Eulália Pereira

Transcatheter Aortic Valve Implantation and Requirements of Pacing Over Time

A permanent pacemaker (PPM) implantation is common after transcatheter aortic valve implantation (TAVI). We sought to evaluate requirements of pacing and incidence of pacemaker dependency during the first year after TAVI.

Incremental value of adenosine stress cardiac magnetic resonance in coronary artery disease detection

INTRODUCTION Cardiac magnetic resonance myocardial perfusion imaging (CMR-MPI) is considered a state-of-the-art non-invasive modality for ischemia detection but its additive value in a multiple-test strategy in patients with suspected coronary artery disease (CAD) is not fully validated. We aimed to evaluate CMR-MPI integration with exercise treadmill test (ETT) for the diagnostic workup of patients with suspected CAD, having invasive fractional flow reserve (FFR) as reference standard. METHODS In this prospective single-center study, patients with suspected CAD underwent sequential ETT, CMR-MPI and X-ray invasive coronary angiography (XA). Significant CAD was defined by the presence of stenosis >40% with FFR ≤ 0.8 in vessels >2 mm or ≥90% stenosis/occlusion. RESULTS 80 symptomatic patients (68% male, 61 ± 8 years) were enrolled. Compared to ETT, CMR-MPI showed similar sensitivity (81%) and higher specificity (93 vs. 58%, p < 0.001) for CAD detection (prevalence = 46%) translating into better diagnostic performance (AUC 0.87 vs. 0.70; p = 0.002). CMR-MPI improved accuracy independently of ETT in all patients with high pre-test probability and in intermediate-probability patients but those with a clearly positive-ETT (symptoms + ST-shift), in whom ETT correctly identified CAD. In the low-probability group CMR-MPI was useful as a gatekeeper for XA after a positive-ETT. The best integrating protocol achieved a global accuracy of 89% (AUC 0.88) and was clearly superior to an approach based solely in ETT (AUC 0.70, p < 0.001), yet similar to isolated CMR-MPI (AUC 0.87, p = ns). CONCLUSIONS CMR-MPI has high sensitivity and specificity for CAD detection and may be combined with ETT in a diagnostic workflow aiming to increase accuracy and reduce the number of unnecessary catheterizations.

Aborted sudden cardiac death as first presentation of Wolff–Parkinson–White syndrome

Sudden cardiac death (SCD) can be the first clinical manifestation of Wolff-Parkinson-White (WPW) syndrome. Catheter ablation of accessory pathways is now a safe and effective procedure, and is widely recommended in patients with WPW syndrome. However, management of the asymptomatic WPW patient remains controversial. Recent studies have readdressed the issue of risk stratification and prophylactic catheter ablation. We describe a case of malignant arrhythmia and aborted SCD as first presentation of WPW syndrome in a previously asymptomatic 17-year-old patient.

Diffuse aneurysmal and obstructive coronary artery disease: A do-not-intervene patient

Coronary artery aneurysms are uncommon but potentially hazardous entities found on a small percentage of coronary angiograms. The best management strategy remains to be determined; the coexistence of obstructive coronary artery disease is the main determinant of prognosis. We report the case of a middle-aged woman with mixed aneurysmal and obstructive coronary artery disease presenting as an acute myocardial infarction, probably due to atherosclerosis. The unusual severity and complexity of the angiographic presentation of this case, with involvement of all major coronary arteries, raises important issues in terms of the patients treatment options.

Incremental value of cardiac magnetic resonance with adenosine stress perfusion in coronary artery disease detection

Background A multiple-test strategy in often needed in the evaluation of patients (pts) with suspected coronary artery disease (CAD). Cardiac magnetic resonance (CMR) has potential advantages in this context allowing simultaneous evaluation of ventricular function, myocardial perfusion and scar detection with high spatial resolution and no ionizing radiation exposure. We aimed to compare the diagnostic accuracy of adenosine stress CMR myocardial perfusion imaging (CMR-MPI) with exercise treadmill test (ETT) for detection of CAD using invasive fractional flow reserve (FFR) as the reference standard, and to assess the best performing diagnostic algorithm using these tests in patients with suspected CAD.

Cardiogenic shock due to sexually transmitted disease – A rare cause of acute myocardial infarction

A 55-year-old male patient, who was a smoker and chronic alcoholic, was admitted to the emergency department with epigastric pain and vomiting which had lasted 14 hours. He had signs of cardiogenic shock. The electrocardiogram showed atrial fibrillation with slow ventricular response and ST-segment elevation in leads II, III, aVF, V1 and V2 (A). Cardiac angiography was performed immediately showing a normal left coronary artery (Figure 1B and C); the right coronary artery (RCA) could not be catheterized. Computed tomography angiography was performed and showed aortic root (AR) and ascending aorta (AA) dilation with diffuse circumferential wall thickening occluding the ostium of the RCA (Figure 1D-F). The wall thickening also extended to the descending aorta (Figure 1D and G). On transesophageal echocardiography, the circumferential

Improvement in left intraventricular pressure gradients after aortic valve replacement in aortic stenosis patients

What is the central question of this study? Normal diastolic and systolic intraventricular pressure gradients are decreased when left ventricular filling and/or emptying are compromised. We hypothesized that in patients with severe aortic valve stenosis, a condition that interferes with ventricular filling and emptying, those gradients would be disturbed. What is the main finding and its importance? We showed the existence of intraventricular pressure gradients throughout the cardiac cycle in the human left ventricle. Moreover, we demonstrated, for the first time, that diastolic and systolic gradients, which are markers of normal ventricular filling and emptying, respectively, improved in patients with severe aortic valve stenosis immediately after valve replacement.

Is it too late to treat me

p t b a ( a w p h r We present the case of a 76-year-old Caucasian man with a type 1 endoleak at the proximal edge of a thoracic stentgraft (TalentTM 38 mm × 114 mm) detected four years after endovascular treatment of a large symptomatic saccular aneurysm in the distal aortic arch. The patient refused any interventional treatment for the endoleak and remained on medical therapy with no evolving symptoms. Surveillance cardiac tomography (CT) showed the aneurysm continuing to expand, extending towards the chest wall and causing erosion of the ribs (Figure 1). After two years, the patient caught influenza with intense cough and suddenly noticed a pulsatile lump in his left chest wall. A new CT revealed the aneurysm expanding through the first left intercostal space, reaching the chest wall surface (Figure 2).

LDRD final report on light-powered nanovehicles.

We have investigated the possibility of constructing nanoscale metallic vehicles powered by biological motors or flagella that are activated and powered by visible light. The vehicles body is to be composed of the surfactant bilayer of a liposome coated with metallic nanoparticles or nanosheets grown together into a porous single crystal. The diameter of the rigid metal vesicles is from about 50 nm to microns. Illumination with visible light activates a photosynthetic system in the bilayer that can generate a pH gradient across the liposomal membrane. The proton gradient can fuel a molecular motor that is incorporated into the membrane. Some molecular motors require ATP to fuel active transport. The protein ATP synthase, when embedded in the membrane, will use the pH gradient across the membrane to produce ATP from ADP and inorganic phosphate. The nanoscale vehicle is thus composed of both natural biological components (ATPase, flagellum; actin-myosin, kinesin-microtubules) and biomimetic components (metal vehicle casing, photosynthetic membrane) as functional units. Only light and storable ADP, phosphate, water, and weak electron donor are required fuel components. These nano-vehicles are being constructed by self-assembly and photocatalytic and autocatalytic reactions. The nano-vehicles can potentially respond to chemical gradients and other factors such as light intensity and field gradients, in a manner similar to the way that magnetic bacteria navigate. The delivery package might include decision-making and guidance components, drugs or other biological and chemical agents, explosives, catalytic reactors, and structural materials. We expected in one year to be able only to assess the problems and major issues at each stage of construction of the vehicle and the likely success of fabricating viable nanovehicles with our biomimetic photocatalytic approach. Surprisingly, we have been able to demonstrate that metallized photosynthetic liposomes can indeed be made. We have completed the synthesis of metallized liposomes with photosynthetic function included and studied these structures by electron microscopy. Both platinum and palladium nanosheeting have been used to coat the micelles. The stability of the vehicles to mechanical stress and the solution environment is enhanced by the single-crystalline platinum or palladium coating on the vesicle. With analogous platinized micelles, it is possible to dry the vehicles and re-suspend them with full functionality. However, with the liposomes drying on a TEM grid may cause the platinized liposomes to collapse, although probably stay viable in solution. It remains to be shown whether a proton motive force across the metallized bilayer membrane can be generated and whether we will also be able to incorporate various functional capabilities including ATP synthesis and functional molecular motors. Future tasks to complete the nanovehicles would be the incorporation of ATP synthase into metallized liposomes and the incorporation of a molecular motor into metallized liposomes.