Catheter-induced mechanical trauma to accessory pathways during radiofrequency ablation: incidence, predictors and clinical implications

AbstractOBJECTIVESTo evaluate the incidence, predictors and clinical implications of nonintentionally catheter-induced mechanical trauma to accessory pathways during radiofrequency ablation procedures.BACKGROUNDData on the incidence and significance of catheter-induced trauma to accessory pathways are scarce.METHODSConsecutive patients (n = 381) undergoing radiofrequency ablation of accessory pathways at two different institutions were closely monitored for appearance of mechanical block of accessory pathways during catheter manipulation.RESULTSMechanical trauma to accessory pathways was observed in 37 (9.7%) patients. According to a multivariate analysis, the only independent variable associated with this phenomenon was the anatomical pathway location (p = 0.0001). The incidence of trauma of either right anteroseptal (38.5%) or right atriofascicular pathways (33.3%) was significantly greater than that of pathways (≤10%) at all remaining locations (p < 0.0001). The duration of conduction block observed ranged from ≤1 min to >30 min in 19% and 35% of patients, respectively. “Immediate” application of radiofrequency pulses at sites of mechanical block (<1 min after occurrence) was associated with a 78% long-term success rate at follow-up. This contrasted with a 25% long-term success rate in patients in whom pulses were delivered 30 min after occurrence of block (“delayed pulses”). Finally, in 24% of patients persistent trauma-induced conduction block led to discontinuation of the ablation procedure.CONCLUSIONSTrauma to accessory pathways is more common than previously recognized and frequently results in prolongation or discontinuation of the ablation procedure and in lower success rates. The only independent predictor of catheter-trauma to accessory pathways is the pathway location

Apical Ballooning Syndrome: A Complication of Dual Chamber Pacemaker Implantation

Apical ballooning is a cardiac syndrome (Takotsubo Cardiomyopathy) described as a typical form of acute transient left ventricular dysfunction. While its onset has often been associated with emotionally or physically stressful situations, it has an overall favorable prognosis. We describe here a case of transient apical ballooning following permanent pacemaker implantation

Projektiranje i analiza digitalnog sata

Sat je jedan od najstarijih ljudskih otkrića. U principu, potrebno je znati osnovne fizičke procese koji se ponavljaju s određenom učestalošću, i način da se izmjeri koliko taj proces traje. Kao što se godišnja doba i faze mjeseca mogu iskoristiti za mjerenje protoka određenih dužih perioda vremena, tako se i kraći periodi mogu koristiti za mjerenje sati i minuta. Sunčani sat koji mjeri vrijeme dana pomoću smjera sjenke koju baca određeni predmet osvjetljen suncem, bio je dobro poznat u drevnim vremenima. Pješčani satovi mjerili su vrijeme prolaskom sitnog pijeska kroz uzani otvor na staklenoj posudi. Razvoj elektronike u 20. stoljeću doveo je do satova bez ikakvog mehanizma. Vrijeme na ovakvim satovima mjerilo se na razne načine, na primjer pomoću kvarcnih kristala ili raspadanjem radioaktivnih elemenata. Čak su i mehanički satovi napajani baterijama, čime je navijanje sata postalo suvišno. Cilj ovog rada je projektirati i analizirati jedan digitalni zidni sat s integriranim krugom Maxim IC type DS3231 koji je kvalificiran od strane proizvođača kao „iznimno točan I2C sat u stvarnom vremenu (RTC), s integriranim temperaturno kompenziranim kristalnim oscilatorom (TCXO) i kristalom.“[1] Smatra se da integracija kristalnog rezonatora povećava dugotrajnu točnost uređaja, garantirajući maksimalnu pogrešku manju od 64 sekunde u godini, i temperaturni opseg od 0 do 40 °C (32 do 104 °F). Uređaj uključuje baterijski ulaz koji održava rad uređaja u odsutnosti vanjskog izvora.Clock is one of the oldest human inventions. In principle, it is necessary to know basic physical processes which are repeated with a certain frequency and method to measure how much this process lasts. Such as the season and phase of the month can be used to measure flow of certain lengthy periods of time, so are shorter periods used to measure hours and minutes. A sunidial shows the time by displaying the position of shadow on flat surface. Hourglasses measured time by passing of the fine sand through narrow opening on a glass container. The objective of this article is to project and analyze digital wall clock with Maxim IC type DS3231, qualified by its manufacturer as an „extremely accurate I2C real time clock (RTC) with integrated temperature compensated crystal oscillator (TCXO) and crystal.“ It is considered that integration of the crystal resonator enhances the long-term accuracy of derive, guaranteeing a maximum error of less than 64 seconds over a year, and over a temperature range 0 to 40 °C (32 to 104 °F). The device incorporates a battery input which maintains running of the device in the absence of external power

Non-classical Indications for Cardiac Resynchronization Therapy

Based on randomized controlled studies, cardiac resynchronization therapy (CRT) is currently indicated in patients with systolic heart failure of New York Heart Association (NYHA) functional class III and IV, left ventricular ejection fraction &lt; 35% and wide QRS (&gt;120 ms). Most of the enrolled patients were in sinus rhythm, were not previously paced and had mainly LBBB. Thus, there are uncertainties regarding several other populations, not included or underrepresented in the main studies. These populations include patients with atrial fibrillation (AF), previous pacemakers considered for upgrade to CRT, RBBB, narrow QRS &lt; 120 ms, NYHA functional class &lt;III, or right heart failure. These non-classical indications are herein reviewed. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Although CRT seems to benefit patients with AF and patients with preexisting pacemakers, in patients with NYHA functional class II-III, or with narrow QRS, or with RBBB, or in those with predominant right heart failure, the role of CRT is not established yet and further relevant clinical trials are needed

Short-term therapy with R568 ameliorated secondary hyperparathyroidism but does not prevent aortic valve calcification in uremic rats

IntroductionRenal failure associated aortic valve calcification (AVC) is the result of hyperphosphatemia and hyperparathyroidism. Calcimimetics is an effective tool for management of secondary hyperparathyroidism. Our goal was to evaluate the effect of the medical intervention with calcimimetic R568 on the AVC process.Methods and resultsThe experimental design consisted of administering a uremia-inducing phosphate-enriched diet to rats for six weeks. Rats received a daily R568 injection at different times. Biochemical analysis demonstrated increased urea (34.72 ± 3.57 vs. 5.18 ± 0.15 mmol/L, p&lt;0.05) and creatinine (293.93 ± 79.6 vs. 12.82 ± 1.56 µmol/L, p&lt;0.05). R568 treatment markedly reduced parathyroid hormone (PTH) levels in both treated groups (192.63 ± 26.85, 301.23 ± 101.79 vs. 3570 ± 986.63 pg/mL, p&lt;0.05), with no impact on serum calcium and phosphate. von Kossa staining showed increase in AVC in uremic rats compared to control (1409 ± 159.5 vs. 27.33 ± 25.83, p&lt;0.05). AVC was not affected by R568 in both groups (3343 ± 2462, 1593 ± 792 vs. 1409 ± 159.5, NS). Similarly, the inflammatory marker CD68 was elevated in uremic rats (15592 ± 3792 vs. 181.8 ± 15.29, p&lt;0.01), and was not influenced by R568 treatment (8453 ± 818.5, 9318 ± 2232 vs. 15592 ± 3792, NS). Runt-related transcription factor 2 (Runx2), the regulator of osteoblast differentiation, was upregulated in uremic rats (23186 ± 9226 vs. 3184 ± 2495), that accompanied by elevated levels of Osteopontin (158395 ± 45911 vs. 237.7 ± 81.5, p&lt;0.05) and Osteocalcin (22203 ± 8525 vs. 489.7 ± 200.6, p&lt;0.05). R568 had no impact on osteoblastic markers (Runx2: 21743 ± 3193, 23004 ± 10871 vs. 23186 ± 9226, NS; osteopontin: 57680 ± 19522, 137116 ± 60103 vs. 158395 ± 45911, NS; osteocalcin: 10496 ± 5429, 8522 ± 5031 vs. 22203 ± 8525, NS).ConclusionIn an adenine-induced uremic rat model, we showed that short-term R568 therapy had no effect on AVC. Treatment with R568 decreased PTH levels but had no effect on high phosphate levels. Regression of AVC necessitates not only a decrease in PTH levels, but also a decline in phosphate levels. To achieve improved outcomes, it is advisable to consider administering a combination of R568 with other medications, such as calcium supplements or phosphate binders. Additional studies are required for further evaluation of the potential treatment of chronic kidney disease (CKD)-associated AVC

Outcomes of conduction system pacing compared to right ventricular pacing as a primary strategy for treating bradyarrhythmia: systematic review and meta-analysis

Background Right ventricular pacing (RVP) may cause electrical and mechanical desynchrony leading to impaired left ventricular ejection fraction (LVEF). We investigated the outcomes of RVP with His bundle pacing (HBP) and left bundle branch pacing (LBBP) for patients requiring a de novo permanent pacemaker (PPM) for bradyarrhythmia. Methods and results Systematic review of randomized clinical trials and observational studies comparing HBP or LBP with RVP for de novo PPM implantation between 01 January 2013 and 17 November 2020 was performed. Random and fixed effects meta-analyses of the effect of pacing technology on outcomes were performed. Study outcomes included all-cause mortality, heart failure hospitalization (HFH), LVEF, QRS duration, lead revision, atrial fibrillation, procedure parameters, and pacing metrics. Overall, 9 studies were included (6 observational, 3 randomised). HBP compared with RVP was associated with decreased HFH (risk ratio [RR] 0.68, 95% confidence interval [CI] 0.49–0.94), preservation of LVEF (mean difference [MD] 0.81, 95% CI − 1.23 to 2.85 vs. − 5.72, 95% CI − 7.64 to -3.79), increased procedure duration (MD 15.17 min, 95% CI 11.30–19.04), and increased lead revisions (RR 5.83, 95% CI 2.17–15.70, p = 0.0005). LBBP compared with RVP was associated with shorter paced QRS durations (MD 5.6 ms, 95% CI − 6.4 to 17.6) vs. (51.0 ms, 95% CI 39.2–62.9) and increased procedure duration (MD 37.78 min, 95% CI 20.04–55.51). Conclusion Of the limited studies published, this meta-analysis found that HBP and LBBP were superior to RVP in maintaining physiological ventricular activation as an initial pacing strategy

Qual a Contribuiçao do Tilt Training (treinamento postural) na Prevençao da Síncope Vasovagal?

Histórico: A síncope vasovagal é um dos quadros clínicos mais comuns em adultos jovens. Estudos anteriores demonstram a eficiência do tilt training (treinamento postural) no tratamento desse transtorno clínico. Realizou-se um estudo prospectivo e randomizado com o objetivo de avaliar a contribuiçao do tilt training no tratamento de adultos jovens acometidos pela síncope vasovagal. Métodos: Quarenta e seis soldados, 25 dos quais do sexo masculino, média de idade de 19,4 ± 0,8 anos e diagnóstico clínico de síncope vasovagal pelo tilt test, foram divididos aleatoriamente em dois grupos: um grupo controle e outro submetido a tilt training diariamente, por três meses. Nos dois grupos, os participantes foram instruídos a aumentar a ingestao de líquidos e sal e evitar situaçoes indutoras da síncope, tais como permanecer em pé por períodos longos. Resultados: A adesao ao programa de treinamento, caracterizada pela realizaçao de 50% ou mais das sessoes diárias de tilt training, foi de 91% durante o primeiro mês, caindo para 58% nos três meses. Os que realizaram o treinamento apresentaram uma média (distância interquartílica) de 5,0 episódios de síncope (0,5 a 16,0) durante um ano de acompanhamento, enquanto o grupo controle apresentou média de 2,0 episódios (0 a 6,0; P = 0,737). Após a randomizaçao, nao houve diferença significativa no tempo de ocorrência do primeiro episódio de síncope entre os dois grupos: média de 1,0 por mês (0,5 a 2,0) no grupo em tratamento e 0,8 (0,5 a 2,0) no grupo controle (P = 0,336). Conclusoes: A realizaçao diária do tilt training, aliada às modificaçoes de estilo de vida, nao produziu melhora no resultado do tratamento de adultos jovens com síncope vasovagal. Verificou-se ainda a dificuldade de obter boa adesao ao programa de treinamento postural

Qual a Contribuiçao do Tilt Training (treinamento postural) na Prevençao da Síncope Vasovagal?

Histórico: A síncope vasovagal é um dos quadros clínicos mais comuns em adultos jovens. Estudos anteriores demonstram a eficiência do tilt training (treinamento postural) no tratamento desse transtorno clínico. Realizou-se um estudo prospectivo e randomizado com o objetivo de avaliar a contribuiçao do tilt training no tratamento de adultos jovens acometidos pela síncope vasovagal. Métodos: Quarenta e seis soldados, 25 dos quais do sexo masculino, média de idade de 19,4 ± 0,8 anos e diagnóstico clínico de síncope vasovagal pelo tilt test, foram divididos aleatoriamente em dois grupos: um grupo controle e outro submetido a tilt training diariamente, por três meses. Nos dois grupos, os participantes foram instruídos a aumentar a ingestao de líquidos e sal e evitar situaçoes indutoras da síncope, tais como permanecer em pé por períodos longos. Resultados: A adesao ao programa de treinamento, caracterizada pela realizaçao de 50% ou mais das sessoes diárias de tilt training, foi de 91% durante o primeiro mês, caindo para 58% nos três meses. Os que realizaram o treinamento apresentaram uma média (distância interquartílica) de 5,0 episódios de síncope (0,5 a 16,0) durante um ano de acompanhamento, enquanto o grupo controle apresentou média de 2,0 episódios (0 a 6,0; P = 0,737). Após a randomizaçao, nao houve diferença significativa no tempo de ocorrência do primeiro episódio de síncope entre os dois grupos: média de 1,0 por mês (0,5 a 2,0) no grupo em tratamento e 0,8 (0,5 a 2,0) no grupo controle (P = 0,336). Conclusoes: A realizaçao diária do tilt training, aliada às modificaçoes de estilo de vida, nao produziu melhora no resultado do tratamento de adultos jovens com síncope vasovagal. Verificou-se ainda a dificuldade de obter boa adesao ao programa de treinamento postural