What Do We Know So Far About Ventricular Arrhythmias and Sudden Cardiac Death Prediction in the Mitral Valve Prolapse Population? Could Biomarkers Help Us Predict Their Occurrence?

PURPOSE OF THE REVIEW: To summarize currently available data on the topic of mitral valve prolapse (MVP) and its correlation to the occurrence of atrial and ventricular arrhythmias. To assess the prognostic value of several diagnostic methods such as transthoracic echocardiography, transesophageal echocardiography, cardiac magnetic resonance, cardiac computed tomography, electrocardiography, and electrophysiology concerning arrhythmic episodes. To explore intra and extracellular biochemistry of the cardiovascular system and its biomarkers as diagnostic tools to predict rhythm disturbances in the MVP population. RECENT FINDINGS: MVP is a common and mainly benign valvular disorder. It affects 2-3% of the general population. MVP is a heterogeneous and highly variable phenomenon with three structural phenotypes: myxomatous degeneration, fibroelastic deficiency, and forme fruste. Exercise intolerance, supraventricular tachycardia, and chest discomfort are the symptoms that are often paired with psychosomatic components. Though MVP is thought to be benign, the association between isolated MVP without mitral regurgitation (MR) or left ventricle dysfunction, with ventricular arrhythmia (VA) and sudden cardiac death (SCD) has been observed. The incidence of SCD in the MVP population is around 0.6% per year, which is 6 times higher than the occurrence of SCD in the general population. Often asymptomatic MVP population poses a challenge to screen for VA and prevent SCD. Therefore, it is crucial to carefully assess the risk of VA and SCD in patients with MVP with the use of various tools such as diagnostic imaging and biochemical and genetic screening.

Lip print evidence: Poland as the Last Bastion of Practical Cheiloscopy.

Cheiloscopic examinations have long been conducted, and many scientists have reported the usefulness of cheiloscopy for personal identification with a characteristic and individual pattern of furrows on the vermilion lip. For almost 40 years, research conducted in Poland has determined the patterns of these furrows and the separation and development of their individual features. This was the basis for forming expert opinions and presenting them in court as evidence. In Poland, cheiloscopic expertise is performed and the results of precise procedures that are accredited and assessed serve as evidence. Although the legal system in Poland (continental system) is completely different from the American system, cheiloscopic expertise was also assessed in detail according to the American standards of evidence. This narrative review presents the problem of cheiloscopic expertise as a scientific and practical issue and provides a brief historical overview of this field and the foundations of the Polish cheiloscopic identification method. We conclude that Poland has sufficient historical background and a robust development of cheiloscopy in the field on a scientific and legal basis; however, due to its reports being in the Polish language, its absence from the most relevant specialized literature, or simply a lack of cooperation between countries and experts, the country has unfairly been left out of the discussion. We believe that a new look at the Polish contribution to lip print identification is necessary to reinsert this topic into the current discussion of a new identification paradigm.

Echocardiographic markers of dyssynchrony as predictors of super-response to cardiac resynchronisation therapy - a pilot study.

BACKGROUND: Some patients with congestive heart failure have greater improvement of cardiac remodelling after cardiac resynchronisation therapy (CRT) and they are identified as super-responders (SRs). It remains unclear if echocardiographic markers of dyssynchrony could accuratelly predict super-response to CRT. The aim of this study is to evaluate potential echocardiographic predictors associated with super-response to CRT. METHODS: Fifthy nine CRT patients (mean age 52.9 ± 9.0 years, 88% men) with congestive heart failure (54% ischaemic and 46% non-ischaemic aetiology) II-IV NYHA functional class were enrolled. To assess mechanical dyssynchrony we evaluated interventricular mechanical delay, the maximum delay between peak systolic velocities of the septal and posterior walls of left ventricle, duration of left ventricular pre-ejection period (LVPEP), left ventricular and interventricular dyssynchrony by tissue Doppler imaging and systolic dyssynchrony index by 3D echocardiography. After six months the patients were assessed for response and classified as SRs (reduction in left ventricular end-systolic volume (LVESV) ≥30%, n = 20) and non-SRs (reduction in LVESV < 30%, n = 39) and baseline data were analyzed to identify the predictors. RESULTS: Both groups demonstrated significant improvement in NYHA functional class, increase in left ventricular ejection fraction and reduction in LVESV. All parameters of mechanical dyssynchrony at baseline were significantly higher in SR group. Multiple logistic regression analysis showed that LVPEP (HR 1.031; 95% CI 1.007-1.055; p = 0.011) was an independent predictor for CRT super-response. In ROC curve analysis LVPEP with a cut-off value of 147 ms demonstrated 73.7% sensitivity and 75% specificity (AUC = 0.753; p = 0.002) for the prediction of super-response to CRT. CONCLUSION: Greater mechanical dyssynchrony is associated with super-response to CRT in patients with congestive heart failure. It is probable that an LVPEP > 147 ms can be used as independent predictor of super-response.

Subclinical chronic left ventricular systolic dysfunction resulting from phosphine poisoning.

We present a case of a 32-year-old male crew member of a cargo ship, accidentally exposed to phosphine, a fumigating substance. He and other crew members developed increasing fatigue and digestive disorders 24 h later; two died from acute pulmonary oedema. The patient was admitted to hospital, where bilateral pneumonia, acute nephritis, hepatopathy, electrolyte imbalance and leucopenia were diagnosed. He was discharged from hospital 3 weeks later. He was examined 4 months later for possible chronic consequences of acute phosphine poisoning, which included echocardiography showing normal heart size and cardiac function. However, on advanced quantitative analysis, using two-dimensional speckle tracking echocardiography, depressed global longitudinal strain was found. Our report extends previously published findings of phosphine-induced left ventricular (LV) dysfunction by demonstrating that subclinical myocardial dysfunction resulting from acute phosphine exposure may persist several months after the exposure in an otherwise asymptomatic patient, and potentially may not be entirely reversible. The persistence of subclinical abnormalities of LV longitudinal function can be diagnosed using the advanced quantitative echocardiographic analysis we describe.

Harvesting, Coupling, and Control of Single-Exciton Coherences in Photonic Waveguide Antennas.

We perform coherent nonlinear spectroscopy of individual excitons strongly confined in single InAs quantum dots (QDs). The retrieval of their intrinsically weak four-wave mixing (FWM) response is enabled by a one-dimensional dielectric waveguide antenna. Compared to a similar QD embedded in bulk media, the FWM detection sensitivity is enhanced by up to 4 orders of magnitude, over a broad operation bandwidth. Three-beam FWM is employed to investigate coherence and population dynamics within individual QD transitions. We retrieve their homogenous dephasing in a presence of low-frequency spectral wandering. Two-dimensional FWM reveals off-resonant Förster coupling between a pair of distinct QDs embedded in the antenna. We also detect a higher order QD nonlinearity (six-wave mixing) and use it to coherently control the FWM transient. Waveguide antennas enable us to conceive multicolor coherent manipulation schemes of individual emitters.

In vitro and in vivo characteristics of connexin 43-modified human skeletal myoblasts as candidates for prospective stem cell therapy for the failing heart.

BACKGROUND: Previously, connexin 43-modified skeletal myoblasts (MbCx) were shown to reduce the pro-arrhythmic effect during the regeneration of heart tissue in an animal model of infarction. To increase the relevance to clinical implementation, in this study, we introduced connexin 43 into human myoblasts using a highly safe non-viral vector and demonstrated that their transplantation had a positive effect on the function of the injured heart. METHODS AND RESULTS: Myoblasts were efficiently transfected with a pCiNeo-GJA1 plasmid (65.72%). qPCR analysis revealed over 32-fold higher expression of the connexin 43 gene in the MbCx cell population compared to 'native' controls. The susceptibility of the myoblasts to oxidative stress conditions (p<0.001) and the fusion index (p<0.01) were increased in the MbCx cells. Additionally, we observed changes in the MYOG and MYH2 gene expression levels in the GJA1-modified myoblasts. Finally, we observed a significant improvement in the post-infarction echocardiographic parameters after intervention using MbCx cells compared with non-transfected myoblasts (MbWt) and the control (0.9% NaCl), wherein a significant decrease in the left ventricular area change in the short axis (SAX AC%) was observed at the two-month follow-up (p<0.05 and p<0.01, respectively). CONCLUSIONS: We demonstrated the positive effect of connexin 43 overexpression on the biology and function of human skeletal myoblasts in the context of their potential clinical applications. Our preclinical studies using a mouse infarction model indicated the positive effect of MbCx implantation on the function of the injured heart.

Microcavity controlled coupling of excitonic qubits.

Controlled non-local energy and coherence transfer enables light harvesting in photosynthesis and non-local logical operations in quantum computing. This process is intuitively pictured by a pair of mechanical oscillators, coupled by a spring, allowing for a reversible exchange of excitation. On a microscopic level, the most relevant mechanism of coherent coupling of distant quantum bits--like trapped ions, superconducting qubits or excitons confined in semiconductor quantum dots--is coupling via the electromagnetic field. Here we demonstrate the controlled coherent coupling of spatially separated quantum dots via the photon mode of a solid state microresonator using the strong exciton-photon coupling regime. This is enabled by two-dimensional spectroscopy of the sample's coherent response, a sensitive probe of the coherent coupling. The results are quantitatively understood in a rigorous description of the cavity-mediated coupling of the quantum dot excitons. This mechanism can be used, for instance in photonic crystal cavity networks, to enable a long-range, non-local coherent coupling.

Pocket-size echocardiograph--a valuable tool for nonexperts or just a portable device for echocardiographers?

PURPOSE: The diagnostic value of examinations performed with the use of pocket-size echocardiograph by medical professionals with different levels of experience remains to be determined. The aim of this study was to assess the diagnostic value of bedside echocardiographic examinations performed with the use of pocket-size echocardiograph by experienced cardiologist and medical students. MATERIAL/METHODS: The study group comprised 90 patients (63 men, 27 women; mean age 64±14 years) admitted to the cardiac intensive care unit and 30 patients from an out-patient clinic (21 men, 9 women; mean age 62±17 years). All patients underwent bedside echocardiographic examination performed with pocket-size echocardiograph by two briefly trained medical students (n=90 patients) or cardiologist (n=30 patients). Major findings were recorded using a simplified questionnaire. Within 24 hours standard echocardiographic examination was performed in all patients by another cardiologist using a full sized echocardiograph. The study group was divided into 4 subgroups: A / B - first / second half of in-patients examined by students, group C - inpatients examined by cardiologist, group D- out-patients examined by students. RESULTS: The agreement between standard transthoracic echocardiography (sTTE) and major findings on bedside transthoracic echocardiography (bTTE) was fair to moderate (kappa 0.293-0.57) in group A, moderate to very good (kappa 0.535-1.00) in group B, good to very good (kappa 0.734-1.00) in group C and moderate to very good (kappa 0.590-1.00) in group D. CONCLUSIONS: Pocket-size echocardiograph enables an expert echocardiographer to perform reliable bedside examinations. When used by briefly trained medical students it provides an acceptable diagnostic value with notable learning curve effect.

Beneficial effects of cardiac rehabilitation in patients with incomplete revascularization after primary coronary angioplasty.

BACKGROUND: There are no reliable data concerning the safety and benefits of physical rehabilitation in patients with a two-vessel disease before the second stage of angioplasty. The aim of this study was to evaluate the efficiency of early cardiac rehabilitation in patients with acute coronary syndromes and with angiographically significant residual coronary artery stenosis after a successful percutaneous coronary intervention (PCI) into the culprit lesion. DESIGN: Retrospective analysis of the results of coronary angiograms and exercise tests of patients who underwent stationary rehabilitation after their first ACS and first PCI. SETTING: Cardiac Rehabilitation Department. POPULATION: One hundred ninety patients divided into 2 groups according to the completeness of myocardial revascularization; 49 with significant (≥70%) coronary artery stenosis in a non-culprit vessel, the mean diameter reduction 80±9%; and 141 without any residual stenosis. The prevalence of classical risk factors was comparable in both groups. Rehabilitation was conducted as a stationary 3-week program. METHODS: Comparison of the initial and final exercise test workload in both groups, as well as the frequency of adverse effects during the program. RESULTS: Physical training in patients with incomplete revascularization (IR) was safe and well tolerated. Significant increase of workload capacity after the rehabilitation program was observed in both groups: in the IR group from 7.3±3.0 to 8.8±2.9 MET (P<0.0001) and in the complete revascularization (CR) group - from 7.6±2.8 to 9.2±2.9 MET (P<0.0001). No significant difference was observed in initial workload capacities (P=0.9813) nor in final workload capacities (P=0.8571) between the two groups. Two patients in the group with residual lesion (4%) and one in the group without residual lesion (0.7%) required urgent PCI during the rehabilitation program, P=0.1637. CONCLUSION: Early postinfarction physical training is safe and efficient for patients after complete revascularization and for those with untreated non-culprit coronary artery stenosis. Gradual increase in physical training intensity under cardiologist supervision is essential in identifying those rare patients for whom the second stage of angioplasty should not be delayed. CLINICAL REHABILITATION IMPACT: Our study shows that patients with incomplete revascularization may be qualified for cardiac rehabilitation programs.

Up on the Jaynes-Cummings ladder of a quantum-dot/microcavity system.

In spite of their different natures, light and matter can be unified under the strong-coupling regime, yielding superpositions of the two, referred to as dressed states or polaritons. After initially being demonstrated in bulk semiconductors and atomic systems, strong-coupling phenomena have been recently realized in solid-state optical microcavities. Strong coupling is an essential ingredient in the physics spanning from many-body quantum coherence phenomena, such as Bose-Einstein condensation and superfluidity, to cavity quantum electrodynamics. Within cavity quantum electrodynamics, the Jaynes-Cummings model describes the interaction of a single fermionic two-level system with a single bosonic photon mode. For a photon number larger than one, known as quantum strong coupling, a significant anharmonicity is predicted for the ladder-like spectrum of dressed states. For optical transitions in semiconductor nanostructures, first signatures of the quantum strong coupling were recently reported. Here we use advanced coherent nonlinear spectroscopy to explore a strongly coupled exciton-cavity system. We measure and simulate its four-wave mixing response, granting direct access to the coherent dynamics of the first and second rungs of the Jaynes-Cummings ladder. The agreement of the rich experimental evidence with the predictions of the Jaynes-Cummings model is proof of the quantum strong-coupling regime in the investigated solid-state system.

Formation of an exciton polariton condensate: thermodynamic versus kinetic regimes.

We measure the polariton distribution function and the condensation threshold versus the photon-exciton detuning and the lattice temperature in a CdTe microcavity under nonresonant pumping. The results are reproduced by simulations using semiclassical Boltzmann equations. At negative detuning we find a kinetic condensation regime: the distribution is not thermal and the threshold is governed by the relaxation kinetics. At positive detuning, the distribution becomes thermal and the threshold is governed by the thermodynamic parameters of the system. Both regimes are a manifestation of polariton lasing, whereas only the latter is related to Bose-Einstein condensation defined as an equilibrium phase transition.

Second-order time correlations within a polariton Bose-Einstein condensate in a CdTe microcavity.

Second-order time correlations of polaritons have been measured across the condensation threshold in a CdTe microcavity. The onset of Bose-Einstein condensation is marked by the disappearance of photon bunching, demonstrating the transition from a thermal-like state to a coherent state. Coherence is, however, degraded with increasing polariton density, most probably as a result of self-interaction within the condensate and scatterings with noncondensed excitons and polaritons. Such behavior clearly differentiates polariton Bose condensation from photon lasing.

Bose-Einstein condensation of exciton polaritons.

Phase transitions to quantum condensed phases--such as Bose-Einstein condensation (BEC), superfluidity, and superconductivity--have long fascinated scientists, as they bring pure quantum effects to a macroscopic scale. BEC has, for example, famously been demonstrated in dilute atom gas of rubidium atoms at temperatures below 200 nanokelvin. Much effort has been devoted to finding a solid-state system in which BEC can take place. Promising candidate systems are semiconductor microcavities, in which photons are confined and strongly coupled to electronic excitations, leading to the creation of exciton polaritons. These bosonic quasi-particles are 10(9) times lighter than rubidium atoms, thus theoretically permitting BEC to occur at standard cryogenic temperatures. Here we detail a comprehensive set of experiments giving compelling evidence for BEC of polaritons. Above a critical density, we observe massive occupation of the ground state developing from a polariton gas at thermal equilibrium at 19 K, an increase of temporal coherence, and the build-up of long-range spatial coherence and linear polarization, all of which indicate the spontaneous onset of a macroscopic quantum phase.

[Prevalence of dangerous arrhythmia during pharmacological stress echocardiography]. / Czestosc wystepowania groznych zaburzen rytmu podczas farmakologicznej echokardiografii obciazeniowej.

UNLABELLED: Pharmacological stress echocardiography (SE) has become a routine diagnostic and prognostic method in patients with ischemic heart disease. However, all stress tests can provoke undesirable adverse effects including dangerous arrhythmia. The aim of the study was to access the prevalence and types of arrhythmia that can appear during SE. MATERIALS AND METHODS: A retrospective study included the cohort of patients studied using SE in our Department of Cardiology between 1995 and 2002. We followed the data of 836 patients (pts) (615 men, aged 52 +/- 5 yrs). Dobutamine SE was performed in 695 pts (83.2%) and dipyridamole SE in a group of 141 pts (16.8%). Additionally, atropine was administrated to achieve submaximal heart rate in a group of 694 pts (83%). 519 pts (62%) underwent SE was performed according to high dose protocol and in 317 pts (35%)--low dose protocol. RESULTS: During SE the following arrhythmia events were observed: one persistent ventricular tachycardia (0.12%) and two paroxysmal atrial fibrillation (0.24%) in dobutamine test. The set of unsustained ventricular tachycardia in six patients (0.72%) 5 patients from dobutamine group and 1 from dipyridamole group). Complex forms of ventricular extrasystoles (as bigeminy and trigeminy) in 46 pts (5.5%) 43 in dobutamine SE and 3 in dipyridamole SE. All arrhythmias were mild and withdrew spontaneously or after beta-blockers administration. CONCLUSIONS: The risk of dangerous arrhythmia during either dobutamine SE or dipyridamole SE is small and similar in both groups. Dobutamine SE tends to provoke of mild arrhythmia (p = 0.075) more often.

Increase in plasma plasminogen activators inhibitor type 1 concentration after fibrinolytic treatment in patients with acute myocardial infarction is associated with 4G/5G polymorphism of PAI-1 gene.

BACKGROUND: Preliminary data suggest that plasma concentration of plasminogen activators inhibitor type 1 (PAI-1) is genetically determined and may be related to differential regulation of plasma PAI-1 concentration at baseline and after stimulation. AIM: This study aimed to evaluate whether increase in the plasma PAI-1 antigen concentration or activity after fibrinolytic therapy in patients with acute myocardial infarction is associated with the -675 4G/5G genetic polymorphism in the promoter region of PAI-1 gene. RESULTS & CONCLUSIONS: Our study revealed that a rebound effect is observed in PAI-1 activity (ActPAI-1) and PAI-1 antigen (AgPAI-1) concentration after standard streptokinase treatment with maximal values of 3 h (t3) after the completion of streptokinase infusion. Both ActPAI-1 and AgPAI-1 were significantly higher at t3 compared to the levels before fibrinolytic treatment: 37.3 (20.0-67.7) vs. 10.0 (3.6-26.0) IU L(-1); P = 0.00001 and 29.9 (15.6-42.3) vs. 20.9 (13.0-30.2) ng mL(-1); P = 0.001, respectively. The stratification of the patients by genotype revealed that carriers of the 4G allele had higher concentrations of PAI-1 antigen 3 h after streptokinase infusion: 30.9 vs. 13.8 ng mL(-1); P = 0.019. No significant association between PAI-1 activity and genotype was found. In conclusion, the rebound effect in serum PAI-1 concentration observed after streptokinase treatment may be related to the 4G/5G polymorphism in the PAI-1 gene promoter.

Arterial dysfunction in syndrome X: results of arterial reactivity and pulse wave propagation tests.

OBJECTIVE: To assess arterial distensibility using pulse wave velocity (PWV) measurements and its relation with endothelium dependent vasodilatation (EDV) in patients with cardiological syndrome X. METHODS: The study group consisted of 92 patients: 52 with syndrome X (34 women, 18 men, mean (SD) age 45 (3) years) and 40 healthy volunteer controls (27 women, 13 men, mean (SD) age 41 (2) years) without risk factors of atherosclerosis and with negative ECG exercise test and normal proximal coronaries on transoesophageal echocardiography. Patients with arterial hypertension, diabetes mellitus, valvar disease, or cardiomyopathy were excluded. PWV measured by a Complior Colson device was calculated for each patient. EDV was assessed from two dimensional Doppler measurement using an Acuson Sequoia with 8 MHz linear transducer at rest, during postischaemic reactive hyperaemia, and after an oral dose of 400 micro g of glyceryl trinitrate. RESULTS: PWV was significantly higher in patients with syndrome X than in healthy subjects (9.3 (0.7) m/s v 8.2 (0.9) m/s, respectively, p < 0.001). Baseline brachial artery diameter was similar in the syndrome X and control groups (4.0 (0.6) mm v 4.08 (0.64) mm, NS). EDV was impaired in patients with syndrome X compared with controls (6.6 (3.0)% v 11.1 (3.9)%, p < 0.001). Endothelium independent vasodilatation was similar in both groups. In patients with syndrome X there was a positive correlation between PWV and the degree of EDV (r = 0.864, p < 0.001). The cut off value for PWV was 8.5 m/s, with a sensitivity of 62% and a specificity of 91%. CONCLUSIONS: EDV but not glyceryl trinitrate induced vasodilatation is decreased in patients with syndrome X. There is a strong correlation between PWV and the degree of endothelial dysfunction of peripheral arteries in patients with syndrome X. PWV assessment may be useful to identify abnormal vascular physiology in these patients.

Investigation of the free radical scavenging activity of Ginkgo biloba L. leaves.

The free radical scavenging activity of methanolic, ethanolic and aqueous extracts from Ginkgo biloba leaves, has been determined by EPR (electron paramagnetic resonance) using the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging method. The investigation has also included selected constituents of G. biloba leaves, protocatechuic and p-coumaric acids, quercetin, rutin, isoginkgetin and (+)-catechin.