Abstract 17184: An Increase in the Respiratory Effort Immediately Intensifies the Hemodynamic Congestion; a Mechanism for Progressive Cardiac Decompensation

Introduction: An increase in the pulmonary wedge pressure (PCWP) is associated with an increase in the respiratory effort and the sensation of dyspnea. Hypothesis: We investigated the inverse cause and effect relationship, whether an increase in the respiratory effort can by itself aggravate the hemodynamic congestion. Methods: We scrutinized the cardiopulmonary interactions by simultaneously measuring hemodynamic and respiratory indices in heart failure (HF) patients undergoing right heart catheterization. The immediate effects of the respiratory effort on the hemodynamic indices were analyzed by asking the patients to perform short events of apnea and intentional vigorous breathing. The cardiac waves are superimposed on the respiratory waves in the PCWP. To quantify the respiratory effort, the PCWP was decomposed into cardiac and respiratory waves. The respiratory effort (PRESP) was defined as the peak to peak swing in the respiratory wave that modulated the PCWP. Results: HF patients (n=38) exhibited a high PRESP of 9.0±3.2 mmHg, ~3.5-fold higher than the reported normal respiratory effort. The end-expiratory PCWP rose with PRESP, by 0.83±0.06 mmHg for every 1 mmHg of PRESP (p<0.01). The pulmonary artery pressure (PAP) rose with PRESP by 1.40±0.09 mmHg for every 1 mmHg of PRESP. The changes in the respiratory effort had immediate effect on PCWP, within a single breathing-cycle (t =1.67±0.40 s) in all patients. Interestingly, similar changes in the PCWP with PRESP were obtained in all the patients, independently of the HF etiology. Conclusions: An increase in the respiratory effort is not just a result of cardiac decompensation. The respiratory effort has immediate detrimental effects on the PCWP, PAP and the workloads of the heart. The results highlight the existence of a cardiopulmonary vicious cycle the can lead to progressive decompensation, where the respiratory effort plays a pivotal role.

The Shared Pathogenesis of Pulmonary Artery Hypertension

Pulmonary artery hypertension is defined as an increased in pulmonary artery pressureexceeding 25 mmHg with normal pulmonary wedge pressure. The pathogenesis of pulmonaryartery hypertension involves interaction among vascular, cellular and biomarker componentsin the pulmonary tissue; with eventual result is elevated pulmonary artery pressure. Vascularcomponents are remodeling of intimal, medial and adventitial layers. Cellular components areplayed by apoptosis-resistant endothelial cells, proliferative-prone pulmonary artery smoothmuscle cells, fibroblasts and inflammatory cells. The functional biomarkers are produced andmediated by these cellular changes, mainly endothelin-1, thromboxane, serotonin, nitric oxide,and prostacyclin. The pulmonary vascular remodeling in pulmonary artery hypertension arediverse and may present in various severity based on underlying etiology. Understanding theshared pathogenesis in pulmonary artery hypertension is of paramount importance in order toimprove the disease management and treatment approach.

Pulmonary arterial hypertension and atrial arrhythmias: incidence, risk factors, and clinical impact

Atrial arrhythmia (AA) occurrence in pulmonary arterial hypertension (PAH) may determine clinical deterioration and affect prognosis. In this study we assessed AA incidence in idiopathic (IPAH) and systemic sclerosis related PAH (SSc-PAH) and evaluated risk factors, management, and impact on mortality. We collected baseline data from consecutive IPAH or SSc-PAH patients prospectively enrolled in the Johns Hopkins Pulmonary Hypertension Registry between January 2000 and July 2016. During follow-up AA onset, treatment, and outcome were recorded. Among 317 patients (201 SSc-PAH, 116 IPAH), 42 developed AA (19 atrial fibrillation, 10 flutter-fibrillation, 9 atrial flutter, and 4 atrial ectopic tachycardia) with a 13.2% cumulative incidence. Most events were associated with hospitalization (90.5%). Electrical or pharmacological cardioversion was attempted in most cases. Patients with AA had higher right atrial pressure, pulmonary wedge pressure ( P < 0.005), NT-proBNP ( P < 0.05), and thyroid disease prevalence ( P < 0.005). Higher mortality was observed in patients with AA, though not statistically significant (LogRank P = 0.323). Similar long-term mortality between IPAH with AA and SSc-PAH without AA was observed (LogRank P = 0.098). SSc-PAH with AA had the worst prognosis. In PAH patients AA occurrence is a matter of significant concern. Therapeutic strategies aimed at restoring sinus rhythm may represent an important goal.

Meandering right pulmonary vein associated with severe and progressive “idiopathic-like” pulmonary hypertensive vascular disease

Congenital anomalies of the pulmonary veins are rare. Meandering right pulmonary vein, considered a part of the Scimitar syndrome spectrum, is often an incidental finding during chest imaging. We present the case of a 4-year-old girl diagnosed with meandering pulmonary vein, who developed pulmonary hypertensive disease with an aggressive course, in spite of absence of hypoxia or elevated pulmonary wedge pressure.