Tachycardia-related cardiomyopathy: a common cause of ventricular dysfunction in patients with atrial fibrillation referred for atrioventricular ablation

Clinical Characterization of Arrhythmia-Induced Cardiomyopathy in Patients With Tachyarrhythmia and Idiopathic Heart Failure

BACKGROUND

Arrhythmia-induced cardiomyopathy (AIC) is a known entity, but prospective evidence for its characterization is limited.

OBJECTIVES

This study aimed to: 1) determine the relative frequency of the pure form of AIC in the clinically relevant cohort of patients with newly diagnosed, otherwise unexplained left ventricular systolic dysfunction (LVSD) and tachyarrhythmia; 2) assess the time to recovery from LVSD; and 3) identify parameters for an early diagnosis of AIC.

METHODS

Patients were prospectively included, underwent effective rhythm restoration, and were followed-up at 2, 4, and 6 months to evaluate clinical characteristics, biomarkers, and cardiac imaging including cardiac magnetic resonance imaging. Patients with recurred arrhythmia were excluded from analysis.

RESULTS

41 of 50 patients were diagnosed with AIC 6 months after rhythm restoration. Left ventricular (LV) ejection fraction increased 2 months after rhythm restoration from 35.4% ± 8.2% to 52.7% ± 8.0% in AIC patients vs 37.0% ± 9.5% to 43.3% ± 7.0% in non-AIC patients. From month 2 to 6, LV ejection fraction continued to increase in AIC patients (57.2% ± 6.1%; P < 0.001) but remained stable in non-AIC patients (44.0% ± 7.8%; P = 0.628). Multivariable logistic regression analysis revealed that lower LV end-diastolic diameter at baseline could be used for early diagnosis of AIC, whereas biomarkers and other morphological or functional parameters, including late LV gadolinium enhancement, did not show suitability for early diagnosis.

CONCLUSIONS

We observed a high prevalence of AIC in patients with otherwise unexplained LVSD and concomitant tachyarrhythmia, suggesting that this condition may be underdiagnosed in clinical practice. Most patients recovered fast, within months, from LVSD. A low initial LV end-diastolic diameter may constitute an early marker for diagnosis of AIC.

Tachycardia-induced metabolic rewiring as a driver of contractile dysfunction

Prolonged tachycardia-a risk factor for cardiovascular morbidity and mortality-can induce cardiomyopathy in the absence of structural disease in the heart. Here, by leveraging human patient data, a canine model of tachycardia and engineered heart tissue generated from human induced pluripotent stem cells, we show that metabolic rewiring during tachycardia drives contractile dysfunction by promoting tissue hypoxia, elevated glucose utilization and the suppression of oxidative phosphorylation. Mechanistically, a metabolic shift towards anaerobic glycolysis disrupts the redox balance of nicotinamide adenine dinucleotide (NAD), resulting in increased global protein acetylation (and in particular the acetylation of sarcoplasmic/endoplasmic reticulum Ca2+-ATPase), a molecular signature of heart failure. Restoration of NAD redox by NAD+ supplementation reduced sarcoplasmic/endoplasmic reticulum Ca2+-ATPase acetylation and accelerated the functional recovery of the engineered heart tissue after tachycardia. Understanding how metabolic rewiring drives tachycardia-induced cardiomyopathy opens up opportunities for therapeutic intervention.

Catheter ablation versus medical therapy in atrial fibrillation: an umbrella review of meta-analyses of randomized clinical trials

This umbrella review synthesizes data from 17 meta-analyses investigating the comparative outcomes of catheter ablation (CA) and medical treatment (MT) for atrial fibrillation (AF). Outcomes assessed were mortality, risk of hospitalization, AF recurrence, cardiovascular events, pulmonary vein stenosis, major bleeding, and changes in left ventricular ejection fraction (LVEF) and MLHFQ score. The findings indicate that CA significantly reduces overall mortality and cardiovascular hospitalization with high strength of evidence. The risk of AF recurrence was notably lower with CA, with moderate strength of evidence. Two associations reported an increased risk of pulmonary vein stenosis and major bleeding with CA, supported by high strength of evidence. Improved LVEF and a positive change in MLHFQ were also associated with CA. Among patients with AF and heart failure, CA appears superior to MT for reducing mortality, improving LVEF, and reducing cardiovascular rehospitalizations. In nonspecific populations, CA reduced mortality and improved LVEF but had higher complication rates. Our findings suggest that CA might offer significant benefits in managing AF, particularly in patients with heart failure. However, the risk of complications, including pulmonary vein stenosis and major bleeding, is notable. Further research in understudied populations may help refine these conclusions.

Ablation versus medical therapy for patients with atrial fibrillation: An updated meta-analysis

To investigate the effect of ablation compared to medical therapy on clinical outcomes of patients with atrial fibrillation (AF). PubMed, Scopus, Embase, and Web of Science databases were searched using ablation, medical treatment, AF, and related words. The effect of ablation and medical therapy was sought to be gathered on stroke or transitional ischemic attack, mortality, hospitalization, recurrence of AF, progression of AF, and left ventricular ejection fraction. Analyses were performed using R software. 31 studies (the results of 27 randomized controlled trials), compromising an overall 6965 patients (Ablation, n = 3643; Medical treatment, n = 3322) were reviewed in our study, revealed that catheter ablation would result in substantial benefits for patients with AF without significant difference in serious adverse events compared to medical management (Risk Ratio: 0.92, [95% Confidence Interval (CI), 0.64-1.33]). Catheter ablation in patients with AF significantly resulted in a 29% reduction in all-cause mortality (RR: 0.71, [95% CI, 0.57-0.88]), a 57% reduction in hospitalization (RR: 0.43, [95% CI, 0.27-0.67]), a 53% reduction in AF recurrence (RR: 0.47, [95% CI, 0.36-0.61]), and a dramatic reduction, 89%, in progression of paroxysmal to persistent AF (RR: 0.11, [95% CI, 0.02-0.65]); also associated with a remarkable improvement in their left ventricular ejection fraction (LVEF) (Mean Difference, MD: 6.84%, [95% CI, 3.27-10.42]) compared to medical therapy. Our study showed that ablation may be superior to medical therapy in patients with AF regarding AF recurrence, mortality, LVEF improvement, hospitalization, and AF progression outcomes.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Atrial fibrillation ablation in patients with arrhythmia-induced cardiomyopathy: a prospective multicentre study

AIMS

This study aims to investigate the clinical and biochemical characteristics of patients with atrial fibrillation (AF) referred for ablation who develop arrhythmia-induced cardiomyopathy (AiCM) as well as their long-term outcomes after catheter ablation (CA).

METHODS AND RESULTS

A prospective multicentre study was conducted on consecutive AF patients who underwent CA. AiCM was defined as the development of heart failure in the presence of AF and an improvement of left ventricular fraction by at least 10% at 6 months after ablation. A subgroup of patients underwent peripheral and left atrial blood samples [galectin-3, fatty acid-binding protein 4 (FABP4), and soluble receptor for advanced glycation end products (sRAGE)] at the time of the procedure. Of the 769 patients who underwent AF ablation, 135 (17.56%) met the criteria for AiCM. Independent predictors of AiCM included persistent AF, male gender, left atrial volume, QRS width, active smoking, and chronic kidney disease (CKD). Biomarker analysis revealed that sRAGE, FABP4, and galectin-3 levels were not predictive of AiCM development nor did they differ between groups or predict recurrence. There were no differences in AF recurrence between patients with and without AiCM (30.83% vs. 27.77%; P = 0.392) during a median follow-up of 23.83 months (inter-quartile range 9-36).

CONCLUSIONS

In the subset of patients referred for AF ablation, the development of AiCM was associated with persistent AF and CKD. Biomarker analysis was not different between groups nor predicted recurrence. Patients with AiCM benefited from ablation, with a significant improvement in left ventricular ejection fraction and similar AF recurrence rates to those without AiCM.

Atrial Fibrillation

Evidence for diagnosis and treatment of atrial fibrillation (AF) has expanded substantially since 2017, when In the Clinic last considered this subject. Direct oral anticoagulants have become the predominant therapy for thromboembolic disease, and antidotes for these drugs are now available. Device-based left atrial appendage occlusion is frequently used in patients who cannot tolerate systemic anticoagulation, and growing evidence suggests that early rhythm control improves outcomes. Catheter ablation is now frequently performed to prevent recurrent AF. Managing risk factors for AF, such as hypertension, diabetes, and obesity, remains paramount in prevention of this condition.

Case report: Catecholamine cardiomyopathy in children with neuroblastoma

INTRODUCTION

Many endocrine diseases, such as neuroblastoma (NB), can be linked with acquired cardiomyopathy and heart failure. Neuroblastoma's cardiovascular manifestations are typically hypertension, electrocardiogram (ECG) changes, and conduction disturbances.

CASE PRESENTATION

A 5-year-old 8-month-old girl was admitted to the hospital with ventricular hypertrophy and hypertension (HT) and heart failure. She had no previous history of HT. On color doppler echocardiography, the left atrium and left ventricle were enlarged. The left ventricular ejection fraction (EF) was as low as 40%, and the ventricular septum and left ventricular free wall were thickened. The internal diameters of both coronary arteries were widened. Abdominal computed tomography scan (CT) demonstrated an 8.7 cm × 7.1 cm × 9.5 cm tumor behind the left peritoneum. In urine catecholamines analysis, free-norepinephrine (f-NE), free-dopamine (f-DA), free-normetanephrine (f-NMN), free-3-methoxytyramine (f-3MT), vanillylmandelic acid (VMA), and homovanillic acid (HVA) levels were all greater than the normal range for 24 h except free-metanephrine (f-MN) and free-epinephrine (f-E). Based on these findings, we diagnosed her as NB complicated by catecholamine cardiomyopathy manifested by hypertrophic cardiomyopathy (HCM). Oral metoprolol, spironolactone, captopril and amlodipine furosemide, and intravenously injected sodium nitroprusside and phentolamine were employed for treating HT. After the tumor resection, the blood pressure (BP) and urinary catecholamine levels were all restored. After a follow-up of 7 months, echocardiography indicated normalization of ventricular hypertrophy and function.

CONCLUSION

This is a rare report showing catecholamine cardiomyopathy in NB children. Tumor resection leads to a return to normal of the catecholamine cardiomyopathy manifested as HCM.

Echocardiographic Evaluation of LV Function in Patients with Tachyarrhythmia and Reduced Left Ventricular Function in Response to Rhythm Restoration

AIMS

Tachyarrhythmia due to atrial fibrillation (AF) is often associated with reduced left ventricular (LV) function and has been proposed to cause arrhythmia-induced cardiomyopathy (AIC). However, the precise diagnostics of AIC and reversibility after rhythm restoration are poorly understood. Our aim was to investigate systolic LV function in tachycardic AF and to evaluate the direct effect of rhythm restoration.

METHODS

We prospectively studied 24 patients (71% male, age 65 ± 9 years) with tachycardic AF and newly diagnosed reduced left ventricular ejection fraction (LVEF). Just before and immediately after electrical cardioversion (ECV), transthoracic echocardiography was performed. Geometric as well as functional data were assessed.

RESULTS

Patients presented with a heart rate (HR) of 117.4 ± 21.6/min and a 2D-/3D-LVEF of 32 ± 9/31 ± 8%. ECV to sinus rhythm normalized HR to 77 ± 11/min with an increase of 2D-/3D-LVEF to 37 ± 9/37 ± 10% (p < 0.01 vs. baseline, each). Left ventricular geometry changed with an increase of end-diastolic volume (LVEDV) while end-systolic volume (LVESV) remained unchanged. Parameters concerning myocardial deformation (global longitudinal strain (GLS), strain rate (SR)) decreased whereas the RR interval-corrected GLS (GLSc) remained unchanged. In a simple linear regression model, GLS correlated with 2D- and 3D-LVEF not only before (pre) ECV, but also after (post) ECV. We demonstrate that the increase of LVEF and GLS (ratios pre/post) correlates with the change of HR (ΔHR; R² = 0.20, 0.33 and 0.32, p < 0.05 each), whereas ratios of GLSc and SR do not significantly correlate with HR (R² = 0.03 and 0.01, p = n.s. each).

CONCLUSION

In patients with tachyarrhythmia and reduced ejection fraction, ECV leads to immediate improvement in EF and GLS while HR-corrected LV contractility remains unchanged. This suggests that the immediate effects of rhythm restoration are mostly related to changes in left ventricular volume, but not to an acute improvement of heart-rate independent contractility.

[Perioperative Atrial Fibrillation]

New atrial fibrillation is a risk factor for increased morbidity and mortality in the perioperative phase. The prevalence and incidence of atrial fibrillation depend on age, previous illnesses and the intercurrent diagnoses in the perioperative phase. Pathomechanisms for both permanent and acute forms of atrial fibrillation relate to electrophysiological, histopathological and other pathophysiological abnormalities. In the perioperative phase, decompensated heart failure, systemic inflammation, sepsis and cardiac surgery are risk factors for conversion to atrial fibrillation and/or rapid transition. The consequences of newly occurring and/or rapidly transferred atrial fibrillation are cardiac instability due to a drop in blood pressure or cardiac output volume or coronary underperfusion due to tachycardia and the risk of thromboembolism. Associated with this is a significantly increased long-term mortality risk in the elderly if atrial fibrillation occurs again in the perioperative phase. The diagnosis of atrial fibrillation is made in the monitor or 12-channel electrocardiogram. Echocardiography and the adenosine test can be included in the differential diagnosis in cases of doubt. Important current guidelines for the treatment of atrial fibrillation are the ESC (atrial fibrillation) and the ERC (Advanced Cardiac Life Support) guidelines. The conversion into the sinus rhythm can be done electrically or medicinally. It is indicated in cases of acute instability or symptomatic atrial fibrillation despite frequency control after cardiac thrombi have been excluded by echocardiography. A step-by-step concept for thromboembolism prophylaxis from initial parenteral and secondary oral therapy must take place up to four weeks after conversion to sinus rhythm or permanently in the case of permanent atrial fibrillation. The individual indication for thromboembolism prophylaxis results from the CHA2-DS2-VASc score.

Arrhythmia-induced cardiomyopathy: A potentially reversible cause of refractory cardiogenic shock requiring venoarterial extracorporeal membrane oxygenation

BACKGROUND

The most severe form of arrhythmia-induced cardiomyopathy in adults- refractory cardiogenic shock requiring mechanical circulatory support-has rarely been reported.

OBJECTIVE

The purpose of this study was to describe the management of critically ill patients admitted for acute, nonischemic, or worsening of previously known cardiac dysfunction and recent-onset supraventricular arrhythmia who developed refractory cardiogenic shock requiring venoarterial extracorporeal membrane oxygenation (VA-ECMO).

METHODS

This study is a retrospective analysis of prospectively collected data.

RESULTS

Between 2004 and 2018, 35 patients received VA-ECMO for acute, nonischemic cardiogenic shock and recent supraventricular arrhythmia (77% atrial fibrillation [AF]). Cardiogenic shock was the first disease manifestation in 21 patients (60%). Characteristics at ECMO implantation [median (interquartile range)] were Sequential Organ Failure Assessment score 10 (7-13); inotrope score 29 (11-80); left ventricular ejection (LVEF) fraction 10% (10%-15%); and lactate level 8 (4-11) mmol/L. For 12 patients, amiodarone and/or electric cardioversion successfully reduced arrhythmia, improved LVEF, and enabled weaning off VA-ECMO; 11 had long-term survival without transplantation or long-term assist device. Eight patients experiencing arrhythmia-reduction failure underwent ablation procedures (7 atrioventricular node [AVN] with pacing, 1 atrial tachycardia) and were weaned off VA-ECMO; 7 survived. Of the remaining 15 patients without arrhythmia reduction or ablation, only the 6 bridged to heart transplantation or left ventricular (LV) assist device survived.

CONCLUSION

Arrhythmia-induced cardiomyopathy, mainly AF-related, is an underrecognized cause of refractory cardiogenic shock and should be considered in patients with nonischemic cardiogenic shock and recent-onset supraventricular arrhythmia. VA-ECMO support allowed safe arrhythmia reduction or rate control by AVN ablation while awaiting recovery, even among those with severe LV dilation.

A Novel Non-Invasive Assessment of Cardiac Hemodynamics in Patients With Heart Failure and Atrial Fibrillation

Background

Heart failure (HF) and atrial fibrillation (AF) often coexist. The hemodynamic alterations induced by AF in patients with HF are well studied; however we lack reliable and non-invasive means to study these hemodynamic alterations in ambulatory patients. We sought to evaluate the clinical utility of impedance cardiography (ICG) as a novel and non-invasive tool to evaluate cardiac hemodynamics in ambulatory patients with HF and AF.

Methods

This was a single-center observational study. A convenient sample of ambulatory patients with chronic HF underwent non-invasive electrocardiogram (ECG) and hemodynamic monitoring using BioZ Dx impedance cardiographer. Hemodynamics were automatically computed and ECG data were interpreted by an independent reviewer.

Results

A total of 32 patients (62 ± 14 years of age; 66% male; ejection fraction 33±13%) were enrolled. There were no baseline demographic or clinical differences between those with AF (28%) and those without AF (72%). However, patients with AF exhibited lower stroke volume (60 ± 7 vs. 89 ± 29, P = 0.008), left ventricular work (33 ± 9 vs. 45 ± 13, P = 0.016), cardiac contractility (30 ± 8 vs. 40 ± 13, P = 0.037), and arterial elasticity (13 ± 5 vs. 21 ± 5, P = 0.012), as well as higher cardiac afterload (203 ± 57 vs. 151 ± 49, P = 0.015).

Conclusions

Using non-invasive ICG, we have shown that it is feasible to characterize hemodynamics in ambulatory HF patients. We show that AF compromises left ventricular function in patients with HF and is associated with excess afterload and reduced arterial elasticity.

Current Management Strategies in Patients with Heart Failure and Atrial Fibrillation: A Review of the Literature

Heart Failure (HF) and Atrial Fibrillation (AF) are common diseases which lead to significant morbidity and mortality. Each disease can be a challenge to treat clinically, especially when they present together. We performed a review of the literature including clinical trials, metanalyses, and guidelines regarding the management of patients with HF and AF. This review describes the pathophysiologic mechanisms behind each disease state, their associated prognosis, and epidemiologic features. Strategies for prevention of stroke in patients with AF, including use of novel oral anticoagulants as well as prevention of the development of AF are discussed. We review the medical and catheter-based therapies for AF and present an original algorithm for the management of AF in patients with HF.

Multi-parametric system for risk stratification in mitral regurgitation: A multi-task Gaussian prediction approach

BACKGROUND

We hypothesized that a multi-parametric approach incorporating medical comorbidity information, electrocardiographic P-wave indices, echocardiographic assessment, neutrophil-to-lymphocyte ratio (NLR) and prognostic nutritional index (PNI) calculated from laboratory data can improve risk stratification in mitral regurgitation (MR).

METHODS

Patients diagnosed with mitral regurgitation between 1 March 2005 and 30 October 2018 from a single centre were retrospectively analysed. Outcomes analysed were incident atrial fibrillation (AF), transient ischemic attack (TIA)/stroke and mortality.

RESULTS

This study cohort included 706 patients, of whom 171 had normal inter-atrial conduction, 257 had inter-atrial block (IAB) and 266 had AF at baseline. Logistic regression analysis showed that age, hypertension and mean P-wave duration (PWD) were significant predictors of new-onset AF. Low left ventricular ejection fraction (LVEF), abnormal P-wave terminal force in V1 (PTFV1) predicted TIA/stroke. Age, smoking, hypertension, diabetes mellitus, hypercholesterolaemia, ischemic heart disease, secondary mitral regurgitation, urea, creatinine, NLR, PNI, left atrial diameter (LAD), left ventricular end-diastolic dimension, LVEF, pulmonary arterial systolic pressure, IAB, baseline AF and heart failure predicted all-cause mortality. A multi-task Gaussian process learning model demonstrated significant improvement in risk stratification compared to logistic regression and a decision tree method.

CONCLUSIONS

A multi-parametric approach incorporating multi-modality clinical data improves risk stratification in mitral regurgitation. Multi-task machine learning can significantly improve overall risk stratification performance.

Multi-modality machine learning approach for risk stratification in heart failure with left ventricular ejection fraction ≤ 45

AIMS

Heart failure (HF) involves complex remodelling leading to electrical and mechanical dysfunction. We hypothesized that machine learning approaches incorporating data obtained from different investigative modalities including atrial and ventricular measurements from electrocardiography and echocardiography, blood inflammatory marker [neutrophil-to-lymphocyte ratio (NLR)], and prognostic nutritional index (PNI) will improve risk stratification for adverse outcomes in HF compared to logistic regression.

METHODS AND RESULTS

Consecutive Chinese patients referred to our centre for transthoracic echocardiography and subsequently diagnosed with HF, between 1 January 2010 and 31 December 2016, were included in this study. Two machine learning techniques, multilayer perceptron and multi-task learning, were compared with logistic regression for their ability to predict incident atrial fibrillation (AF), transient ischaemic attack (TIA)/stroke, and all-cause mortality. This study included 312 HF patients [mean age: 64 (55-73) years, 75% male]. There were 76 cases of new-onset AF, 62 cases of incident TIA/stroke, and 117 deaths during follow-up. Univariate analysis revealed that age, left atrial reservoir strain (LARS) and contractile strain (LACS) were significant predictors of new-onset AF. Age and smoking predicted incident stroke. Age, hypertension, type 2 diabetes mellitus, chronic kidney disease, mitral or aortic regurgitation, P-wave terminal force in V1, the presence of partial inter-atrial block, left atrial diameter, ejection fraction, global longitudinal strain, serum creatinine and albumin, high NLR, low PNI, and LARS and LACS predicted all-cause mortality. Machine learning techniques achieved better prediction performance than logistic regression.

CONCLUSIONS

Multi-modality assessment is important for risk stratification in HF. A machine learning approach provides additional value for improving outcome prediction.

Atrial fibrillation in the elderly: a risk factor beyond stroke

Atrial fibrillation (AF) represents the most common arrhythmia worldwide and its prevalence exponentially increases with age. It is related to increased risk of ischemic stroke or systemic embolism, which determines a significant burden of morbidity and mortality, as widely documented in the literature. AF also constitutes a risk factor for other less investigated conditions, such as heart failure, pulmonary embolism, impairment in physical performance, reduced quality of life, development of disability, mood disorders and cognitive impairment up to dementia. In the elderly population, the management of AF and its complications is particularly complex due to the heterogeneity of the ageing process, the lack of specific evidence-based recommendations, as well as the high grade of comorbidity and disability characterizing the over 65 years aged people. In the present review, we aim to summarize the pieces of the most updated evidence on AF complications beyond stoke, mainly focusing on the elderly population.

Arrhythmia-Induced Cardiomyopathy: JACC State-of-the-Art Review

Arrhythmias coexist in patients with heart failure (HF) and left ventricular (LV) dysfunction. Tachycardias, atrial fibrillation, and premature ventricular contractions are known to trigger a reversible dilated cardiomyopathy referred as arrhythmia-induced cardiomyopathy (AiCM). It remains unclear why some patients are more prone to develop AiCM despite similar arrhythmia burdens. The challenge is to determine whether arrhythmias are fully, partially, or at all responsible for an observed LV dysfunction. AiCM should be suspected in patients with mean heart rate >100 beats/min, atrial fibrillation, and/or premature ventricular contractions burden ≥10%. Reversal of cardiomyopathy by elimination of the arrhythmia confirms AiCM. Therapeutic choice depends on the culprit arrhythmia, patient comorbidities, and preferences. Following recovery of LV function, patients require continued follow-up if an abnormal myocardial substrate is present. Appropriate diagnosis and treatment of AiCM is likely to improve quality of life and clinical outcomes and to reduce hospital admission and health care spending.

Catheter Ablation Versus Medical Therapy for Atrial Fibrillation: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Despite the publication of several randomized clinical trials comparing catheter ablation (CA) with medical therapy (MT) in patients with atrial fibrillation (AF), the superiority of one strategy over another is still questioned by many. In this meta-analysis of randomized controlled trials, we compared the efficacy and safety of CA with MT for AF.

METHODS

We systematically searched MEDLINE, EMBASE, and other online sources for randomized controlled trials of AF patients that compared CA with MT. The primary outcome was all-cause mortality. Secondary outcomes included cardiovascular hospitalizations and recurrence of atrial arrhythmia. Subgroup analyses stratified by the presence of heart failure with reduced ejection fraction, type of AF, age, and sex were performed. Risk ratios (RRs) with 95% CIs were calculated using a random effects model, and Mantel-Haenszel method was used to pool RR.

RESULTS

Eighteen randomized controlled trials comprising 4464 patients (CA, n=2286; MT, n=2178) were included. CA resulted in a significant reduction in all-cause mortality (RR, 0.69; 95% CI, 0.54-0.88; P=0.003) that was driven by patients with AF and heart failure with reduced ejection fraction (RR, 0.52; 95% CI, 0.35-0.76; P=0.0009). CA resulted in significantly fewer cardiovascular hospitalizations (hazard ratio, 0.56; 95% CI, 0.39-0.81; P=0.002) and fewer recurrences of atrial arrhythmias (RR, 0.42; 95% CI, 0.33-0.53; P<0.00001). Subgroup analyses suggested that younger patients (age, <65 years) and men derived more benefit from CA compared with MT.

CONCLUSIONS

CA is associated with all-cause mortality benefit, that is driven by patients with AF and heart failure with reduced ejection fraction. CA reduces cardiovascular hospitalizations and recurrences of atrial arrhythmia for patients with AF. Younger patients and men appear to derive more benefit from CA.

Lifestyle of Patients with Atrial Fibrillation Following Self-Management Interventions: a Randomized Clinical Trial

Introduction: Cardiovascular diseases are the most common cause of death in most countries, such as Iran. Cardiac arrhythmias, including Atrial Fibrillation (AF) comprise an important category of these diseases. During recent years, AF has become a serious medical condition. This study aimed to investigate the effect of self-management interventions on the lifestyle of patients with AF. Methods: In this Randomized Clinical Trial study, 88 patients were selected and randomly assigned to intervention and control groups. The intervention group received self-management interventions, including education and telephone follow-ups. The data were collected using a demographic questionnaire and Walker's health-promoting lifestyle profile II, before the intervention and four and twelve weeks after the intervention. The significance level was considered to be 0.05. Results: The results showed a significant increase in the intervention group's lifestyle mean score, four and twelve weeks after the intervention as compared with control group However, this increase was not similar in all the lifestyle dimensions. Conclusion: In conclusion, implementation of self-management interventions could improve the lifestyle of the patients with Atrial Fibrillation. The results can help nurses to conduct self-management interventions into such patients' care plan and prevent many physical, psychological, and social problems that negatively affect patients and their lifestyle.

Impact of atrial fibrillation on patients hospitalized for acute myocarditis: Insights from a nationally-representative United States cohort

BACKGROUND

Atrial fibrillation (AF) is associated with increased all-cause mortality in the general population. However, the impact of AF on the in-hospital outcomes of acute myocarditis (AM) patients is not well characterized.

METHODS

Patients (age ≥ 18 years) with a primary diagnosis of AM in the National Inpatient Sample from 2007 to 2014 were included, using the ICD-9-CM diagnostic codes. We compared the in-hospital outcomes between the AF group and propensity score-matched control group without AF.

RESULTS

AF was reported in 602 (9%) of the AM patients. Compared to those without AF, AM patients with AF experienced higher in-hospital mortality (odds ratio [OR] 1.7, 95% confidence interval [CI] 1.1-2.7, P = 0.02). AF was associated with higher risk of cardiogenic shock (OR 1.9, 95% CI 1.3-2.8, P < 0.001), cardiac tamponade (OR 5.6, 95% CI 1.2-25.3, P = 0.002) and acute kidney injury (OR 1.6, 95% CI 1.1-2.1, P = 0.02). Furthermore, patients with AF were more likely to have non-routine hospital discharge (31.6% vs 38.4% P = 0.02), longer length of stay and higher cost of hospitalization.

CONCLUSIONS

AF was associated with increased risk of in-hospital mortality and complications in patients admitted to the hospital with acute myocarditis.

Tachycardia induced Cardiomyopathy

Recent studies on radiofrequency catheter ablation (RFCA) in atrial fibrillation show its effectiveness in heart failure (HF) patients; hence, tachycardia-induced cardiomyopathy (T-CMP) is gaining attention. Tachycardia-mediated cardiomyopathy is a reversible left ventricular (LV) dysfunction, which can be induced by any tachyarrhythmia. Early recognition of T-CMP with appropriate treatment of the arrhythmia culprit will lead to the recovery of LV function. Patients with tachycardia and LV dysfunction should be suspected of having T-CMP, with or without established etiology of HF, because T-CMP may present by itself or contribute as a co-existent component. Therapeutic options include rate control, anti-arrhythmic drugs, or catheter ablation. Unlike in animal models, clinical data on human T-CMP is limited. Hence, future research should be more focused on tachyarrhythmia-induced cardiomyopathy as its burden is increasing.

Paradoxical hypertension

Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological syndrome characterized by white matter vasogenic edema affecting the posterior occipital and parietal lobes of the brain predominantly. A 48-year-old female patient presented to ER with complaints of breathlessness and developed sudden painless loss of vision while eliciting history. The patient had a heart rate of 104/min and accelerated hypertension (BP of 220/120 mm of Hg). MRI Brain showed subcortical white matter T2/Fluid-attenuated inversion recovery hyperintensities, suggestive of PRES. The patient regained vision completely over 5 days after nitroglycerin infusion and calcium channel blockers. Beta blocker was started in view of increased BP and anxiety. Blood pressure paradoxically increased from 170/90 mm of Hg to 200/100 mm of Hg. Urine and plasma metanephrines were elevated. Contrast-enhanced computerized tomography abdomen showed locally infiltrative, retroperitoneal mass in left para-aortic prevertebral region diagnosed as paraganglioma. The patient improved with alpha blockers and surgical removal of paraganglioma. 0.1% of hypertensive patients harbor a pheochromocytoma or paraganglioma and its presentation as PRES is very rare.

Risk Factors for Failure of Direct Current Cardioversion in Patients with Type 2 Diabetes Mellitus and Atrial Fibrillation

Introduction

Type 2 diabetes mellitus (T2DM) is a well-recognised risk factor for cardiovascular disease and the prevalence of atrial fibrillation (AF) is higher among patients with T2DM. Direct current cardioversion (DCCV) is an important management option in persistent AF. We sought to determine independent risk factors for immediate and short-term outcomes of DCCV for treatment of AF in patients with T2DM.

Methods

Retrospective outcome analysis of DCCV for persistent AF in 102 T2DM patients compared with 102 controls.

Results

DCCV was successful in 68 (66.6%) people with T2DM compared to 86 (84.3%) in the control group (P = 0.003). After initial successful cardioversion, only 38 (37.2%) T2DM patients remained in sinus rhythm compared to 63 (61.8%) in the control group (P = 0.007) at a median follow-up of 74.5 days (IQR 69.4-77.4). Multiple logistic regression analysis showed that the presence of T2DM (P = 0.014), digoxin use (P = 0.01), statin use (P = 0.005), left-atrial size (P = 0.01), and LV ejection fraction (P = 0.008) were independent risk factors for immediate DCCV failure. T2DM (P = 0.034) was an independent risk factor for AF relapse. Among patients with T2DM, previous DCCV (P = 0.033), digoxin use (P = 0.035), left-atrial size (P = 0.01), LV ejection fraction (P = 0.036), and HbA1c (P = 0.011) predicted immediate failure of DCCV whilst digoxin use (P = 0.026) was an independent risk factor for relapse of AF.

Conclusion

T2DM, higher HbA1c, digoxin treatment, and structural and functional cardiac abnormalities are independent risk factors for immediate DCCV failure and AF relapse.

Atrial Fibrillation in Heart Failure: a Therapeutic Challenge of Our Times

Atrial fibrillation (AF) and heart failure (HF) are growing cardiovascular disease epidemics worldwide. There has been an exponential increase in the prevalence of AF and HF correlating with an increased burden of cardiac risk factors and improved survival rates in patients with structural heart disease. AF is associated with adverse prognostic outcomes in HF and is most evident in mild-to-moderate left ventricular (LV) dysfunction where the loss of "atrial kick" translates into poorer quality of life and increased mortality. In the absence of underlying structural heart disease, arrhythmia can independently contribute to the development of cardiomyopathy. Together, these 2 conditions carry a high risk of thromboembolism due to stasis, inflammation and cellular dysfunction. Stroke prevention with oral anticoagulation (OAC) remains a mainstay of treatment. Pharmacologic rate and rhythm control remain limited by variable efficacy, intolerance and adverse reactions. Catheter ablation for AF has resulted in a paradigm shift with evidence indicating superiority over medical therapy. While its therapeutic success is high for paroxysmal AF, it remains suboptimal in persistent AF. A better mechanistic understanding of AF as well as innovations in ablation technology may improve patient outcomes in the future. Refractory cases may benefit from atrioventricular junction ablation and biventricular pacing. The value of risk factor modification, especially with regard to obesity, sleep apnea, hypertension and diabetes, cannot be emphasized enough. Close interdisciplinary collaboration between HF specialists and electrophysiologists is an essential component of good long-term outcomes in this challenging population.

Treatment of Patients With Atrial Fibrillation and Heart Failure With Reduced Ejection Fraction

Atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF) frequently coexist, and each complicates the course and treatment of the other. Recent population-based studies have demonstrated that the 2 conditions together increase the risk of stroke, heart failure hospitalization, and all-cause mortality, especially soon after the clinical onset of AF. Guideline-directed pharmacological therapy for HFrEF is important; however, although there are various treatment modalities for AF, there is no clear consensus on how best to treat AF with concomitant HFrEF. This in-depth review discusses the available data for the treatment of AF in the setting of HFrEF, focuses on areas where more investigation is necessary, examines the clinical implications of randomized and observational clinical trials, and presents suggestions for individualized treatment strategies for specific patient groups.

Comparative Efficacy of Nebivolol and Metoprolol to Prevent Tachycardia-Induced Cardiomyopathy in a Porcine Model

Chronic tachycardia is a well-known cause of nonischemic cardiomyopathy. We hypothesized that nebivolol, a β-blocker with nitric oxide activity, would be superior to a pure β-blocker in preventing tachycardia-induced cardiomyopathy in a porcine model. Fifteen healthy Yucatan pigs were randomly assigned to receive nebivolol, metoprolol, or placebo once a day. All pigs underwent dual-chamber pacemaker implantation. The medication was started the day after the pacemaker implantation. On day 7 after implantation, each pacemaker was set at atrioventricular pace (rate, 170 beats/min), and the pigs were observed for another 7 weeks. Transthoracic echocardiograms, serum catecholamine levels, and blood chemistry data were obtained at baseline and at the end of the study. At the end of week 8, the pigs were euthanized, and complete histopathologic studies were performed. All the pigs developed left ventricular cardiomyopathy but remained hemodynamically stable and survived to the end of the study. The mean left ventricular ejection fraction decreased from baseline by 34%, 20%, and 20% in the nebivolol, metoprolol, and placebo groups, respectively. These changes did not differ significantly among the 3 groups (P =0.51). Histopathologic analysis revealed mild left ventricular perivascular fibrosis with cardiomyocyte hypertrophy in 14 of the 15 pigs. Both nebivolol and metoprolol failed to prevent cardiomyopathy in our animal model of persistent tachycardia and a high catecholamine state.

What About Tachycardia-induced Cardiomyopathy?

Long-standing tachycardia is a well-recognised cause of heart failure and left ventricular dysfunction, and has led to the nomenclature, tachycardia-induced cardiomyopathy (TIC). TIC is generally a reversible cardiomyopathy if the causative tachycardia can be treated effectively, either with medications, surgery or catheter ablation. The diagnosis is usually made after demonstrating recovery of left ventricular function with normalisation of heart rate in the absence of other identifiable aetiologies. One hundred years after the first reported case of TIC, our understanding of the pathophysiology of TIC in humans remains limited despite extensive work in animal models of TIC. In this review we will discuss the proposed mechanisms of TIC, the causative tachyarrhythmias and their treatment, outcomes for patients diagnosed with TIC, and future directions for research and clinical care.

Novel perspectives on arrhythmia-induced cardiomyopathy: pathophysiology, clinical manifestations and an update on invasive management strategies

Arrhythmia-induced cardiomyopathy is a partially or completely reversible form of myocardial dysfunction due to sustained supraventricular and ventricular arrhythmias. Asynchrony, rapid cardiac rates and rhythm irregularities are the main factors involved in the development of the disease. The reversible nature of arrhythmia-induced cardiac dysfunction allows only for a retrospective diagnosis of the disease once cardiac function is restored following heart rate control. A high level of suspicion is needed to make a diagnosis at an early stage and prevent further progression of the disease. Although reversible, arrhythmia-induced cellular and molecular changes may remain, increasing the risk for sudden death even when normal ejection fraction is restored as well as causing rapid deterioration of cardiac function and development of heart failure symptoms if arrhythmia recurs. Appropriate management based on a combination of pharmacologic and nonpharmacologic strategies to achieve rate control and prevent arrhythmia recurrence is pivotal to avoid further cardiac function deterioration and to control symptoms, significantly reducing the risk of heart failure and sudden cardiac death.

Comorbidity of atrial fibrillation and heart failure

Atrial fibrillation (AF) and heart failure (HF) are evolving epidemics, together responsible for substantial human suffering and health-care expenditure. Ageing, improved cardiovascular survival, and epidemiological transition form the basis for their increasing global prevalence. Although we now have a clear picture of how HF promotes AF, gaps remain in our knowledge of how AF exacerbates or even causes HF, and how the development of HF affects the outcome of patients with AF. New data regarding HF with preserved ejection fraction and its unique relationship with AF suggest a possible role for AF in its aetiology, possibly as a trigger for ventricular fibrosis. Deciding on optimal treatment strategies for patients with both AF and HF is increasingly difficult, given that results from trials of pharmacological rhythm control are arguably obsolete in the age of catheter ablation. Restoring sinus rhythm by catheter ablation seems successful in the medium term and improves HF symptoms, functional capacity, and left ventricular function. Long-term studies to examine the effect on rates of stroke and death are ongoing. Guidelines continue to evolve to keep pace with this rapidly changing field.

Device therapy for acute systolic heart failure and atrial fibrillation

Patients with newly diagnosed cardiomyopathy require careful assessment of cause and initiation of treatment before the decision is made to implant an internal cardiac defibrillator. In patients with medicine-refractory atrial fibrillation and cardiomyopathy, atrioventricular node ablation and implantation of a biventricular pacemaker is the therapy of choice when tachycardia-induced cardiomyopathy is suspected and curative therapy is not possible.

Pheochromocytoma-induced atrial tachycardia leading to cardiogenic shock and cardiac arrest: resolution with atrioventricular node ablation and pacemaker placement

Pheochromocytoma should be considered in young patients who have acute cardiac decompensation, even if they have no history of hypertension. Atrioventricular node ablation and pacemaker placement should be considered for stabilizing pheochromocytoma patients with cardiogenic shock due to atrial tachyarrhythmias. A 38-year-old black woman presented with cardiogenic shock (left ventricular ejection fraction, <0.15) that did not respond to the placement of an intra-aortic balloon pump. A TandemHeart(®) Percutaneous Ventricular Assist Device was inserted emergently. After atrioventricular node ablation and placement of a temporary pacemaker, the TandemHeart was removed. Computed tomography of the abdomen revealed a pheochromocytoma. After placement of a permanent pacemaker, the patient underwent a right adrenalectomy. This is, to our knowledge, the first reported case of pheochromocytoma-induced atrial tachyarrhythmia that led to cardiogenic shock and cardiac arrest unresolved by the placement of 2 different ventricular assist devices, but that was completely reversed by radiofrequency ablation of the atrioventricular node and the placement of a temporary pacemaker. We present the patient's clinical, laboratory, and imaging findings, and we review the relevant literature.

Tachycardiomyopathy complicated by focal atrial tachycardia: incidence, risk factors, and long-term outcome

OBJECTIVE

Focal atrial tachycardias (ATs) are known to have the potential to develop tachycardiomyopathy (TCM). The aim of the study was to investigate the incidence, risk factors, and long-term outcome of TCM patients complicated by focal ATs.

METHODS AND RESULTS

A total of 237 patients undergoing electrophysiological studies were enrolled, among which 216 patients were diagnosed as focal ATs. In total, 18 patients (8.3%, 13 males) were identified to have TCM. The TCM patients were younger (29.8 ± 20.1 vs. 45.9 ± 17.3; P < 0.000) and were more frequently males (13/18 vs. 80/198; P = 0.014). The ATs were more likely to be persistent (11/18 vs. 32/198; P < 0.001). There was no difference between the 2 groups in terms of the tachycardia cycle length (392 milliseconds vs. 380 milliseconds; P = 0.56) and heart rate (144 bpm vs. 156 bpm; P = 0.15). The persistence and incidence of symptoms and prevalence of structural heart disease were comparable between the groups. In a multivariable analysis, the younger age and persistent nature were independently associated with TCM. In a 56 ± 21-month follow-up, all TCM patients had improved left ventricle ejection fraction after successful catheter ablation or medical therapy (43.9 ± 5.8% vs. 61.1 ± 3.5%; P ＜ 0.05). However, 1 patient suffered sudden cardiac death due to unauthorized withdrawal of the drug and progressive heart failure.

CONCLUSIONS

The incidence of TCM in focal ATs patients was 8.3%. Younger age and persistent nature were the independent risk factors of TCM. Most TCM patients had a benign outcome; however, long-term risk of sudden death does exist.

Pathologic and Cardiovascular Characterization of Pheochromocytoma-Associated Cardiomyopathy in Dogs

Pheochromocytoma-associated catecholamine-induced cardiomyopathy is a well-known entity in man, nonhuman primates, and mice but has not been described in dogs. In this retrospective study, 9 dogs were identified with pheochromocytomas and concurrent cardiovascular pathology observed histologically ( n = 6), echocardiographically ( n = 4), and/or electrocardiographically ( n = 5). Cardiac lesions included multifocal cardiomyocyte necrosis with contraction bands, cardiomyocyte degeneration, myocardial hemorrhage, lymphohistiocytic myocarditis, and interstitial fibrosis. Clinical procedures, including electrocardiographic and echocardiographic examinations, Doppler blood pressure measurement, and auscultation, were available for 5 dogs and consistently revealed concentric or mixed (eccentric and concentric) ventricular hypertrophy. Additional changes observed included arrhythmias, systemic hypertension, and heart murmurs. The myocardial lesions observed in this series of dogs are similar to those observed in humans with pheochromocytoma-associated catecholamine-induced cardiomyopathy. Since the clinical manifestations of catecholamine-induced cardiac disease are amenable to medical treatment, recognition of this cardiomyopathy has the potential to reduce morbidity and mortality in dogs with pheochromocytoma.

Atrial Fibrillation and Heart Failure: A Review of the Intersection of Two Cardiac Epidemics

Atrial fibrillation and heart failure are closely linked cardiac conditions that are both increasing in prevalence due to shared risk factors and common disease mechanisms. The presence of both disease entities portends an increase in morbidity and mortality. There are significant similarities in the treatment strategies of these conditions, and the adequate management of one disease may prevent the development of the other. To this date, a rhythm control strategy, even in the heart failure population, has not been proven to be superior to a rate control strategy. This may in large be due to study design coupled with deleterious effects of antiarrhythmic agents. There have been considerable advances over the past decade in catheter and device based management of atrial fibrillation and studies aimed to examine their long-term effect in patients with heart failure are underway.

Role of imaging in the detection of reversible cardiomyopathy

Heart failure is a major clinical problem in developed countries with about half of heart failure patients exhibiting decreased left ventricular systolic function. The correct identification and prompt treatment of some specific etiologies can reverse heart failure, and recognition of myocardial recovery may avoid long-term therapy. However, the echocardiographic patterns of patients with a variety of etiologies of heart failure are similar, so the selective use of other imaging techniques is necessary for identification of specific etiologies. The role of repeat imaging in monitoring the therapeutic response is controversial, as is the cessation of medical therapy in patients demonstrating recovery.

Time course of recovery of left ventricular systolic dysfunction in patients with premature ventricular contraction-induced cardiomyopathy

BACKGROUND

Idiopathic ventricular arrhythmias in the form of frequent, monomorphic premature ventricular contractions (PVC) can cause PVC-induced cardiomyopathy (PICMP). The aim of this study was to determine the baseline echocardiographic characteristics and the time course and degree of recovery of left ventricular (LV) systolic dysfunction in patients with PICMP.

METHODS

Study population consisted of 348 consecutive patients (205F/143M, 44 ± 19 y/o) with frequent PVCs and/or ventricular tachycardia. PICMP was defined as LV ejection fraction (LVEF) of <55% in the absence of any detectable underlying heart disease and improvement of LVEF ≥ 15% following treatment of ventricular arrhythmia. Patients with PCIMP underwent transthoracic echocardiography for LV size and function at 1 week and at 1-3 to 6-12 months of follow-up.

RESULTS

Twenty-four patients (8F/16M, 47 ± 18 y/o) with PICMP with complete echocardiographic data were included in the study. Average baseline LV end-diastolic diameter, LV end-systolic volume, LV mass index, and LVEF were 55.4 ± 6.8 mm, 69.6 ± 23.3 mL, 110.2 ± 28.3 g/m2, and 41 ± 8.4%, respectively. Mild-to-moderate mitral regurgitation (MR) was present in 13 (54%) patients. Early improvement (≥25% increase in LVEF at 1-week follow-up compared to baseline) was observed in 13 (54%) patients. Patients with early improvement had higher LVEF at 12 months of follow-up compared to patients without early improvement (58.8 ± 5.0% vs 52.5 ± 6.7%, P = 0.019).

CONCLUSIONS

PCIMP is characterized by mild-to-moderate global LV systolic dysfunction with slightly increased LV mass and mild-to-moderate MR. Greatest improvement in LV systolic dysfunction was observed at 1-week follow-up in our study population. Early improvement in LVEF may potentially predict the complete reversibility of LV systolic dysfunction.

Atrial fibrillation: profile and burden of an evolving epidemic in the 21st century

BACKGROUND

Atrial fibrillation (AF) represents an increasing public health challenge with profound social and economic implications.

METHODS

A comprehensive synthesis and review of the AF literature was performed. Overall, key findings from 182 studies were used to describe the indicative scope and impact of AF from an individual to population perspective.

RESULTS

There are many pathways to AF including advancing age, cardiovascular disease and increased levels of obesity/metabolic disorders. The reported population prevalence of AF ranges from 2.3%-3.4% and historical trends reflect increased AF incidence. Estimated life-time risk of AF is around 1 in 4. Primary care contacts reflect whole population trends: AF-related case-presentations increase from less than 0.5% in those aged 40 years or less to 6-12% for those aged 85 years or more. Globally, AF-related hospitalisations (primary or secondary diagnosis) showed an upward trend (from ~35 to over 100 admissions/10,000 persons) during 1996 to 2006. The estimated cost of AF is greater than 1% of health care expenditure and rising with hospitalisations the largest contributor. For affected individuals, quality of life indices are poor and AF confers an independent 1.5 to 2.0-fold probability of death in the longer-term. AF is also closely linked to ischaemic stroke (3- to 5-fold risk), chronic heart failure (up to 50% develop AF) and acute coronary syndromes (up to 25% develop AF) with consistently worse outcomes reported with concurrent AF. Future projections predict at least a doubling of AF cases by 2050.

SUMMARY

AF represents an evolving, global epidemic providing considerable challenges to minimise its impact from an individual to whole society perspective.

Ventricular Fibrillation in a Patient with Tachycardia-Induced Cardiomyopathy after Liver Transplantation

We report a case of atrial fibrillation-related tachycardia induced cardiomyopathy and ventricular fibrillation after liver transplantation in a 41-year-old man with end-stage liver failure. Atrial fibrillation and congestive heart failure occurred postoperatively. Cardiac arrests due to ventricular fibrillation occurred 6 months after the operation with subsequent implantations of an implantable cardioverter-defibrillator. Ventricular arrhythmias did not recur during the 18 months after normalization of heart functions with guideline-directed medical treatments.