Prevention of atrial fibrillation after coronary artery bypass grafting via atrial electromechanical interval and use of amiodarone prophylaxis

Navigating the Incidence of Postoperative Arrhythmia and Hospitalization Length: The Role of Amiodarone and Other Antiarrhythmics in Prophylaxis

Antiarrhythmic drugs play a pivotal role in managing and preventing arrhythmias. Amiodarone, classified as a class III antiarrhythmic, has been used prophylactically to effectively prevent atrial fibrillation postoperatively in cardiac surgeries. However, there is a lack of consensus on the use of amiodarone and other antiarrhythmic drugs as prophylaxis to reduce the occurrence of all types of postoperative arrhythmias in cardiac and non-cardiac surgeries. A comprehensive PubMed query yielded 614 relevant papers, of which 52 clinical trials were analyzed. The data collection included the class of antiarrhythmics, timing or method of drug administration, surgery type, type of arrhythmia and its incidence, and hospitalization length. Statistical analyses focused on prophylactic antiarrhythmics and their respective reductions in postoperative arrhythmias and hospitalization length. Prophylactic amiodarone alone compared to placebo demonstrated a significant reduction in postoperative arrhythmia incidence in cardiac and non-cardiac surgeries (24.01%, p<0.0001), and it was the only treatment group to significantly reduce hospitalization length versus placebo (p = 0.0441). Prophylactic use of class 4 antiarrhythmics versus placebo also demonstrated a significant reduction in postoperative arrhythmia incidence (28.01%, p<0.0001), and while there was no significant statistical reduction compared to amiodarone (4%, p=0.9941), a lack of abundant data provides a case for further research on the prophylactic use of class 4 antiarrhythmics for this indication. Amiodarone prophylaxis remains a prime cornerstone of therapy in reducing postoperative arrhythmia incidence and hospitalization length. Emerging data suggests a need for a broader exploration of alternative antiarrhythmic agents and combination therapies, particularly class 4 antiarrhythmics, in both cardiac and non-cardiac surgeries. This meta-analysis depicts the effectiveness of amiodarone, among other antiarrhythmics, in postoperative arrhythmia incidence and hospitalization length reduction in cardiac and non-cardiac surgeries.

Prevention of postoperative atrial fibrillation in cardiac surgery: a quality improvement project

PURPOSE

Postoperative atrial fibrillation (POAF) has an incidence of 20-60% in cardiac surgery. The Society of Cardiovascular Anesthesiologists and the European Association of Cardiothoracic Anaesthesiology Practice Advisory have recommended postoperative beta blockers and amiodarone for the prevention of POAF. By employing quality improvement (QI) strategies, we sought to increase the use of these agents and to reduce the incidence of POAF among our patients undergoing cardiac surgery.

METHODS

This single-centre QI initiative followed the traditional Plan, Do, Study, Act (PDSA) cycle scientific methodology. A POAF risk score was developed to categorize all patients undergoing cardiac surgery as either normal or elevated risk. Risk stratification was incorporated into a preprinted prescribing guide, which recommended postoperative beta blockade for all patients and a postoperative amiodarone protocol for patients with elevated risk starting on postoperative day one (POD1). A longitudinal audit of all patients undergoing cardiac surgery was conducted over 11 months to track the use of prophylactic medications and the incidence of POAF.

RESULTS

Five hundred and sixty patients undergoing surgery were included in the QI initiative from 1 December 2020 to 1 November 2021. The baseline rate of POAF across all surgical subtypes was 39% (198/560). The use of prophylactic amiodarone in high-risk patients increased from 13% (1/8) at the start of the project to 41% (48/116) at the end of the audit period. The percentage of patients receiving a beta blocker on POD1 did fluctuate, but remained essentially unchanged throughout the audit (34.8% in December 2020 vs 46.7% in October 2021). After 11 months, the overall incidence of POAF was 29% (24.9% relative reduction). Notable reductions in the incidence of POAF were observed in more complex surgical subtypes by the end of the audit, including multiple valve replacement (89% vs 56%), aortic repair (50% vs 33%), and mitral valve surgery (45% vs 33%).

CONCLUSIONS

This single-centre QI intervention increased the use of prophylactic amiodarone by 28% for patients at elevated risk of POAF, with no change in the early postoperative initiation of beta blockers (46.7% of patients by POD1). There was a notable reduction in the incidence of POAF in patients at elevated risk undergoing surgery.

The relationship of benign prostatic hyperplasia's symptoms severity with the risk of developing atrial fibrillation

Background

Attention is drawn to the increased incidence of atrial fibrillation (AF) in benign prostatic hyperplasia (BPH) patients recently. Early predicting of AF in these patients can help in decreasing its clinical consequences. The aim of our study is to determine the association between BPH symptoms and AF predictors atrial electromechanical delay (AEMD) and the P-wave dispersion (PWD).

Methods

218 healthy individuals recently diagnosed with BPH were assigned into three groups according to symptoms severity using the International prostate symptom score (IPSS) questionnaire. The first group with mild symptoms (IPSS score between 0 and 7, n = 78), the second group with moderate symptoms (IPSS score between 8 and 19, n = 86), and the third group with severe symptoms (IPSS score between 20 and 35, n = 54). PWD and AEMD calculations were performed for all participants.

Results

There were statistically significant differences between the three groups in terms of AEMD and PWD (p < .01 and p < .01, respectively). In all three study groups, a significant positive correlation was observed between IPSS questionnaire scores and both AEMD and PWD (for AEMD r = .29, p = .013 and for PWD r = .27, p = .017). On the other hand, there were significant differences between the three groups in terms of the inflammatory markers C-reactive protein (CRP) and fibrinogen (p < .01 and p < .01, respectively) and in terms of serum testosterone levels (p < .01).

Conclusions

We concluded that periodic evaluation of patients with BPH in terms of symptoms severity can be helpful not only from urological aspect, but also in the early prediction of possible serious cardiovascular morbidity and mortality.

Atrial electromechanical duration prolongs in patients with erectile dysfunction

Background: It is well known that erectile dysfunction (ED) is associated with increased risk of atrial fibrillation (AF) development. On the other hand, prolongation of the duration of atrial electromechanical delay (AEMD) is known to be a precursor for AF development. We aimed to evaluate AEMD in patients with ED patients without documented AF.Methods: Total of 68 outpatients with previously documented vascular ED and 44 participants without ED were enrolled to the current study. Sixty-eight patients with ED called as ED group and 44 participants without ED served as control group. We performed International Index of Erectile Function (IIEF-5) questionnaire for all participants to determine the disease severity of ED groups and to diagnose ED in control groups. Patients with a IIEF-5 score ≥22 were defined as having normal erectile functions. Both intra- and inter-AEMD were measured with tissue Doppler imaging. P-wave dispersion (PWD) was measured on a 12-lead electrocardiogram.Results: Basal characteristics were similar between the two groups. PWD, inter- and right intra-AEMD were significantly prolonged in patients with ED, compared to the control group (p = .02, p < .001 and p < .001, respectively). In the correlation analysis, IIEF-5 score was significantly negative correlated with systolic blood pressure, right intra- and inter-AEMD (r = -0.37, p = .02; r= -0.27, p = .02; r = -0.39, p = .001, respectively).Conclusions: According to current study results, AEMD is significantly correlated with ED severity and may be useful to stratify ED patients to the high-risk group for future development of AF as a cheap and easy method.

Precise Drug Sequential Therapy Can Improve the Cardioversion Rate of Atrial Fibrillation with Valvular Disease after Radiofrequency Ablation

OBJECTIVE

Based on pathogenesis of atrial fibrillation (AF), investigate the effects of precision drugs continuous therapy on AF cardioversion rate after radiofrequency catheter ablation.

METHODS

We included 1334 patients who underwent mitral valve replacement with bipolar radiofrequency ablation due to mitral valve disease with AF during June 2011 to July 2017. The data of clinical and related laboratory examinations at discharge and follow-up were recorded. All patients were treated with or without angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II-receptor blocker (ARB) drugs according to their conditions and doctor's willingness. The heart rhythm was evaluated after treatment and follow-up of 6 months.

RESULTS

All 1162 cases were followed up, including 825 cases in mitral stenosis (MS) group, 337 cases in mitral regurgitation (MR) group. In MS group, left atrial diameter(LAD) and left ventricular diameter(LVD) of the patients taking ACEI and ARB were significantly lower (P < 0.05), and they can increase AF cardioversion rate from 79.1% of the control group to 83.7% and 82.8%, respectively (P = 0.03 and 0.04). In MR group, the patients with ACEI compared with control group, there were no significant differences in LAD, LVD, right atrial diameter (RAD), right ventricular diameter (RVD), left ventricular ejection fraction(LVEF), and left ventricular fractional shortening(LVFS) (P > 0.05); but ARB group, LAD, LVD decreased significantly (P < 0.05). And ACEI can increase AF cardioversion rate from 76.1% in the control group to 77.2% (P = 0.62), ARB to 81.6% (P = 0.02).

CONCLUSION

It does improve AF cardioversion rate after radiofrequency catheter ablation that the precise anti-structural remodeling drugs continuous therapy was adopted based on the pathogenesis of AF.

Prophylactic amiodarone vs dronedarone for prevention of perioperative arrhythmias in offpump coronary artery bypass grafting: A pilot randomized controlled trial

The aim of this study was to compare the effects of prophylactic dronedarone and amiodarone in prevention of arrhythmias during and following off-pump coronary artery bypass grafting (OPCAB). This randomized, controlled, double-blinded, parallel-group study was carried out on 36 adult male patients aged 30-70 years, with modified Parsonnet score 0-10 undergoing offpump coronary artery bypass grafting. After obtaining approval from the institutional ethics committee and informed consent, the patients were randomly allocated to two equal groups (n=18). In one group, patients were given inj. amiodarone 3mg/kg in 100ml of normal saline prior to skin incision intravenously over 20 minutes. In the second group patients received tablet dronedarone 400mg orally twice daily, commencing three days prior to the date of surgery. Patients in the amiodarone group received placebo tablet while patients in the dronedarone group received placebo infusion for the sake of blinding. The frequency and profile of arrhythmias intraoperatively and 24 hours postoperatively were studied. Intraoperative arrhythmias occurred in 50% of patients receiving amiodarone and 16.67% of patients receiving dronedarone. Maximum ventricular rate during atrial fibrillation was significantly lower in the dronedarone group (121 beats per min) than in the amiodarone group (168 beats per min). The study concludes that dronedarone appears to be at least as effective as amiodarone in prophylaxis of intraoperative and postoperative arrhythmias in patients undergoing OPCAB, with a better control of ventricular response.

Atrial Function in Patients with Breast Cancer After Treatment with Anthracyclines

Background:

Atrial electromechanical delay (EMD) is used to predict atrial fibrillation, measured by echocardiography.

Objectives:

The aim of this study was to assess atrial EMD and mechanical function after anthracycline-containing chemotherapy.

Methods:

Fifty-three patients with breast cancer (48 ± 8 years old) who received 240 mg/m2of Adriamycin, 2400 mg/m2 of cyclophosphamide, and 960 mg/m2 of paclitaxel were included in this retrospective study, as were 42 healthy subjects (47 ± 9 years old). Echocardiographic measurements were performed 11 ± 7 months (median 9 months) after treatment with anthracyclines.

Results:

Left intra-atrial EMD (11.4 ± 6.0 vs. 8.1 ± 4.9, p=0.008) and inter-atrial EMD (19.7 ± 7.4 vs. 14.7 ± 6.5, p=0.001) were prolonged; LA passive emptying volume and fraction were decreased (p=0.0001 and p=0.0001); LA active emptying volume and fraction were increased (p=0.0001 and p=0.0001); Mitral A velocity (0.8 ± 0.2 vs. 0.6 ± 0.2, p=0.0001) and mitral E-wave deceleration time (201.2 ± 35.6 vs. 163.7 ± 21.8, p=0.0001) were increased; Mitral E/A ratio (1.0 ± 0.3 vs. 1.3 ± 0.3, p=0.0001) and mitral Em (0.09 ± 0.03 vs. 0.11 ± 0.03, p=0.001) were decreased; Mitral Am (0.11 ± 0.02 vs. 0.09 ± 0.02, p=0.0001) and mitral E/Em ratio (8.8 ± 3.2 vs. 7.6 ± 2.6, p=0.017) were increased in the patients.

Conclusions:

In patients with breast cancer after anthracycline therapy: Left intra-atrial, inter-atrial electromechanical intervals were prolonged. Diastolic function was impaired. Impaired left ventricular relaxation and left atrial electrical conduction could be contributing to the development of atrial arrhythmias.

Fundamento:

Atraso eletromecânico atrial (AEA) é utilizado para prever fibrilação atrial, medido pela ecocardiografia.

Objetivos:

O propósito deste estudo era verificar o AEA e a função mecânica após quimioterapia com antraciclinas.

Métodos:

Cinquenta e três pacientes com câncer de mama (48 ± 8 anos) que receberam 240 mg/m2 de adriamicina, 2400 mg/m2 de ciclofosfamida, e 960 mg/m2 de paclitaxel foram incluídas neste estudo retrospectivo, além de 42 indivíduos saudáveis (47 ± 9 anos). Medidas ecocardiográficas foram realizadas por aproximadamente 11 ± 7 meses (média de 9 meses) após tratamento com antraciclinas.

Resultados:

AEA esquerdo intra-atrial (11,4 ± 6,0 vs. 8,1 ± 4,9, p=0,008) e AEA interarterial (19,7 ± 7,4 vs. 14,7 ± 6,5, p=0,001) foram prolongados; Volume de esvaziamento passivo e fracionamento de AE diminuíram (p=0,0001 e p=0,0001); Volume de esvaziamento ativo e fracionamento de AE (p=0,0001 e p=0,0001); Tempo de aceleração mitral A (0,8 ± 0,2 vs. 0,6 ± 0,2, p=0,0001) e de desaceleração de onda-E mitral (201,2 ± 35,6 vs. 163,7 ± 21,8, p=0,0001) aumentarão; Razão mitral E/A (1,0 ± 0,3 vs. 1,3 ± 0,3, p=0,0001) e mitral Em (0,09 ± 0,03 vs. 0,11 ± 0,03, p=0,001) diminuíram; Razão mitral Am (0,11 ± 0,02 vs. 0,09 ± 0,02, p=0,0001) e mitral E/Em (8,8 ± 3,2 vs. 7,6 ± 2,6, p=0,017) aumentaram nos pacientes.

Conclusões:

Em pacientes com câncer de mama após terapia com antraciclina: intervalos eletromecânicos intra-atriais esquerdos, intra-atriais foram prolongados. A função diastólica foi prejudicada. O relaxamento ventricular esquerdo foi prejudicado, e a condução elétrica atrial esquerda pode estar contribuindo para o desenvolvimento de arritmias atriais.

Long-term anabolic androgenic steroid use is associated with increased atrial electromechanical delay in male bodybuilders

We investigated the effect of long-term supraphysiologic doses of anabolic androgenic steroids (AAS) on atrial electromechanical delay (AEMD) in male bodybuilders. We clearly demonstrated that long-term consumption of supraphysiologic doses of AAS is associated with higher values of inter- and intra-AEMD in healthy young bodybuilders.

Clinical and echocardiographic predicators of postoperative atrial fibrillation

BACKGROUND

Postoperative atrial fibrillation is the most common arrhythmia after coronary artery bypass grafting, with a reported incidence of 10% to 60%. Preoperative clinical and echocardiographic data, especially the atrial electromechanical interval, predict postoperative atrial fibrillation in elective coronary artery bypass patients.

METHODS

A prospective study evaluated preoperative clinical and echocardiographic data in 192 patients who underwent elective coronary artery bypass from 2010 to 2012.

RESULTS

18 (9.37%) patients developed postoperative atrial fibrillation. Compared to patients without postoperative atrial fibrillation, these 18 had significantly longer intensive care unit and hospital stays, they were significantly older (58.62 ± 10.02 vs. 53.22 ± 8.23 years; p = 0.02), with a larger left atrial volume (83.39 ± 8.31 vs. 55.47 ± 8.37 cm(3), p = 0.001), longer atrial electromechanical interval (133.67 ± 8.15 vs. 98.05 ± 6.71 ms p < 0.0001), and lower tissue Doppler imaging systolic velocity wave amplitude (6.6 ± 1 vs. 9.4 ± 2.2 cm·s(-1); p = 0.001); they also had a higher prevalence of hypertension (61.11% vs. 38.5%; p = 0.04). Using 115 ms as the cutoff value of atrial electromechanical interval enabled us to detect patients who developed postoperative atrial fibrillation with 100% sensitivity, 77% specificity, 78% positive predictive value, and 100% negative predictive value.

CONCLUSION

Older hypertensive patients are at higher risk of developing postoperative atrial fibrillation. Preoperative measurement of atrial electromechanical interval by tissue Doppler echocardiography is a useful predictor of postoperative atrial fibrillation in coronary artery bypass patients.

Interventions for preventing post-operative atrial fibrillation in patients undergoing heart surgery

BACKGROUND

Atrial fibrillation is a common post-operative complication of cardiac surgery and is associated with an increased risk of post-operative stroke, increased length of intensive care unit and hospital stays, healthcare costs and mortality. Numerous trials have evaluated various pharmacological and non-pharmacological prophylactic interventions for their efficacy in preventing post-operative atrial fibrillation. We conducted an update to a 2004 Cochrane systematic review and meta-analysis of the literature to gain a better understanding of the effectiveness of these interventions.

OBJECTIVES

The primary objective was to assess the effects of pharmacological and non-pharmacological interventions for preventing post-operative atrial fibrillation or supraventricular tachycardia after cardiac surgery. Secondary objectives were to determine the effects on post-operative stroke or cerebrovascular accident, mortality, cardiovascular mortality, length of hospital stay and cost of treatment during the hospital stay.

SEARCH METHODS

We searched the Cochrane Central Register of ControlLed Trials (CENTRAL) (Issue 8, 2011), MEDLINE (from 1946 to July 2011), EMBASE (from 1974 to July 2011) and CINAHL (from 1981 to July 2011).

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) that included adult patients undergoing cardiac surgery who were allocated to pharmacological or non-pharmacological interventions for the prevention of post-operative atrial fibrillation or supraventricular tachycardia, except digoxin, potassium (K(+)), or steroids.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted study data and assessed trial quality.

MAIN RESULTS

One hundred and eighteen studies with 138 treatment groups and 17,364 participants were included in this review. Fifty-seven of these studies were included in the original version of this review while 61 were added, including 27 on interventions that were not considered in the original version. Interventions included amiodarone, beta-blockers, sotalol, magnesium, atrial pacing and posterior pericardiotomy. Each of the studied interventions significantly reduced the rate of post-operative atrial fibrillation after cardiac surgery compared with a control. Beta-blockers (odds ratio (OR) 0.33; 95% confidence interval) CI 0.26 to 0.43; I(2) = 55%) and sotalol (OR 0.34; 95% CI 0.26 to 0.43; I(2) = 3%) appear to have similar efficacy while magnesium's efficacy (OR 0.55; 95% CI 0.41 to 0.73; I(2) = 51%) may be slightly less. Amiodarone (OR 0.43; 95% CI 0.34 to 0.54; I(2) = 63%), atrial pacing (OR 0.47; 95% CI 0.36 to 0.61; I(2) = 50%) and posterior pericardiotomy (OR 0.35; 95% CI 0.18 to 0.67; I(2) = 66%) were all found to be effective. Prophylactic intervention decreased the hospital length of stay by approximately two-thirds of a day and decreased the cost of hospital treatment by roughly $1250 US. Intervention was also found to reduce the odds of post-operative stroke, though this reduction did not reach statistical significance (OR 0.69; 95% CI 0.47 to 1.01; I(2) = 0%). No significant effect on all-cause or cardiovascular mortality was demonstrated.

AUTHORS' CONCLUSIONS

Prophylaxis to prevent atrial fibrillation after cardiac surgery with any of the studied pharmacological or non-pharmacological interventions may be favored because of its reduction in the rate of atrial fibrillation, decrease in the length of stay and cost of hospital treatment and a possible decrease in the rate of stroke. However, this review is limited by the quality of the available data and heterogeneity between the included studies. Selection of appropriate interventions may depend on the individual patient situation and should take into consideration adverse effects and the cost associated with each approach.

Extent of left ventricular hypertrophy is related to interatrial conduction delay in hypertensive patients

The aim of this study was to investigate the relationship between left ventricular mass (LVM) and interatrial conduction delay (CD) measured by tissue Doppler echocardiography. In enrolled 66 hypertensive patients, positive correlation between interatrial CD and LVM index (r = 0.32) was detected. Meanwhile, intra-atrial CD was correlated to early diastolic tissue Doppler mitral annular velocity measured from septum (r = 0.34), tricuspid annular velocity (r = 0.29), and left atrial volume index (r = 0.26). By using stepwise linear regression analysis, LVM index was determined as an independent predictor of interatrial CD.

Circulating and local renin-angiotensin-aldosterone system express differently in atrial fibrillation patients with different types of mitral valvular disease

Mitral valvular disease is strongly related to atrial fibrillation (AF), but the different types of mitral valvular disease have a different prevalence of AF. In this study we explored the expressions of the circulating and local renin-angiotensin-aldosterone system (RAAS) in order to determine the relationship between circulating and local RAAS expressions and its effects on AF in different types of mitral valvular disease patients. Our study group consisted of 24 mitral valvular disease patients scheduled for mitral valve replacement surgery. Peripheral blood samples and left atrial appendage tissue samples were obtained from all patients. Radioimmunoassay was performed to assess the expression levels of circulating and local renin, angiotensin II and aldosterone. In mitral valvular diseases, linear correlation analyses were done for local and circulating renin, angiotensin II and aldosterone; the p values were 0.979, 0.518 and 0.125, respectively. Expression levels of local angiotensin II, circulating angiotensin II and local aldosterone were significantly increased in the AF group compared with sinus rhythm; the p values were 0.023, 0.042 and 0.035, respectively. In mitral stenosis patients, AF was primarily associated with local angiotensin II (p=0.010), as well as being associated with circulating angiotensin II (p=0.038). In mitral regurgitation patients, AF was only significantly associated with local angiotensin II (p=0.038). Circulating and local RAAS expressions are associated with AF in mitral valvular disease patients. The levels of circulating and local RAAS expressions were different in AF patients with different types of mitral valvular diseases. The differentiation of circulating and local RAAS expression levels in AF patients between different types of mitral valvular disease can potentially improve the specific pharmacological interventions outcomes for these patients.

Assessment of atrial conduction time by tissue Doppler echocardiography and P-wave dispersion in smokers

INTRODUCTION

The aim of this study was to evaluate the relationship between cigarette smoking and atrial rhythm disorders with the use of noninvasive methods.

METHODS

The study population consisted of 50 healthy volunteer smokers and 40 healthy volunteer non-smokers who had normal echocardiographic parameters and similar sex and age profiles. P-wave dispersion (PWD) was calculated from the 12-lead surface ECG. Left ventricle (LV) end-systolic and end-diastolic diameters, LV ejection fraction, and interatrial and intraatrial electromechanical delay were measured by tissue Doppler imaging and conventional echocardiography.

RESULTS

Isovolumetric relaxation time and deceleration time were significantly higher (91.5 ± 11 vs. 82.35 ± 8.6, p < 0.0001; 215.7 ± 37.1 vs. 175.3 ± 17.7, p < 0.0001, respectively), and HDL cholesterol was significantly lower in smokers (39.34 ± 7.5 vs.44.3 ± 8.07, p = 0.003). There were no significant differences between the groups with respect to Sm and Em values, Am value, and E/A and E/Em ratios. However, the Em/Am ratio was significantly lower in smokers (1.28 ± 0.21 vs. 1.44 ± 0.33, p < 0.006). Inter- and intraatrial electromechanical delay were significantly higher in smokers when compared with non-smokers (51.11 ± 1.54 vs. 27.30 ± 3.36, p < 0.0001, and 30.63 ± 3.2 vs. 12.24 ± 3.26, p < 0.0001, respectively). The amount of smoking was strongly correlated with interatrial electromechanical delay (r = 0.567, p < 0.0001), and a significant correlation was detected between PWD and interatrial electromechanical delay (r = 0.653, p = 0.001).

CONCLUSION

We have demonstrated the relationship between inter- and intraatrial electromechanical delay and PWD. These parameters may be useful predictive markers for the development of AF in the asymptomatic period before cardiac rhythm disturbances occur. This finding may indicate that smokers have an increased risk of developing atrial rhythm disturbances.

Acute sleep deprivation is associated with increased atrial electromechanical delay in healthy young adults

BACKGROUND

Sleep deprivation (SD) is known to be associated with an increased incidence of adverse cardiovascular outcome. Atrial electromechanical delay (AEMD) calculated from tissue Doppler imaging has been shown to detect atrial impairment in paroxysmal atrial fibrillation. The aim of the study was to investigate whether AEMD would increase in otherwise healthy young adults with acute SD.

METHODS

Twenty-seven healthy volunteers were included into the study (mean age: 26 ± 3 years). The participants underwent an echocardiographic examination after a night with SD. AEMD defined as the interval from the onset of P wave to the onset of late diastolic Am wave (PA) was calculated from the lateral and septal mitral annulus, and lateral tricuspid annulus (PA lateral, PA septum, and PA tricuspid, respectively).

RESULTS

Subjects had similar values of PA tricuspid duration in milliseconds after the night of sleep debt when compared after regular sleep, whereas they had significantly higher values of PA lateral and PA septal durations (69.05 ± 10.64 ms vs 51.31 ± 11.32 ms, P < 0.001 and 51.75 ± 7.15 ms vs 41.37 ± 8.52 ms, P < 0.001; respectively). Moreover, participants had higher inter-AEMD and intra-AEMD values after the night of sleep debt when compared after regular sleep [30.19 ± 9.84 ms vs 14.72 ± 6.81 ms, P < 0.001 and 12.82 ± 7.09 ms vs 4.41 ± 3.60 ms, P < 0.001; respectively]. Pearson's correlation analyses suggest that inter-AEMD and intra-AEMD were inversely correlated with sleep time (r =-0.628, r =-0.499, r =-0.696, and r =-0.572, respectively [all P < 0.001]).

CONCLUSION

In conclusion, in this cross-sectional study, we clearly found that even one night of SD is associated with higher values of inter-AEMD and intra-AEMD in healthy young adults.

Assessment of atrial electromechanical delay by tissue Doppler echocardiography in obese subjects

Our aim was to evaluate whether atrial electromechanical delay measured by tissue Doppler imaging (TDI), which is an early predictor of atrial fibrillation (AF) development, is prolonged in obese subjects. A total of 40 obese and 40 normal-weight subjects with normal coronary angiograms were included in this study. P-wave dispersion (PWD) was calculated on the 12-lead electrocardiogram (ECG). Systolic and diastolic left ventricular (LV) functions, inter- and intra-atrial electromechanical delay were measured by TDI and conventional echocardiography. Inter- and intra-atrial electromechanical delay were significantly longer in the obese subjects compared with the controls (44.08 ± 10.06 vs. 19.35 ± 5.94 ms and 23.63 ± 6.41 vs. 5.13 ± 2.67 ms, P < 0.0001 for both, respectively). PWD was higher in obese subjects (53.40 ± 5.49 vs. 35.95 ± 5.93 ms, P < 0.0001). Left atrial (LA) diameter, LA volume index and LV diastolic parameters were significantly different between the groups. Interatrial electromechanical delay was correlated with PWD (r = 0.409, P = 0.009), high-sensitivity C-reactive protein (hsCRP) levels (r = 0.588, P < 0.0001). Interatrial electromechanical delay was positively correlated with LA diameter, LA volume index, and LV diastolic function parameters consisting of mitral early wave (E) deceleration time (DT) and isovolumetric relaxation time (IVRT; r = 0.323, P = 0.042; r = 0.387, P = 0.014; r = 0.339, P = 0.033; r = 0.325, P = 0.041; respectively) and, negatively correlated with mitral early (E) to late (A) wave ratio (E/A) (r = -0.380, P = 0.016) and myocardial early-to-late diastolic wave ratio (E(m)/A(m)) (r = -0.326, P = 0.040). This study showed that atrial electromechanical delay is prolonged in obese subjects. Prolonged atrial electromechanical delay is due to provoked low-grade inflammation as well as LA enlargement and early LV diastolic dysfunction in obese subjects.

Assessment of atrial electromechanical delay and influential factors in patients with obstructive sleep apnea

PURPOSE

The interaction between moderate-to-severe obstructive sleep apnea (OSA) and cardiac arrhythmias, especially atrial fibrillation (AF), is well known. We aimed to determine whether atrial electromechanical parameters assessed by tissue Doppler imaging (TDI) would be affected in moderate-to-severe OSA, and detect the influential factors of atrial electromechanical parameters in these patients.

METHODS AND RESULTS

Interatrial and intra-atrial electromechanical delay was measured by TDI in patients with moderate-to-severe OSA (n = 64) and control subjects (n = 39). P-wave dispersion (PWD) was calculated on the 12-lead ECG. Interatrial and intra-atrial electromechanical delay was significantly higher in the OSA group when compared with the controls (52.26 ± 12.9 vs 29.61 ± 11.26, P < 0.0001 and 18.90 ± 8.13 vs 8.71 ± 5.46, P < 0.0001; respectively). PWD was higher in the OSA group (46.09 ± 13.40 ms vs 34.10 ± 10.75 ms, P < 0.0001). Interatrial electromechanical delay had a positive correlation with PWD (r = 0.490, P < 0.0001), left atrial (LA) diameter (r = 0.383, P = 0.002), LA volume index (r = 0.354, P = 0.004), and apnea-hypopnea index (r = 0.365, P = 0.003). In addition, interatrial electromechanical delay was negatively correlated with the magnitude of the lowest oxygen saturation percentage (r = -0.498, P < 0.0001).

CONCLUSION

This study showed that interatrial and intra-atrial electromechanical delay and PWD were prolonged in patients with moderate-to-severe OSA. LA dilatation, hypoxemia, and the severity of the disease may contribute a prolongation in interatrial electromechanical delay via atrial structural and electrical alterations, which may predict the risk of future AF development in patients with moderate-to-severe OSA.

Intraoperative loading dose of amiodarone for prophylaxis against atrial fibrillation after valvular heart surgery

Objective:

Benefit of amiodarone in restoring sinus rhythm (SR) after cardiac surgery was concluded in previous studies that used different protocols for giving amiodarone. The purpose of this study was to assess the use of single parenteral intraoperative loading dose of amiodarone without maintenance as prophylaxis against atrial fibrillation (AF) after valvular heart surgery.

Materials and Methods:

This was a prospective, randomized, double-blind controlled study on 94 patients listed for valvular heart surgery. The patients received either amiodarone, 3 mg/kg diluted in 100 ml of normal saline and started prior to making skin incision and administrated through venous line over a period of 30 minutes, or the same volume of normal saline infused in a similar fashion. The incidence of AF during the first 5 days after surgery was the main outcome measured.

Results:

There was significant difference in favor of the amiodarone group regarding restoration of sinus rhythm after aortic cross-clamp removal, number of patients requiring cardioversion, incidence of AF and the time elapsed before incidence of it postoperatively (P values=0.02, 0.04, 0.02, 0.02, respectively). There was no difference in hospital mortality, major postoperative morbidity, intensive care unit (ICU) stay or hospital stay.

Conclusions:

Amiodarone prophylaxis in a single intraoperative dose was significantly effective in prevention of new-onset postoperative AF after valvular heart surgery. This amiodarone dose is well tolerated and not associated with postoperative complications.