Ruptured aneurysm of the left sinus of Valsalva into the pericardium

Recently, a 67-year-old female patient came to our attention after a collapse, due to cardiac tamponade caused by a ruptured sinus of Valsalva aneurysm (SVA) and intrapericardial bleeding. Despite surgical intervention the patient died before correction.     

Real-time imaging of apoptotic cell-membrane changes at the single-cell level in the beating murine heart.

We report a novel real-time imaging model to visualize apoptotic membrane changes of single cardiomyocytes in the injured heart of the living mouse, using fluorescent labeled annexin-V. Annexin-V binds to externalized phosphatidylserine (PS) of cells undergoing programmed cell death. With high-magnification (x100-160) real-time imaging, we visualized the binding of annexin-V to single cardiomyocytes. Kinetic studies at the single-cell level revealed that cardiomyocytes started to bind annexin-V within minutes after reperfusion, following an ischemic period of 30 minutes. The amount of bound annexin-V increased rapidly and reached a maximum within 20-25 minutes. Caspase inhibitors decreased the number of annexin-V-positive cardiomyocytes and slowed down the rate of PS exposure of cardiomyocytes that still bound annexin-V. This technology to study cell biology in the natural environment will enhance knowledge of intracellular signaling pathways relevant for cell-death regulation and strategies to manipulate these pathways for therapeutic effect.     

CT fractional flow reserve: the next level in non-invasive cardiac imaging

The haemodynamic effect of a coronary artery stenosis is a better predictor of prognosis than anatomical lumen obstruction. Until recently, no individual non-invasive test could provide both accurate coronary anatomy and lesion-specific myocardial ischaemia. However, computer tomography (CT) fractional flow reserve, which can be calculated from a standard CT coronary angiogram, was recently demonstrated to accurately detect and rule out the haemodynamic significance of individual coronary artery stenoses.     

Adolescent with occluded left main coronary artery

Here we report unexpected findings in a 17-year-old female patient referred for coronary angiography and percutaneous intervention. During the angiography we observed a complete occlusion of the left main coronary artery (LMCA).The occurrence of coronary abnormalities at this age is extremely rare and mostly caused by congenital abnormalities. The diagnosis of premature atherosclerosis at this age is unlikely unless the patient suffers from severe lipoprotein disease. Here we describe a rare case of LMCA occlusion, the most likely cause of the disease and the potential implications for therapy.     

Assessment of coronary microvascular resistance in the chronic infarcted pig heart

Pre‐clinical studies aimed at treating ischemic heart disease (i.e. stem cell‐ and growth factor therapy) often consider restoration of the impaired microvascular circulation as an important treatment goal. However, serial in vivo measurement hereof is often lacking. The purpose of this study was to evaluate the applicability of intracoronary pressure and flow velocity as a measure of microvascular resistance in a large animal model of chronic myocardial infarction (MI). Myocardial infarction was induced in Dalland Landrace pigs (n = 13; 68.9 ± 4.1 kg) by a 75‐min. balloon occlusion of the left circumflex artery (LCX). Intracoronary pressure and flow velocity parameters were measured simultaneously at rest and during adenosine‐induced hyperemia, using the Combowire (Volcano) before and 4 weeks after MI. Various pressure‐ and/or flow‐derived indices were evaluated. Hyperemic microvascular resistance (HMR) was significantly increased by 28% in the infarct‐related artery, based on a significantly decreased peak average peak flow velocity (pAPV) by 20% at 4 weeks post‐MI (P = 0.03). Capillary density in the infarct zone was decreased compared to the remote area (658 ± 207/mm² versus 1650 ± 304/mm², P = 0.017). In addition, arterioles in the infarct zone showed excessive thickening of the alpha smooth muscle actin (αSMA) positive cell layer compared to the remote area (33.55 ± 4.25 μm versus 14.64 ± 1.39 μm, P = 0.002). Intracoronary measurement of HMR successfully detected increased microvascular resistance that might be caused by the loss of capillaries and arteriolar remodelling in the chronic infarcted pig heart. Thus, HMR may serve as a novel outcome measure in pre‐clinical studies for serial assessment of microvascular circulation.