Prediction of atrial fibrillation development and progression:current perspectives

Atrial fibrillation(AF) is the most common arrhythmia in clinical practice. Several conventional and novel predictors of AF development and progression(from paroxysmal to persistent and permanent types) have been reported. The most important predictor of AF progression is possibly the arrhythmia itself. The electrical, mechanical and structural remodeling determines the perpetuation of AF and the progression from paroxysmal to persistent and permanent forms. Common clinical scores such as the hypertension, age ≥ 75 years, transient ischemic attack or stroke, chronic obstructive pulmonary disease, and heart failure and the congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65-74 years, sex category scores as well as biomarkers related to inflammation may also add important information on this topic. There is now increasing evidence that even in patients with so-called lone or idiopathic AF, the arrhythmia is the manifestation of a structural atrial disease which has recently been defined and described as fibrotic atrial cardiomyopathy. Fibrosis results from a broad range of factors related to AF inducing pathologies such as cell stretch, neurohumoral activation, and oxidative stress. The extent of fibrosis as detected either by late gadolinium enhancement-magnetic resonance imaging or electroanatomic voltage mapping may guide the therapeutic approach based on the arrhythmia substrate. The knowledge of these risk factors may not only delay arrhythmia progression, but also reduce the arrhythmia burden in patients with first detected AF. The present review highlights on the conventional and novel risk factors of development and progression of AF.

Simple hematological predictors of AF recurrence in patients undergoing atrial fibrillation ablation

Backgound Red cell distribution width(RDW) and neutrophil-to-lymphocyte ratio(NLR) are simple hematologic indices that have been used to predict adverse outcomes in different clinical settings. The aim of our study is to determine whether RDW and NLR can predict atrial fibrillation(AF) recurrence in patients undergoing AF ablation. Methods Consecutive patients, without known hematological disorders, who underwent AF catheter ablation between January 2014 and April 2017 were enrolled into this study. Blood samples were taken one day before and five hours after the ablation procedure. Results A total of 346 patients(224 males(65%), mean age: 59 ± 11 years old) were included. After a mean follow up of 26.2 ± 12.1 months, 80(23.1%) patients experienced late AF recurrence(defined as any recurrence after the blanking period of three months), while 97(28%) patients experienced early AF recurrence during the blanking period. Univariate analysis showed that early arrhythmia recurrence, type of AF and NLR after the procedure were significantly associated with late AF recurrence, while early arrhythmia recurrence and NLR remained significant in multivariate analysis. RDW was not associated with late AF recurrence. None of the parameters above predicted early arrhythmia recurrence. Conclusions Simple and inexpensive hematological indices such as NLR should be evaluated for their ability to predict AF recurrence in patients undergoing catheter ablation in larger prospective studies.

Ibutilide and novel indexes of ventricular repolarization in persistent atrial fibrillation patients

AIM: To examine the effect of ibutilide on novel indexes of repolarization in patients with persistent atrial fibrillation (AF). METHODS: We studied consecutive patients scheduled for elective electrical cardioversion. Intravenous ibutilide (1+1mg) was administered before the electrical cardioversion while close electrocardiographic (ECG) monitoring was performed. ECG indexes such as corrected QT interval (QTc), the interval from the peak until the end of T wave (Tpe), and the Tpe/QT ratio were measured before ibutilide infusion and 10 min after the end of infusion. RESULTS: The final study population consisted of 20 patients (mean age: 67.1±9.9 years, 10 men). Six patients were cardioverted pharmacologically and did not proceed to electrical cardioversion. Two patientsdeveloped short non-sustained episodes of torsades de pointes ventricular tachycardia. All but one of the aforementioned ECG indexes increased significantly after ibutilide administration. In specific, the QTc interval increased from 442 ± 29 to 471 ± 37 ms (P=0.037), the Tpe interval in precordial leads from 96 ms (range 80-108 ms) to 101 ms (range 91-119 ms) (P=0.021), the Tpe interval in lead Ⅱ from 79 ms (range 70-88 ms) to 100 ms (range 87-104 ms) (P<0.001), the Tpe/QT ratio in precordial leads from 0.23 ms (range 0.18-0.26 ms) to 0.26 ms (range 0.23-0.28 ms) (P=0.028), and the Tpe interval dispersion from 25 ms (range 23-30 ms) to 35 ms (range 27-39 ms) (P=0.012). However, the Tpe/QT ratio in lead II did not change significantly. CONCLUSION: Ibutilide increases the duration and dispersion of ventricular repolarization. The prognostic value of Tpe and Tpe/QT in the setting of drug-induced proarrhythmia needs further study.

Mechanisms of drug-induced proarrhythmia in clinical practice

Drug-induced proarrhythmia represents a great challenge for those involved in the development of novel pharmaceuticals and in the regulatory bodies for drug approval as well as for the prescribing clinicians.Our understanding of the mechanisms that underlie druginduced proarrhythmia has grown dramatically over the last two decades.A growing number of cardiac and non-cardiac agents have been shown to alter cardiac repolarization predisposing to fatal cardiac arrhythmias such as ventricular tachycardia or ventricular fibrillation and sudden cardiac death.These agents may induce the phenotype of long QT syndrome and less commonly of short QT syndrome and Brugada syndrome(BS).Although,genetic susceptibility underlie drug-induced proarrhythmia in certain cases,current data are limited regarding this topic.The present review surveys the current published literature on the mechanisms and the offending medical agents that predispose to drug-induced long QT syndrome,short QT syndrome and BS.Drug-induced proarrhythmia should be considered as a predictor of sudden cardiac death and should prompt critical re-evaluation of the risks and benefits of the suspicious medication.Survivors of drug-induced proarrhythmia and family members require careful examination and possibly genetic testing for the presence of a channelopathy.Treating physicians are advised to follow the lists of agents implicated in drug-induced proarrhythmia in order to minimize the risk of arrhythmia and sudden cardiac death.

Headache:An unusual presentation of acute myocardial infraction

Acute myocardial infarction should be diagnosed as early as possible for the appropriate management to salvage ischemic myocardium. Accurate diagnosis is typically based on the typical symptoms of angina. Headache is an unusual symptom in patients with acute myocardial infraction. We report a patient with ST-segment elevation acute myocardial infarction who presented to the emergency department complaining of severe occipital headache without chest discomfort.

A review on atrioventricular junction ablation and pacing for heart rate control of atrial fibrillation

有永久心律调整器培植的心房与心室的连接脱离是在有 atrial 纤维性颤动和对另外的治疗形式抵抗的高室的率的病人的一条高度有效的治疗途径，在特别老或那些与严重 comorbidities。与药理学治疗相比独自一个，所谓的 &#x0201c；切除并且 pace&#x0201d；途径为室的率的更柔韧的控制提供潜力。心房与心室的连接脱离和踱步的策略在症状，生活的质量，和锻练能力与改进被联系。给在 atrial 纤维性颤动和心失败之间的靠近的关系，有在有 atrial 的病人的如此的率控制的一个特别好处纤维性颤动和减少的收缩功能。正在增加心脏的再同步治疗设备可能在在心房与心室的连接脱离以后的选择人口是有益的证据。为心房与心室的连接脱离的当前的建议的现在的评论文章焦点并且与 atrial 在病人为心率控制踱步纤维性颤动。这种技术，最佳的培植时间，和在心房与心室的连接脱离以后的合适的设备选择也被讨论。

Catheter ablation of persistent atrial fibrillation:The importance of substrate modification

Accumulating data have shown that elimination of atrial fibrillation(AF) sources should be the goal in persistent AF ablation. Pulmonary vein isolation, linear lesions and complex fractionated atrial electrograms(CFAEs) ablation have shown limited efficacy in patients with persistent AF. A combined approach using voltage, CFAEs and dominant frequency(DF) mapping may be helpful for the identification of AF sources and subsequent focal substrate modification. The fibrillatory activity is maintained by intramural reentry centered on fibrotic patches. Voltage mapping may assist in the identification of fibrotic areas. Stable rotors display the higher DF and possibly drive AF. Furthermore, the single rotor is usually consistent with organized AF electrograms without fractionation. It is therefore quite possible that rotors are located at relatively "healthy islands" within the patchy fibrosis. This is supported by the fact that high DF sites have been negatively correlated to the amount of fibrosis. CFAEs are located in areas adjacent to high DF. In conclusion, patchy fibrotic areas displaying the maximum DF along with high organization index and the lower fractionation index are potential targets of ablation. Prospective studies are required to validate the efficacy of substrate modification in left atrial ablation outcomes.

Efficacy and safety of novel anticoagulants in the elderly

Atrial 纤维性颤动和静脉的 thromboembolism (VTE ) 是与有害 thrombotic 事件联系的普通混乱，特别地在老病人。Polypharmacy，合作病态，和改变的 pharmacokinetics，在这些病人经常在场，使抗凝剂的使用变为相当挑战性。新奇口头的抗凝剂(NOAC ) 最近作为维生素 K 对手(VKA ) 的选择出现了并且主要因为他们的更少药和食物相互作用和容易使用，逐渐地正在增加他们的流行。他们的有效性和安全在一般人口是生长得很好的但是在利益和伤害在之间的平衡老仍然是不清楚的。在这些病人的平淡的使用是不平常的。积累的数据证明了 NOAC 的利益在所有年龄组之中是一致的，展示在阻止 thrombotic 事件的相等或更大的功效。过量流血与与 VKA 相比的 NOAC 是更低的，但是为模式放血在他们之中并且面对面是迥异的比较不是可得到的。在老人口的新奇抗凝剂的功效和安全上的现在的评论热点。