Abnormal coronary vasoreactivity in transient left ventricular apical ballooning (tako-tsubo) syndrome.

Background: The exact etiology and pathophysiologic mechanisms of tako-tsubo syndrome (TTS) remain controversial.

Objective: To further evaluate the abnormal coronary vasoreactivity and its possible anatomical substrate in TTS.

Methods: We studied 47 patients (46 women; age 67±12years) who underwent diagnostic cardiac catheterization and evaluation of coronary vasoreactivity by sequential acetylcholine (Ach), nitroglycerine and adenosine testing with angiographic and intracoronary pressure-Doppler flow monitoring.

Epicardial and microvascular coronary vasomotor dysfunction and its relation to myocardial ischemic burden in patients with non-obstructive coronary artery disease.

Aim: To assess the relative contribution of epicardial endothelium-dependent (EDD) and microvascular endothelium-independent (EIMVD) coronary vasomotor dysfunction to the extent of myocardial ischemia in patients with normal angiograms or non-obstructive coronary artery disease (NOCAD).

Methods: Coronary vasomotion was evaluated by quantitative angiography and blood flow (CBF) measurements during intracoronary acetylcholine, nitroglycerine, and adenosine in 101 patients. Myocardial SPECT ischemic burden was evaluated by semi-quantitative scoring of summed stress (SSS) and summed ischemic (SDS) perfusion defect size.

Clinical role of post-angioplasty hyperemic microvascular resistances in chronic ischemic left ventricular dysfunction.

Aims: To investigate the impact of hyperemic microvascular resistances (HMRs) on myocardial perfusion and contractility after percutaneous coronary intervention (PCI) in chronic ischemic left ventricular dysfunction (CILVD).

Methods: The current retrospective study included 48 patients with CILVD of the left anterior descending territory undergoing HMRs assessment before and after PCI with a dual-sensor intracoronary pressure-flow wire. The severity of resting myocardial underperfusion and contractile dysfunction of the left anterior descending territory was scored as summed rest score (SRS-T) by single photon emission tomography, wall motion score index (WMSI-T) and left ventricular ejection fraction (LVEF) by transthoracic echocardiography before PCI and after 3 months.

A mathematical model for the vessel recruitment in coronary microcirculation in the absence of active autoregulation.

This paper proposes a mathematical model for vessel recruitment in the microvascular coronary network. The model is based on microvascular network units (MVNUs), where we define a MVNU as a portion of the microvascular network comprising seven generations of identical, parallel-arranged vessels (upstream arteries, large and small arterioles, capillaries, small and large venules, and downstream veins). The model implements a new mechanism to describe the variation in the number of MVNU in response to sudden variations of the local input pressure.

Larger perfusion defects with exercise compared with dipyridamole SPECT (exercise-dipyridamole mismatch) may reflect differences in epicardial and microvascular coronary dysfunction: when the stressor matters.

Background: Previous studies have reported larger myocardial perfusion defects with exercise as compared with dipyridamole. The aim of this study was to assess the hypothesis that this mismatch may reflect differences in epicardial and microvascular coronary vasomotor function.

Methods And Results: The response to intracoronary acetylcholine, nitroglycerin, and adenosine was studied in 36 patients with suspected angina and normal or near-normal coronary angiography findings who underwent both exercise and dipyridamole perfusion imaging.

Performing versus deferring coronary angioplasty based on functional evaluation of vessel stenosis by pressure measurements: a clinical outcome study.

Aim: The present study aimed to prospectively evaluate whether application of the concept of fractional flow reserve (FFR) guides the immediate decision to perform or to defer coronary angioplasty in unselected consecutive patients with one or more angiographically intermediate (50-70%) stenoses and non-conclusive or lacking non-invasive testing.

Methods: We studied 112 patients (81 males and 31 females, aged 31-81 years) including 71 multivessel disease patients (63%) and 30 patients (27%) with unstable symptoms. FFR was measured with the use of a pressure-wire after adenosine-induced hyperaemia and compared with quantitative coronary angiography in 171 stenoses.

A case of transient left ventricular apical ballooning. A condition simulating an acute myocardial infarction.

Transient left ventricular apical ballooning, sometimes associated with intraventricular pressure gradient, is a condition simulating an acute myocardial infarction and may occur in patients presenting with chest pain, electrocardiographic changes and minimal myocardial enzyme release typically without coronary angiographic stenosis. It was originally described in the Japanese population and is often associated with cerebrovascular accidents, surgical procedures and emotional and physical stress. We report the case of a 65-year-old woman presenting with chest pain typical of myocardial ischemia, dyspnea, electrocardiographic abnormalities and signs of hemodynamic instability, occurring after a severe emotional stress.