Extraction of a 6-year-old leadless pacemaker (MICRA transcatheter pacing system) using commercially available removal tools: A case report.

INTRODUCTION: Leadless pacemakers are associated with a low risk of infection, so indications for their removal are rare. One can expect that the dwell time of the device correlates with a more difficult removal, but it has not been proved so far. METHODS AND RESULTS: We present a case of a patient in whom MICRA transcatheter pacing system was successfully removed with nondedicated commercially available tools, 70 months after implantation. CONCLUSION: A successful removal of the MICRA leadless pacemaker is possible, and may be safe even many years after the device implantation, despite a lack of dedicated tools. Due to the potential risk of complications, the benefits and risks of the procedure should be weighted before making a final decision.

Assessment of Myocardial Diastolic Dysfunction as a Result of Myocardial Infarction and Extracellular Matrix Regulation Disorders in the Context of Mesenchymal Stem Cell Therapy.

The decline in cardiac contractility due to damage or loss of cardiomyocytes is intensified by changes in the extracellular matrix leading to heart remodeling. An excessive matrix response in the ischemic cardiomyopathy may contribute to the elevated fibrotic compartment and diastolic dysfunction. Fibroproliferation is a defense response aimed at quickly closing the damaged area and maintaining tissue integrity. Balance in this process is of paramount importance, as the reduced post-infarction response causes scar thinning and more pronounced left ventricular remodeling, while excessive fibrosis leads to impairment of heart function. Under normal conditions, migration of progenitor cells to the lesion site occurs. These cells have the potential to differentiate into myocytes in vitro, but the changed micro-environment in the heart after infarction does not allow such differentiation. Stem cell transplantation affects the extracellular matrix remodeling and thus may facilitate the improvement of left ventricular function. Studies show that mesenchymal stem cell therapy after infarct reduces fibrosis. However, the authors did not specify whether they meant the reduction of scarring as a result of regeneration or changes in the matrix. Research is also necessary to rule out long-term negative effects of post-acute infarct stem cell therapy.

A New Era in Epicardial Access for the Ablation of Ventricular Arrhythmias: The Epi-Co2 Registry.

OBJECTIVES: This multicenter registry aimed to assess the reproducibility and safety of intentional coronary vein exit and carbon dioxide insufflation to facilitate subxiphoid epicardial access in the setting of ventricular tachycardia ablation. BACKGROUND: Epicardial ablation for ventricular tachycardia is not a widespread technique due to the significant potential complications associated with subxiphoid puncture. The first experience in 12 patients showed that intentional coronary vein exit and carbon dioxide insufflation was technically feasible. METHODS: A branch of the coronary sinus was cannulated by means of a diagnostic JR4 coronary catheter. Intentional perforation at the distal portion of that branch was performed with a high tip load 0.014-inch angioplasty wire. A microcatheter was advanced over the wire into the pericardial space. Carbon dioxide was then insufflated into the pericardial space, allowing direct visualization of the anterior pericardial space to facilitate subxiphoid puncture. RESULTS: Intentional coronary vein exit was attempted in 102 consecutive patients in 16 different centers and successfully completed in 101 patients. Significant pericardial adhesions were confirmed in 3 patients, preventing carbon dioxide insufflation and epicardial ablation. None of the punctures were complicated with inadvertent right ventricular puncture or damage to a coronary artery. Significant bleeding (>80 ml) due to coronary vein exit occurred in 5 patients, without hemodynamic compromise. None of the patients required surgery. CONCLUSIONS: Coronary vein exit and carbon dioxide insufflation can be safely and reproducibly achieved to facilitate subxiphoid pericardial access in the setting of ventricular tachycardia ablation.

Heart Failure with Preserved Ejection Fraction-a Concise Review.

PURPOSE OF REVIEW: Heart failure with preserved ejection fraction (HFpEF) is a relatively new disease entity used in medical terminology; however, both the number of patients and its clinical significance are growing. HFpEF used to be seen as a mild condition; however, the symptoms and quality of life of the patients are comparable to those with reduced ejection fraction. The disease is much more complex than previously thought. In this article, information surrounding the etiology, diagnosis, prognosis, and possible therapeutic options of HFpEF are reviewed and summarized. RECENT FINDINGS: It has recently been proposed that heart failure (HF) is rather a heterogeneous syndrome with a spectrum of overlapping and distinct characteristics. HFpEF itself can be distilled into different phenotypes based on the underlying biology. The etiological factors of HFpEF are unclear; however, systemic low-grade inflammation and microvascular damage as a consequence of comorbidities associated with endothelial dysfunction, oxidative stress, myocardial remodeling, and fibrosis are considered to play a crucial role in the pathogenesis of a disease. The H2FPEF score and the HFpEF nomogram are recently validated highly sensitive tools employed for risk assessment of subclinical heart failure. Despite numerous studies, there is still no evidence-based pharmacotherapy for HFpEF and the mortality and morbidity associated with HFpEF remain high. A better understanding of the etiological factors, the impact of comorbidities, the phenotypes of the disease, and implementation of machine learning algorithms may play a key role in the development of future therapeutic strategies.

Clinical presentation, surgical management, and outcomes of patients treated for aortic stenosis and coronary artery disease. Does age matter?

BACKGROUND: Aortic stenosis and coronary artery disease (CAD) sharing similar risk factors are associated with aging of the human population. AIM: The purpose of this study was to examine whether age affects clinical presentation, intraoperative management, and outcomes of patients who undergo simultaneous operations of aortic valve replacement (AVR) and coronary artery bypass grafting (CABG). METHODS: The study involved 452 consecutive patients aged 64.8 ± 8.2 years (range 38-79 years), who underwent combined AVR and CABG between 2005 and 2015. They were divided into three groups: Y (young; below the first quartile; n = 114), M (middle-aged; 58-71 years; n = 225) and E (elderly; above the third quartile; n = 113). Pre- and intraoperative variables were analysed. The deaths that occurred in hospital and throughout follow-up were defined as cardiac- or non-cardiac-related. The probability of survival was calculated with the use of Kaplan-Meier curves. RESULTS: Coronary artery disease was more extensive in group E than in group Y (p < 0.05). Complete myocardial revasculari-sation was performed in 94.1%, 76.2%, and 62.8% in groups Y, M, and E, respectively (p < 0.05). In-hospital mortality was 2.0%, 5.3%, and 6.4%, in groups Y, M, and E, respectively. Early morbidity was significantly higher in group E than in groups M or Y. The 12- and 60-month freedom from cardiac-related death was higher in group Y (0.98 ± 0.02 and 0.94 ± 0.03) than in group E (0.93 ± 0.02 and 0.85 ± 0.03; p = 0.023, respectively). Left ventricular ejection fraction below 0.4 and incomplete revascularisation were associated with worse prognosis, particularly in group E. CONCLUSIONS: Elderly patients undergoing combined procedures of AVR and CABG having more extensive CAD less often receive complete revascularisation, are at higher risk of early organ failure, and present markedly reduced rates of freedom from cardiac-related deaths throughout follow-up than younger subjects.

Patients treated with bivalirudin are still at higher risk of stent thrombosis: a comprehensive meta-analysis of randomised clinical trials of bivalirudin and heparin for percutaneous coronary interventions.

BACKGROUND: Although the current practice guidelines recommend using both heparin and bivalirudin for percutaneous coronary interventions (PCI), the research data are ambiguous. AIM: The aim of the study was to compare the impact of bivalirudin and heparin on major clinical endpoints in PCI patients with particular emphasis on periprocedural stent thrombosis. METHODS: A total of 18 randomised clinical trials involving 41,752 subjects were included. The endpoints comprised: net adverse clinical event (NACE: death, myocardial infarction [MI], unscheduled revascularisation, major bleeding), major adverse cardiovascular event (MACE: death, MI, or stroke), and acute/subacute stent thrombosis (ST). A subanalysis for planned and provisional glycoprotein IIb/IIIa inhibitor (GPI) use with heparin was performed. Results were presented as risk ratios (RR) and 95% confidence intervals (CI). RESULTS: Bivalirudin significantly reduced NACE risk (RR 0.85, 95% CI 0.76-0.96) and increased the incidence of MI (RR 1.09, 95% CI 1.01-1.18), ST (RR 1.50, 95% CI 1.13-1.99), and MACEs (RR 1.06, 95% CI 0.99-1.13). Comparing to heparin with provisional or planned GPI use, there was higher risk of acute ST with bivalirudin (RR 2.14, 95% CI 1.01-4.56 and RR 5.53, 95% CI 2.32-13.18, respectively). Comparing to heparin and provisional GPIs, bivalirudin failed to reduce NACEs and major bleeding. However, it decreased rates of NACEs (RR 0.81, 95% CI 0.69-0.96) and major bleeding (RR 0.64, 95% CI 0.48-0.85) compared with heparin and planned GPI use. CONCLUSIONS: The advantages of bivalirudin are undoubtedly related to GPI use in the heparin arms. Bivalirudin-based regimens are more beneficial when compared with heparin and planned GPI use in terms of NACE and major bleedings; this was not observed when compared to heparin and provisional GPI use. Regardless of adjunctive GPI use, stent thrombosis episodes were significantly more common in bivalirudin-treated subjects. Therefore, the safety and economic issues may urge revision of this aspect of current clinical practice and guidelines.

Double atrial potentials in left-sided accessory pathways are associated with paroxysmal atrial fibrillation.

INTRODUCTION: Muscular connections between the coronary sinus (CS) and left atrium probably impact distribution of electrical activity. Double atrial potentials (DP) may be their presentation. The aim was to investigate the presence of DP in CS recordings during atrioventricular reentrant tachycardia (AVRT) and its contribution to the occurrence of paroxysmal atrial fibrillation (AF). METHODS: A group of 247 patients with accessory pathways (AP) were screened for DP. The patients with DP during AVRT were compared to those without DP. RESULTS: DP during AVRT were found only among the left-sided AP (AP-L). Patients with AP-L were divided into Group 1 (n  =  17) with DP during AVRT and Group 2 (n  =  108) without DP. Patients in Group 1 had higher incidence of AF in history (47.1% vs. 23.1%; P  =  0.0376), AF induced during electrophysiological (EP) study (70.6% vs. 25%; P  =  0.0002). Group 1 had higher heart rate (HR) during AVRT in the EP study (197.2 ± 27 vs. 175.1 ± 26.3 bpm; P  =  0.0019), but HR of clinical AVRT (208.5 ± 30.8 vs. 191.6 ± 27.8 bpm) was not significant different (P  =  ns). Additionally, electrical alternans of QRS amplitude during AVRT in the EP study was more frequent in Group 1 (52.9 vs. 20.4 %; P  =  0.0048). CONCLUSION: Patients with DP and AP-L were more prone to develop AF. The presence of DP was associated with faster AVRT rate. The direction of atrium depolarization during AVRT may be different in the presence of DP and probably plays a role in development of AF in this group of patients.

Safety, feasibility and effectiveness of first in-human administration of muscle-derived stem/progenitor cells modified with connexin-43 gene for treatment of advanced chronic heart failure.

AIMS: To assess the safety and efficacy of transendocardial delivery of muscle-derived stem/progenitor cells with connexin-43 overexpression (Cx-43-MDS/PC) in advanced heart failure (HF). METHODS AND RESULTS: Thirteen subjects with advanced HF, New York Heart Association (NYHA) class II-III were enrolled and treated with targeted injection of Cx-43-MDS/PCs and then monitored for at least 6 months. Overexpression of Cx43 (Cx43+) was significantly higher in all but one subject (Cx43-). Injection of MDS/PCs was associated with significant improvement of exercise capacity: NYHA (3 ± 0 vs. 1.8 ± 0.7, P = 0.003), exercise duration (388.69 ± 141.83 s vs. 462.08 ± 176.69 s, P = 0.025), peak oxygen consumption (14.38 ± 3.97 vs. 15.83 ± 3.74 ml/kg.min, P = 0.022) and oxygen pulse (10.58 ± 2.89 vs. 18.88 ± 22.63 mLO2 /heart rate, P = 0.012). Levels of BNP, left ventricular (LV) ejection fraction and LV end-diastolic volumes tended to improve. There was a significant improvement of the mean unipolar voltage amplitudes measured for the injected segments and the entire left ventricle (9.62 ± 2.64 vs. 11.62 ± 3.50 mV, P = 0.014 and 8.83 ± 2.80 vs. 10.22 ± 3.41 mV, P = 0.041, respectively). No deaths were documented, Cx43+ (n = 12) subjects presented no significant ventricular arrhythmia; one Cx43- subject suffered from ventricular tachycardia (successfully treated with amiodarone). CONCLUSIONS: Injection of Cx-43-MDS/PCs in patients with severe HF led to significant improvement in exercise capacity and myocardial viability of the injected segments while inducing no significant ventricular arrhythmia. This may arise from improved electrical coupling of the injected cells and injured myocardium and thus better in-situ mechanical cooperation of both cell types. Therefore, further clinical studies with Cx43+ MDS/PCs are warranted.

From primary tricuspid regurgitation to arrhythmogenic right ventricular cardiomyopathy.

Since arrhythmogenic right ventricular dysplasia is still an under-recognised clinical entity, its 'deceitful' course requires alertness of physicians, and - in particular - awareness of its less typical manifestations. Therefore, we present a case report of a 52-year-old male subject with signs and symptoms of right ventricular heart failure and marked tricuspid regurgitation.

Asymmetry of the variability of heart rate and conduction time between atria and ventricles.

BACKGROUND: Heart rate asymmetry is caused by an unequal contribution of heart rate decelerations and accelerations to heart rate variability. This study evaluates the asymmetric properties of the variability of the AA, HH, VV, AH and HV intervals. METHODS AND RESULTS: We recorded 50 1-min intracardiac ECG tracings from 10 patients (18-66 years old; 8 females) during a routine electrophysiological study. Standard descriptors of variance asymmetry were calculated for all intervals. Nonparametric tests were used for statistical comparisons. The prolongations of VV (P=0.0297), AH (P=0.0133) and HV (P=0.0004) intervals contributed significantly more than their shortenings to their short-term variance. The proportion of recordings with a larger contribution of prolongations than shortenings was significantly different from random for VV (0.66, P=0.0328), AH (0.68, P=0.0154) HV (0.74, P=0.0009). CONCLUSIONS: In addition to heart rate asymmetry (VV interval), the conduction from the atria, through the atrioventricular node, His-Purkinje system to ventricles shows asymmetric properties in 1-min tracings.

Shortening baroreflex delay in hypertrophic cardiomyopathy patients -- an unknown effect of ß-blockers.

AIMS: Hypertrophic cardiomyopathy (HCM) is characterized by left ventricular hypertrophy and impaired diastolic and systolic function. Abnormal sympathetic-parasympathetic balance is a potential stimulus for left ventricular hypertrophy in HCM patients. ß-Blockers are routinely used in HCM for their strong negative inotropic effect; however, these drugs also influence the sympathetic-parasympathetic balance. This study aimed to determine the autonomic control of the cardiovascular system and the autonomic effects of ß-blockers in HCM patients treated or untreated with ß-blockers. METHODS: Among 51 HCM outpatients (18-70 years old; 29 men) there were 19 individuals with no medication and 32 subjects treated with a ß-blocker. Fourteen age- and gender-matched (23-70 years old; nine men) healthy volunteers were enrolled in the control group. Continuous, non-invasive finger blood pressure was recorded during supine rest for 30 min. Autonomic regulation of the cardiovascular system was measured by heart rate variability and spontaneous baroreflex function (cross-correlation sequence method). RESULTS: The mean pulse interval, time domain and spectral measures of heart rate variability and baroreflex sensitivity were comparable between HCM patients, treated or not with ß-blockers, and the control group. However, the delay of the baroreflex was significantly longer in HCM patients who were not treated with ß-blockers [2.0 (1.6-2.3) s] in comparison with HCM patients receiving ß-blockers [1.4 (1.1-1.8) s; P = 0.0072] or control subjects [1.2 (0.8-1.8) s; P = 0.0025]. This delay did not differ between HCM patients treated with ß-blockers and the control group. CONCLUSIONS: Hypertrophic cardiomyopathy not treated with ß-blockers is accompanied by prolonged baroreflex delay. The use of ß-blockers normalizes this delay.

Exudative pericarditis in a pregnant woman as the first sign of non-Hodgkin's lymphoma.

This case report presents a 25 year-old pregnant female diagnosed with exudative pericarditis which was the first sign of cardiac lymphoma. Such a manifestation of this disease is rare and it represents a significant diagnostic and therapeutic problem in pregnant women.