Supraventricular Premature Beats Research Articles

Long-Term Follow Up of Secundum Atrial Septal Defect Closure with the Amplatzer Septal Occluder

During the past 15 years, closure of a secundum atrial septal defect (ASD) has moved from a surgical to a percutaneous transcatheter approach. Few long-term studies of the efficacy and safety of closure of an ASD by an Amplatzer septal occluder (ASO) exist. To examine the long-term results of secundum ASD closure using the ASO, data on 94 patients who underwent secundum ASD closure with the ASO between 1998 and 2002 were available and reviewed. Data regarding residual shunt, chest pain, palpitations, arrhythmias, headaches, transient ischemic attacks, cerebrovascular accidents, and mortality were collected. Seven (7.4%) subjects had residual shunts immediately following ASO placement. During follow-up, 4 residual shunts closed for a complete closure rate of 97%. Eighteen (19%) patients reported chest pain during the follow-up period. Twenty-three patients (24%) reported palpitations during the follow up period, 7 were documented arrhythmias, including supraventricular tachycardia, atrial fibrillation, and premature ventricular beats. Migraine headaches were new-onset in 4 patients. Migraine cessation occurred in 2 patients after secundum ASD closure. One child died from a cerebral vascular event 18 months following device placement. Only 1 patient developed mild aortic insufficiency. These data indicate that for up to 120 months of patient follow-up, the ASO continues to be a safe device. Residual shunts and arrhythmias have low incidence post-ASO placement. Given the mortality in one high-risk patient, further investigation into anti-platelet therapy after device placement is warranted.

QT dynamicity, microvolt T-wave alternans, and heart rate variability during 24-hour ambulatory electrocardiogram monitoring in the healthy newborn of first to fourth day of life

Background Twenty-four hour ambulatory electrocardiogram (AECG) monitoring is an established technique for integrated assessment of heart rhythm; however, comprehensive description of serial changes in cardiac electrophysiology over the first days of life in humans is lacking. The aim of this study was to determine the patterns of circadian heart rhythm based on AECG evaluation in newborns. Methods Twenty healthy newborns (14 boys and 6 girls) were serially examined with AECG at days 1, 2, and 4 after birth. Heart rate (HR), arrhythmias, QT dynamicity, microvolt T-wave alternans, and various indices of HR variability (HRV) including deceleration/acceleration capacity analysis were analyzed. Results There were no sex differences in HR. Supraventricular premature beats were noted in 35%, ventricular—in 15 % of newborns. Slope QT/RR was 0.35 (0.3-0.5); intercept QT/RR was 124 (93-148), QT/RR correlation coefficient ( r) was 0.63 (0.53-0.85). Peak value of T-wave alternans was 32 ± 8 (12-55) μV. Low level of HRV was typical for all parameters of time-domain analysis compared with normal limits for older children. The overall mean values of deceleration/acceleration capacity were 3.38 ± 0.57 (2.16-4.13) and −3.58 ± 0.67 (−2.13 to −4.38) milliseconds, respectively. Conclusion The healthy newborns exhibit peculiarities of 24-hour cardiac rhythm with isolated premature beats, pauses of sinus rhythm less 1000 milliseconds, steep slope of QT/RR by analysis of QT dynamicity. There are low HRV, and symmetrical AC/DC capacity was typically for autonomic regulation of HR, probably due to high sympathetic activity at this age.

Solification with Hydrobromic Acid as a Factor Defining the Antiarrhythmic Effect of Lappaconitine Derivatives

Abstract: Alkaloid lappaconitine (I) and its derivatives – N(20)-deethyllappaconitine (II) and 5'-bromolappaconitine (III) in the base form and as salts - hydrochloride (I•HCl), hydrobromide (preparation allapinine) (I•HBr), hydrobromide (II•HBr), hydrobromide (III•HBr), succinate (I•Su) were taken for research of pharmacology activity. Moreover, phar-macology activity was investigated for a clathrates of lappaconitine – the bases, hydrochloride and hydrobromide with glycyrrhizic acid (IV) (I-IV; I•HCl-IV; I•HBr-IV). It is shown that, neither the base nor the salts, with the exception for hydrobromide, possess antiarrhythmic action on any of the models. Among glycyrrhizic acid clathrates, only the clathrate with hydrobromide of lappaconitine (I•H r-IV) has a high activity on the two models of arrhythmia. Keywords : Antiarrhythmic agent, Lappaconitine compounds, Clathrate. INTRODUCTION The diterpenic alkaloid lappaconitine (I) in the form of hydrobromide (the allapinine preparation [1]) has been rec-ognized as a domestic antiarrhythmic drug. Allapinine is recommended at supraventricular and ventricular premature beats, paroxysms, blinking and trembling of auricles, parox-ysmal supraventricular and ventricular tachycardia, arrhyth-mias on the background of a heart attack of a myocardium [2]. In the literature there are no data about influence of structural changes of the lappaconitine molecule on antiar-rhythmic activity [3], besides the role of salt-forming acid components has not been discussed. For research the base I and the water dissolved com-pounds - I•HCl, I•HBr, succinate I•Su were selected. Moreover, pharmacological activity was checked for clath-rates of lappaconitine – the bases, hydrochloride and hydro-bromide with glycyrrhizic acid. The previous researches have shown that molecular structure of clathrate has a ratio I: IV = 1:4 Fig. (

Palpitationen beim Leistungssportler

Cardiovascular screening tests to prevent sudden cardiac death in athletes are discussed controversially, but they should include diligent patient history and physical examination as well as registration of an ECG. If palpitations or tachycardias are described or if preexcitation, supraventricular or ventricular arrhythmias are documented, further risk stratification is mandatory. Specifically the origin and the complexity of the arrhythmia need to be analyzed and any form of structural cardiac pathologies has to be ruled out. Sinus tachycardia, supraventricular and ventricular premature beats, atrial fibrillation as well as supraventricular and ventricular tachycardia may serve as substrate for palpitations. Each of these arrhythmias is associated with a different amount of cardiac risk and can be evidence for certain forms of structural cardiac disease. Recommendations to limit physical activity and specific treatment options depend on the type of the arrhythmia and the presence and the nature of underlying cardiac disease.

Mechanical cardiac remodeling and new-onset atrial fibrillation in long-term follow-up of subjects with chronic Chagas' disease

Atrial fibrillation (AF) affects subjects with Chagas' disease and is an indicator of poor prognosis. We investigated clinical, echocardiographic and electrocardiographic variables of Chagas' disease in a long-term longitudinal study as predictors of a new-onset AF episode lasting >24 h, nonfatal embolic stroke and cardiac death. Fifty adult outpatients (34 to 74 years old, 62% females) staged according to the Los Andes classification were enrolled. During a follow-up of (mean +/- SD) 84.2 +/- 39.0 months, 9 subjects developed AF (incidence: 3.3 +/- 1.0%/year), 5 had nonfatal stroke (incidence: 1.3 +/- 1.0%/year), and nine died (mortality rate: 2.3 +/- 0.8%/year). The progression rate of left ventricular mass and left ventricular ejection fraction was significantly greater in subjects who experienced AF (16.4 +/- 20.0 g/year and -8.6 +/- 7.6%/year, respectively) than in those who did not (8.2 +/- 8.4 g/year; P = 0.03, and -3.0 +/- 2.5%/year; P = 0.04, respectively). In univariate analysis, left atrial diameter >/=3.2 cm (P = 0.002), pulmonary arterial hypertension (P = 0.035), frequent premature supraventricular and ventricular contraction counts/24 h (P = 0.005 and P = 0.007, respectively), ventricular couplets/24 h (P = 0.002), and ventricular tachycardia (P = 0.004) were long-term predictors of AF. P-wave signal-averaged ECG revealed a limited long-term predictive value for AF. In chronic Chagas' disease, large left atrial diameter, pulmonary arterial hypertension, frequent supraventricular and ventricular premature beats, and ventricular tachycardia are long-term predictors of AF. The rate of left ventricular mass enlargement and systolic function deterioration impact AF incidence in this population.

Frequency and Outcome of Arrhythmias Complicating Admission During Pregnancy: Experience From a High‐volume and Ethnically‐diverse Obstetric Service

Arrhythmias are reported during pregnancy, although hospitalization for these infrequent events is not fully characterized. The frequency and outcome of arrhythmias during pregnancy are unknown. Between 1992 and 2000, there were 136,422 pregnancy-related admissions to Parkland Memorial Hospital (Dallas, TX, USA). Using the discharge diagnosis data bank and the International Classification of Disease, 9th revision, Clinical Modification (ICD-9-CM) coding system, we identified 226 admissions (218 patients) where cardiac arrhythmias and intrauterine pregnancy were both reported. The most common rhythm disturbances during pregnancy were sinus tachycardia (ST), sinus bradycardia (SB), or sinus arrhythmia (SA) (104 episodes/100,000 pregnancies). This was followed by paroxysmal supraventricular tachycardia (PSVT) and premature beats, with a frequency of 24/100,000 and 33/100,000, respectively. Paroxysmal supraventricular tachycardia occurred most frequently in the third trimester or peripartum. All episodes terminated spontaneously or were safely terminated with medical therapy. Advanced heart block or lethal arrhythmias were exceedingly rare during pregnancy. Most frequently reported cardiac arrhythmias in pregnancy are benign and do not require intervention. Supraventricular tachycardia (SVT), being one of the most common complicated cardiac arrhythmias during pregnancy, can be treated effectively and safely with standard medical therapy. Ventricular arrhythmias or high-degree atrioventricular block (AVB) during pregnancy are extremely rare. Cardiac arrest is also rare, and is often caused by a different etiology from the conventional ones for sudden cardiac death.

8-OH-DPAT prevents cardiac arrhythmias and attenuates tachycardia during social stress in rats

The aim of this study was to apply a behavioural stress paradigm for studying the neural mechanisms underlying stress-induced arrhythmias, and to test whether such arrhythmias could be suppressed by systemic administration of 8-OH-DPAT, a 5-HT1A agonist possessing central sympatholytic properties. The study was conducted on adult male rats instrumented for telemetric recordings of ECG, body temperature and locomotor activity. In the first experiment, rats were subjected to social defeat after either 8-OH-DPAT (100 µg/kg s.c.) or vehicle injection. In the second experiment, prior to vehicle/8-OH-DPAT administration, animals were pre-treated with zatebradine, a blocker of the pacemaker current. 8-OH-DPAT caused prolongation of basal RR interval, increase in locomotion and hypothermia. Subjecting vehicle-treated animals to social defeat caused shortening in RR interval, increase in locomotor activity and hyperthermia, and provoked the occurrence of premature ventricular and supraventricular beats; all these effects were substantially attenuated by 8-OH-DPAT. Zatebradine caused prolongation of RR interval. In zatebradine/vehicle-treated rats, the incidence of ventricular and supraventricular premature beats during defeat increased 2.5-fold and 3.5-fold, respectively. 8-OH-DPAT administered after zatebradine significantly reduced these stress-induced arrhythmias. We conclude that: i) pharmacologically induced prolongation of RR interval may contribute to an increased susceptibility to stress-induced cardiac arrhythmias, possibly due to the prolongation of the ventricular diastolic period with restored excitability; and ii) systemic administration of 8-OH-DPAT abolishes these arrhythmic events, likely by suppressing stress-induced cardiac sympathetic outflow.

Increased frequency of pulmonary hypertension in psoriasis patients

Several reports have demonstrated an association between psoriasis and cardiovascular diseases such as hypertension, valvular disease and arrhythmia. However, the data is scarce. Forty-seven psoriasis patients and 20 healthy people underwent transthoracic echocardiographic examination including pulse- and tissue Doppler analysis and 24-h ambulatory electrocardiographic monitoring including heart rate variability (HRV) analysis. Patients having systemic hypertension, diabetes mellitus, history of structural or ischemic heart disease, chronic obstructive pulmonary disease and any associated systemic disease were excluded. Psoriasis Area and Severity Index (PASI) was calculated and severe psoriasis was defined in the case of history of hospitalizations for psoriasis and/or getting systemic therapy. Mean age of the patients was 35.7 +/- 12.9 years and disease duration was 123.2 +/- 84.3 (3-360) months. PASI ranged from 0.4 to 34.0 (mean +/- SD: 7.1 +/- 6.6) and 20 (42.6%) patients had severe psoriasis. There were no significant differences between psoriasis patients and control group with respect to mean values of blood pressure, body mass index, lipid profile and cardiac dimensions. However, frequency of being overweight was significantly higher in psoriasis patients (42.6 vs. 10.0%, P = 0.011). No patient had valvular disease. Mild pulmonary hypertension (PH) (30-40 mmHg) was significantly more frequent in psoriasis patients (31.9 vs. 0%, P = 0.003). Pulse wave mitral Doppler deceleration and isovolumetric relaxation times were significantly longer in psoriasis patients (195.9 +/- 29.7 vs. 191.6 +/- 14.7 ms, P = 0.002 and 91.6 +/- 14.7 vs. 79.6 +/- 10.5 ms, P = 0.001, respectively). However, frequency of diastolic dysfunction was not significantly different than the control group (8.5 vs. 0%, P = 0.309). HRV parameters and frequency of supraventricular and ventricular premature beats were not significantly different between the groups. No patient had ventricular tachycardia. Echocardiographic follow-up of psoriasis patients may be important due to possible association of PH. However, incidences of structural heart disease and arrythmia are not increased in psoriasis according to our results.

The prevalence of supraventricular arrhythmias with regard to the type and degree of left ventricular hypertrophy in patients with hypertensive heart disease

We investigated the correlation between the type and degree of left ventricular hypertrophy and the prevalence of supraventricular arrhythmias in patients with hypertensive heart disease. The study included 179 patients (79 men, 100 women, aged 43-80 years, median 68 years) with left ventricular hypertrophy. Patients were classified into three groups (concentric, eccentric and asymmetric types of hypertrophy) and into three subgroups (mild, moderate and severe hypertrophy). After discontinuation of all medication for 48 h, blood pressure was measured, electrocardiography and echocardiography performed and the prevalence of supraventricular arrhythmias assessed using Holter monitoring and bicycle ergometry. Antihypertensive drugs and duration of previous treatment were taken into consideration. Atrial fibrillation or paroxysmal supraventricular tachycardia were found in 43% of patients. The analysis showed no significant correlation between the prevalence of atrial fibrillation and/or paroxysmal supraventricular tachycardia and the degree (P = 0.607) and type of left ventricular hypertrophy (P = 0.455). However, the frequency of supraventricular premature beats was higher in the concentric and eccentric types than in the asymmetric type (P = 0.048) and increased with the degree of hypertrophy (significantly in men with the concentric type, P = 0.015). Concentric and eccentric types of left ventricular hypertrophy have a greater impact on the frequency of atrial arrhythmias. In the concentric type the prevalence of supraventricular premature beats correlates with the degree of left ventricular hypertrophy. Patients with moderate and severe concentric and eccentric left ventricular hypertrophy should be always tested using Holter monitoring and bicycle ergometry and treated with the maximum tolerable doses of antihypertensives, particularly with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers.

Complications due to Stress Echocardiography

Objective: to assess the prevalence of minor and major complications and side effects during stress echocardiography (stress-EchoCG) in a group of patients with suspected coronary heart disease (CHD). Subjects and methods: The study included 1359 patients with suspected CHD, who had undergone stress EchoCG; the latter using the following standard study protocols (dipyridamole/atropine (n=184), dobutamine/atropine (n=231); transesophageal atrial pacing (TEAP) (n=154), semirecumbent bicycle ergometry (BEM) (n=122)) was performed in 691 patients. Six hundred and sixty-eight patients underwent combined stress-EchoCG using the following study protocols: dipyridamole/TEAP (n=151), dobuta-mine/TEAP (n=243); dipyridamole/dobutamine (n=162), dipyridamole/pair BEM (n=112). The adverse reactions included ventricular and supraventricular premature beats, headache, nausea, and muscle shivering. The minor complications were short (less than 2 minutes) paroxysms of hemodynamically insignificant supraventricular and ventricular tachycardia. The major complications were the development of acute coronary syndrome and ventricular fibrillations. Results: The most common complications during stress EchoCG were rare ventricular premature beats (26.0 and 18.9% in the dobuta-mine and BEM protocols, respectively) headache (16.7% in the dipyridamole protocol). Major complications were noted in two (0.147%) cases. With the use of the standard dipyridamole protocol, one patient developed acute coronary syndrome with ST-segment elevation, which required emergency coronarography and angioplasty of the right coronary artery. When the standard dobutamine/atropine protocol, with 0.25 ml of 0.1% atropine solution being given during the administration of dobutamine at a rate of 40 ^g/kg/min, was used, another patient developed ventricular fibrillation requiring resuscitative measures. Conclusion: Stress EchoCG is generally a safe highly informative noninvasive technique for diagnosing CHD, but it may be attended by adverse reactions caused by stress agents, minor and major complications during testing, which require that patients compulsorily give their informed consent.

Trauma Associated With Cardiac Dysrhythmias: Results From a Large Matched Case-Control Study

Various cardiac dysrhythmias such as supraventricular and ventricular premature beats, supraventricular and ventricular paroxysmal tachycardia, atrial and ventricular fibrillation and atrial flutter have been reported in case series, as complications of blunt cardiac and thoracic trauma. The objective of this research was to determine whether thoracic or blunt cardiac injury is associated with cardiac dysrhythmia in a large multistate hospitalized population. Cases and matched (by age) controls were identified based on hospital discharge information that was collected from 986 acute general hospitals across 33 states in 2001. Both the exposure (thoracic trauma and blunt cardiac injury) and the outcome (cardiac dysrhythmias) were identified based on ICD-9-CM discharge diagnoses. Unadjusted and conditional adjusted (for gender, race, length of stay, and primary source of payment) multivariate logistic regression analyses were performed. After adjusting for potential confounders, patients 50 years and younger diagnosed with blunt cardiac injury had a fourfold (95% confidence interval, 1.40-11.60) increase in the risk of cardiac dysrhythmia. Independent of potential confounding factors, discharge for blunt cardiac injury among patients 51 to 70 years old was associated with a twofold (95% confidence interval, 1.36-3.82) increased risk for cardiac dysrhythmia. Blunt cardiac injury was found to be a significant risk factor for cardiac dysrhythmia. Longitudinal studies are needed to better establish the association between trauma and cardiac dysrhythmias.

Cardiac safety of formoterol 12 μg twice daily in patients with chronic obstructive pulmonary disease

Background: Some evidence suggests an increased risk of myocardial infarction and dysrhythmia events associated with β 2-agonist use in patients with chronic obstructive pulmonary disease (COPD). This prospective, multicenter, randomized, double-blind, placebo-controlled study compared the cardiac safety of formoterol and placebo in patients with COPD. Methods: After a 3–14-day run-in, 204 patients were randomized to receive formoterol 12 μg dry powder inhalation or matching placebo twice daily for 8 weeks. Twenty four-hour continuous electrocardiography (Holter monitoring) was performed at screening and after 2 and 8 weeks of treatment. Results: Only a small number of patients met the predefined criteria for a proarrhythmic event (4 formoterol and 2 placebo patients). No patients had sustained postbaseline ventricular tachycardia events, postbaseline run of ventricular ectopic beats associated with relevant symptoms (e.g. hypotension, syncope), or an episode of ventricular flutter or fibrillation. Holter monitoring data were variable but showed no clinically meaningful differences between the formoterol and placebo groups, respectively, for variables such as (mean±SD at end of treatment): heart rate (80±8.6 vs. 80±10.6 bpm), number and rate of ventricular premature beats (total 732±2685.4 vs. 650±2090.6; rate 35±131.0 vs. 30±101.3 per h), ventricular tachycardia events (total 0.4±1.70 vs. 1.0±9.23; rate 0.02±0.082 vs. 0.05±0.479 per h), and supraventricular premature beats (total 504±1844.1 vs. 823±2961.8; rate 22±80.6 vs. 37±129.6 per h). Vital signs and electrocardiogram data, including corrected QT intervals (Bazett and Fridericia), were similar across treatment groups. The overall adverse event experience was similar in the formoterol ( n=26 [27%]) and placebo ( n=33 [31%]) groups. The most common adverse events, infections and respiratory events, were expected for this patient population. The incidence of cardiac adverse events was low (1 formoterol and 4 placebo patients). Conclusions: The results of this study confirm the good cardiovascular safety profile of formoterol in patients with COPD.

Levothyroxine Replacement Therapy in Patients With Subclinical Hypothyroidism and Coronary Artery Disease

To assess the potential benefits and risks associated with levothyroxine (LT4) therapy in patients with subclinical hypothyroidism (SH) and concomitant coronary artery disease (CAD). We enrolled 33 patients (4 male and 29 female subjects) with SH and CAD in this study. The study cohort consisted of 2 groups: 19 patients who were randomly assigned to receive LT4 therapy, titrated to maintain a normal serum thyrotropin level (main group), and 14 patients who did not receive any LT4 replacement therapy (control group). Variables of the lipid profile and left ventricular diastolic function were measured and 24-hour electrocardiographic monitoring was performed before randomization and at 6-month follow-up. Medical therapy for the CAD remained unchanged throughout the 6-month study period. In the main group, no statistically significant differences were found in the lipids, variables of left ventricular diastolic function, and heart rate pattern between the hypothyroid and euthyroid states. Individual analysis revealed, however, that LT4 therapy was beneficial in terms of lipid abnormalities in those patients with lower body mass index, shorter history of CAD, and higher cholesterol levels at baseline. In the control group, we noted statistically significant prolongation of early filling deceleration time after 6 months, which indicated less flexibility of the left ventricular myocardium and diastolic myocardial dysfunction with long-term SH. In reference to adverse effects of LT4 therapy, 5 of the 19 patients had an increased rate of ventricular premature beats. These 5 patients were significantly older and initially had more supraventricular and ventricular premature beats than the rest of the main group. No ST depressions were recorded during LT4 therapy. In patients with SH and CAD, LT4 therapy can be beneficial in diminishing lipid abnormalities in those with lower body mass index, briefer duration of CAD, and higher levels of cholesterol at baseline. Patients in our study who experienced adverse effects of LT4 treatment were older and had more supraventricular premature beats at baseline in comparison with the other patients.

Effects of Ambient Particles and Carbon Monoxide on Supraventricular Arrhythmias in a Rat Model of Myocardial Infarction

The association between short-term increases in particulate air pollution and increased cardiovascular morbidity and mortality is well documented. Recent studies suggest an association between particulate matter with aerodynamic diameter < 2.5 μm (PM2.5) and supraventricular arrhythmias (SVA), but the results have been inconsistent. We evaluated this hypothesis in a rat model of acute myocardial infarction (AMI). Diazepam-sedated Sprague-Dawley rats with AMI were exposed (1 h) to either filtered air (n = 16), concentrated ambient fine particles (CAPS; mean = 645.7 μg/m3; n = 23), carbon monoxide (CO; 35 ppm; n = 19), or CAPs and CO (n = 24). Each exposure was immediately preceded and followed by a 1-h exposure to filtered air (baseline and postexposure periods, respectively). Surface electrocardiograms were recorded and the frequency of supraventricular premature beats was quantified. Among rats in the CAPS group, the probability of observing any SVA decreased from baseline to the exposure and postexposure periods. This patterm was significantly different than that observed for the filtered air group during the exposure period (p = .048) only. In the subset of rats with one or more SVA during the baseline period, the change in SVA rate from baseline to exposure period was significantly lower in the CAPS (p = .04) and CO (p = .007) groups only, as compared to the filtered air group. No significant effects were observed in the group simultaneously exposed to CAPS and CO. Thus, the results of this study do not support the hypothesis that exposure to ambient air pollution increases the risk or frequency of supraventricular arrhythmias.

The role of premature atrial contractions as the main triggers of postoperative atrial fibrillation

To better understand the pathogenesis of postoperative atrial fibrillation (AF), the mode of onset of AF after coronary artery bypass grafting was analyzed with respect to the autonomic balance, the heart rate (HR), and the presence of arrhythmias preceding the onset of sustained AF. Method Holter recordings of 24 hours, obtained from the first postoperative morning until clinically documented sustained AF, were analyzed in 29 untreated patients and in 13 patients treated with thoracic epidural anesthesia (TEA), who all developed AF after coronary artery bypass grafting. The presence of arrhythmias, the HR, and the autonomic balance, assessed by heart rate variability in the frequency domain, were analyzed at predefined time intervals within the 3-hour period before AF onset. Supraventricular premature beats (SPBs) and ventricular premature beats triggering the onset of AF were also evaluated. Result An SPB triggering the onset of AF can be identified in 21 (72.4%) of 29 untreated patients and in 12 (100%) of 12 TEA-treated patients in whom the recordings permitted such an analysis. The heart rate variability components analyzed during 5-minute periods for 30 minutes before AF onset did not differ significantly from those at corresponding times at the first postoperative day in either patient group. The HR during the 8 beats immediately before AF onset was lower in TEA-treated than in untreated patients. Conclusion The finding of an SPB at the onset of postoperative AF in most of the patients and irrespective of changes in HR supports the hypothesis that postoperative AF is primarily triggered by latent focal atrial activity. The autonomic tone did not seem to be of major importance in the population studied.

Der Umgang mit Herzrhythmusstörungen beim Kind

Premature supraventricular or ventricular beats are frequently seen in children of all age groups and are in most instances a benign condition. Intermittent and infrequent premature beats usually are not an indication for a cardiologic work-up. If ventricular or supraventricular premature beats are frequent and persist over a period of weeks or months, we usually recommend a cardiological evaluation. In those patients where ventricular or supraventricular tachycardias are found, the treatment is based on symptomatology, frequency of arrhythmias and impact on quality of life. In ventricular tachycardias, the presence of underlying cardiac disease is of prognostic importance and treatment more aggressive. Idiopathic ventricular tachycardia without structural heart disease usually shows a benign course and has a good prognosis.

Rocuronium attenuates oculocardiac reflex during squint surgery in children anesthetized with halothane and nitrous oxide

The oculocardiac reflex (OCR) may be activated during squint surgery. The aim of this study was to test whether rocuronium 0.4 mg kg(-1) could reduce the frequency of OCR, and also whether a single dose of succinylcholine 1 mg kg(-1) could affect the frequency of OCR during anesthesia with halothane in a nitrous oxide/oxygen mixture. A total of 161 ASA I children, 3-10 years old, undergoing elective surgery of the medial rectus muscle (MRM) were randomly assigned to three groups. Group R (n = 51), received 0.4 mg kg(-1) of rocuronium intravenously before endotracheal intubation. Group S (n = 58) received 1 mg kg(-1) of succinylcholine. Group C (controls, n = 52) received no relaxant. Oculocardiac reflex was defined as a reduction in heart rate (HR) > or = 15% and/or the appearance of any other arrhythmias, during manipulation of the MRM. Analysis of variance (anova), chi-squared, Kruskal-Wallis, and Student's t-tests were used for statistical analysis; P< 0.05 was considered statistically significant. In group R, OCR occurred in 15/51 (29%) of children, in group S in 31/58 (53%), and in group C in 23/52 (44%) (chi2 = 6.46, P = 0.049). In group R, the incidence of arrhythmias such as nodal rhythms, supraventricular and ventricular premature beats was 6%, compared with 22% in group S and 19% in group C (chi2 = 6.01, P = 0.040). However, there was no reduction in the occurrence of bradycardia (chi2 = 0.16, P = 0.924). Rocuronium reduced the frequency of OCR, mainly by reducing the incidence of supraventricular and ventricular premature beats.

ARRHYTHMOGENESIS IN HUMAN RESPONSE TO PARTICULATE AIR POLLUTANTS

ISEE-16 Introduction: Epidemiologic studies have shown that exposure to particulate matter (PM) increased arrhythmia-related mortality and morbidity. Patients with arrhythmia are also found to be more sensitive to the PM-mediated acute cardiac effects. Although these epidemiologic observations are supported by results of many animal studies, direct human data so far have only provided evidence supporting the contribution of arrhythmia to population susceptibility. Methods: We investigated whether particulate pollutants result in arrhythmogenesis in a short-term prospective study of 10 male boilermakers (age 34.3±8.1 years) with no overt cardiac diseases. They were exposed to high levels of metal particulates in their workplace. Episodes of extrasystoles within each 5-minute epoch were determined by validated algorithms across 24-hour Holter recordings. The PM2.5 (PM with aerodynamic diameter ≤2.5 um) levels were monitored concurrently using personal air samplers. Information on the time profile of daily activities was retrieved from detailed diary records. We used autoregressive logistic regression to model the probability of extrasystoles, and employed autoregressive Poisson regression to estimate the average counts of premature complexes. Supraventricular and ventricular extrasystoles were analyzed separately. Results: The cross-shift average PM2.5 level was 1.78 ± 1.25 mg/m3. Of all the recorded 5-min epochs, 7.6% (95% CI: 6.3, 9.1) had supraventricular extrasystoles and 23% (95% CI: 19, 28) had ventricular extrasystoles. Within each positive recording, the average number of extrasystoles was 1.6 (ranging from 1.3-1.9) per 5-min for supraventricular beats and 5 (ranging from 4.0 to 6.5) per 5-min for ventricular beats. We found a statistically significant association between exposures to PM2.5 and the increased extrasystole frequency. For each 1-mg/m3 increase in the preceding 4-hour average concentration of PM2.5, the associated OR was 1.82 (95% confidence interval [CI]: 1.52, 2.17) for having supraventricular extrasystoles, and the frequency of supraventricular premature beats increased by 72% (95% CI: 52, 94). For each 1-mg/m3 increase in the preceding 6-hour average concentration of PM2.5, the associated OR was 1.58 (95% CI: 1.18, 2.12) for having ventricular extrasystoles, and the frequency of ventricular premature beats increased by 21% (95% CI: 10, 32). After adjusting for circadian rhythm (morning, afternoon, evening, night), sleeping, smoking, alcohol use, coffee drinking, 5-min average heart rate, and personal coronary risk profiles, we observed a consistently positive association between PM2.5 and supraventricular extrasystoles. The adjusted analyses revealed a slightly stronger association between PM2.5 and the probability and frequency of ventricular premature complexes. Discussion: These results provide significant evidence indicating that high levels of metal particulates may induce extrasystoles in healthy working men without overt heart diseases.

Électrocardiogramme du sujet âgé

Electrocardiographic findings are very similar in healthy elderly subjects and middle age subjects. But in geriatric patients, 70 years of age or older, who have an abnormal ECG, it is difficult to define what results from the normal aging process and from an underlying disease, because ischemic and hypertensive heart diseases are so frequent at this age. Abnormalities frequently found on the resting electrocardiogram in the aged are first-degree atrioventricular block, left axis deviation, left anterior hemiblock, right bundle branch block and ST-T wave changes. Left ventricular hypertrophy, left bundle block branch and atrial fibrillation correlate strongly with heart disease. Twenty-four-hour ambulatory electrocardiography is much more sensitive than the resting ECG to identify arrhythmias, mainly isolated and unifocal supraventricular and ventricular premature beats most commonly asymptomatic in 80 to 100 % of subjects, to detect silent myocardial ischemia predictive of future coronary events and to assess heart rate variability which is reduced in the elderly.

Cardiovascular effects in patrol officers are associated with fine particulate matter from brake wear and engine emissions

BackgroundExposure to fine particulate matter air pollutants (PM2.5) affects heart rate variability parameters, and levels of serum proteins associated with inflammation, hemostasis and thrombosis. This study investigated sources potentially responsible for cardiovascular and hematological effects in highway patrol troopers.ResultsNine healthy young non-smoking male troopers working from 3 PM to midnight were studied on four consecutive days during their shift and the following night. Sources of in-vehicle PM2.5 were identified with variance-maximizing rotational principal factor analysis of PM2.5-components and associated pollutants. Two source models were calculated. Sources of in-vehicle PM2.5 identified were 1) crustal material, 2) wear of steel automotive components, 3) gasoline combustion, 4) speed-changing traffic with engine emissions and brake wear. In one model, sources 1 and 2 collapsed to a single source. Source factors scores were compared to cardiac and blood parameters measured ten and fifteen hours, respectively, after each shift. The "speed-change" factor was significantly associated with mean heart cycle length (MCL, +7% per standard deviation increase in the factor score), heart rate variability (+16%), supraventricular ectopic beats (+39%), % neutrophils (+7%), % lymphocytes (-10%), red blood cell volume MCV (+1%), von Willebrand Factor (+9%), blood urea nitrogen (+7%), and protein C (-11%). The "crustal" factor (but not the "collapsed" source) was associated with MCL (+3%) and serum uric acid concentrations (+5%). Controlling for potential confounders had little influence on the effect estimates.ConclusionPM2.5 originating from speed-changing traffic modulates the autonomic control of the heart rhythm, increases the frequency of premature supraventricular beats and elicits pro-inflammatory and pro-thrombotic responses in healthy young men.