Arterial stiffness and atrial fibrillation: A review

Arterial stiffness has been investigated as part of the physiopathology of arterial hypertension since the 1970s. Its role in increasing the “pulsatile load” imposed over the Left Ventricle (LV) has been intensely studied recently and has helped in understanding the mechanisms of Atrial Fibrillation (AF) in hypertensive patients. This paper aims to review the main evidence on this issue and establish possible mechanisms involved in the development of AF in patients with arterial stiffness. A PubMed search was performed, and selected articles were searched for references focusing on this topic. In the long term, lower blood pressure levels allow for arterial wall remodeling, leading to a lower stiffness index. To this day, however, there are no available treatments that directly promote the lowering of arterial wall stiffness. Most classes of anti-hypertensive drugs ‒ with stronger evidence for beta-blockers and diuretics ‒ could be effective in reducing arterial stiffness. There is strong evidence demonstrating an association between arterial stiffness and AF. New studies focusing on arterial stiffness and pre-fibrillatory stages would strengthen this causality relation

Arterial stiffness and analysis of left atrial function in hypertensive patients with non-sustained atrial tachycardia

Introdução: O aumento da rigidez arterial é atualmente reconhecido como um fator de risco independente para fibrilação atrial, mas os mecanismos fisiopatológicos desta arritmia permanecem pouco compreendidos. Objetivos: Este estudo tem como objetivo investigar a associação da rigidez arterial com a presença de taquicardia atrial não sustentada (TANS) em pacientes hipertensos, possivelmente uma fase premonitória da fibrilação atrial. Métodos: Estudo transversal, de natureza exploratória do tipo prova de conceito. A rigidez arterial foi avaliada pela velocidade da onda de pulso carótido-femoral (VOPcf) e pelo Augmentation Index corrigido para uma frequência cardíaca de 75 bpm (AIx@75). A ecocardiografia speckle-tracking foi usada para avaliar a função do átrio esquerdo (AE), incluindo propriedades de reservatório, conduto e contração do mesmo. Os pacientes também foram categorizados, de acordo com o achado de TANS ao Holter de 24 h (10 ou mais batimentos consecutivos), em grupo TANS e grupo controle (sem esta arritmia). Resultados: Foram incluídos setenta participantes de um único centro sem doença cardiovascular evidente, após serem submetidos a exame clínico cardiovascular padrão. O grupo TANS, quando comparado ao grupo controle, apresentava maior idade média (70,09 ± 7,29 vs. 63,68 ± 7,11, valor p 0,001), maior proporção de níveis elevados de BNP (28,1 % vs. 0,0%, valor p <0,001), menores níveis de colesterol HDL (51,03 ± 12,16 vs. 58,81 ±16,50, valor p 0,027), maior índice de massa do ventrículo esquerdo (VE) (90,00 ±19,95 vs. 76,05 ±15,60, valor p 0,002) e maior quantidade de extrassístoles atriais em 24h (531,00 [173,00;5890,00] vs. 17,00 [9,00;35,00], valor p <0,001). A VOPcf se correlacionou positivamente com maior densidade de extrassístoles atriais em 24h, de modo independente do índice de massa do VE. O aumento da VOPcf se correlacionou com a diminuição dos valores de strain do AE (reservatório e conduto). Conclusão: Neste estudo com 70 pacientes hipertensos, foi possível demonstrar a correlação positiva entre a VOPcf e a presença de maior densidade de arritmias atriais no Holter de 24h. Além disto, uma maior VOPcf se associou a menores valores de strain do átrio esquerdo para as funções de reservatório e conduto, representando assim um possível mecanismo fisiopatológico no desenvolvimento de arritmias atriaisIntroduction: Increased arterial stiffness is currently recognized as an independent risk factor for atrial fibrillation, but the pathophysiological mechanisms of this arrhythmia remain poorly understood. Objectives: This study aims to investigate the association of arterial stiffness with the presence of nonsustained atrial tachycardia (NSAT) in hypertensive patients, possibly a premonitory phase of atrial fibrillation. Methods: Cross-sectional, exploratory, proof-of-concept study. Arterial stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV) and by the Augmentation Index corrected for a heart rate of 75 bpm (AIx@75). Speckle-tracking echocardiography was used to assess left atrial (LA) function, including its reservoir, conduit and contraction properties. Patients with NSAT of 10 or more beats on 24h-ECG were categorized in the NSAT group and controls without this arrhythmia were selected for the non-NSAT group. Results: Seventy participants from a single centre without evident cardiovascular disease after undergoing a standard cardiovascular clinical examination were included. The NSAT group, when compared to the control group, had a higher mean age (70.09 ± 7.29 vs. 63.68 ± 7.11, p-value 0.001), a higher BNP levels (28.1% vs. 0.0%, p-value <0.001), lower HDL cholesterol levels (51.03 ± 12.16 vs. 58.81 ±16.50, p-value 0.027), higher left ventricular (LV) mass index (90.00 ±19.95 vs. 76.05 ±15.60, p-value 0.002) and higher density of premature atrial beats in 24h (531.00 [173.00;5890.00] vs 17.00 [9.00;35.00], p-value <0.001). The cfPWV was correlated with highest premature atrial beats density in 24h Holter monitoring, independently of the LV mass index, and the increase in cfPWV correlated with the decrease in LA strain values (reservoir and conduit). Conclusion: In this study with 70 hypertensive patients, it was possible to demonstrate a positive correlation between cfPWV and the presence of higher density of atrial arrhythmias on 24-hour Holter Monitoring. In addition, higher cfPWV was associated with lower left atrial strain values for reservoir and conduit functions, thus representing a possible pathophysiological mechanism in the development of atrial arrhythmias other than atrial fibrillatio

Amusia and its electrophysiological correlates in neurofibromatosis type 1

ABSTRACT Auditory processing deficits are common in people with neurofibromatosis type 1 (NF1) and they often report difficulties in musical performance. Objective: We investigated whether NF1 could be associated with amusia as well as with some impairment of primary auditory cortex activity. Methods: Eighteen people with NF1 and 22 healthy volunteers, matched for age, sex and educational level, were evaluated with the Montreal Battery Evaluation of Amusia – short version. The integrity of cortical primary auditory processing areas was evaluated by evoked potential mismatch negativity. Results: Amusia was correlated with NF1 (p = 0.001, odds ratio = 42.0, confidence interval 4.5–39.6). Patients with NF1 exhibited a greater prevalence of amusia than healthy controls (67% vs. 4.5%) and difficulties in both melodic and temporal music perception. Worse performance on the Montreal Battery Evaluation of Amusia was correlated with a greater mismatch negativity latency in NF1 group. Conclusions: Amusia is a common feature in NF1 and may result from impairment of activity in primary auditory processing areas

Characterisation of microbial attack on archaeological bone

As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved