Current incidence of postmyocardial infarction (Dressler''s) syndrome

This study examines the current incidence of postmyocardial infarction (Dressler's) syndrome. During 1980, 282 patients with documented myocardial infarction were admitted to our coronary care unit. Early postmyocardial infarction pericarditis was present in 18 patients (6.4%). Six of these patients received steroids and the remainder were treated with salicylates or other anti-inflammatory drugs. Anticoagulation was used in 149 patients (53%) during hospitalization. One hundred forty-four (51%) were receiving heparin and 133 (47%) received no anticoagulation. Information on the patient's status at 6 months was available in 229 patients who were discharged alive. Sixteen patients had died within 6 months after discharge and 4 patients were lost to follow-up study. There were no documented cases of Dressler's syndrome.

It is concluded that Dressler's syndrome has decreased in incidence and perhaps disappeared. This decrease is most likely related to decreased use of oral anticoagulants and to more aggressive treatment of postmyocardial infarction pericarditis.     

Arrhythmia surveillance by transtelephonic monitoring: comparison with Holter monitoring in symptomatic ambulatory patients.

We have evaluated a patient-actuated transtelephonic monitoring system (TTM) in order to determine its ability to document the cardiac rhythm at the time of symptoms; results have been compared to a simultaneously recorded 24-hour Holter Monitor (HM).Forty patients submitted an average of 15.6 TTM recordings/patient over a 7-day recording period. Twenty-six patients reported significant symptoms during the period of study: 11 had demonstrated arrhythmias, and these were documented by HM alone in one, by TTM alone in four, and by both HM and TTM in six.In 15 patients, no arrhythmia was seen during symptoms. HM alone was useful in excluding arrhythmia as a cause for the symptoms in two patients, TTM alone in six patients, and both in the remaining seven patients. Cumulative diagnostic usefulness in evaluating the significance of symptoms potentially attributable to arrhythmia is summarized: HM alone useful in three patients, TTM alone useful in 10 patients, and both HM and TTM useful in 13; TTM was significantly more useful than HM (χ² = 3.69; P < 0.05).Of note is that six patients had significant arrhythmias during asymptomatic periods, including VPC's (four), severe sinus bradycardia (one), and rapid atrial fibrillation (one). In these few patients, both techniques appeared equally able to document asymptomatic arrhythmias.These observations demonstrate that TTM carried out over a 7-day period is superior to a 24-hour Holter monitor recording in its ability to establish the significance of symptoms potentially attributable to arrhythmia, and appeared equally sensitive to HM in demonstrating periods of asymptomatic arrhythmia.TTM can therefore be considered a simple, accurate, and useful technique for arrhythmia surveillance in the symptomatic patient.     

Functional significance of hypertrophy of the noninfarcted myocardium after myocardial infarction in humans

Hypertrophy of the noninfarcted left ventricle as a chronic response to myocardial infarction has been demonstrated in animals and at autopsy in humans. However, the functional significance of postmyocardial infarction hypertrophy is a subject of dispute. The purpose of this study was to determine the time course of development of postmyocardial infarction hypertrophy of the noninfarcted myocardium in humans and to assess its functional significance. Subcostal view, two-dimensional echocardiograms were recorded at rest and during peak exercise, 6 and 40 weeks postmyocardial infarction in 45 patients (16 anterior, 20 inferior, nine non-Q wave infarcts), for measurement of left ventricular mass and ejection fraction. The left ventricular mass index increased from 94 +/- 30 to 118 +/- 27 g/m2 (p less than 0.01) during the time of the two studies. There was a significant correlation between the change in left ventricular mass index and improved resting ejection fraction (r = 0.48, p less than 0.001) and exercise ejection fraction (r = 0.48, p less than 0.001) at the follow-up study. Of the 32 patients who increased their left ventricular mass index greater than 7%, 18 improved their rest ejection fraction greater than 0.05 units and 17 improved their exercise ejection fraction greater than 0.05 units. Conversely, of the 13 patients who failed to increase their left ventricular mass index, only three improved their rest ejection fraction and one improved the exercise ejection fraction (Fisher's exact test, p less than 0.05). We reached three conclusions. First, in humans, significant hypertrophy of the noninfarcted myocardium can be detected by two-dimensional echocardiography, 9 months postmyocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characteristics, prevalence, and prognosis of postmyocardial infarction syndrome.

Among 1809 patients with myocardial infarction, 60 (3.3%) later developed a postmyocardial infarction syndrome. These 60 patients were compared with controls with myocardial infarction but without postmyocardial infarction syndrome. Cases with postmyocardial infarction syndrome had larger and more complicated infarcts than control subjects. Five year cumulative mortality was higher among cases (26%) than among control subjects (18%) but this difference was not statistically significant. Corticosteroid treatment did not adversely affect the prognosis of the postmyocardial infarction syndrome, which we conclude is mainly determined by the severity of the underlying coronary heart disease.     

Polymorphism in the angiotensinogen gene, hypertension, and ethnic differences in the risk of recurrent coronary events

The M235T mutation of the human angiotensinogen gene has been shown to be associated with elevated circulating angiotensinogen concentrations and essential hypertension. The frequencies of the 235T allele are significantly different in black and white subjects. We analyzed the independent contribution of the angiotensinogen M235T mutation to the development of recurrent coronary events (coronary-related death, nonfatal myocardial infarction, or unstable angina) in a cohort of 916 black (n=145) and white (n=771) postmyocardial infarction patients who were prospectively studied during an average follow-up of 28 months. The frequency of the 235T allele was significantly higher among black (82%) than among white (44%) patients (P<0.001). There was no evidence for Hardy-Weinberg disequilibrium. During follow-up, 41 cardiac events (28%) occurred in blacks and 197 (26%) in whites (P=0.49). Multivariate Cox proportional hazards regression analysis demonstrated that 235T homozygosity was independently associated with increased risk of coronary events among black (hazard ratio: 2.37; P=0.04) but not white (hazard ratio: 0.93; P=0.68) patients, with a significant ethnic-related interaction effect (P for the difference=0.04). Among hypertensive black patients, the TT genotype was associated with a 3.3-fold (P=0.02) increase in the risk of coronary events. Our findings suggest that homozygosity for the 235T mutation in the angiotensinogen gene is an independent risk factor for coronary events in black postmyocardial infarction patients. The presence of hypertension significantly augments the risk associated with this genetic mutation.     

Correlation of symptoms with occurrence of paroxysmal supraventricular tachycardia or atrial fibrillation: a transtelephonic monitoring study. The Flecainide Supraventricular Tachycardia Study Group.

The purpose of this study was to determine whether symptoms recorded at the time of transtelephonic ECG monitoring (TTEM) correlate with attacks of paroxysmal supraventricular tachycardia (PSVT) or paroxysmal atrial fibrillation (PAF). We studied 113 patients with these arrhythmias who made a total of 3319 TTEM calls during their participation in double-blind, placebo-controlled, crossover, multicenter trials of flecainide therapy. Among 49 patients with PSVT, 62.7% of symptomatic calls were associated with ECG-documented PSVT as compared with 6.8% of asymptomatic calls (p less than 0.001). Similarly, among 69 patients with PAF, 69% of symptomatic calls were associated with ECG-documented PAF compared with 10.6% of asymptomatic calls (p less than 0.001). Both in patients with PSVT and PAF, an attack of PSVT or PAF could be documented by ECG in more than 70% of the calls when patients complained of tachycardia, increased sweating, or dyspnea. The sensitivity of a symptomatic call was 91% for PSVT and 89% for PAF, and it was not influenced by flecainide therapy. However, flecainide therapy was associated with a decrease in the positive predictive value of symptomatic TTEM calls and an increase in false positive TTEM transmissions. We conclude that in patients with symptomatic PSVT or PAF, there is a temporal relationship between symptoms and the occurrence of ECG-documented attacks of PSVT or PAF. However, sole reliance should not be placed on the presence or absence of symptoms as a measure of drug failure or efficacy, and it is important to document the cardiac rhythm by TTEM at the time symptoms are recorded.     

Prevention of Sudden Cardiac Death After a First Myocardial Infarction by Pharmacologic or Surgical Antiadrenergic Interventions

Antiadrenergic Interventions and Prevention of Sudden Death after MI. Introduction: Growing evidence points to sympathetic hyperactivity as one critical trigger for life-threatening arrhythmias among postmyocardial infarction patients. Methods and Results: We have evaluated, in a placebo-controlled multicenter study, the efficacy of a β-adrenergic blocking agent (oxprenolol 160 mg) and of a selective left cardiac sympathetic denervation in preventing sudden death in patients with a first and anterior myocardial infarction. Two patient groups were studied. The high-risk group included 144 patients who survived a myocardial infarction complicated by either ventricular tachycardia or fibrillation. The relatively low-risk group included 869 patients whose myocardial infarction did not have these complications; they were allocated only to placebo or oxprenolol. Randomization took place 30 days postmyocardial infarction; mean follow-up was 22 months. In the high-risk group the sudden cardiac death (crude rate) in the placebo subgroup was indeed high (21.3%), and was strikingly reduced to 2.7% and to 3.6% by oxprenolol and by left cardiac sympathetic denervation, respectively (P < 0.05). In the low-risk group the sudden cardiac death (crude rate) in the placebo subgroup was 5.2% and was still reduced by oxprenolol to 1.6% (P < 0.05). The results for total mortality were quite similar to those for sudden death iu both groups. Conclusion: This study, unique for the populations studied and for one of the treatments used, demonstrates that pharmacologic and surgical antiadrenergic interventions significantly reduce sudden cardiac death in postmyocardial infarction patients at high and at low risk. With due consideration to the relatively small size of the high-risk group, it seems reasonable to suggest that left cardiac sympathetic denervation may be considered as a possible alternative for high-risk patients with contraindications to beta blockers. (J Cardiovasc Electrophysiol, Vol 3, pp. 2–16, February 1992)     

Similar result of percutaneous transluminal coronary angioplasty for women and men with postmyocaedial infarction ischemia

Objectives. The purpose of this study was to determine whether there are gender differences in the outcome of percutaneous transluminal coronary angioplasty performed for postmyocardial infarction ischemia.Background. Although women have a higher mortality rate after myocardial infarction than that of men, they are less frequently referred for coronary angioplasty (and coronary artery bypass graft surgery) than are men, possibly because of expectations of a worse procedural outcome.Methods. We analyzed the morbidity and mortality at coronary angioplasty and during a mean follow-up period of 34.4 months for women and 34.2 months for men in 505 consecutive patients (164 women and 341 men) with postmyocardial infarction ischemia between 1981 and 1989.Results. Compared with men, women had similar procedural success rates (89.6% and 91.2%, respectively), need for coronary artery bypass surgery (3.7% and 2.6%) and mortality rates at coronary angioplasty (0.6% and 0.9%). During the follow-up period there were no significant gender differences in the requirement for coronary artery bypass surgery (3.6% and 4%), repeat angioplasty (18.7% and 17.3%), reinfarction (5.8% and 6%) and death (3.6% and 3.7%) or the combined end points of all four events (26.6% and 26.6%). Women had significantly more recurrent angina than did men (54% vs. 42.5%, p < 0.01), even though the extent of coronary artery disease and frequency of incomplete revascularization were similar in men and women.Conclusions. The procedural outcome of coronary angioplasty for postmyocardial infarction ischemia is similar in women and men. Long-term follow-up is also similar except that women experience an increased incidence of recurrent angina, an outcome also reported after bypass surgery. Therefore, concerns over the safety of coronary angioplasty in women should not adversely influence decisions concering referral of women for coronary angioplasty after myocardial infarction complicated by ischemia.     

Myocardial asynchrony in patients with postinfarction intraventricular conduction defects

BACKGROUND: Postinfarction intraventricular conduction defects lead to asynchronous activation of the myocardium.Hypothesis: The aim of the current study is to evaluate contraction asynchrony in postinfarction patients with intraventricular conduction defects. METHODS: A total of 158 patients 6 months postmyocardial infarction and 15 healthy subjects underwent echocardiography to evaluate atrioventricular, interventricular, intraventricular asynchrony, and myocardial performance index (MPI). A subgroup of 126 patients had intraventricular conduction defects in ECG, whereas 32 with normal QRS complex served as controls. RESULTS: All patients postmyocardial infarction showed intraventricular asynchrony and markedly higher MPI. Comparing groups with and without intraventricular conduction defects postmyocardial infarction, those with left bundle branch block (BBB) had significantly higher parameters of all asynchrony types; those with right BBB and left posterior hemiblock (LPH) had significantly higher interventricular asynchrony parameters; those with left anterior hemiblock did not show significant differences in asynchrony parameters as compared with subjects without postinfarction conduction defects. CONCLUSIONS: (1) Patients 6 months postmyocardial infarction show intraventricular asynchrony and markedly higher MPI. (2) Postinfarction patients with LBBB have the highest parameters of atrioventricular, interventricular and intraventricular asynchrony as compared with postinfarction patients with other and without conduction defects. (3) In postinfarction patients with RBBB or LPH parameters of interventricular asynchrony are significantly higher as compared with postinfarction patients without intraventricular conduction defects.     

The effect of early prehospital transtelephonic coronary intervention on morbidity and mortality: experience with 284 postmyocardial infarction patients in a pilot program

We have evaluated, in a pilot study, the effects of subsequent mortality and morbidity of a prehospital program for postmyocardial infarction patients experiencing recurrent chest pain. Two hundred eighty-four patients were enrolled during their late hospital period: 161 in a program incorporating patient education, routine transtelephonic follow-up, and emergency prehospital CCU-controlled intervention; 124 in a control group receiving usual medical care. Cardiac mortality over a median of 13 months of follow-up was significantly reduced in the treatment group (5.8%) vs control (12.9%), p = 0.036, although the incidence of acute events (nonfatal infarction plus cardiac death) was similar in both groups. This suggests that the program does not affect the acute incident but rather the mortality subsequent to it. Prehospital ventricular arrhythmias present in 7 of 54 treatment patients with recurrent chest pain did not recur following self-injection by a prefilled lidocaine syringe; only one patient who was initially arrhythmia-free had ventricular ectopic beats after lidocaine injection. Delay from onset of symptoms to hospital arrival was 1.9 hours. Routine telephone follow-up uncovered ventricular arrhythmias in 30% of treatment patients and, despite the program's patient educational efforts, unreported angina in 20% of the treatment group. In the treatment group there were 99 emergency calls placed by 62 patients, 50% within 12 weeks after discharge and 80% by 35 weeks, resulting in 74 Emergency Department evaluations and 57 hospital admissions. Overuse of the emergency system occurred with only one patient, and physician acceptance was high.(ABSTRACT TRUNCATED AT 250 WORDS)     

Therapy of symptomatic pericarditis after myocardial infarction: Retrospective and prospective studies of aspirin,indomethacin, prednisone,and spontaneous resolution

We studied the efficacy of aspirin and indomethacin therapy in relieving the discomfort of postmyocardial infarction pericarditis (PMIP) in two studies: (1) a retrospective evaluation of patients with symptomatic PMIP during a 5-year period and (2) a prospective, randomized, single-blind comparison of aspirin and indomethacin in similar patients. In the retrospective study, 36 episodes of symptomatic PMIP in 34 patients were identified; in the prospective study, 25 episodes of PMIP in 24 patients occurred. Relief from the discomfort of PMIP was noted within 48 hours in almost all patients with either indomethacin or aspirin therapy. Minor gastrointestinal bleeding developed in two patients in the retrospective study and in two patients in the prospective study. In the retrospective study, mild discomfort of PMIP abated within 48 hours in five of eight patients who received either no treatment or minor analgesic therapy. Aspirin and indomethacin are equally efficacious in relieving the discomfort of PMIP.     

Silent ischemia predicts infarction and death during 2 year follow-up of unstable angina

Silent myocardial ischemia as detected on Holter electrocardiographic (ECG) monitoring is present in greater than 50% of patients with unstable angina despite intensive medical therapy. The presence and the extent of silent ischemia have been correlated with an increased risk of early (1 month) unfavorable outcome including myocardial infarction and need for coronary revascularization for persistent symptoms. Seventy patients with unstable angina who had undergone continuous ECG monitoring for silent ischemia were followed up for 2 years; 37 patients (Group I) had Holter ECG evidence of silent ischemia at bed rest in the coronary care unit during medical treatment with nitrates, beta-receptor blockers and calcium channel antagonists; the other 33 patients (Group II) had no ischemic ST segment changes (symptomatic or silent) on Holter monitoring. Over a 2 year follow-up period, myocardial infarction occurred in 10 patients in Group I (in 2 it was fatal) compared with one nonfatal infarction in Group II (p less than 0.01 by Kaplan-Meier analysis); revascularization with either coronary bypass surgery or angioplasty for symptomatic ischemia was performed in 11 Group I and 5 Group II patients (p less than 0.05). Multivariate Cox's hazard analysis demonstrated that the presence of silent ischemia was the best predictor of 2 year outcome. Therefore, persistent silent myocardial ischemia despite medical therapy in patients with unstable angina carries adverse prognostic implications that persist over a 2 year period.     

Prospective evaluation of intrahisian conduction delay.

We prospectively evaluated 46 patients who had intrahisian conduction delay. Twenty-three had a split His potential and 23 had a prolonged HV interval with a normal QRS complex. In those with a split His, the interval between the two His potentials averaged 32.7 msec (range 9--90 msec); in nine patients this split His was demonstrated only by atrial pacing. The 20 patients from this group with 1:1 atrioventricular conduction have been followed for an average of 18.1 months (range 2--48 months). All are alive. Three have had syncope, but Holter monitoring revealed no bradyarrhythmias. In the 23 patients with a narrow QRS and prolonged HV interval, the HV interval averaged 73.7 msec (range 57--180 msec). Twelve of these patients received pacemakers at the time of the His bundle study, six had symptomatic atrioventricular block and five had symptomatic sinus pauses. The 11 patients who did not receive pacemakers have been followed for an average of 15.1 months (range 2--44 months). In three with recurrent syncope and five with dizziness, monitoring has revealed no bradyarrhythmias. One patient died from a myocardial infarction without arrhythmias. Further prospective evaluation of patients with intrahisian conduction delay without documented bradyarrhythmias is needed, but with follow-up averaging 17 months and up to 4 years, patients with intrahisian conduction delay and without documented bradyarrhythmias appear not to require prophylactic permanent pacemakers to decrease morbidity or mortality.     

Myocardial healing and repair after experimental infarction in the rabbit

Adequacy of healing after acute myocardial infarction may determine the incidence of postmyocardial infarction rupture and ventricular aneurysm. Accordingly, in 36 rabbits, from 1 to 8 days after coronary ligation, and in 18 shams, we measured collagen formation and mechanical resistance of the infarcted left ventricle to stretch and rupture. Prolyl hydroxylase, an intracellular enzyme of collagen synthesis, increased from control activity of 3970 +/- 431 to 9224 +/- 643 counts/min per mg (cpm/mg) extractable protein (P less than 0.01) at 48 hours and was nearly maximal at 3 days postmyocardial infarction (14,518 +/- 2,030 cpm/mg, P less than 0.01). Lysyl oxidase, an extracellular collagen cross-linkage enzyme, increased from control activity of 29.6 +/- 4.8 to 74.7 +/- 18.8 cpm/mg extractable protein (P less than 0.01) at 72 hours and peaked at 121.5 +/- 7.3 (P less than 0.01) 4-6 days postmyocardial infarction. Hydroxyproline, a measure of collagen content, increased from control of 2.8 +/- 0.2 to 5.3 +/- 0.6 mg/g dry weight (P less than 0.05) at 72 hours and continued to increase at 8 days postmyocardial infarction (14.5 +/- 1.7 mg/g dry weight; P less than 0.01). When enzyme activities and hydroxyproline content were expressed relative to other reference bases, including DNA, tissue protein, dry weight, and total left ventricle, similar results were obtained. The mechanical properties of the infarcted left ventricle were determined by filling a balloon in the excised left ventricle until rupture. The rupture threshold in the normal left ventricle, [664 +/- 43 mm Hg (n = 16)], was not significantly different from that of the infarcted left ventricle on days 1-8 postmyocardial infarction. However, left ventricular rupture occurred more often through the myocardial infarction on days 1-4 postmyocardial infarction (59%) than on days 6 and 8 (18%; P = 0.03) when collagen content had significantly increased. Wall stress at the point of rupture in left ventricles from shams and normals was 30 +/- 2 g/mm2; tensile strength in isolated left ventricle muscle strips was 25 +/- 4 g/mm2 and in isolated scar strips at 7 days postmyocardial infarction was 59 +/- 7 g/mm2. The passive stiffness of the infarcted left ventricle increased from control of 61 +/- 5 to 94 +/- 6 mm Hg/100 microliters (P less than 0.05) at 4 days and 100 +/- 7 mm Hg/100 microliters (P less than 0.01) at 6 days postmyocardial infarction. Stiffness correlated with hydroxyproline content over the 8 days postmyocardial infarction (r = 0.599; P less than 0.001). Thus, the acutely infarcted ventricle was highly resistant to rupture during the initial 48 hours postmyocardial infarction, before any increase in collagen occurred. This result suggests that the preinfarction collagen content has an important role in preventing rupture. After 72 hours postmyocardial infarction, collagen synthesis appeared to be a determinant of infarct stiffness and resistance of the infarcted ventricle to rupture.     

Events in the cardiac arrhythmia suppression trial: baseline predictors of mortality in placebo-treated patients

Patients randomized to placebo in the encainide and flecainide arms of the Cardiac Arrhythmia Suppression Trial (CAST) have been found to have a relatively low 1-year mortality rate of 3.9% in comparison with previous studies of patients in the postmyocardial infarction period. To determine the comparability of CAST with previous studies, baseline variables were examined in the 743 patients randomized to placebo in the flecainide and encainide arms of CAST. Twenty-three baseline characteristics were correlated with major outcome events: arrhythmic death (16 events), total mortality (26 events) and congestive heart failure (51 events). On multivariate analysis the risk of new or worsening congestive heart failure was significantly associated with diuretic use, diabetes, high New York Heart Association functional class, age, prolonged QRS duration and low ejection fraction. The risk of arrhythmic death or resuscitated cardiac arrest was significantly associated with an index Q wave myocardial infarction, history of heart failure, use of digitalis, diabetes and prolonged QRS duration. Total mortality or resuscitated cardiac arrest was significantly associated with an index Q wave myocardial infarction, diabetes, ST segment depression, high functional class, prolonged QRS duration and low ejection fraction. The variables at baseline associated with mortality from all causes or arrhythmic death or resuscitated cardiac arrest and heart failure in the CAST placebo-treated patients are similar to those identified in previous postmyocardial infarction studies. Thus, the observation of increased mortality in CAST associated with the administration of encainide and flecainide for suppression of ventricular premature depolarizations is probably applicable to any comparably defined group of patients in the postmyocardial infarction period.     

Prognostic value of dipyridamole thallium-201 imaging in elderly patients.

The prognostic value of intravenous dipyridamole myocardial perfusion imaging has not been studied in a large series of elderly patients. Patients greater than or equal to 70 years of age with known or suspected coronary artery disease were evaluated to determine the predictive value of intravenous dipyridamole thallium-201 imaging for subsequent cardiac death or nonfatal myocardial infarction. Of the 348 patients, 207 were symptomatic and 141 were asymptomatic; 52% of the asymptomatic group had documented coronary artery disease. During 23 +/- 15 months of follow-up, there were 52 cardiac deaths, 24 nonfatal myocardial infarctions and 42 revascularization procedures (percutaneous transluminal coronary angioplasty in 20; coronary artery bypass surgery in 22). Clinical univariate predictors of a cardiac event included previous myocardial infarction, congestive heart failure symptoms, hypercholesterolemia and diabetes (all p less than 0.05). The presence of a fixed, reversible or combined thallium-201 defect was significantly associated with the occurrence of cardiac death or myocardial infarction during follow-up (p less than 0.05). Cardiac death or nonfatal myocardial infarction occurred in only 7 (5%) of 150 patients with a normal dipyridamole thallium-201 study (p less than 0.001). Stepwise logistic regression analysis of clinical and radionuclide variables revealed that an abnormal (reversible or fixed) dipyridamole thallium-201 study was the single best predictor of cardiac events (relative risk 7.2, p less than 0.001). As has been demonstrated in younger patients, previous myocardial infarction (relative risk 1.8, p less than 0.001) and symptoms of congestive heart failure at presentation (relative risk 1.6, p = 0.02) were also significant independent clinical predictors of cardiac death or myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Transient ST-segment elevation with postmyocardial infarction angina: prognostic significance

Fifty-seven patients with acute myocardial infarction were observed for early postmyocardial infarction angina and associated transient ST-segment changes. Nine patients had postinfarction angina with transient ST-segment elevation (Group 1), seventeen patients had postinfarction angina with ST-segment depression or no ST-segment changes (Group 2), and 31 patients had no postinfarction angina (Group 3). The patients in Group 1 had a statistically significant increased incidence of early reinfarction and death, when compared with the other two groups, singly or combined. There was no significant difference in the incidence of reinfarction and death when Group 2 is compared with Group 3. Patients with transient ST-segment elevation associated with early postmyocardial infarction angina may be an appropriate group in whom to consider newer, more aggressive modes of postinfarction management.     

Short-term effect of coronary artery bypass grafting on the signal-averaged electrocardiogram

Ventricular late potentials at the end of the QRS can be detected on the body surface during sinus rhythm by recording a signal-averaged electrocardiogram (SAECG). In patients with coronary artery disease, these late potentials have been shown to be markers for spontaneous or inducible ventricular tachycardia, or both. The short-term (before and 10 +/- 4 days after coronary revascularization) influence of coronary artery bypass grafting (CABG) on the quantitative SAECG variables was studied in 40 patients with chronic coronary artery disease. Twenty-five of these patients had a previous myocardial infarction. In the 15 patients without previous myocardial infarction, no abnormal SAECG indexes were recorded before CABG and no change in the quantitative SAECG variables was observed after surgery. In the patients with a previous myocardial infarction, 7 (28%) had a late potential before CABG. After CABG, 5 (71%) patients remained late potential-positive, whereas the other 2 (29%) lost their late potential. The mean values of their SAECG variables improved after coronary revascularization. In the entire group of postmyocardial infarction patients, the high-frequency QRS duration had shortened (p less than 0.01) after CABG (the other SAECG indexes did not change). The postoperative arrhythmic complications (transient atrial fibrillation, new onset of ventricular couplets) tended to be more frequent in the postmyocardial infarction group and in patients with late potentials. Our findings suggest that the reported increase in ventricular arrhythmias after CABG is probably not related to a change in the arrhythmogenic substrate for ventricular reentry but is associated with changes in the arrhythmogenic milieu.     

电话传送心电图监测与常规心电图诊断心肌缺血的对比研究

目的 探讨单通道双极导联电话传送心电图监测(transtelephomic electrocardiographic monitoring,TTM)诊断心肌缺血的实用价值.方法 同时检测178例次心肌缺血患者的常规心电图(ECG)和TTM,调整TTM的监测电极部位与ECG的导联位置完全相同,观察两者在同一时间、相同导联的S-T、T缺血变化,并以31例正常者作对照.结果178例次ECG明确S-T、T心肌缺血改变者在TTM有相同变化者共170例次,TTM与ECG的符合率及敏感性达95.5%(P>0.05).而31例对照组ECG无S-T、T心肌缺血的患者,TTM亦无变化,特异性100%.结论TTM对心肌缺血的检测有高度敏感性及可靠的诊断价值.