Angiotensin-converting enzyme inhibitors as adjunctive therapy in patients with persistent atrial fibrillation

Objectives

The purpose of the current study was to assess the effect of angiotensin-converting enzyme inhibitor (ACEI) therapy in facilitating cardioversion from persistent atrial fibrillation (AF) and maintaining sinus rhythm.

Background

Pharmacologic therapy and electrical cardioversion for AF are often unsuccessful in maintaining long-term sinus rhythm.

Methods

The current study, a 1-year, prospective follow-up, comprised 47 patients with persistent AF undergoing electrical cardioversion. Patients receiving ACEI were compared with those receiving other medications. The study end point was the number of defibrillation attempts required for atrial defibrillation and the number of hospital admissions. A secondary end point was change in signal-averaged P-wave duration (SAPD) 1 year after successful electrical cardioversion.

Results

Of those admitted and requiring electrical defibrillation, the number of defibrillation attempts required for successful cardioversion was significantly less in the ACEI group (P < .001). The incidence rate ratio for admissions comparing recipients of ACEI with others was 0.14 (P = .03). Patients receiving ACEI therapy had significantly lower SAPD at 1 year when compared with the no-ACEI group (135 ms ± 3 vs 150 ms ± 2, P = .002).

Conclusions

The use of long-term ACEI therapy facilitated electrical defibrillation in patients with persistent AF. ACEI therapy also reduced SAPD, suggesting amelioration of the arrhythmogenic substrate. Furthermore, we confirmed that SAPD is prolonged in patients with persistent AF.     

An early phase of slow myocardial activation may be necessary in order to benefit from cardiac resynchronization therapy

Background

Not all patients with a QRS duration longer than 140 milliseconds respond to cardiac resynchronization therapy (CRT). The same QRS duration may correspond to different spatiotemporal patterns of myocardial activation that influence response to CRT.

Methods

Electrocardiographic ima'ging based on 80 chest wall electrodes was used to construct the spatiotemporal myocardial activation map in 46 consecutive patients before CRT. The cumulative percentage of myocardium activated was plotted against time expressed in terms of quintiles of the overall QRS duration. Changes in the left ventricular ejection fraction and end-diastolic diameter, maximum oxygen consumption per minute, brain natriuretic peptide level, and 6-minute walk distance after 6 months of CRT were compared across different patterns with 1-way analysis of variance.

Results

Data from 34 patients were available for analysis. Four spatiotemporal patterns of myocardial activation could be identified: triphasic (fast-slow-fast) (13), uniform (8), fast-slow (7), and slow-fast (6). The overall QRS duration was similar in the 4 groups (166 ± 19 vs 138 ± 21 vs 157 ± 26 vs 152 ± 37 milliseconds, P = not significant [NS]). The ejection fraction showed a trend of greater increases for the triphasic (6.5% ± 7.0%) and slow-fast (15.5% ± 6.4%) patterns than for the uniform (4.0% ± 13.3%) and fast-slow (8.0% ± 6.1%) patterns (P = NS). The end-diastolic diameter showed a trend of greater decreases for the triphasic (−3.7% ± 5.3%) and slow-fast (−7.0% ± 6.7%) patterns than for the uniform (0.8% ± 6.7%) and fast-slow (0.0% ± 4.6%) patterns (P = NS). The maximum oxygen consumption per minute showed a trend of greater increases for the triphasic (1.2 ± 4.2 mL/kg/min) and slow-fast (4.1 ± 2.7 mL/kg/min) patterns than for the uniform (0.1 ± 4.1 mL/kg/min) and fast-slow (1.0 ± 2.1 mL/kg/min) patterns (P = NS). The brain natriuretic peptide level decreased significantly more for the triphasic (−450 ± 1269) and slow-fast (−3121 ± 1512) patterns than for the uniform (762 ± 1036) and fast-slow (718 ± 2530) patterns (P = .0003). The 6-minute walk distance increased significantly more for the triphasic (29 ± 89) and slow-fast (40 ± 23) patterns than for the uniform (6 ± 87) and fast-slow (37 ± 45) patterns (P = .0003).

Conclusions

Different spatiotemporal patterns of myocardial activation exist among patients with broad QRS complex and may affect response to CRT. An early phase of slow myocardial activation (the triphasic fast-slow-fast and the slow-fast patterns) may be necessary for a patient to benefit from CRT.     

Short-term prevention of thromboembolic complications in patients with atrial fibrillation with aspirin plus clopidogrel: the Clopidogrel-Aspirin Atrial Fibrillation (CLAAF) pilot study

Background

We evaluated the short-term safety and efficacy of aspirin-plus-clopidogrel as antithrombotic therapy in nonvalvular atrial fibrillation (AF).

Methods and results

Thirty patients (11 women, 45 to 75 years of age) with non-high-risk permanent (n = 12) or persistent AF awaiting cardioversion (n = 18) underwent transesophageal echocardiography to exclude left heart thrombi and were then randomly assigned to receive warfarin (international normalized ratio, 2 to 3 for 3 weeks) or aspirin (100 mg/d alone for 1 week)-plus-clopidogrel (75 mg/d added to aspirin for 3 weeks). Bleeding time and serum thromboxane B2 were measured at entry and at 3 weeks. Bleeding time, not affected by warfarin, was prolonged by 71% by aspirin (P < .05) and further, by 144%, by adding clopidogrel (P < .01 vs aspirin alone; +319%, P < .01, vs baseline). Thromboxane B2, not affected by warfarin, was reduced by aspirin (−98%, P < .01) but not further by clopidogrel. No thrombi or dense spontaneous echo-contrast were found at the 3-week transesophageal echocardiography. Seven of 9 patients receiving warfarin and 7 of 9 patients receiving aspirin-plus-clopidogrel, undergoing electrical cardioversion, achieved sinus rhythm. No thromboembolic or hemorrhagic events occurred in both arms throughout the 3-week treatment and a further 3-month follow-up.

Conclusions

Aspirin-plus-clopidogrel and warfarin were equally safe and effective in preventing thromboembolism in this small group of patients with non-high-risk AF.     

Fibrillation atriale, description de la prise en charge par les cardiologues, étude observationnelle. Résultats de l’étude Factuel

Objectives

To describe the management of patients with atrial fibrillation (AF) and to study consistency with guidelines on management of AF.

Patients and methods

Observational study on a random sample of cardiologists from a French national database. Each cardiologist had to recruit the first five patients meeting inclusion criteria (patients diagnosed with AF between January 2004 and one month before inclusion and accepting the collection of their medical data).

Results

Between December 2006 and January 2207, 1789 patients aged 71 on average have been recruited by 481 cardiologists. Fifty-one percent were diagnosed with paroxysmal, 15% with persistent and 33% with permanent AF. Restoration of sinus rhythm was preferred in forms considered as paroxysmal or persistent forms whereas control of the ventricular rate was more frequent in AF considered as permanent. Overall, therapeutic guidelines are applied in practice, despite a frequent use of amiodarone in patients with no associated heart disease. Prevention of thromboembolism was observed in 88% of the patients.

Conclusions

FACTUEL is the biggest observational study on AF ever conducted in France. The therapeutic strategies used by the cardiologists are consistent with the objectives of preventing thromboembolism and controlling heart rhythm and/or rate. In most cases, the treatment used is consistent with the therapeutic guidelines.     

Atrial Fibrillation: A Real-Life Observational Study in the Québec Population

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia and has been associated with heart failure, stroke, and mortality. The prevalence of AF is expected to rise with the aging population. Our objectives were to characterize the Québec AF patient population at the time of diagnosis of AF, quantify medical resource use prior to and after the initial diagnosis of AF, and determine overall survival.

Methods

A retrospective cohort study was undertaken using the Régie de l'Assurance Maladie du Québec databases to evaluate patients diagnosed with AF between January 1, 1998, and April 30, 2009.

Results

A total of 64,157 patients were included in our study population. At the time of diagnosis of AF, patients also suffered from several diseases, including heart failure (15.8%) and angina pectoris (15.1%). Compared with the year prior to AF diagnosis, in the year after AF diagnosis patients were more frequently hospitalized (1.5 vs 1.1 hospitalizations) and for longer periods (5.6 vs 3.3 days), and had more outpatient visits (12.9 vs 11.7). Survival rapidly decreased during the first 60 days (60-day mortality, 6.1%) and steadily declined thereafter, with mortality rates of 14.7% and 36.8% at 1 and 5 years, respectively.

Conclusion

At the time of diagnosis of AF, patients often suffer from several comorbidities. Diagnosis of AF is associated with an increase in medical resource use and higher mortality rates, particularly within the first 60 days.     

Coronary ischemic events after first atrial fibrillation: risk and survival

Purpose

We aimed to determine the long-term, gender-specific incidence and mortality risk of coronary ischemic events after first atrial fibrillation (AF).

Methods

In this longitudinal cohort study, adult residents of Olmsted County, Minnesota, with an electrocardiogram-confirmed AF first documented in 1980 to 2000 and without prior coronary heart disease, were followed to 2004. The primary outcome was first coronary events (angina with angiographic confirmation, unstable angina, nonfatal myocardial infarction, or coronary death). Sex-specific incidence of coronary ischemic events and survival after development of such events were assessed using Cox proportional hazards modeling. Kaplan-Meier estimates of risks for coronary ischemic events were compared with those predicted by the Framingham equation.

Results

Of the 2768 subjects (mean age 71 years, 48% were men), 463 (17%) had a first coronary event during a follow-up of 6.0 ± 5.2 years. The unadjusted incidence was 31 per 1000 person-years, and there was no difference between men and women. The incidence was higher in men (hazard ratio 1.32, P = .004) after adjusting for age. The 10-year event estimates were 22% and 19% in men and women, respectively, by our Kaplan-Meier analyses, and 21% and 11%, respectively, by Framingham risk equation. The mortality risk after coronary events was higher in women (hazard ratio 2.99 vs 2.33; P = .044), even after multiple adjustment.

Conclusions

First AF marks a high risk for new coronary ischemic events in both men and women. AF conferred additional risk for coronary events beyond conventional risk prediction in women only. The excess mortality risk associated with the development of coronary events was significantly greater in women.     

Circadian variation of arrhythmia onset patterns in patients with persistent atrial fibrillation

Background

The circadian onset patterns and cycle lengths of atrial tachyarrhythmias (AT) were determined in a group of patients with persistent atrial fibrillation.

Methods

Fifteen patients, mean age 63 ± 14 years and 80% male, were implanted with the Jewel AF atrial defibrillator (Medtronic, Minneapolis, Minn) for persistent atrial fibrillation only. Onset times of AT and median onset atrial cycle lengths were determined from device memory.

Results

Over a follow-up period of 23.3 ± 7 months, 227 episodes of persistent AT were treated by patient-activated atrial defibrillation. The peak onset of persistent AT was nocturnal, with 74% of episodes initiating between 8 pm and 8 am. Eighty-seven percent of the patients experienced an additional 403 paroxysmal AT episodes. These episodes showed a “double-peaked” pattern with the least number of episodes occurring between midnight and 8 am. The mean onset atrial cycle length of persistent AT was significantly shorter than the paroxysmal AT episodes (200 ± 37 ms vs 240 ± 39 ms, P < .005). The atrial cycle lengths at arrhythmia onset of both paroxysmal and persistent AT episodes also demonstrated circadian variation.

Conclusion

There is a circadian distribution of onsets for persistent AT with predominance at night. Patients with persistent AF have >1 type of atrial arrhythmia with differences in the onset patterns and atrial cycle lengths, suggesting different triggers and onset mechanisms.     

Atrial septal pacing to prevent atrial fibrillation in patients with sinus node dysfunction: results of a randomized controlled study

Background

In order to assess the preventive effects of right atrial septal pacing on atrial fibrillation (AF) in patients with sinus node dysfunction, we conducted a prospective randomized controlled study in patients requiring atrial pacing.

Methods

The inclusion criterion was the presence of a sinus node dysfunction with or without episodes of AF. Pacing sites were randomized to either the right atrial septum or appendage. Patients with permanent AF or with atrioventricular (AV) block without sinus node dysfunction were excluded. Patients were discharged at a pacing rate of 65 beats per minute after setting of the optimal AV delay. The antiarrhythmic therapy remained unchanged until the first recurrence of AF. Sequential analyses were performed with the triangular test.

Results

Mean baseline characteristics were not different between the septum (n = 57) and the appendage (n = 67) groups. The triangular test evidenced a lack of effect of septal pacing at the last sequential analysis. The rates of AF-free survival were not different between the septum and the appendage group (65% vs 64%, P = .28).In the subgroup of patients with at least 1 episode of AF 3 months before pacing, AF-free survival was increased by atrial septal pacing (70% vs 40%, P = .018). The mean follow-up was 16 ± 13 months (range, 1-54).

Conclusions

Atrial septal pacing does not have a preventive effect on the occurrence of AF in patient requiring atrial pacing for sinus node dysfunction. Subgroup analysis suggests that atrial septal pacing may benefit patients with ≥1 episode of AF in the 3 months preceding pacing.     

Right ventricular apical lead position is associated with prolonged signal-averaged P-wave duration

Aim

The study aimed to determine if right ventricular apical pacing is associated with adverse change in atrial substrate compared with right ventricular septal pacing.

Methods

Patients with septal leads and dual-chamber devices with more than 3 months of follow-up and 70% or higher cumulative percentage of ventricular pacing were compared with a matched group of apically implanted leads with a cumulative percentage ventricular pacing of 70% or higher. Device parameters were recorded, and high-resolution recordings were obtained for signal-averaged P-wave (SAPW) analysis. Previously obtained SAPW recordings taken from 49 healthy patients and 73 patients with paroxysmal atrial fibrillation were used as negative and positive controls, respectively.

Results

Ten patients with septal leads (mean age, 71.9 ± 12.1 years; mean months implanted, 10.5 ± 3.2 months) and 9 patients with apical leads (mean age, 71.9 ± 5.7 years; mean months implanted, 11.4 ± 6.4 months) were enrolled. The SAPW duration was longer in the apical cohort compared with the septal cohort (144.8 ± 6.9 and 133.0 ± 5.5 milliseconds, respectively; P = .001), whereas there was no significant difference between septal and normal cohorts (133.0 ± 5.5 and 129.3 ± 7.1 milliseconds, respectively; P = .08).

Conclusions

Apical pacing is associated with prolonged P-wave duration relative to septal pacing and controls: this may manifest as increased risk of atrial tachycardias and presents a potentially novel benefit of septal pacing.     

Spatial characteristics of atrial fibrillation electrocardiograms

Background

The present study investigates spatial properties of atrial fibrillation (AF) by analyzing vectorcardiogram loops synthesized from 12-lead electrocardiograms (ECGs).

Methods

After atrial signal extraction, spatial properties are characterized through analysis of successive, fixed-length signal segments and expressed in loop orientation, that is, azimuth and elevation, as well as in loop morphology, that is, planarity and planar geometry. It is hypothesized that more organized AF, expressed by a lower AF frequency, is associated with decreased variability in loop morphology. Atrial fibrillation frequency is determined using spectral analysis.

Results

Twenty-six patients with chronic AF were analyzed using 60-second ECG recordings. Loop orientation was similar when determined from either entire 60- or 1-second segments. For 1-second segments, the correlation between AF frequency and the parameters planarity and planar geometry were 0.608 (P < .001) and 0.543 (P < .005), respectively.

Conclusions

Quantification of AF organization based on AF frequency and spatial characteristics from the ECG is possible. The results suggested a relatively weak coupling between loop morphology and AF frequency when determined from the surface ECG.     

Impact of new criteria for anticoagulant treatment in atrial fibrillation

Introduction and objectives

The guidelines for the management of atrial fibrillation (AF) incorporate new risk factors for thromboembolism, trying to de-emphasize the use of the ‘low’, ‘moderate’, and ‘high’ risk categories. The objective of this study was to determine the impact of the new scheme CHA₂DS₂-VASc and of the new recommendations for oral anticoagulation (OAC) in a contemporary sample of patients with AF seen by primary physicians and cardiologists.

Methods

Multicenter, observational, cross-sectional study on the epidemiology of hypertension and its control, designed by the arterial hypertension department. Each researcher enrolled the first 6 consenting patients who came for examination during a 5-day period.

Results

Of 25 137 individuals recruited, 1544 were diagnosed with AF. The vast majority of the sample had a CHADS₂ score ≥2 (77.3%). Individuals with a risk score lower than 2 were categorized according to the CHA₂DS₂-VASc score: 14.4% were aged 75 years or older (CHA₂DS₂-VASc = 2). Of those younger than 75, 42.3% had a CHA₂DS₂-VASc = 2; 23.7% CHA₂DS₂-VASc = 3, and 1.1% CHA₂DS₂-VASc = 4. This means that the 85.1% of the patients with a CHADS₂ score <2 and no contraindications are indicated for OAC.

Conclusions

The new recommendations will result in a significant increase in patients with indications for OAC, at the expense of those previously characterized as low-to-moderate risk. Therefore, patients at risk of thromboembolic events must be identified, although an evaluation of bleeding risk should be part of the patient assessment before starting anticoagulation.Full English text available from: www.revespcardiol.org     

The prognostic value of the Tpeak-Tend interval in patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction

Introduction

The Tpeak-Tend interval (TpTe) has been linked to increased arrhythmic risk. TpTe was investigated before and after primary percutaneous coronary intervention (pPCI) in patients with ST-segment elevation myocardial infarction (STEMI).

Method

Patients with first-time STEMI treated with pPCI were included (n = 101; mean age 62 years; range 39-89 years; 74% men). Digital electrocardiograms were taken pre- and post-PCI, respectively. Tpeak-Tend interval was measured in leads with limited ST-segment deviation. The primary end point was all-cause mortality during 22 ± 7 months (mean ± SD) of follow-up.

Results

Pre- and post-PCI TpTe were 104 milliseconds [98-109 milliseconds] and 106 milliseconds [99-112 milliseconds], respectively (mean [95% confidence interval], P = .59). A prolonged pre-PCI TpTe was associated with increased mortality (hazard ratio, 10.5 [1.7-20.4] for a cutoff value of 100 milliseconds). Uncorrected QT and heart rate-corrected QT intervals (Fridericia-corrected QT) were prolonged after PCI (QT: 401 vs 410 milliseconds, P = .022, and Fridericia-corrected QT: 430 vs 448 milliseconds, P < .0001).

Conclusion

In patients with STEMI undergoing pPCI, pre-PCI TpTe predicted subsequent all-cause mortality, and the QT interval was increased after the procedure.     

Left ventricular lead position and nonspecific conduction delay are predictors of mortality in patients during cardiac resynchronization therapy

Background

Cardiac resynchronization therapy (CRT) is an established treatment of severe systolic heart failure with intraventricular conduction delay. The influence on mortality of the left ventricular (LV) pacing site and the type of bundle-branch block during CRT is unclear.

Objectives

This study investigates the clinical significance of LV lead position, as well as nonspecific conduction delay, in CRT.

Methods

143 consecutive patients (mean age, 63.9 ± 8.9 years; 121 men) underwent implantation of a CRT device according to established criteria. At the time of implantation, the LV lead position and the type of bundle-branch block were recorded. The etiology of the heart failure was ischemic in 49 patients (34.3%) and nonischemic in 94 patients (65.7%).

Results

After a median follow-up of 19 months, 39 patients (27.3%) died, most of them (72%) of cardiovascular causes. The mortality was significantly higher in patients with an anterior or anterolateral LV lead position (P = 0.03). Multivariate analysis suggests that an anterior or anterolateral LV lead position, a nonspecific conduction delay, male sex, and a New York Heart Association functional class worse than III, are all independent predictors of mortality during the follow-up period.

Conclusion

LV lead position and nonspecific conduction delay are predictors of mortality in patients during cardiac resynchronization therapy.     

Do baseline atrial electrocardiographic and infarction patterns predict new-onset atrial fibrillation after ST-elevation myocardial infarction? Insights from the Assessment of Pexelizumab in Acute Myocardial Infarction Trial

Background

Atrial infarction reportedly occurs in 0.7% to 52% of ST-elevation myocardial infarctions (STEMIs), up to two thirds of whom develop atrial fibrillation and flutter (AF). Prospective validation of electrocardiographic atrial infarction patterns is lacking. Hence, in STEMI patients treated with primary percutaneous coronary intervention, we examined whether baseline atrial electrocardiographic changes or atrial infarction patterns predicted new AF or mortality.

Methods

Within the Assessment of Pexelizumab in Acute Myocardial Infarction trial, a nested case-control study was conducted. Patients with new AF were matched 1:1 with controls, and baseline atrial electrocardiographic variables were examined.

Results

Abnormal P wave morphology (Liu minor criterion for atrial infarction) was significantly associated with new AF (adjusted odds ratio, 1.68; 1.03-2.73). This was also independently associated with 90-day mortality in the overall case-control cohort (adjusted hazard rate, 1.90; 1.04-3.46) and among patient with new-onset AF (adjusted hazard rate, 2.43; 1.22-4.84).

Conclusions

Abnormal P wave morphology significantly predicted new AF and 90-day mortality in STEMI patients.     

Monosensitization and polysensitization in allergic rhinitis

Background

Polysensitization is common in patients with allergic rhinitis (AR) and may affect clinical feature. However, there are patients who remain monosensitized.

Objective

This cross-sectional study aimed at evaluating a large cohort of AR patients to define the percentage and the features of mono- and poly-sensitized subjects.

Methods

This observational cross-sectional study included a large group of AR patients: 2415 subjects (1958 males, mean age 24.6 ± 5 years) were consecutively evaluated. Symptom severity, type and number of sensitizations, and AR duration were considered.

Results

621 patients (25.7%) were monosensitized: 377 to Parietaria, 194 to house dust mites, 19 to birch, 17 to grasses, 12 to molds, 2 to olive, and 1 to cypress. There was no difference between mono- and polysensitized patients concerning the duration of rhinitis (6 ± 2.14 years vs 6 ± 3.7).Severity of symptoms was higher in polysensitized patients than in monosensitized (p < 0.05); in addition, there was a difference among monosensitized patients: Parietaria-allergy induces the most severe symptoms.

Conclusion

This study conducted in a large AR population might suggest that monosensitized and polysensitized AR patients could constitute two different categories. In addition, the specific type of allergy may condition the clinical feature.     

The decrease in QRS amplitude after aortic valve replacement in patients with aortic valve stenosis

Purpose

The purpose of this study was to evaluate the effect of aortic valve replacement on electrocardiogram (ECG) in patients with aortic valve stenosis.

Methods

Serial 12-lead ECGs were obtained in 15 patients with aortic valve stenosis who underwent aortic valve replacement. Three ECG indexes for left ventricular hypertrophy were manually measured in each ECG: Sokolow-Lyon index (sum of S wave in V₁ and R wave in V₅), Cornell voltage index (sum of R wave in aVL and S wave in V₃), and Gubner index (sum of R wave in I and S wave in III).

Results

After aortic valve replacement, Sokolow-Lyon index gradually decreased during 2 years (51.1 ± 17.9 to 34.8 ± 12.5 mm, P < .01). Cornell voltage index (25.6 ± 7.0 to 15.0 ± 4.8 mm, P < .01) and Gubner index (15.8 ± 7.6 to 10.3 ± 5.5 mm, P < .01) also gradually decreased during 2 years. ST depression in V₆ was found in 14 patients (93%) before aortic valve replacement. It resolved in 9 of 14 patients during 2 years.

Conclusions

Electrocardiographic evidence of left ventricular hypertrophy gradually resolved after aortic valve replacement in patients with aortic valve stenosis.     

Yield of stress single-photon emission computed tomography in asymptomatic patients with diabetes

Background

Patients with diabetes without clinically apparent coronary artery disease are at increased risk of cardiac death. The value of screening stress testing in these patients remains controversial. The goal of this study was to examine the yield of stress single-photon emission computed tomography (SPECT) in asymptomatic diabetic patients.

Methods

The results of stress SPECT in patients without prior myocardial infarction or coronary revascularization were compared in asymptomatic diabetics (n = 1738) versus symptomatic diabetic patients (n = 2998), asymptomatic nondiabetic patients (n = 6215), and symptomatic nondiabetic patients (n = 16,214).

Results

Abnormal scans were present in 58.6% of asymptomatic diabetic patients, approximately equal to the percentage in symptomatic diabetic (59.5%) (P = not significant) and higher than in asymptomatic nondiabetic (46.2%) (P < .001) and symptomatic nondiabetic (44.4%) (P < .001) patients. The breakdown of high-risk scans followed a similar pattern in the 4 patient subsets: asymptomatic diabetic, 19.7% versus symptomatic diabetic, 22.2% (P = .051); asymptomatic nondiabetic, 11.1% (P < .001); and symptomatic nondiabetic, 12.5% (P < .001). Patients with diabetes had more electrocardiographic and scan evidence for silent myocardial infarction versus those without diabetes.

Conclusions

Asymptomatic diabetic patients have a high prevalence of both abnormal and high-risk SPECT scans. The finding that approximately 1 in 5 of these individuals has a high-risk scan suggests a potentially more widespread application of screening stress SPECT in asymptomatic diabetic patients to identify those with severe coronary artery disease.     

Amiodarone versus sotalol for the treatment of atrial fibrillation after open heart surgery: the Reduction in Postoperative Cardiovascular Arrhythmic Events (REDUCE) trial

Objectives

This prospective, randomized, double-blind, placebo-controlled study compared the efficacy and safety of amiodarone and sotalol in the prevention of atrial fibrillation (AF) following open heart surgery.

Background

The incidence of supraventricular arrhythmias following open heart surgery ranges from 20% to 40%, with AF being the most common. Both amiodarone and sotalol have been shown to be effective in reducing postoperative arrhythmias, but no direct comparison of these agents has been conducted.

Methods

A total of 160 patients were randomized, of whom 134 underwent coronary artery bypass graft surgery (CABG) alone, 17 underwent CABG and concomitant aortic valve replacement surgery (AVR), 9 underwent AVR only, and 1 patient's surgery was canceled. Patients with signs or symptoms of congestive heart failure (CHF), ejection fraction ≤30%, estimated creatinine clearance <30 mL/min, or serum creatinine ≥2.5 mg/dL were excluded. Patients were randomized to receive either sotalol 80 mg 2 times per day (n = 76) or intravenous amiodarone 15 mg/kg over 24 hours followed by oral amiodarone 200 mg 3 times per day (n = 83). Study drug was started at the time of surgery and continued for 7 days or until discharge, whichever came first.

Results

AF occurred in 17% of patients randomized to amiodarone and 25% of the patients randomized to sotalol (P = .21). However, the duration of AF was significantly shorter in amiodarone-treated patients (169 ± 224 min) compared to sotalol treated patients (487 ± 505 min; P = .04). In a subgroup analysis, the incidence of AF in patients undergoing AVR or CABG with AVR was significantly less with amiodarone (1/15, 7%) compared to sotalol (9/11, 82%) (P < .001). Blood pressure was lower immediately after surgery with amiodarone but comparable to sotalol at 24 hours. Of the hemodynamic indices measured, only stroke volume was significantly lower in patients randomized to sotalol at 24 hours (P = .035).

Conclusions

Amiodarone and sotalol share similar efficacy and safety in reducing postoperative AF. Hemodynamic effects were similar between both drugs at 24 hours, with the exception that stroke volume was lower in sotalol-treated patients. In patients undergoing more complex surgery, postoperative AF occurred more frequently with sotalol than with amiodarone.     

Characterization of the electrocardiographic pattern of individuals with cerebral palsy

Background

Dentists of Lar São Francisco observed during dental treatment that children with cerebral palsy (CP) had increased heart rate (HR) and lower production of saliva. Despite the high prevalence of CP found in the literature (2.08-3.6/1000 individuals), little is known about the electrocardiographic (ECG) characteristics, especially HR, of individuals with CP.

Objective

This study aimed to investigate the hypothesis that individuals with CP have a higher HR and to define other ECG characteristics of this population.

Methods

Ninety children with CP underwent clinical examination and 12-lead rest ECG. Electrocardiographic data on rhythm, HR, PR interval, QRS duration, P/QRS/T axis, and QT, QTc and T_peak-end intervals (minimum, mean, maximum, and dispersion) were measured and analyzed then compared with data from a control group with 35 normal children. Fisher and Mann-Whitney U tests were used, respectively, to compare categorical and continuous data.

Results

Groups cerebral palsy and control did not significantly differ in age (9 ± 3 × 9 ± 4 years) and male gender (65% × 49%). Children with CP had a higher HR (104.0 ± 20.6 × 84.2 ± 13.3 beats per minute; P < .0001), shorter PR interval (128.8 ± 15.0 × 138.1 ± 15.1 milliseconds; P = .0018), shorter QRS duration (77.4 ± 8.6 × 82.0 ± 8.7 milliseconds; P = .0180), QRS axis (46.0° ± 26.3° × 59.7° ± 24.8°; P = .0024) and T-wave axis (34.3° ± 28.9° × 42.9° ± 17.1°; P = .034) more horizontally positioned, and greater mean QTc (418.1 ± 18.4 × 408.5 ± 19.4 milliseconds; P = .0110). All the electrocardiogram variables were within the reference range for the age group including those with significant differences.

Conclusion

Children with CP showed increased HR and other abnormal ECG findings in the setting of this investigation. Further studies are needed to explain our findings and to correlate the increased HR with situations such as dehydration, stress, and autonomic nervous disorders.     

Low prevalence of atrial fibrillation in community-dwelling Chinese aged 55 years or older in Singapore: a population-based study

Background

The prevalence of atrial fibrillation (AF) in Asian populations appears to be lower than that in Western populations according to limited data. We conducted a community study to (a) estimate the prevalence of AF in Chinese adults aged 55 years or older in Singapore and (b) examine associated risk factors.

Methods

We conducted a whole-survey area population screening of 1839 Chinese residents aged 55 years or older in the southeast region of Singapore with a single electrocardiographic recording. We performed structured interviews and anthropometric as well as clinical measurements, including blood pressure.

Results

The estimated overall AF prevalence was 1.5% (95% confidence interval = 1.1-2.2); specifically, the prevalence was higher in men (2.6%) than in women (0.6%) and increased sharply to 5.8% only in individuals aged 80 years or older. This latter rate is lower than age-standardized rates in Western populations by approximately half and consistent with similarly low prevalence rates reported for Korea and China. Of the 26 cases of AF in this study, only 10 were known cases; 3 of the 10 patients were receiving anticoagulant therapy, whereas the rest were receiving antiplatelet therapy. Atrial fibrillation was significantly associated in multivariate analyses with male sex (odds ratio [OR] = 4.10), heart failure (OR = 3.11), and stroke (OR = 3.60).

Conclusions

These data add support to the view that the prevalence of AF in Asian populations is lower than that in Western populations. The observations from these contrasting populations warrant attention in future studies.