Objective Tako-Tsubo cardiomyopathy (TTC) is associated with regional left ventricular dysfunction, independent of the presence of fixed coronary artery disease. Previous studies have used T2-weighted cardiac MRI to demonstrate the presence of periapical oedema. The authors sought to determine the distribution, resolution and correlates of oedema in TTC. Patients 32 patients with TTC were evaluated at a median of 2 days after presentation, along with 10 age-matched female controls. Extent of oedema was quantified both regionally and globally; scanning was repeated in patients with TTC after 3 months. Correlations were sought between oedema and the extent of hypokinesis, catecholamine release, release of N-terminal prohormone of B-type natriuretic peptide (NT-proBNP), and markers of systemic inflammatory activation (high-sensitivity C-reactive protein and platelet response to nitric oxide). Results In the acute phase of TTC, T2-weighted signal intensity was greater at the apex than at the base (p<0.0001) but was nevertheless significantly elevated at the base (p<0.0001), relative to control values. Over 3 months, T2-weighted signal decreased substantially, but remained abnormally elevated (p<0.02). The regional extent of oedema correlated inversely with radial myocardial strain (except at the apex). There were also direct correlations between global T2-weighted signal and (1) plasma normetanephrine (r=0.39, p=0.04) and (2) peak NT-proBNP (r=0.39, p=0.03), but not with systemic inflammatory markers. Conclusions TTC is associated with slowly resolving global myocardial oedema, the acute extent of which correlates with regional contractile disturbance and acute release of both catecholamines and NT-proBNP.
Pulmonary hypertension (PH) due to left heart disease (LHD) is the most common type of PH and is defined as mean pulmonary artery systolic pressure of >20 mm Hg and pulmonary capillary wedge pressure >15 mm Hg during right heart catheterization. LHD may lead to elevated left atrial pressure alone, which in the absence of intrinsic pulmonary vascular disease will result in PH without changes in pulmonary vascular resistance. Persistent elevation in left atrial pressure may, however, also be associated with subsequent pulmonary vascular remodeling, vasoconstriction, and an increase in pulmonary vascular resistance. Hence, there are 2 subgroups of PH due to LHD, isolated postcapillary PH and combined post- and precapillary PH, with these groups have differing clinical implications. Differentiation of pulmonary arterial hypertension and PH due to LHD is critical to guide management planning; however, this may be challenging. Older patients, patients with metabolic syndrome, and patients with imaging and clinical features consistent with left ventricular dysfunction are suggestive of LHD etiology rather than pulmonary arterial hypertension. Hemodynamic measures such as diastolic pressure gradient, transpulmonary gradient, and pulmonary vascular resistance may assist to differentiate pre- from postcapillary PH and offer prognostic insights. However, these are influenced by fluid status and heart failure treatment. Pulmonary arterial hypertension therapies have been trialed in the treatment with concerning results reflecting disease heterogeneity, variation in inclusion criteria, and mixed end point criteria. The aim of this review is to provide an updated definition, discuss possible pathophysiology, clinical aspects, and the available treatment options for PH due to LHD.
13 January 2016 in Journal of the American Heart Association
Background: Mitochondrial reactive oxygen species ( ROS ) are associated with metabolic heart disease ( MHD ). However, the mechanism by which ROS cause MHD is unknown. We tested the hypothesis that mitochondrial ROS are a key mediator of MHD . Methods and Results: Mice fed a high‐fat high‐sucrose ( HFHS ) diet develop MHD with cardiac diastolic and mitochondrial dysfunction that is associated with oxidative posttranslational modifications of cardiac mitochondrial proteins. Transgenic mice that express catalase in mitochondria and wild‐type mice were fed an HFHS or control diet for 4 months. Cardiac mitochondria from HFHS ‐fed wild‐type mice had a 3‐fold greater rate of H 2 O 2 production ( P =0.001 versus control diet fed), a 30% decrease in complex II substrate–driven oxygen consumption ( P =0.006), 21% to 23% decreases in complex I and II substrate–driven ATP synthesis ( P =0.01), and a 62% decrease in complex II activity ( P =0.002). In transgenic mice that express catalase in mitochondria, all HFHS diet–induced mitochondrial abnormalities were ameliorated, as were left ventricular hypertrophy and diastolic dysfunction. In HFHS ‐fed wild‐type mice complex II substrate–driven ATP synthesis and activity were restored ex vivo by dithiothreitol (5 mmol/L), suggesting a role for reversible cysteine oxidative posttranslational modifications. In vitro site‐directed mutation of complex II subunit B Cys100 or Cys103 to redox‐insensitive serines prevented complex II dysfunction induced by ROS or high glucose/high palmitate in the medium. Conclusion: Mitochondrial ROS are pathogenic in MHD and contribute to mitochondrial dysfunction, at least in part, by causing oxidative posttranslational modifications of complex I and II proteins including reversible oxidative posttranslational modifications of complex II subunit B Cys100 and Cys103.