and limitations of the "bridge-to-recovery" strategy and to identify the patients most likely to benefit from it.

Epidemiology and management of right ventricular-predominant heart failure and shock in the cardiac intensive care unit

Cardiogenic shock from left ventricular failure is a common presentation in the intensive care unit. In contrast, right ventricular (RV)-predominant heart failure (HF) causing shock is less well recognized. We review the epidemiology and mechanisms of RV-predominant HF and discuss pharmacologic and device-based approaches for the management of this challenging clinical problem.

The Impact of Breathing Hypoxic Gas and Oxygen on Pulmonary Hemodynamics in Patients With Pulmonary Hypertension

Background

Pure oxygen breathing (hyperoxia) may improve hemodynamics in patients with pulmonary hypertension (PH) and allows to calculate right-to-left shunt fraction (Qs/Qt), whereas breathing normobaric hypoxia may accelerate hypoxic pulmonary vasoconstriction (HPV). This study investigates how hyperoxia and hypoxia affect mean pulmonary artery pressure (mPAP) and pulmonary vascular resistance (PVR) in patients with PH and whether Qs/Qt influences the changes of mPAP and PVR.

Study Design and Methods

Adults with pulmonary arterial or chronic thromboembolic PH (PAH/CTEPH) underwent repetitive hemodynamic and blood gas measurements during right heart catheterization (RHC) under normoxia [fractions of inspiratory oxygen (FiO2) 0.21], hypoxia (FiO2 0.15), and hyperoxia (FiO2 1.0) for at least 10 min.

Results

We included 149 patients (79/70 PAH/CTEPH, 59% women, mean ± SD 60 ± 17 years). Multivariable regressions (mean change, CI) showed that hypoxia did not affect mPAP and cardiac index, but increased PVR [0.4 (0.1–0.7) WU, p = 0.021] due to decreased pulmonary artery wedge pressure [−0.54 (−0.92 to −0.162), p = 0.005]. Hyperoxia significantly decreased mPAP [−4.4 (−5.5 to −3.3) mmHg, p &lt; 0.001] and PVR [−0.4 (−0.7 to −0.1) WU, p = 0.006] compared with normoxia. The Qs/Qt (14 ± 6%) was &gt;10 in 75% of subjects but changes of mPAP and PVR under hyperoxia and hypoxia were independent of Qs/Qt.

Conclusion

Acute exposure to hypoxia did not relevantly alter pulmonary hemodynamics indicating a blunted HPV-response in PH. In contrast, hyperoxia remarkably reduced mPAP and PVR, indicating a preserved vasodilator response to oxygen and possibly supporting the oxygen therapy in patients with PH. A high proportion of patients with PH showed increased Qs/Qt, which, however, was not associated with changes in pulmonary hemodynamics in response to changes in FiO2.

Agitated Saline Contrast Echocardiography in the Identification of Intra- and Extracardiac Shunts: Connecting the Dots

Agitated saline contrast studies are an essential component of contemporary echocardiography. Agitated saline contrast plays a critical role in the elucidation of intracardiac versus intrapulmonary shunting and can have major therapeutic implications, particularly in light of the evolution of percutaneous treatment options for atrial septal defects or a patent foramen ovale. Despite their perceived simplicity, however, there are numerous pitfalls of these investigations that can occur during their performance and interpretation. As such, the authors review the "bubble study" in identifying intracardiac and extracardiac shunts, including the history of its development, the physics and physiology of contrast enhancement, how to optimally perform and interpret an agitated saline contrast study, and its safety in unique populations.

Patent Foramen Ovale in Fetal Life, Infancy and Childhood

A patent foramen ovale (PFO) is a common, incidental echocardiographic finding in otherwise healthy and asymptomatic infants and children. However, a variety of clinical conditions have been ascribed to the presence of a PFO in childhood, such as cryptogenic stroke, platypnea-orthodeoxia syndrome, decompression sickness and migraine, although the data on these are controversial and sometimes contradictory. This review discusses embryology and correlation with post-natal anatomy, anatomical variations of the atrial septum, diagnostic modalities in special circumstances of PFO associated clinical syndromes, and the role of PFO in congenital heart disease, pulmonary hypertension, dilated cardiomyopathy and heart failure in children who require an extracorporeal membrane oxygenator or ventricular assist device as life support.

Critical Care of Patients After Pulmonary Thromboendarterectomy

Pulmonary thromboendarterectomy (PTE) remains the only curative surgery for patients with chronic thromboembolic pulmonary hypertension (CTEPH). Postoperative intensive care unit care challenges providers with unique disease physiology, operative sequelae, and the potential for detrimental complications. Central concerns in patients with CTEPH immediately after PTE relate to neurologic, pulmonary, hemodynamic, and hematologic aspects. Institutional experience in critical care for the CTEPH population, a multidisciplinary team approach, patient risk assessment, and integration of current concepts in critical care determine outcomes after PTE surgery. In this review, the authors will focus on specific aspects unique to this population, with integration of current available evidence and future directions. The goal of this review is to provide the cardiac anesthesiologist and intensivist with a comprehensive understanding of postoperative physiology, potential complications, and contemporary intensive care unit management immediately after pulmonary endarterectomy.