Rhythmos (E-Journal - First Department of Cardiology / Evagelismos General Hospital of Athens)
Not a member yet
289 research outputs found
Sort by
Arterial Stiffness
Get PDFWith advancing age, all organ systems undergo anatomical and functional changes. Vasculature suffers generalized stiffening as a hallmark of this process. Although this phenomenon has been described long ago, only in recent years has the clinical significance of the stiffening of the large arteries been widely understood and its correlation with hypertension, coronary heart disease, stroke, heart failure and atrial fibrillation has been recognized. It has also been accepted that it mediates the vascular effects of diabetes mellitus, atherosclerosis and renal disease. 1-5The arterial systems consists of two functional components with different structural characteristics: a) the large elastic arteries (aorta, carotid and iliac arteries) which store part of the blood ejected during systole and expel it to the periphery during diastole to provide the tissues with a relatively steady flow through the entire cardiac cycle and b) the muscular arteries (arteries below the axillary and femoral ones) which regulate the vascular tone and hence determine the peripheral resistance. The former have a thick tunica media in which the elastic fibers dominate and form numerous concentric layers. The later possess a tunica media characterized mainly by smooth muscle cells and the elastic component is confined to the thin internal and external elastic laminae. The different mechanical properties of the arterial tree along its course and the varying diameter of the arterial branches, gives rise to the reflected waves which are produced when the pulse wave encounters sites with different impedance. A part of these secondary waves amplifies the forward moving wave and another part moves backward to enhance the pressure of the central aorta. Normally it reaches its target in late systole or early diastole and it contributes to the diastolic flow towards the coronary arteries and the periphery... (excerpt
Evaluation of Left Ventricular Diastolic Function by Echocardiography
Get PDFDespite the knowledge that the heart spends almost two-thirds of its time in diastole (relaxing and filling), its contractile activity was for a long time considered the core of its mechanical function and over which major concerns had been focused. It was after the 1980s that the scientific community began to realize the clinical significance of diastolic dysfunction among patients with signs and symptoms of heart failure (HF) but in whom ejection fraction was rather preserved. The recognition of the latter condition as “heart failure with preserved ejection fraction” (HF-PEF) impelled major efforts in order to identify the pathophysiological mechanisms underlying this emerging concept. The impact of diastolic dysfunction on cardiac morbidity and mortality is becoming increasingly understood. The hallmark of diastolic dysfunction is the impaired capacity to fill or maintain stroke volume without a compensatoy increase in filling pressures. Historically, invasive hemodynamics have provided useful information with respect to diastolic filling pressures, e.g., left atrial (LA) pressure and left ventricular (LV) end-diastolic pressure; left ventricular relaxation (time constant of relaxation-dP/dt) and operant chamber stiffness (pressure-volume loops, diastolic pressure contour). However, advances in echocardiographic assessment of LV diastolic function can lead to the replacement of invasive hemodynamics in the vast majority of patients. In the crucial question “can echocardiography accurately measure diastolic function?”, there are reasoned arguments on either side of the debate. Undoubtedly echocardiography has played a central role in the evaluation of LV diastolic function over the past two decades... (excerpt
Vanishing Collaterals Immediately Post-Percutaneous Coronary Revascularization
Get PDFA 74-year-old gentleman with history of diabetes mellitus, hypercholesterolemia, tobacco use and prior myocardial infarction, was admitted via the emergency room due to unstable angina. He had sustained a lateral non-ST elevation myocardial infarction 6 years earlier, when he was submitted to percutaneous coronary intervention (PCI) and stenting of the obtuse marginal branch of the left circumflex coronary artery, considered the culprit lesion and during the same session, stenting was also performed of a stenosis of borderline angiographic significance of the left anterior descending (LAD) coronary artery. During his current admission, urgent coronary angiography was performed, which revealed a total proximal occlusion of the LAD (panel A, arrow); full collateral supply of the LAD was noted from the right coronary artery (panel B, arrows). A significant proximal lesion of the right coronary artery was also detected (not shown).The patient consented to an attempt to revascularize the occluded vessel via PCI, which was successfully accomplished with implantation of 3 coronary stents (panel C, thick arrow). Successful direct stenting was also performed of the proximal lesion of the right coronary artery. Upon completion of the PCI procedure, contrast injection of the right coronary artery revealed the disappearance of the collateral vessels supplied to the LAD (panel D, dashed arrows). Echocardiographic examination showed a near-normal systolic function of the left ventricle (ejection fraction ~55%)
Vitamin D and Cardiovascular Disease
Get PDFVitamin D exists in several forms comprising steroid-like fat-soluble molecules (secosteroids). Cholecalciferol (vitamin D3) is synthesized in the skin in response to ultraviolet irradiation producing photochemical cleavage of a cholesterol precursor (7-dehydro-cholesterol). Irradiation of ergosterol, a membrane sterol found in the Ergot fungus, produces ergocalciferol (vitamin D2). Dietary sources of vitamin D include fish oils (D3), egg yolk (D3), mushrooms (D2), and fortified cereals and dairy products (D2 or D3). Vitamin D derived from all different sources undergoes two successive hydroxylation steps, first in the liver (25-hydroxyvitamin D) and then the kidney (1, 25-hydroxyvitamin D2 / calcitriol). The former form has a longer half-life than the latter (weeks vs. several hours). The biologic effects of vitamin D result largely from its binding to the vitamin D receptor (VDR), a nuclear steroid hormone found in almost every tissue. Calcitriol (D2) appears to have the greatest affinity for the receptor. The prevalence of vitamin D deficiency is estimated around 30–50% in the adult population in developed countries, mostly the result of insufficient cutaneous production due to decreased exposure to sunlight, and to a less degree from low dietary intake. Serum levels of 25-hydroxyvitamin D >30 ng/mL are considered adequate, while levels < 20 ng/mL are diagnostic of vitamin D deficiency.The endocrine functions of vitamin D in relation to bone metabolism and mineral ion homoeostasis are well known. Vitamin D deficiency results in reduced intestinal absorption of calcium, which stimulates the production of parathyroid hormone with an ensuing accelerated bone de-mineralization to maintain serum calcium concentration, with all these alterations leading to the clinical effects of hypocalcemia. These may rarely result in tetany, but due to gradual and insidious development, more commonly produce local, or diffuse musculo-skeletal aches and pains.Importantly, more recent epidemiological studies have linked vitamin D deficiency with the pathogenesis of cardiovascular disease (CVD) and an attendant increase in cardiovascular morbidity and mortality, but data for a causal relationship are still missing... (excerpt
Cardiology News /Recent Literature Review / Last Quarter 2011
Get PDFThe ACC Meeting is slated for 24-27/3/2012 in Chicago The Athens Cardiology Update 2012 is slated for April 5-7, 2012 The HRS 33rd Meeting will be held in Boston, 9-12/5/12 The ESC Congress will be held in Munich, 25-29/8/2012 ALLHAT Trial: Once Heart Failure Develops in High-Risk Hypertensive Patients, Mortality is High At a mean follow-up of 8.9 years, of 1761 participants in the ALLHAT trial with incident heart failure (HF) in-trial, 1348 (77%) died. Mortality rates were similar across treatment comparisons, with adjusted 10-year all-cause mortality rates per 100 persons of 83 for chlorthalidone, 86 for amlodipine, and 87 for lisinopril. Mortality was similar for those with preserved (81%) and low ejection fraction (84%). Thus, once HF develops, risk of death is high and consistent across randomized treatment groups. Measures to prevent the development of HF, especially blood pressure control, must be a priority if mortality associated with the development of HF is to be addressed (Piller LB et al, Circulation 2011;124:1811-1818). Isolated Low HDL-Cholesterol is Associated with Increased Coronary RiskData from 220 060 participants (87% Asian) in 37 studies from the Asia-Pacific region indicated low HDL-C (HDL <40 mg/dl in men and <50 mg/dl in women) among 33.1% of Asians vs 27.0% of non-Asians (P<0.001). The prevalence of low HDL-C in the absence of other lipid abnormalities (isolated low HDL-C) was higher in Asians compared with non-Asians: 22.4% vs 14.5%, respectively (P<0.001). After 6.8 years, there were 574 coronary heart disease and 739 stroke events. There was an inverse relationship between low HDL-C with coronary heart disease in all individuals (hazard ratio, 1.57). In Asians, isolated low levels of HDL-C were as strongly associated with coronary heart disease risk as low levels of HDL-C combined with other lipid abnormalities (hazard ratio, 1.67 vs 1.63, respectively). There was no association between low HDL-C and stroke risk (Huxley RR et al, Circulation2011;124:2056-2064)... (excerpt
Cardiology News /Recent Literature Review / First Quarter 2012
Get PDFThe Athens Cardiology Update 2012 is slated for April 5-7, 2012 The HRS 33rd Meeting will be held in Boston, 9-12/5/12 The ESC Congress will be held in Munich, 25-29/8/2012 TCT Meeting will take place in Miami, 22-26/10/12 HCS Meeting to be held in Athens, 1-3/11/12 AHA 2012 is scheduled for Los Angeles, 3-7/11/12 PARTNER Trial (Cohort B): TAVI Remains Cost-Effective for Patients with Severe Aortic Stenosis who are not Candidates for Surgery The PARTNER trial randomized patients with symptomatic, severe aortic stenosis who were not candidates for surgery to transcatheter aortic valve implantation (TAVI) (n=179) or standard therapy (n=179). Mean costs for the initial TAVI procedure and hospitalization were 78,542, respectively. Follow-up costs through 12 months were lower with TAVI (53,621) because of reduced hospitalization rates, but cumulative 1-year costs remained higher (53,621). Projection was that over a patient’s lifetime, TAVI would increase discounted life expectancy by 1.6 years (1.3 quality-adjusted life-years-QALY) at an incremental cost of 50,200 per year of life gained or $61,889 per QALY gained. The authors concluded that TAVI increases life expectancy at an incremental cost per life-year gained well within accepted values for commonly used cardiovascular technologies. (Reynolds MR et al, Circulation 2012;125:1102-1109). SCAAR Registry: Lower Risk of Stent Thrombosis & Restenosis with Unrestricted Use of ‘New-Generation’ Drug-Eluting Stents A total of 94,384 consecutive stent implantations, including bare metal (BMS, n=64,631), older generation drug-eluting stents (o-DES, n=19,202), and new generation DES (n-DES, n = 10 551) were evaluated in Sweden. Older generation DES comprised Cypher and Cypher Select, Taxus Express and Taxus Liberte, and Endeavor Sprint, while n-DES included Endeavor Resolute, XienceV, Xience Prime, Promus, and Promus Element. A statistically significant lower risk of restenosis was shown for n-DES compared with BMS [adjusted hazard ratio (HR) 0.29] and o-DES (HR 0.62). A lower risk of definite ST was found in n-DES compared with BMS (HR 0.38) and o-DES (HR, 0.57). The risk of death was significantly lower in n-DES compared with o-DES (adjusted HR: 0.77) and BMS (adjusted HR: 0.55). The authors concluded that PCI with n-DES is associated with a 38% lower risk of clinical restenosis, a 43% lower risk of definite ST, and a 23% lower risk of death compared with o-DES (Sarno G et al, Eur Heart J 2012;33:606-613)... (excerpt
Biological Pacemaker: Science Fiction or a Feasible Project?
Get PDFArtificial electronic pacemakers have been successfully driving the hearts and reliably saving the lives of millions by providing cardiac pacing for a variety of cardiac bradyarrhythmias. However, there are several caveats to this technology not merely limited to procedural and hardware complications associated with its usage. These hurdles have prompted research in the development of a biological counterpart which could replace or supplement its electronic version. The concept of the biological pacemaker is very appealing, albeit most challenging. If normal working myocytes or conduction system cells could be transformed to perform the pacemaker function, there would be no need to replace pulse generator, and no issues with circuit or lead failure, size mismatch or foreign body infection would ever arise. Two general approaches have been pursued in the development of biological pacemakers, gene transfer into cardiac myocytes to create or enhance the pacemaker function, and cell transplantation into the heart that can perform the pacemaker function on their own or in conjunction with native cardiac myocytes. There are always pros and cons of these different approaches. Importantly, in order to develop such a biologic pacemaker, two elements are deemed essential: to select a gene that can direct cells of non-automatic tissue to induce spontaneous phase 4 depolarization in a reliable and automatic manner, similar to the native sinus node cells or other conduction tissue with inherent automaticity; and subsequently to develop a technique to deliver this gene into the target tissue. Gene transfer methods may use injection of adenoviral vectors, of genetically engineered stem cells or use of gene-carrying mesenchymal stem cells. Thus, biologic pacing could be accomplished either by genetic engineering, cellular therapy or a combination of both. Over the past decade, gene therapy has been explored to upregulate β2-adrenergic receptors, to downregulate inward rectifier current, and to overexpress pacemaker current as potential sources of biological pacemakers. Cell therapy approaches have explored the ‘‘forcing’’ of embryonic stem cells to evolve along cardiac pacemaker cell lines and the use of adult mesenchymal stem cells as platforms for delivery of specific gene therapies... (excerpt
Development of Transcatheter Aortic Valve Implantation and its Clinical Implications
Get PDFIn the early 1990s the concept of transcatheter aortic valve implantation (TAVI) appeared challenging and totally unrealistic. It was a true “resurrection” for Cribier and his whole team performing the first TAVI in an inoperable patient in 2002, using a transeptal antegrade approach and balloon-expandable aortic valve prosthesis. Since then TAVI has been performed in more than 50000 patients worldwide. TAVI is currently indicated in patients with severe symptomatic aortic stenosis (AS) and acceptable life expectancy who are not suitable for aortic valve replacement (AVR) (indication class IB) or as an alternative to aortic valve replacement (AVR) in selected high-risk operable patients (class IIB), according to the “Heart Team” assessment. The TAVI Heart Team comprised of clinical cardiologists, interventionalists, surgeons, anaesthetists and imaging specialists with expertise in the treatment of valve disease, selects patients suitable for TAVI taking into account advantages and disadvantages of both AVR and TAVI. A logistic EuroSCORE ≥20% (logistic EuroSCORE I tends to overestimate observed mortality risk by a factor of 2 to 3 and a newly updated logistic EuroSCORE II is currently available in clinical practice) or a Society of Thoracic Surgeons (STS) score >10% are suggested as indications for TAVI therapy. Recent publications have identified a number of baseline variables independently associated with mortality or poor outcome in patients undergoing TAVI (low body mass, functional status, left ventricular dysfunction, NT-proBNP, prior stroke, diabetes, chronic kidney disease, anemia, severe tricuspid and mitral regurgitation, porcelain aorta or history of chest radiation) which could be integrated into new scoring systems to quantify and predict the prognosis of TAVI both in the immediate and in the long term... (excerpt
The Electrocardiogram (ECG) in the Athlete
Get PDFAthlete`s Heart or Athletic Heart Syndrome is a benign entity characterized by morphological changes of the heart muscle as a result of long-term adaptation to exercise. The hallmark of these alterations is a substantial enlargement of the heart due to both heart chamber dilatation and heart muscle mass hypertrophy. Although athlete’s heart has long been considered as a benign condition, there are data suggesting an association with sudden cardiac death (SCD) which can occur in athletes during exercise or even during daily activities. Indeed, hypertrophic cardiomyopathy (HCM), also characterized by marked cardiac hypertrophy, is the most common cause of SCD in young athletes. The association between HCM and athlete’s heart has been a matter of extensive discussion and debate among clinicians since an eccentric biventricular hypertrophy is almost universally present in athletes with a left ventricular diastolic volume >58 mm. This conflict has not yet been resolved, but, we have nowadays evidence that the ECG, although commonly altered by athletic cardiac remodeling, can assist in selecting athletes who are at substantial risk for an episode of SCD... (excerpt
Cardiology News /Recent Literature Review / Mid Quarter 2012
Get PDFThe ESC Congress will be held in Munich, 25-29/8/2012 TCT Meeting will take place in Miami, 22-26/10/12 HCS Meeting to be held in Athens, 1-3/11/12 AHA 2012 is scheduled for Los Angeles, 3-7/11/12 TWENTE Trial: the Resolute Zotarolimus Eluting Stents are Noninferior to Xience V Everolimus Eluting Stents in Treating “Real-World” Patients with Complex Lesions and “Off-label” Indications for DES A total of 1,391 patients were randomly assigned to zotarolimus eluting stents (ZES) (n = 697) or everolimus eluting stents (EES) (n = 694). Acute coronary syndromes were present in 52% and “off-label” feature in 77% of patients. Of the lesions, 70% were type B2/C; the post-dilation rate was very high (82%). In ZES and EES, target vessel failure (TVF) occurred in 8.2% and 8.1%, respectively (absolute risk-difference 0.1%; p (noninferiority) = 0.001). The definite-or-probable stent thrombosis rates were relatively low and similar for ZES and EES (0.9% and 1.2%, respectively, p = NS). Definite stent thrombosis rates were also low (0.58% and 0%, respectively, p = NS). In EES, probable stent thrombosis beyond day 8 was observed only in patients not adhering to dual antiplatelet therapy. The authors concluded that resolute ZES were noninferior to Xience V EES in treating “real-world” patients with a vast majority of complex lesions and “off-label” indications for drug-eluting stents (DES), which were implanted with liberal use of post-dilation (von Birgelen C et al, J Am Coll Cardiol 2012;59:1350–1361). The TARGET Study: Placement of the LV Lead to the Latest Sites of Contraction and Away from the Scar Confers the Best Response to CRT Among 220 patients receiving cardiac resynchronization therapy (CRT), the left ventricular (LV) lead was positioned at the latest site of peak contraction (as determined by echocardiographic speckle-tracking 2-dimensional radial strain imaging) with an amplitude of >10% to signify freedom from scar (n=110, TARGET group), while in the control group (n=110) standard unguided CRT was performed. In the TARGET group, there was a greater proportion of responders at 6 months (70% vs 55%, p = 0.031) with an absolute difference in the primary endpoint (>15% reduction in LV end-systolic volume at 6 months) of 15%. Compared with controls, TARGET patients had a higher clinical response (83% vs 65%, p = 0.003) and lower rates of the combined endpoint (all-cause mortality and heart failure–related hospitalization) (p = 0.031). The authors concluded that compared with standard CRT treatment, the use of speckle-tracking echocardiography to the target LV lead placement yields significantly improved response and clinical status and lower rates of combined death and heart failure–related hospitalization (Khan FZ et al, J Am Coll Cardiol 2012;59:1509–1518)... (excerpt