Cannabis sativa L. is a plant belonging to the Cannabaceae family known primarily for its recreational use due to the psychoactive properties of Δ9-tetrahydrocannabinol (THC). Despite this, several compounds belonging to the category of phytocannabinoids have shown in recent years a number of potentially promising therapeutic effects that have increased the interest in the pharmaceutical field towards this plant. However, the content of these compounds is very variable and influenced by different factors, such as growing conditions and time of the year. An indication of the status and age of Cannabis samples is provided by the content of CBN, a minor phytocannabinoid and degradation product of other phytocannabinoids, including THC. In this research work an innovative, solid state analytical approach has been developed to observe and evaluate the variations in the content of two phytocannabinoids (CBN and CBD) in Cannabis-derived products over time. In order to simulate the ageing of the Cannabis samples, an artificially accelerated ageing procedure has been developed and optimised by using high temperatures. The analyses were carried out using an innovative ATR-FTIR method for solid state analysis, enabling direct analysis of a solid sample without any pretreatment phase. This study has allowed the development of an innovative analytical approach for the evaluation of the age and state of conservation of Cannabis samples and may be a useful tool both in the industrial, pharmaceutical and forensic fields.

• MeSH
• Cannabis * chemistry   MeSH
• Time Factors MeSH
• Cannabidiol analysis   chemistry   MeSH
• Cannabinoids * analysis   chemistry   MeSH
• Plant Extracts chemistry   analysis   MeSH
• Spectroscopy, Fourier Transform Infrared methods   MeSH
• Drug Stability MeSH
• Dronabinol analysis   chemistry   MeSH
• Publication type
• Journal Article MeSH

Nowadays, gait assessment in the real life environment is gaining more attention. Therefore, it is desirable to know how some factors, such as surfaces (natural, artificial) or dual-tasking, influence real life gait pattern. The aim of this study was to assess gait variability and gait complexity during single and dual-task walking on different surfaces in an outdoor environment. Twenty-nine healthy young adults aged 23.31 ± 2.26 years (18 females, 11 males) walked at their preferred walking speed on three different surfaces (asphalt, cobbles, grass) in single-task and in two dual-task conditions (manual task-carrying a cup filled with water, cognitive task-subtracting the number 7). A triaxial inertial sensor attached to the lower trunk was used to record trunk acceleration during gait. From 15 strides, sample entropy (SampEn) as an indicator of gait complexity and root mean square (RMS) as an indicator of gait variability were computed. The findings demonstrate that in an outdoor environment, the surfaces significantly impacted only gait variability, not complexity, and that the tasks affected both gait variability and complexity in young healthy adults.

• MeSH
• Gait * MeSH
• Walking * MeSH
• Humans MeSH
• Young Adult MeSH
• Walking Speed MeSH
• Torso MeSH
• Acceleration MeSH
• Check Tag
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

BACKGROUND: Nonselective His-bundle pacing (nsHBp), nonselective left bundle branch pacing (nsLBBp), and left ventricular septal myocardial pacing (LVSP) are recognized as physiological pacing techniques. OBJECTIVE: The purpose of this study was to compare differences in ventricular depolarization between these techniques using ultra-high-frequency electrocardiography (UHF-ECG). METHODS: In patients with bradycardia, nsHBp, nsLBBp (confirmed concomitant left bundle branch [LBB] and myocardial capture), and LVSP (pacing in left ventricular [LV] septal position without proven LBB capture) were performed. Timings of ventricular activations in precordial leads were displayed using UHF-ECG, and electrical dyssynchrony (e-DYS) was calculated as the difference between the first and last activation. Duration of local depolarization (Vd) was determined as width of the UHF-QRS complex at 50% of its amplitude. RESULTS: In 68 patients, data were collected during nsLBBp (35), LVSP (96), and nsHBp (55). nsLBBp resulted in larger e-DYS than did LVSP and nsHBp [- 24 ms (-28;-19) vs -12 ms (-16;-9) vs 10 ms (7;14), respectively; P <.001]. nsLBBp produced similar values of Vd in leads V5-V8 (36-43 ms vs 38-43 ms; P = NS in all leads) but longer Vd in leads V1-V4 (47-59 ms vs 41-44 ms; P <.05) as nsHBp. LVSP caused prolonged Vd in leads V1-V8 compared to nsHBp and longer Vd in leads V5-V8 compared to nsLBBp (44-51 ms vs 36-43 ms; P <.05) regardless of R-wave peak time in lead V5 or QRS morphology in lead V1 present during LVSP. CONCLUSION: nslbbp preserves physiological LV depolarization but increases interventricular electrical dyssynchrony. LV lateral wall depolarization during LVSP is prolonged, but interventricular synchrony is preserved.

• MeSH
• Bundle-Branch Block physiopathology   therapy   MeSH
• Electrocardiography methods   MeSH
• Ventricular Function, Left physiology   MeSH
• Bundle of His physiopathology   MeSH
• Cardiac Pacing, Artificial methods   MeSH
• Humans MeSH
• Ventricular Septum physiopathology   MeSH
• Follow-Up Studies MeSH
• Prospective Studies MeSH
• Aged MeSH
• Heart Ventricles physiopathology   MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH

BACKGROUND: Micra is a leadless pacemaker that is implanted in the right ventricle and provides rate response via a 3-axis accelerometer (ACC). Custom software was developed to detect atrial contraction using the ACC enabling atrioventricular (AV) synchronous pacing. OBJECTIVE: The purpose of this study was to sense atrial contractions from the Micra ACC signal and provide AV synchronous pacing. METHODS: The Micra Accelerometer Sensor Sub-Study (MASS) and MASS2 early feasibility studies showed intracardiac accelerations related to atrial contraction can be measured via ACC in the Micra leadless pacemaker. The Micra Atrial TRacking Using A Ventricular AccELerometer (MARVEL) study was a prospective multicenter study designed to characterize the closed-loop performance of an AV synchronous algorithm downloaded into previously implanted Micra devices. Atrioventricular synchrony (AVS) was measured during 30 minutes of rest and during VVI pacing. AVS was defined as a P wave visible on surface ECG followed by a ventricular event <300 ms. RESULTS: A total of 64 patients completed the MARVEL study procedure at 12 centers in 9 countries. Patients were implanted with a Micra for a median of 6.0 months (range 0-41.4). High-degree AV block was present in 33 patients, whereas 31 had predominantly intrinsic conduction during the study. Average AVS during AV algorithm pacing was 87.0% (95% confidence interval 81.8%-90.9%), 80.0% in high-degree block patients and 94.4% in patients with intrinsic conduction. AVS was significantly greater (P <.001) during AV algorithm pacing compared to VVI in high-degree block patients, whereas AVS was maintained in patients with intrinsic conduction. CONCLUSION: Accelerometer-based atrial sensing is feasible and significantly improves AVS in patients with AV block and a single-chamber leadless pacemaker implanted in the right ventricle.

• MeSH
• Accelerometry instrumentation   MeSH
• Atrioventricular Block physiopathology   therapy   MeSH
• Equipment Design MeSH
• Adult MeSH
• Electrocardiography methods   MeSH
• Pacemaker, Artificial * MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Follow-Up Studies MeSH
• Prospective Studies MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Heart Rate physiology   MeSH
• Heart Ventricles physiopathology   MeSH
• Heart Atria physiopathology   MeSH
• Feasibility Studies MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Research Support, Non-U.S. Gov't MeSH

• MeSH
• Acute Disease * nursing   rehabilitation   MeSH
• Early Ambulation methods   MeSH
• Inpatients MeSH
• Humans MeSH
• Nutritional Support methods   MeSH
• Prospective Studies MeSH
• Independent Living classification   MeSH
• Aged MeSH
• Muscle Strength MeSH
• Muscle Weakness diagnosis   prevention & control   rehabilitation   MeSH
• Check Tag
• Humans MeSH
• Aged MeSH
• Publication type
• Randomized Controlled Trial MeSH

Interspecific hybridization, polyploidization and transitions from sexuality to asexuality considerably affect organismal genomes. Especially the last mentioned process has been assumed to play a significant role in the initiation of chromosomal rearrangements, causing increased rates of karyotype evolution. We used cytogenetic analysis and molecular dating of cladogenetic events to compare the rate of changes of chromosome morphology and karyotype in asexually and sexually reproducing counterparts in European spined loach fish (Cobitis). We studied metaphases of three sexually reproducing species and their diploid and polyploid hybrid clones of different age of origin. The material includes artificial F1 hybrid strains, representatives of lineage originated in Holocene epoch, and also individuals of an oldest known age to date (roughly 0.37 MYA). Thereafter we applied GISH technique as a marker to differentiate parental chromosomal sets in hybrids. Although the sexual species accumulated remarkable chromosomal rearrangements after their speciation, we observed no differences in chromosome numbers and/or morphology among karyotypes of asexual hybrids. These hybrids possess chromosome sets originating from respective parental species with no cytogenetically detectable recombinations, suggesting their integrity even in a long term. The switch to asexual reproduction thus did not provoke any significant acceleration of the rate of chromosomal evolution in Cobitis. Asexual animals described in other case studies reproduce ameiotically, while Cobitis hybrids described here produce eggs likely through modified meiosis. Therefore, our findings indicate that the effect of asexuality on the rate of chromosomal change may be context-dependent rather than universal and related to particular type of asexual reproduction.

• MeSH
• Biological Evolution * MeSH
• Diploidy * MeSH
• Karyotype * MeSH
• Cypriniformes genetics   MeSH
• Reproduction, Asexual genetics   MeSH
• Triploidy * MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Úvod: Chronickú obštrukčnú chorobu pľúc (CHOCHP) charakterizuje porucha prietoku vzduchu prieduškami. Tieto zmeny sú ireverzibilné a zvyčajne progredujú. CHOCHP sa delí na základe funkčných parametrov a fenotypu. Exacerbácia CHOCHP akceleruje chorobu s negatívnymi dopadmi pre pacienta, priebeh a prognózu choroby. Rozvoj akútnej dychovej nedostatočnosti je častou príčinou ich hospitalizácie. Tretina pacientov hospitalizovaných pre respiračnú insuficienciu si vyžaduje ventilačnú podporu. Pre vysokú mortalitu invazívne ventilovaných pacientov sa v dnešnej dobe preferujú konzervatívne liečebné postupy a neinvazívna ventilačná podpora. Cieľ práce bol retrospektívny prehľad priebehu, komplikácií a mortality pacientov vo vyšších štádiách CHOCHP s ťažkým respiračným zlyhaním a nutnosťou ventilačnej podpory. Naše skúsenosti: Behom ročného obdobia na jednotke intenzívnej starostlivosti pľúcnej kliniky sme zaznamenali až 69% úspešnosť zvládnutia ťažkého respiračného zlyhania za pomoci neinvazívnej ventilačnej podpory. Takto sme sa mohli vyhnúť nutnosti intubácie. Priemerná doba neinvazívnej ventilácie bola 93 hodín. Preferovaný bol tlakovo podporný režim. Ventilácia bola vykonávaná intermitentne s prestávkami po zlepšení klinického stavu a úprave alebo stabilizácii krvných plynov. Najčastejšou komplikáciou bola nespolupráca pacienta. Druhú skupinu tvorili pacienti s CHOCHP na oddelení intenzívnej medicíny (za ročné obdobie), ktorých bolo nutné invazívne ventilovať pre ťažké respiračné zlyhanie, u väčšiny pacientov bola prítomná aj cirkulačná instabilita. Vyvolávajúcim faktorom exacerbácie bola u väčšiny pacientov infekcia. Všetci pacienti mali realizovanú tracheostómiu pre predpokladanú dlhšiu dobu ventilácie a za účelom jednoduchšieho odpájania od umelej pľúcnej ventilácie. Priemerná doba UPV bola 12 dní a priemerná doba odpájania 4 dni. Diskusia: Rozvoj akútnej dychovej nedostatočnosti je častou príčinou hospitalizácie pacientov s CHOCHP. Tretina hospitalizovaných pacientov si vyžaduje ventilačnú podporu. Ventilačná podpora pacientov s CHOCHP s invazívnym zaistením dýchacích ciest, je vzhľadom na vysokú až 30% mortalitu vyhradená pre pacientov, u ktorých zlyhali menej invazívne postupy. Hlavným cieľom ventilačnej mechanickej podpory u pacientov s exacerbovanou CHOCHP je zmiernenie problémov, zníženie mortality a morbidity. Vo viacerých štúdiách bolo dokázané, že neinvazívna ventilačná podpora v krvných plynoch zvyšuje pH a znižuje PaCO2, znižuje dychovú prácu, zmierňuje dýchavicu, skracuje dobu hospitalizácie, znižuje mortalitu a bráni nutnosti intubácie. V porovnaní s invazívnou mechanickou ventilačnou podporou je jednoduchší odvykací proces, znížené riziko nozokomiálnych infekcií dýchacích ciest a v neposlednom rade znížená mortalita. Indikácie na invazívnu pľúcnu ventiláciu sú zároveň aj indikáciami na preklad na OIM. Nepriaznivými faktormi invazívnej pľúcnej ventilácie je nutnosť analgosedácie a zabránenie prirodzenej schopnosti očisty dýchacích ciest. Záver: Rozvoj závažnej akútnej respiračnej nedostatočnosti u pacientov s vyššími štádiami CHOCHP predstavuje závažný medicínsky problém, ako aj nemalý ekonomický problém a odhaľuje aj etické problémy. U pacientov, ktorí vyžadujú ventilačnú podporu je napriek relatívne priaznivej krátkodobej prognóze, dlhodobá prognóza veľmi nepriaznivá.

Background: Chronic obstructive pulmonary disease (COPD) is characterized by impaired air flow in the bronchi. These changes are irreversible and usually progressive. COPD is classified based on functional parameters and phenotypes. Exacerbation of COPD accelerates the disease with negative impacts on the patient, course and prognosis. Development of acute respiratory insufficiency is a frequent cause of hospital admissions. One third of patFents hospitalized for respiratory Insufficiency require ventilatory support. Due to high mortality rates associated with invasive ventilation, conservative treatment and non-invasive ventilatory support are preferred today. The aim was a retrospective overview of the course, complications and patient mortality rates of advanced COPD with severe respiratory failure and a need for ventilatory support. Our experiences: Over a 1-year period at a department of pulmonary medicine intensive care unit, a success rate of up to 69% was achieved in the management of severe respiratory failure with non-invasive ventilation support. Thus, necessary intubation was avoided. The mean time of non-invasive intubation was 93 hours. Pressure controlled ventflation was preferred. Ventilation was intermittent with pauses after clinical condition improvement and normalization or stabilization of blood gases. The most frequent complication was patient non-compliance. Another group comprised COPD patients at a department of intensive care medicine (over a 1-year period) requiring invasive ventilation due to severe respiratory failure, with circulatory instability being present in most patients. All patients underwent tracheostomy due to expected prolonged ventilation and to facilitate weaning from artificial pulmonary ventilation. The mean time of artificial pulmonary ventilation was 12 days and the mean weaning time was 4 days. Discussion: The development of acute respiratory insufficiency is a frequent cause for hospitalization of patients with COPD. One third of hospitalized patients require ventilatory support. Given the mortality rates of up to 30 %, ventilatory support with invasive airway management is only used in tiiose COPD patients in whom less invasive procedures failed. The main goals of mechanical ventilation in patients with COPD exacerbations are to reduce problems and to decrease mortality and morbidity rates. Several studies have shown that non-invasive ventilatory support increases pH and lowers PaC02 in blood gases, decreases respiratory effort, reduces dyspnea, shortens hospital stays, reduces mortality and prevents the need for intubation. Unlike invasive mechanical ventilation, it is associated with a simpler weaning process, lower risk of nosocomial airway infections and, last but not least, reduced mortality. Indications for invasive pulmonary ventilation are also indications for transfer of patients to a department of intensive care medicine. The adverse factors of invasive pulmonary ventilation are the need for analgesia and sedation and inhibited ability to clear the airways. Conclusion: The development of acute respiratory insufficiency in patients with advanced COPD is both a serious health issue and not a small economic problem, also revealing ethical issues. Despite a relatively favorable short-time prognosis, patients requiring ventilatory support have a very poor long-term prognosis.

• MeSH
• Pulmonary Disease, Chronic Obstructive * epidemiology   etiology   complications   MeSH
• Humans MeSH
• Mortality MeSH
• Noninvasive Ventilation utilization   MeSH
• Prognosis MeSH
• Respiratory Insufficiency epidemiology   etiology   therapy   MeSH
• Retrospective Studies MeSH
• Respiration, Artificial * methods   mortality   MeSH
• Patient Selection MeSH
• Check Tag
• Humans MeSH

PURPOSE OF THE STUDY Motion-preservation technologies for spinal disorders have evolved and come into use in the last decade. Three principal systems are currently available: total disc replacement, posterior neutralisation transpedicular system and interspinous implants. The aim of this retrospective study was to evaluate our group of lumbar total disc replacements at a follow-up of 2 years. MATERIAL AND METHODS A total of 42 disc prostheses were implanted in 37 patients. Of these, 31 with 35 artificial discs were followed up for 2 years. There were 11 men and 20 women with an average age of 42.9 years (range, 21 to 61 years). The indication for surgery was lumbar disc pain without radicular syndrome and contraindications included advanced degenerative facet joint disease and obesity with a body mass index over 30. Surgery was carried out through the pararectal retroperitoneal approach. Early and late complications were recorded. The group evaluation was based on radiological outcomes, and VAS and ODI scores reported by the patients at 6 weeks, and 3, 6, 12 and 24 months after surgery. RESULTS The average operative time was 68 minutes (range, 36 to 120 min) for single-level lumbar total disc replacement and 92 minutes (range, 72 to 130 min) for two-level procedures. The average hospital stay was 5.2 days (range, 3 to 12). Both keels of the prosthesis were in the exact center in 25 cases, they were shifted laterally in nine cases up to 2 mm and in one case more than 2 mm. Horizontal rotation of the prosthesis was seen in two patients, but not more than 5 degrees to the left. There was no disc loosening or subsidence, and no acceleration of adjacent segment degeneration. Two patients showed heterotopic ossification. Subjective evaluation was recorded as marked improvement in 15, partial improvement in 11 and no change in five patients. None of the patients reported deterioration. Low back pain assessed by the VAS score had an average value of 66.3 before surgery and 14.1 at 2 years after surgery. The average pre-operative ODI value was 48.9 and that at 2 years post-operatively was 24.5. DISCUSSION Pain relief evaluated by the VAS score in our study is comparable with or slightly better than is reported by the other authors. Some recorded average values for lumbago were 74 before surgery and 35 at 2 years of follow-up, or 62.3 before and 25.4 at 2 years after surgery, while our patients had the average VAS score of 66.3 before surgery and that of 18.4 at 2 years after surgery. The ODI values in our group were similar to those of other authors. When we compare this group with the group of our patients who were treated by spinal fusion surgery, the outcomes at 1 year are better in the total disc replacement group, as shown by the VAS for lumbago of 17.8 and ODI of 24.5 in the former versus the respective values of 18.1 and 29.0 in the latter group. CONCLUSION Based on the results it can be concluded that total disc replacement is an efficient method of treating degenerative inter-vertebral disc disease of the lumbar spine in young, active and motivated patients with no posterior spinal structure degeneration.

• MeSH
• Lumbar Vertebrae surgery   MeSH
• Intervertebral Disc Degeneration surgery   MeSH
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Patient Selection MeSH
• Treatment Outcome MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Female MeSH

The aim of this clinical observation study was to determine the extent to which muscle relaxation induced by anesthesia must be intra-operatively reversed for a reliable identification, by intra-operative monitoring, of the lumbosacral (LS) nerve roots during extreme lateral interbody fusion (XLIF). MATERAL AND METHODS: General anesthesia (midazolam, propofol, sufentanil, oxygen/air/sevofluran - rocuronium) was administrated to all pa - tients. Train-of-four (TOF) stimulation of the ulnar nerve at 10-second intervals and an electromyographic response of the adductor pollicis muscle were used, and the duration of neuromuscular block was measured by the value of the TOF-ratio. When the level of recovery from neuromuscular block was TOF-count = 2, reversion to normal function was still accelerated by sugammadex administration at a dose of 2 mg.kg-1. Subsequently, it was determined at which level of muscle relaxation subsidence the first responses to LS nerve root stimulation were evident. Intra-operative neurophysiologial monitoring (IOM) with use of the NIM - Neuro® 3.0 device allowed for assessment of a triggered electromyographic reaction (tEMG) of LS roots to stimulation during surgery. The neuromuscular reactions were evaluated in 11 patients, five men and six women. The results were analysed by descriptive statistics and presented as median and interquartile-range values. RESULTS: In all patients a reliable monitoring of the depth of muscle relaxation was established. The value of supramaximal impulse was 46 mA (38 to 64 mA). The period from rocuronium administration to a spontaneous recovery of the TOF-count = 2 took 33 min (29 to 35 min). Duration from sugammadex administration to a TOF ratio of . 0.70 was 90 seconds (50 to 140) and to a TOF ratio of . 0.90 was 190 seconds (100 to 220 s). A reliable tEMG response of LS nerve roots to electric stimulation at 10 mA intensity was recorded at a TOF ratio of 0.68 (0.56 to 0.77) and at a 5 mA intensity it was reliable at a TOF ratio of 0.86 (0.75 to 0.90).. None of the patients reported radicular symptoms after surgery. DISCUSSION: From the anatomy of the greater psoas muscle and varied patterns of its LS plexus it is obvious that none of the zones is absolutely safe. In XLIF procedures it is therefore recommended to disect the psoas muscle under both visual and IOM control. Intra-operative checking of the depth of muscle relaxation then will provide information that conditions not affected by rocuronium administration and necessary for the detection of LS roots have been provided. CONCLUSIONS: 1. For a reliable intra-operative identification of LS nerve roots by electric stimulation at a 10 mA intensity it is recommended to achieve the value of TOF ratio equal to at least 0.70. When stimulation at a lower intensity (5 mA) is used, a TOF ratio of . 0.90 is necessary. 2. Administration of sugammadex to reverse an action of the muscle relaxant rocuronium is an effective and quick method to achieve the values required.

• MeSH
• Anesthesia MeSH
• Lumbar Vertebrae surgery   MeSH
• Intervertebral Disc Degeneration surgery   MeSH
• Electric Stimulation MeSH
• Electromyography MeSH
• Failed Back Surgery Syndrome surgery   MeSH
• Spinal Fusion methods   MeSH
• Iatrogenic Disease prevention & control   MeSH
• Internal Fixators MeSH
• Middle Aged MeSH
• Humans MeSH
• Neuromuscular Blockade MeSH
• Lumbosacral Plexus surgery   MeSH
• Postoperative Complications MeSH
• Prospective Studies MeSH
• Prostheses and Implants MeSH
• Muscle Relaxation MeSH
• Treatment Outcome MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Female MeSH

Compared to the natural electrical activation of the myocardium through the His-Purkinje system, right ventricular pacing is associated with prolonged QRS complex duration, thereby impeding the synchronicity of contractions. In left ventricular pacing, a higher pacing voltage decreases the QRS complex duration. The aim of our study was to describe the relation between the right ventricular pacing voltage and the QRS complex duration. Fourteen patients (73.6 +/- 7.6 years) with AV block and implanted pacemakers were paced at a frequency of 100 bpm with various pacing voltages. A signal-averaged QRS vector length was calculated at each degree of pacing voltage. The changes in the QRS complex duration were measured as a relative shift of the terminal region of the vectorcardiographic QRS complex (end-shift) and its most prominent peak (peak-shift) using the cross-correlation method. The nonlinear relationship between stimulation voltage and QRS duration was observed with the highest impact of stimulation voltage changes near the threshold value. The fourfold increase in the stimulation voltage above the threshold caused QRS complex shortening by 3.7 +/- 2.1 ms (range 0.19-7.76 ms). Similar peak- and end-shift responses to altered stimulation energy demonstrated that the acceleration of depolarization occurred in the initial portion of the QRS complex. Older electrodes exhibited smaller and more linear changes in the QRS complex duration.

• MeSH
• Ventricular Function, Right MeSH
• Cardiac Pacing, Artificial MeSH
• Middle Aged MeSH
• Humans MeSH
• Models, Cardiovascular MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Vectorcardiography MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Research Support, Non-U.S. Gov't MeSH