Pulmonary embolism presenting with atrial fibrillation

Permanent atrial fibrillation and pulmonary embolism in elderly patients without deep vein thrombosis: is there a relationship?

BACKGROUND AND AIM

Permanent Atrial Fibrillation (pAF) is associated with increased risk of embolic complications. The relationship between pAF and pulmonary embolism (PE) has not been extensively investigated in elderly patients. Here, we aim at verifying whether pAF is associated to an increased risk of PE in a cohort of elderly patients with and without Deep Vein Thrombosis (DVT).

METHODS

235 patients older than 65 years with PE with or without pAF were retrospectively enrolled and stratified by the absence or presence of DVT. The diagnosis of PE was performed by computed tomography angiography (CTA). Right echocardiographic parameters were monitored. The severity of PE was evaluated by CTA quantization (PE score = 1, involvement of main branches of pulmonary artery) and by dimer-D (> 3000 µg/L).

RESULTS

DVT was identified only in 51 cases of PE (21.7%). pAF prevalence was higher in PE without than in those with DVT (64.9% vs. 35.1%, p < 0.01). PE severity was more evident in pAF patients without than in those with DVT. Multivariate analysis of the role of pAF on PE severity confirms these results (RR = 3.41 for PE score = 1, and 8.55 for dimer-D > 3000 µg/L).

CONCLUSIONS

We conclude that in elderly patients with PE, the prevalence of pFA was doubled, in the absence of DVT, and it is associated with a more severe PE in the absence than in the presence of DVT. Thus, in the absence of DVT, pFA should be considered as cause of PE.

Impact of Atrial Fibrillation On Cardiovascular Mortality in the Setting of Myocardial Infarction

Atrial fibrillation (AF) commonly occurs in patient with acute myocardial infarction (AMI). Potential triggers for AF development in this setting includes reduced left ventricular function, advanced diastolic dysfunction and mitral regurgitation leading to elevated left atrial pressures and atrial stretch. Other triggering mechanisms include inflammation and atrial ischemia. Multiple studies have shown that AF in patients with is associated with increased mortality. However, whether AF is a risk marker or a causal mediator of death remains controversial. There is relative dearth of data with regard to optimal management of AF in the setting of acute coronary syndromes. Patients with AMI who develop AF are at increased risk of stroke. However, the issue of the most appropriate antithrombotic regimens is complex given the need to balance stroke prevention against recurrent coronary events or stent thrombosis and the risk of bleeding. Presently, 'triple therapy' consisting of dual antiplatelet agents plus oral anticoagulants for 3-6 months or longer has been recommended for patients at moderate-high risk of stroke. Atrial fibrillation (AF), the most common sustained arrhythmia seen in clinical practice, often coincides with acute myocardial infarction (AMI), with a reported incidence ranging between 7% and 21%.[1] The development of atrial fibrillation in the acute phase of AMI may aggravate ischemia and heart failure, lead to clinical instability and adversely affect outcome. In the following we will review the pathophysiology, clinical characteristics and importance, and management of AF occurring in the setting of AMI.

Atrial Fibrillation After Lung Transplantation: Incidence, Predictors and Long-Term Implications

Background: Little is known about the frequency of, risk factors predisposing to, and long-term impact of post-operative atrial fibrillation (AF) after lung transplantation. Methods: A prospectively collected registry of 167 consecutive patients who underwent single or bilateral lung transplantation at the University of Minnesota Medical Center from January 1st, 2004 to December 30th, 2008 was reviewed. Post-operative AF was confirmed by review of electrocardiograms by two cardiologists. Kaplan-Meier survival curves were constructed to determine the impact of new onset AF on long-term survival. Results: The mean age (±SD) of the population was 55 ± 11 years and 52% were male. A total of 48 patients (28%) developed AF in the postoperative period. Predictors of postoperative AF in multivariate analysis included: age (per decade) Odds Ratio (OR): 1.61, 95% confidence interval (CI) 1.10-2.34, p=0.01, postoperative thromboembolic disease OR: 9.73 (95% CI: 2.16-43.81, p<0.01, and postoperative pericarditis OR: 3.57, (95% CI: 1.38-9.22, p < 0.01). Of the 48 patients who developed post-operative AF, 41 were discharged in sinus rhythm (SR). Survival among patients who were discharged in AF was significantly lower when compared to patients discharged in SR (HR: 0.08; 0.01-0.43, p<0.05). Conclusions: Postoperative AF is common after lung transplant. Increased age, postoperative thromboembolic disease, and pericarditis are independent predictors of postoperative AF. Persistence of AF at the time of discharge is an identifier of decreased survival.

Atrial fibrillation and pulmonary embolism

Atrial fibrillation is a rare diagnosis in children and adolescents. We report a case of a 17-year-old previously healthy boy who presented to the emergency department with a 3-week history of shortness of breath, chest pain, and 1 episode of hemoptysis. Symptoms persisted despite a course of antibiotics and anti-inflammatory agents. The patient developed palpitations and was found to be in atrial fibrillation at the time of hospitalization. An extensive workup led to the diagnosis of pulmonary embolism. This case highlights the importance of evaluating for thromboembolic events in pediatric patients presenting with new-onset atrial fibrillation and typical electrocardiogram pattern of cor pulmonale with or without respiratory symptoms.

Anti-arrhythmic effects of I (Na), I (Kr), and combined I (Kr)-I (CaL) blockade in an experimental model of acute stretch-related atrial fibrillation

INTRODUCTION

Atrial dilatation is commonly associated with atrial fibrillation (AF), but the electrophysiological mechanisms and the implications for anti-arrhythmic therapy are poorly understood. In a model of acute stretch-related AF in isolated rabbit hearts, we evaluated the electrophysiological effects of three different anti-arrhythmic drugs: dofetilide, flecainide and BRL-32872 (associating I (Kr) and I (CaL) blocking properties).

METHODS

After 30 min of sustained stretch-related AF, we perfused BRL 10-7 M, BRL 3.10-7 M, BRL 10-6 M, flecainide 2.4 10-6 M and dofetilide 10-7 M and iteratively measured atrial effective refractory periods (ERPs), AF inducibility and AF cycle length (AFCL) 15, 30 and 60 min after drug perfusion, respectively.

RESULTS

After a significant shortening of the ERPs by acute atrial stretch in the five groups individually (p < 0.001, stretch vs baseline for each group individually), drug perfusion led to a strong lengthening of AFCL, a very significant prolongation of ERPs (p < 0.001 vs stretch) and a reduction of AF inducibility (p < 0.01 vs control group) for each of the five experimental groups. The relative ERP increase was comparable in all groups, whereas a significantly lower AF inducibility was observed in the BRL 10-6 M group (p < 0.05 vs other BRL concentrations).

CONCLUSION

In a model of acute stretch-related AF, dofetilide, flecainide and BRL-32872 terminated AF and prevented its immediate reinduction after having comparatively prolonged AFCL and ERPs. These comparative results suggest that those drugs are equally efficacious, albeit with different mechanisms, in the setting of acute atrial stretch.

Association of atrial fibrillation and amino-terminal pro-brain natriuretic peptide concentrations in dyspneic subjects with and without acute heart failure: results from the ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) study

BACKGROUND

Amino-terminal pro-brain natriuretic peptide (NT-proBNP) testing is useful for diagnosis or exclusion of heart failure (HF) in dyspneic patients. Atrial fibrillation (AF) may cause dyspnea in the absence of acute HF and may also affect plasma levels of NT-proBNP.

METHODS

We prospectively enrolled 599 patients presenting with dyspnea to the emergency department and obtained a blood sample for NT-proBNP measurement. The diagnosis of AF was identified via presentation electrocardiogram. A final diagnosis of HF was determined by blinded study physicians using all available hospital records for each subject through 60 days of follow-up. We assessed the association between the presence of AF and level of NT-proBNP in subsets of patients with and without HF.

RESULTS

Of 599 dyspneic patients, 75 (13%) were in AF at presentation; these patients had significantly higher median NT-proBNP levels when compared with those without AF (2934 vs 294 pg/mL, P < .0001). Among patients with acute HF, AF was present in 28%; NT-proBNP levels were lower in those with AF versus those without (3488 vs 4492 pg/mL, P < .001), but AF was not independently associated with NT-proBNP after multivariable adjustment. In patients without acute HF, median NT-proBNP concentrations were significantly higher in those with AF than in those without (932 vs 121 pg/mL, P = .02); in these subjects, AF was the strongest predictor of an NT-proBNP concentration in a range consistent with acute HF (odds ratio 9.94, 95% CI 2.97-33.3, P < .001).

CONCLUSION

Atrial fibrillation is associated with higher NT-proBNP concentrations in dyspneic patients, particularly in those without acute HF.

Uncommon etiologies of atrial fibrillation

A newly diagnosed atrial fibrillation warrants a full investigation of the etiopathogenesis of this common arrhythmia. In the adult population, the most frequently associated conditions are systemic hypertension, coronary artery disease, mitral valvulopathy, congestive heart failure, and hyperthyroidism. Nevertheless, more infrequent and even rare, yet correctable, etiologies should not be overlooked. We describe three patients who presented to our hospital with a first episode of atrial fibrillation and who subsequently were demonstrated to have very unusual cardiovascular pathologies subtending this common arrhythmia. In all three cases, trans-esophageal echocardiography was instrumental in reaching an accurate diagnosis that was later confirmed at surgery.