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The Patient with Ischemic Heart Failure
Published in Andreas P. Kalogeropoulos, Hal A. Skopicki, Javed Butler, Heart Failure, 2023
Konstantinos Aznaouridis, Constantina Masoura, Charalambos Vlachopoulos
Remodeling of the left ventricle is an adaptive structural process secondary to acute or chronic ischemic or non-ischemic insults (i.e., valvular regurgitations). In early stages, remodeling is associated with thinning of the wall and dilation of the ventricle, whereas, in later stages, remodeling is due to irreversible fibrosis and scarring of the myocardium. In general, remodeling due to coronary disease is mostly secondary to necrosis and presence of scar tissue following an acute myocardial infarction. However, even hibernated, predominantly non-necrotic myocardium with minimal scar due to chronic obstructive coronary artery disease may also lead to LV remodeling. From a clinical point of view, it is crucial to identify the patients with predominantly hibernating myocardium, and the patients who have scarred myocardium. In patients with heart failure and hibernated, viable myocardium due to coronary artery disease, it is expected that their symptoms and overall prognoses improve after appropriate revascularization.6–9 On the other hand, patients with heart failure and scarred, non-viable myocardium are mainly treated with heart failure medications and devices (biventricular pacemakers and/or implantable cardioverter defibrillators [ICDs]). Therefore, the presence and the extent of viability is important in the management of patients with ischemic heart failure. Several imaging modalities have been developed to detect hibernated/viable myocardium and are briefly described herein.
Non-invasive assessment of ischaemic heart disease
Published in John Edward Boland, David W. M. Muller, Interventional Cardiology and Cardiac Catheterisation, 2019
James Otton, Patrick Pender, Neville Sammel
Myocardial revascularisation (coronary bypass surgery, angioplasty or stenting) is usually undertaken to relieve angina or to abolish myocardial ischemia. In some patients with impaired left ventricular contractility, revascularisation may be indicated to improve left ventricular function. In these patients it is necessary to identify ‘hibernating myocardium’, i.e. myocardium that is not contracting but is still viable and can be expected to contract when perfusion is restored. Where no viability exists, intervention or surgery is generally futile. Viability testing is used to differentiate between ischemic and infarcted tissues. Such testing can also be used to evaluate ‘stunned myocardium’, i.e. myocardium, usually recently vascularised, that is perfused but is temporarily poorly contractile, and has the ability to improve in function over time.
Heart failure
Published in Clive Handler, Gerry Coghlan, Nick Brown, Management of Cardiac Problems in Primary Care, 2018
Clive Handler, Gerry Coghlan, Nick Brown
Theoretically, myocardial revascularisation using either or both (hybrid) coronary angioplasty and coronary artery surgery should improve function in ‘hibernating’ (ischaemic but potentially recoverable) heart muscle, but there is currently no evidence that myocardial revascularisation improves survival. Hibernating myocardium is a presumed diagnosis made in patients in whom the heart muscle, when visualised by echocardiography, shows increased contractility to intravenous dobutamine. Therefore, patients with severe heart failure that is probably due to coronary artery disease should be referred for assessment of underlying myocardial ischaemia and hibernating myocardium. If these are present, coronary angiography should be performed with a view to revascularisation.
Vulnerability for ventricular arrhythmias in patients with chronic coronary total occlusion
Published in Expert Review of Cardiovascular Therapy, 2020
Amira Assaf, Roberto Diletti, Mark G. Hoogendijk, Marisa van der Graaf, Felix Zijlstra, Tamas Szili-Torok, Sing-Chien Yap
There is inconsistency with regard to the role of better collateral flow and the occurrence of VA. Some studies in patients with ICDs for primary prevention have shown a nonsignificant trend toward less VA in those with better collateral flow [6,9,10]. In contrast, the VACTO Secondary study demonstrated that good collateral flow (Rentrop grade 3) was associated with a higher incidence of VA in comparison to patients with less collateral flow (Rentrop grade ≤2 flow) (HR 1.54, 95% CI 1.04–2.26) [5]. The increased susceptibility to VA in patients with good collateral flow can be explained by a greater amount of hibernating myocardium, especially in a peri-infarct area [46]. Contrast-enhanced MRI studies have demonstrated less segmental transmurality and higher chance of improvement of dysfunctional segments after percutaneous coronary intervention (PCI) of a CTO with improving Rentrop grade [48,49]. Although this implies that a good collateral circulation is more likely to supply viable myocardium, this chronic hibernating myocardium is a potential pathophysiologic substrate for VA [50]. Hibernating myocardium displays abnormal and heterogeneous electrical properties and contributes to the formation of a substrate for reentry.