Recovery of autonomic nervous activity after myocardial infarction demonstrated by short-term measurements of SDNN.

OBJECTIVE: Heart rate variability (HRV) has been demonstrated to be a risk factor after acute myocardial infarction (AMI). In the present study serial measurement of SDNN (standard deviation of the mean of qualified NN-interval) in short intervals was used to assess HRV changes after AMI, and determine the role of these as independent risk factors compared to clinical, arrhythmic, ischemic and anamnestic variables. Measurements from a normal healthy middle-aged male population were used as reference (n = 63). METHODS: SDNN from a five-minute period during day and night-time, respectively, was examined in 103 patients 1 week (n = 54), 1 month (n = 72) and 12-16 months (n = 54) after infarction. RESULTS: Day SDNN did not change during one-and-a-half years after AMI, and was significantly reduced compared with healthy males. Night SDNN, low after 1 week, with recovery 1 month after AMI, was significantly reduced compared with healthy males early, but not late after AMI. Thus, the study indicated during day-time a continuous abnormal sympathetic preponderance in the course of 16 months after AMI, and during night-time a gradual recovery of parasympathetic preponderance beginning early after AMI. CONCLUSION: One week after AMI day-time SDNN of <30 ms, and night-time SDNN of < 18 ms, age > or =60 years, and myocardial ischemia (Holter monitoring) were independent predictors of 9 years' mortality. One and 12-16 months after AMI reduced day and night-time SDNN had no prognostic implication.

ST-segment deviation during 24-hour ambulatory electrocardiographic monitoring and exercise stress test in healthy male subjects 51 to 75 years of age: the Copenhagen City Heart Study.

BACKGROUND: Although ST-segment deviation has been evaluated and used during many years both on continuous electrocardiographic Holter monitoring and during exercise stress testing, considerable controversy still remains concerning the prevalence and diagnostic significance of fortuitously discovered ST-segment deviation in asymptomatic healthy persons. METHODS AND RESULTS: The occurrence of ST-segment deviation was studied in a population of 63 clinically healthy male subjects 51 to 75 years of age, with the use of 24-hour Holter monitoring and exercise stress testing. The subjects were recruited from the Copenhagen City Heart Study and were without cardiovascular risk factors, chronic diseases, or medication and without cardiovascular events during 5 to 12 years before and 3 to 5 years after admission. The specificity, that is, the probability of displaying a negative test result in healthy subjects without disease, was 1.0 when using as criterion for significant ST-segment deviation a horizontal or descending ST-segment depression of >0.20 mV or ST-segment elevation >/=0.15 mV during Holter monitoring, and acceptable, for example, 0.95, when using as criterion a horizontal or descending ST-segment depression of >/=0.15 mV during Holter monitoring or at the exercise test, respectively. Furthermore, the specificity was 0.95 when a horizontal or downsloping ST-segment depression of 0.1 mV was displayed in both the Holter and exercise electrocardiographic recording system. CONCLUSIONS: Thus in asymptomatic persons, the usual criterion for significant ST-segment depression of 0.1 mV can be applied when occurring in both electrocardiographic recording systems. However, if one test alone is used, the criterion of significant ST-segment depression should be 0.15 mV. Absence of ST-segment deviation during Holter monitoring and exercise stress testing, indicated with a specificity of 1.0 or 0.95 according to choice of criterion, implies that the person is in a healthy state.

Prognostic implications of ventricular ectopy one week, one month, and sixteen months after an acute myocardial infarction. Danish Study Group on Verapamil in Myocardial Infarction.

BACKGROUND: Ventricular ectopy early after an acute myocardial infarction (AMI) has previously been demonstrated to predict mortality. Less information is available about the prognostic implications of ventricular ectopy occurring late after an AMI, and no information is available about the prognostic implication of the development of ventricular ectopy during the first year after an AMI. HYPOTHESIS: The purpose of the present prospectively conducted trial, a part of the Danish Verapamil Infarction Trial II (DAVIT II), was to evaluate the prognostic implication of (1) ventricular premature complexes (VPCs) recorded by 24-h Holter monitoring 1 week, 1 month, and 16 months after an AMI; and (2) development of > 10 VPCs/h or of any complex ventricular ectopy, that is, pairs, more than two types of VPCs, ventricular tachycardia, or > 10 VPCs/h during follow-up after an AMI. METHODS: Patients were monitored 1 week (n = 250), 1 month (n = 210), and 16 months (n = 201) after AMI. RESULTS: Multivariate analyses based on history, clinical findings, and ventricular ectopy showed the following results: After 1 week, > 10 VPCs/h (p = 0.0006) and heart failure (p < 0.007); after 1 month, > 10 VPCs/h (p = 0.003) and resting heart rate (p < 0.02); and after 16 months, ventricular tachycardia (p = 0.002) independently predicted long-term mortality. Mortality was significantly predicted by the development of > 10 VPCs/h from 1 week to 1 month (p = 0.003) and 16 months (p = 0.03), and from 1 to 16 months (p = 0.007) after AMI, as well as by the development of any complex ventricular ectopy from 1 week to 1 month (p = 0.02) and 16 months (p = 0.01), and from 1 to 16 months (p = 0.04) after AMI. CONCLUSION: The present study demonstrated that 1 week and 1 month after an AMI the quantity of VPCs, that is, > 10 VPCs/h, predicted mortality, whereas 16 months after an AMI the quality of VPCs, that is, ventricular tachycardia, predicted mortality.

Effect of verapamil on heart rate variability after an acute myocardial infarction. Danish Verapamil Infarction Trial II.

Because decreased heart rate variability measured after an acute myocardial infarction (AMI) has been demonstrated to predict subsequent mortality and sudden death, and an efficacy analysis of the Danish Verapamil Infarction Trial II (DAVIT II) demonstrated that long-term postinfarction treatment with verapamil significantly reduced sudden death, the aim of the present substudy was to evaluate the effect of verapamil on heart-rate variability in the time and frequency domain, measured in two 5-minute segments during the day and night. Thirty-eight patients were examined by Holter monitoring, at 1 week, that is, before randomization, and at 1 month after infarction; 22 of the patients were examined 12-16 months after infarction as well. In both treatment groups (verapamil and placebo) no significant alteration of heart rate variability during the day-time was demonstrated from before to after 1 and 12-16 months of treatment. In accord with the known reduction of overall heart rate by verapamil, a significant increase of mean NN interval from before to after 1 (P = 0.0004) and 12-16 months (P = 0.004) of treatment was seen in the verapamil, but not in the placebo, group at night. Parameters generally interpreted as an index of parasympathetic modulation, that is, RMSSD, pNN50, and high-frequency power, increased significantly at 1 month (P = 0.04, P = 0.03, NS, respectively) and 12-16 months (P = 0.03, P = 0.04, P < 0.05) after AMI in the verapamil, but not in the placebo, group. In conclusion, the present study indicates that verapamil shifts the autonomic balance to a vagal preponderance or sympathetic attenuation in the postinfarction period.

Effect of verapamil on the prognosis of patients with early postinfarction electrical or mechanical complications. The Danish Verapamil Infarction Trial II (DAVIT II).

The Danish Verapamil Infarction Trial II (DAVIT II) demonstrated from the second postinfarction week, that long term treatment with verapamil significantly improved reinfarction free survival after an acute myocardial infarction (AMI). The present post hoc analysis of DAVIT II was undertaken with the purpose of evaluating the effect of treatment with verapamil in patients with early electrical complications, i.e. ventricular or atrial fibrillation, ventricular tachycardia, or second or third degree atrioventricular block, with or without mechanical complication, i.e. heart failure, during the first post-AMI week. In the placebo group, the 18-month mortality rate was lowest (9.5%) in patients without electrical or mechanical complications, highest (24.6%) in patients with electrical events only, and in-between (17.5%) in patients with mechanical problems regardless of presence of electrical complications. Verapamil significantly reduced the 18-month mortality rate in patients with early electrical without mechanical complications (60% reduction, P = 0.02), and in patients without mechanical complications (35% reduction, P = 0.02). Verapamil did not change the mortality rate in patients with mechanical complications.

Short- and long-term prognostic implications of in-hospital postinfarction arrhythmias. DAVIT II Study Group.

The purpose of the present study was to evaluate, in patients surviving the first postinfarction week, the short- and long-term prognostic implications of arrhythmias, and their relation to easily obtained anamnestic and clinical parameters presented during hospitalisation. The study consisted of 897 placebo-treated patients of the Danish Verapamil Infarction Trial II (DAVIT II). In patients with and without supraventricular tachycardia mortality within 2 months was 9.2 and 3.7% (p = 0.004), respectively. By multivariate analysis supraventricular tachycardia independently predicted mortality within 2 months. Mortality within 5 years was predicted by the presence of supraventricular tachycardia, atrial fibrillation, advanced atrioventricular block, sinoatrial block, and of the combined arrhythmic parameter, i.e. ventricular and/or atrial fibrillation and/or advanced atrioventricular block. When easily obtained and assessed anamnestic and clinical parameters were included in a multivariate analysis, the presence of supraventricular tachycardia alone gave independent prognostic information on long-term mortality.

Effect of verapamil on arrhythmias and heart rate during 16 months following an acute myocardial infarction. The Danish Study Group on Verapamil in Myocardial Infarction.

The present study was a prospectively planned subset of the postinfarction, double blind, randomized, multicenter, placebo controlled trial of verapamil, DAVIT II. Patients had 24 hours of Holter monitoring before randomization, i.e., second week after infarction (placebo, n = 122; verapamil, n = 128), after 1 month (placebo, n = 108; verapamil, n = 94) and after 16 months (placebo, n = 75; verapamil, n = 63) of treatment. The purpose was to evaluate the effect of verapamil on the prevalence and changes over time of arrhythmias and heart rate. In patients monitored twice, a significant increase of average ventricular premature complexes (VPC) per hour from before to 1 month (p = 0.0007) and 16 months (p = 0.02) after was demonstrated in the placebo group, and from before to 1 months (p = 0.01) after in the verapamil group. Average VPC/hr did not change from 1 to 16 months of treatment. A significant increment of > 10 VPC/hr was found after 1 (p = 0.03) and 16 months (p = 0.05) compared to prerandomization in the placebo, but not in the verapamil group. A significant increase of supraventricular arrhythmias after 1 month compared with prerandomization was found in the placebo group (p = 0.003) but not in the verapamil group. The prevalence of VPC and supraventricular tachycardia was significantly lower in the verapamil compared with the placebo group after 1 month of treatment. At 16 months no significant difference was found between the two groups. The 24 hour mean heart rate was significantly lower, 3 beats/min, in the verapamil compared with placebo after 1 and 16 months of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

The prevalence of myocardial ischemia six months after thrombolytic treatment of acute coronary episodes. A subset of a placebo controlled, randomised trial, the ASSET Study.

The purpose of this prospectively conducted study was to determine the prevalence of transient myocardial ischemia, evaluated from 24 h continuous ECG monitoring and exercise test, 6 months after inclusion in the Anglo Scandinavian Study of Early Thrombolysis (the ASSET trial, a randomised, placebo controlled study of alteplase for survival in patients with suspected acute myocardial infarction (AMI)), and to relate these findings to development of cardiac events. Of the 58 consecutively studied patients ischemic responses were found in 13 (45%) of 29 patients initially treated with placebo, and in 21 (72%) of 29 alteplase treated patients (P = 0.03). After another 6 months, i.e. 12 months after the acute event, two patients were dead, two had non-fatal reinfarctions and three had coronary artery by-pass surgery in the group with ischemic response; no events were recorded in patients without ischemia (P < 0.05). Alteplase treated patients more often had late myocardial ischemia, and cardiac events were found in patients with ischemia. Since the ASSET trial has demonstrated significantly higher short- and long-term survival rate in the alteplase treated group, it was indicated (1) that alteplase treated patients were better positioned for sustaining subsequent ischemia and thus cardiac events due to preservation of viable myocardial tissue, and (2) that late ischemia in the setting of initial alteplase treatment may convey other information than ischemia occurring in placebo treated patients.

Ventricular arrhythmias in patients recovering from myocardial infarction: do residual myocardial ischemia and anti-ischemic medical intervention influence the one-month prevalence? The Danish Study Group on Verapamil in Myocardial Infarction.

The relationship between myocardial ischemia revealed by exercise testing and ventricular arrhythmias on Holter monitoring, and the effect of anti-ischemic intervention on the incidence of ventricular arrhythmias in patients with residual ischemia were studied in 125 patients recovering from myocardial infarction. Prior to discharge exercise testing and 24-h Holter monitoring were carried out. In patients with ST-segment depression (n = 34), ventricular arrhythmias on Holter monitoring were seen in 7 (21%) compared with 20 (22%) patients without ST-segment depression (NS). Patients were hereafter double-blindly randomized to intervention with verapamil (n = 63) or placebo (n = 62). One month after discharge, 24-h Holter monitoring was repeated. In the verapamil group ventricular arrhythmias increased from 25 to 33% (NS). In the placebo group the figures were 18 and 27%, respectively (NS). In patients with ST-segment depression and verapamil treatment, the prevalence increased from 25 to 38% (NS). In the placebo group the figures were 17 and 22%, respectively (NS). The differences between the groups were not significant. A significantly increased prevalence of ventricular arrhythmias was found in patients with either heart failure or non-Q-wave infarct. In these patients myocardial ischemia during exercise did not correlate with ventricular arrhythmias either. ST-segment depression during pre-discharge exercise testing correlated with neither the prevalence nor the incidence of ventricular arrhythmias, and anti-ischemic intervention with verapamil did not influence the incidence of ventricular arrhythmias in both patients with and without myocardial ischemia.

The significance of myocardial ischaemia and verapamil treatment on the prevalence of supraventricular tachyarrhythmias in patients recovering from acute myocardial infarction. Danish Study Group on Verapamil in Myocardial Infarction.

Twenty-four hour Holter monitoring and symptom-limited exercise testing were carried out prior to discharge in 157 patients recovering from acute myocardial infarction. Supraventricular arrhythmias (SVT) during Holter monitoring were recorded in 15%, and ST segment depression during exercise in 27%. No association between exercise-provoked ischaemia and SVT was found in the late hospital phase of myocardial infarction. After the tests, patients were double-blindly randomized to treatment with verapamil 120 mg t.i.d. or placebo. One month after randomization 24 h Holter monitoring was repeated in 125 patients (verapamil = 63, placebo = 62). At one month a significantly increased incidence of SVT was found in the placebo group (25%) compared to the verapamil-treated patients (9%) (P = 0.04). The increased prevalence in the placebo group was mainly due to an increased incidence of SVT in patients with exercise-induced ischaemia (P = 0.03). This increment was blurred in the verapamil group. In conclusion, the prevalence of SVT increases during the first month after myocardial infarction. The increase is most pronounced in patients with residual myocardial ischaemia and seemed to be prevented by treatment with verapamil.

Prevalence of transient myocardial ischaemia during the first year after a myocardial infarction. Effect of treatment with verapamil. The Danish Study Group on Verapamil in Myocardial Infarction.

DAVIT-II is a double-blind, randomized, multicentre, placebo-controlled study of long-term treatment with verapamil 360 mg per day administered to patients who have suffered an acute myocardial infarction (AMI). In the present study, comprising a subset of DAVIT-II, 48 h continuous ECG recordings demonstrated transient ST segment deviation indicative of myocardial ischaemia after one week, prior to randomization, in 18% (10 of 57) of the patients. After one month, 24% (11 of 46) of the placebo and 8% (3 of 39) of the verapamil-treated patients (P = 0.04) had myocardial ischaemia; after one year the figures were 26% (9 of 35) and 4% (1 of 27) (P = 0.02), respectively. At 18 months the 'major' event rate in patients who had had ischaemia before randomization was 40% and 23.8% in patients without ischaemia (P = 0.057). In the placebo group, 63% of 91 episodes of ST depression were recorded between 0600 h and 1800 h, and 62% of 26 episodes of ST elevation between 1800 h and 0600 h (P less than 0.001). Nine episodes of ST depression and no episode of ST elevation were recorded in the verapamil-treated patients. In conclusion, 20-25% of post-AMI patients have transient ischaemia; verapamil prevents ischaemia, and a pronounced circadian variation of ST segment deviations can be demonstrated.

Effect of verapamil on ischemia and ventricular arrhythmias after an acute myocardial infarction: prognostic implications. The Danish Verapamil Infarction Trial II Study Group.

This article is a review of presented subsets of the Danish Verapamil Infarction Trial II (DAVIT II) regarding the effect of verapamil on postinfarction ischemia, ventricular arrhythmias, and heart rate (HR), and the prognostic implications of these findings. Patients underwent Holter monitoring for 24-48 h at 1 week, i.e., before randomization to long-term treatment with placebo or verapamil, and after 1 month and about 1 year of study treatment. Ischemia: 18% of the patients had transient ST-segment deviation before randomization; 24% of the placebo- and 8% of the verapamil-treated patients (p = 0.04) showed ischemia after 1 month; and after 1 year, the figures were 26 and 4%, respectively (p = 0.02). The 18-month major event rate, i.e., first reinfarction or death, in patients with ischemia before randomization were 40 and 23.8% in patients without ischemia (p = 0.06). Arrhythmias: In the placebo group the prevalence and incidence of many ventricular ectopic beats (VEBs), i.e., more than 10 VEBs/h, increased significantly during the first years after infarction; this was not the case in the verapamil patients group. The mean HR was significantly reduced by verapamil treatment after 1 month and after 16 months of treatment. Multivariate analysis demonstrated the presence of more than 10 VEBs/h only early (i.e., 1 week) but not late (i.e., 1 month) after infarction, to be an independent predictor of major events during 18 months' follow-up observation. A HR above 80 beats/min independently predicted major events when appearing both early and late after infarction.(ABSTRACT TRUNCATED AT 250 WORDS)