Konstantinos Iliodromitis

Acute administration of vitamin C abrogates protection from ischemic preconditioning in rabbits.

Vitamin C is considered to be an antioxidant agent that is broadly used. Free radicals are involved in the protective mechanism of preconditioning (PC), but some antioxidant compounds abolish this benefit. The aim of the present study was to evaluate the effect of vitamin C on the protective effect of PC with respect to infarct size and oxidative stress in anesthetized rabbits. Male rabbits were randomly divided into six groups and subjected to 30 min of myocardial ischemia and 3h of reperfusion with the following interventions per group: (1) Control (no intervention), (2) Vit C 150 group (i.v. vitamin C at a total dose of 150 mg/kg for 75 min, starting 40 min before the onset of long ischemia and lasting up to the 5th min of reperfusion), (3) Vit C 300 group (i.v. vitamin C at a total dose of 300 mg/kg as previously described), (4) PC group (two cycles of 5 min ischemia and 10 min reperfusion), (5) combined PC-Vit C 150 group and (6) combined PC-Vit C 300 group. Blood samples were taken at different time points for malondialdehyde (MDA) assessment as a lipid peroxidation marker and for superoxide dismutase (SOD) activity. At the end of the experiment the infarct size was determined. Vitamin C, at both doses, did not reduce the infarct size (35.5+/-4.1%, 38.3+/-7.0% vs. 44.9+/-3.3% in the control group) and diminished the protection afforded by PC (32.0+/-2.7%, 43.8+/-3.3% vs. 15.7+/-2.9% in the PC group, P<0.05). At reperfusion there was an elevation of circulating MDA levels in the control and PC groups while in both vitamin C groups the levels were decreased. SOD activity was enhanced in the PC group compared to the controls; vitamin C did not change SOD activity during ischemia-reperfusion. Vitamin C abrogates the beneficial effect of ischemic PC on infarct size and elicits antioxidant properties during ischemia-reperfusion.

High-risk PCI in acute coronary syndromes with Impella LP 2.5 device support

OBJECTIVES To evaluate feasibility, safety, efficacy as well as acute and short-term outcome of hemodynamically supported percutaneous coronary intervention (PCI) by a percutaneous, catheter-based left ventricular assist device (LVAD) (Impella LP 2.5, Abiomed Europe GmbH, Aachen, Germany) in a high-risk patient population with acute coronary syndrome. BACKGROUND Although hemodynamic support by intraaortic balloon pump favorably affects myocardial oxygen supply and demand, it has modest effects on cardiac output, providing passive support only. In contrast, the Impella LP 2.5 microaxial pump, which is placed within the left ventricular outflow tract and actively ejects blood into the ascending aorta, might offer additional hemodynamic support and thereby procedural safety during PCI. METHODS Thirty-eight consecutive high-risk patients (mean age, 69.7 ± 10.3 years, logistic EuroSCORE, 22.4 ± 14.9%) with unstable angina pectoris or non-ST-segment elevation myocardial infarction and severe three-vessel-disease were included in the study. Clinical and laboratory examinations were performed at baseline as well as at 6, 24 and 48 h after the procedure and 30 days after discharge. RESULTS Device insertion and explantation was feasible in all patients without vascular complications and continuous hemodynamic stability was obtained during PCI. PCI was uneventfully performed in all but one patient for technical reasons. One non procedure-related death occurred 7 days after the intervention, accounting for a total 30-day mortality of 2.86%. Other major cardiac or cerebrovascular events did not occur. CONCLUSIONS LVAD support using a percutaneous microaxial flow pump is a promising and safe approach for high-risk PCI providing good short-term results.

Intimal sarcoma of the pulmonary artery with unusual findings: a case report

Intima sarcoma is a rare tumor often localized in the pulmonary artery. Previous descriptions can be found dating all the way back to 1923 [9]. This tumor’s evolvement is characterized by endoluminal growth with later vessel obstruction. This type of tumor can also originate from the heart valves and the right ventricular outflow tract. Peripheral thromboembolism is a common concomitant finding, often leading to the false diagnosis of chronic thromboembolism. The prognosis of inoperable patients with extensive disease is very poor with a median survival of 6 weeks [7]. Due to the rareness of this tumor, prospective data regarding the benefit of neoadjuvant or adjuvant chemoor radiotherapy are not available. We present the case of a 76-year-old female with persisting shortness of breath over 6 months. The patient has a smoking history of more than 30-pack years. On physical examination, the patient exhibited tachypnea, with 21 breaths per minute, a regular pulse at 92 beats per minute and a blood pressure of 123/80 mmHg. Cardiac auscultation revealed a 3/6 systolic murmur over the second intercostal space at the left sternal border. Further physical examination was unremarkable. Blood count and chemistry profile were within normal range, including the level of brain natriuretic peptide. DDimers were at 0.5 (normal range\0.55 mg/l); CRP was at 1.1 (normal range \0.5 mg/dl). The transthoracic echocardiography showed a hypertrophic free wall of the right ventricle with a mild dilation of the right atrium (area was assessed as 2.2 cm). The color Doppler at the level of the tricuspidal annulus revealed a moderate tricuspidal regurgitation and the systolic pulmonary arterial pressure was assessed with continuous wave Doppler at 78 mmHg plus central venous pressure. The left ventricular ejection fraction was 70% and the transesophageal echocardiography showed an uncommon structure on the wall of the right pulmonary artery (Fig. 1). All echocardiographic measurements of the right ventricle were made in line with similar studies for evaluation of pulmonary artery hypertension [2]. CT diagnostics showed no sign of peripheral pulmonary embolism; however, it revealed a mural thrombus in the right pulmonary artery stem, which seemed to arise from the pulmonary valve (Fig. 1b). Left and right heart catheterization and pulmonary angiogram followed for further diagnostics. A nearly 100% stenosis across the right pulmonary artery trunk was shown. We initially hypothesized the existence of a massive mural thrombus and a concomitant chronic thromboembolic disease (CTEPH) (Fig. 2. The right catheterization recorded a systolic pressure of 78 mmHg proximal and 36 mmHg distal to the stenosis. The same systolic parameter was recorded from the hemodynamic measurements in the left pulmonary artery. The wedge pressure was 3 mmHg. IVUS was performed and confirmed an occluding mass (Fig. 3). The hemodynamic results revealed an isolated M. Hoiczyk (&) S. Bauer M. Schuler West German Cancer Center, University Hospital Essen, Essen, Germany e-mail: mathias.hoiczyk@uk-essen.de

Ischemic and postischemic conditioning of the myocardium in clinical practice: challenges, expectations and obstacles.

Conditioning refers to endogenous mechanisms rendering the myocardium more tolerant against reperfusion injury. Application of brief ischemia-reperfusion cycles prior to the index ischemia has a beneficial effect and limits the infarct size. This is called preconditioning and is mainly mediated by activation of adenosine, bradykinin, opioid and other receptors, with subsequent activation of intracellular mediators leading to mitochondrial protection. A clinical equivalent of preconditioning is preinfarction angina. Benefits for the ischemic and reperfused myocardium are also provided by repetitive short-lived cycles of ischemia-reperfusion applied after the index ischemia. This is termed postconditioning, shares a common pathway with preconditioning, and is more useful and relevant in clinical practice. Finally, benefits are also derived from remote conditioning, i.e. ischemia applied in a remote vascular territory parallel with or immediately after the index myocardial ischemia. Several pharmacological interventions may interfere with these mechanisms leading to enhanced protection of the myocardium and limitation of the infarct size. Despite the huge interest and the great body of evidence that verify the effectiveness of conditioning, clinical application has remained limited due to controversies over the appropriate intervention protocol, but also interference of medication, comorbidities and other factors that may enhance or blur the protective effect.

Various models of cardiac conditioning in single or sequential periods of ischemia: Comparative effects on infarct size and intracellular signaling

BACKGROUND Preconditioning (PreC) and postconditioning (PostC) reduce infarct size. We sought to determine the effects of PreC and PostC, alone or in combination, on infarct size and expression of intracellular signals in different ischemia models. METHODS Male rabbits were subjected to myocardial ischemia followed by 3-hour reperfusion. In a first series we applied 3 ischemia models [a 20-min period (20), a 40-min period (40), and two sequential 20-min periods (20-20)] and 3 types of interventions [no intervention (controls, C), 2 cycles of 5-min ischemia/10-min reperfusion before index ischemia (PreC) and 6 cycles of 10-s ischemia/10-s reperfusion after index ischemia and/or between the sequential ischemic periods (PostC)] (12 groups in total). Infarct size (I) and area at risk (R) were assessed (%I/R). In a second series, samples were taken for western blot analysis of Akt phosphorylation. RESULTS Overall, %I/R differed significantly among groups (p<0.001). In control groups, C-40 had a greater %I/R than C-20 (p=0.006). In intervention groups, no differences were found in %I/R. All intervention groups had significantly lower %I/R compared to C-40 group (p<0.001), whereas, compared to C-20-20 group, PreC-20-20, 20-PostC-20, 20-PostC-20-PostC and PreC-20-20-PostC groups had lower %I/R (all p<0.05). Akt was increased in all groups in which a significant %I/R reduction was achieved (p<0.05 versus all other groups). CONCLUSIONS PreC and PostC, alone or in combination, are effective when an ischemic insult of a given duration is applied either as a single or as sequential periods. Protection from either intervention is associated with an enhanced Akt activation.

Use of leadless pacemakers in Europe: results of the European Heart Rhythm Association survey

The purpose of this European Heart Rhythm Association (EHRA) survey is to provide an overview of the current use of leadless pacemakers (LLPM) across a broad range of European centres. An online questionnaire was sent to centres participating in the EHRA Electrophysiology Research Network. Questions dealt with standards of care and policies used for patient management, indications, and techniques of implantation of LLPM. In total, 52 centres participated in the survey. Most (86%) reported using LLPM, although 82% of these centres implanted <30 LLPM devices during the last 12 months. Non-availability (36%), lack of reimbursement (55%), and cost of the device (91%) were factors limiting the use of LLPM. The most commonly reported indications for LLPM were permanent atrial fibrillation (83%), a history of complicated conventional pacemaker (87%), or an anticipated difficult vascular access (91%). Implantation of LLPM is perceived as an easy-to-do and safe procedure by most implanters (64%), while difficult or risky in 28%, and comparable to conventional pacemakers by only a few (8%). Local vascular complications were the most frequently reported major problems (28%), but a significant number of respondents (36%) have never encountered any issue after LLPM implantation. Although cost and reimbursement issues strongly influence the use of LLPM, most respondents (72%) anticipate a significant increase in device utilization within next 2 years.

Management of ventricular tachycardia in the ablation era: results of the European Heart Rhythm Association Survey

Patients with sustained ventricular tachycardia (VT) are at risk of sudden death. Treatment options for VT include antiarrhythmic drug therapy, insertion of an implantable cardioverter-defibrillator, and catheter ablation. Evidence on indications for VT ablation, timing, ablation strategies, and periprocedural management is sparse. The aim of this European Heart Rhythm Association (EHRA) survey was to evaluate clinical practice regarding management of VT among the European countries. An electronic questionnaire was sent to members of the EHRA Electrophysiology Research Network. Responses were received from 88 centres in 12 countries. The results have shown that management of VTs is very heterogeneous across the participating centres. Indications, periprocedural management, and ablation strategies vary substantially. This EP Wire survey has revealed that catheter ablation is the first-line therapy for the treatment of recurrent monomorphic stable VT in patients without structural heart disease as well as in patients with ischaemic cardiomyopathy and impaired left ventricular ejection fraction in the majority of centres. Furthermore, in patients with ischaemic cardiomyopathy and the first episode of monomorphic VT, most centres (62.0%) performed catheter ablation. On the contrary, in patients with non-ischaemic cardiomyopathy, amiodarone (41.4%) and catheter ablation (37.1%) are used in a very similar proportion. Ablation strategies, endpoints, and post-ablation antithrombotic management vary substantially among European centres.

Radiofrequency Ablation of Atrial Fibrillation in Patients with Ebstein's Anomaly: A Two-Case Report

Ebsteins anomaly (EA) is a rare congenital heart disease characterized by “atrialization” of the right ventricle, due to apical displacement of the tricuspid leaflets into the right ventricle. Patients with EA may develop all kinds of supraventricular arrhythmias requiring radiofrequency ablation. Atrial fibrillation (Afib) is a common arrhythmia in EA patients, and results in debilitating symptoms that often require surgical treatment. This is a follow-up report of 2 patients with EA undergoing radiofrequency ablation for Afib. The first patient underwent pulmonary vein isolation (PVI) and the ablation of a concomitant atrioventricular nodal reentrant tachycardia. The second patient was also treated with a PVI and a redo PVI 8 months later. Both patients remain in sinus rhythm 8 months on. Radiofrequency ablation is the therapy of choice for patients with pharmacological refractory Afib, but it is not common in patients with EA.

Management of patients with ventricular arrhythmias and prevention of sudden cardiac death—translating guidelines into practice: results of the European Heart Rhythm Association survey

Prevention of sudden cardiac death (SCD) remains a partly unsolved task in cardiology. The European Society of Cardiology (ESC) guidelines on management of patients with ventricular arrhythmias and prevention of SCD published in 2015 considered the new insights of the natural history of diseases predisposing to SCD. The guidelines improved strategies for management of patients at risk of SCD and included both drug and device therapies. The intention of this survey was to evaluate the extent of the disparities between daily clinical practice and the 2015 SCD ESC guidelines among electrophysiology centres in Europe. The results suggest that the adherence to guidelines is reasonably high and strategies for the management of ischaemic disease are well-established. Implantable cardioverter-defibrillator indications for primary prevention are a difficult topic, particularly in non-ischaemic dilated cardiomyopathy. Disparities in the use of genetic testing are probably due to differences in local availability.

Translating guidelines into practice for the management of atrial fibrillation: results of an European Heart Rhythm Association Survey

Despite the huge progress made in the both understanding the mechanisms and the management of atrial fibrillation (AF) this arrhythmia still represents an important health and social burden. Atrial fibrillation is increasing in frequency and is a major cause of death, stroke, heart failure, cognitive decline, and hospitalizations. New data have emerged emphasizing the multidisciplinary approach to better management of this common arrhythmia. Despite the availability of AF management guidelines, practice among European centres may differ from the current guideline recommendations. The scope of the current European Heart Rhythm Association (EHRA) survey is to evaluate the extent of the disparities between clinical practice and the 2016 AF European Society of Cardiology (ESC) guidelines. Our survey examined important topics such as screening for AF, initial therapy, rhythm strategy, and stroke and bleeding risk assessment. In general, there was a high adherence to the new ESC AF guidelines among European cardiologists.