Global T wave inversion

Long-term outcome of pre-specified ECG patterns in acute coronary syndrome

BACKGROUND

Long-term outcome of real-life acute coronary syndrome (ACS) patients with selected ECG patterns is not well known.

PURPOSE

To survey the 10-year outcome of pre-specified ECG patterns in ACS patients admitted to a university hospital.

METHODS

A total of 1184 consecutive acute coronary syndrome patients in 2002-2003 were included and followed up for 10 years. The patients were classified into nine pre-specified ECG categories: 1) ST elevation; 2) pathological Q waves without ST elevation; 3) left bundle branch block (LBBB); 4) right bundle branch block (RBBB) 5) left ventricular hypertrophy (LVH) without ST elevation except in leads aVR and/or V₁; 6) global ischemia ECG (ST depression ≥0.5 mm in 6 leads, maximally in leads V_4-5 with inverted T waves and ST elevation ≥0.5 mm in lead aVR); 7) other ST depression and/or T wave inversion; 8) other findings and 9) normal ECG.

RESULTS

Any abnormality in the ECG, especially Q waves, LBBB, LVH and global ischemia, had negative effect on outcome. In age- and gender adjusted Cox regression analysis, pathological Q waves (HR 2.28, 95%CI 1.20-4.32, p = .012), LBBB (HR 3.25, 95%CI 1.65-6.40, p = .001), LVH (HR 2.53, 95%CI 1.29-4.97, p = .007), global ischemia (HR 2.22, 95%CI 1.14-4.31, p = .019) and the combined group of other findings (HR 3.01, 95%CI 1.56-6.09, p = .001) were independently associated with worse outcome.

CONCLUSIONS

During long-term follow-up of ACS patients, LBBB, ECG-LVH, global ischemia, and Q waves were associated with worse outcome than a normal ECG, RBBB, ST elevation or ST depression with or without associated T-wave inversion. LBBB was associated with the highest mortality rates.

The pathogenesis of reversible T-wave inversions or large upright peaked T-waves: Sympathetic T-waves

Reversible electrocardiographic (ECG) repolarization changes including T-wave inversions (TWI), large upright peaked T-waves (LUPTW) and prolongation of the corrected QT interval (P-QTc) have been reported in association with myriads of acute cardiac and non-cardiac diseases. Through the last 70 years, the TWIs have been described under different terms as; cerebral, giant, global, canyon, Wellens or coronary and cardiac memory T waves. During the last 15 years, the reversible TWI and LUPTW in association with P-QTc have been described as characteristic ECG features in takotsubo syndrome (TS), which also may be triggered by the same aforementioned acute cardiac and non-cardiac disease entities. The pathogenesis of these reversible T-wave changes is not clear-cut. In this manuscript, substantial evidences for a causal link between the local cardiac sympathetic disruption and the development of the reversible TWI and LUPTW are presented. As a result, a pathogenetic term for the reversible TWI or LUPTW, which is sympathetic T waves (sympathetic TWI or sympathetic LUPTW), would be the most appropriate term.

Cardiac memory during rather than after termination of left bundle branch block

An 83-year-old woman with chronic left bundle branch block and remote history of pacemaker implantation for intermittent AV block was hospitalized for fatigue and leg swelling. She had no cardiac complaints. Routine 12-lead electrocardiogram showed sinus rhythm with left bundle branch block. There were diffuse negative T waves in the inferior and anterolateral leads that were concordant with the QRS complexes. Echocardiogram was normal and nuclear perfusion heart scan showed no abnormality. It was noted that the negative T waves during left bundle branch block were in the exact same leads as were the deep negative QRS complexes during ventricular pacing. The electrocardiographic changes were consistent with cardiac memory. This case is unique because cardiac memory in patients with intermittent left bundle branch block typically occurs when the QRS complexes normalize and not during left bundle branch block itself. Our findings indicate that memory Ts can develop not only after normalization of wide complex rhythms but also with alternating wide complex rhythms as in the presented case where a ventricular paced rhythm was replaced by left bundle branch block.

Monitoring devices in the intensive care unit

Monitors in the intensive care unit are imperative to taking adequate care of these critically ill patients. Cardiovascular, pulmonary, and neurologic monitors are key to performing these tasks. This article gives an overview of the most common monitors that are used in the intensive care unit.

Global T-wave inversion: limited QT dispersion despite QTc prolongation--a correlate of benignity in patients with strikingly abnormal electrocardiograms

BACKGROUND

The global T-inversion (GTI) electrocardiogram (ECG) is strikingly abnormal with major QTc prolongation, but with a surprisingly good prognosis by Kaplan-Meier curve. This contrasts with most significant QTc prolongations.

HYPOTHESIS

This study was undertaken to ascertain QT interval dispersion (QTd) in global T wave inversion, a clinically benign long QTc ECG.

METHODS

Longest and shortest QT intervals in all 12 leads in 35 consecutive patients with GTI were determined by two mutually blinded observers. QTd was determined by subtraction (maximum-minimum) and QTc was calculated using the Bazett formula.

RESULTS

There was a 2:1 female preponderance QTc was prolonged and equal for men (0.471) and women (0.469). Observer variability of under 2% permitted averaging of QT measurements. Composite mean QTd was 55 ms. The literature revealed a range of QTd in normal subjects of 39 to 59 ms (mostly 49 to 59 ms). Patient series with abnormal QTd were well above this level.

CONCLUSION

Despite a strikingly abnormal ECG with marked QTc prolongation, QT dispersion was limited in global T inversion, consistent with its previously demonstrated benignity.

Electrocardiographic T-wave changes underlying acute cardiac and cerebral events

T-wave inversions produced by myocardial infarction (MI) are classically narrow and symmetric. Electrocardiography T-wave changes including low-amplitude and abnormally inverted T waves may be the result of noncardiac path physiology. We present a series of cases that presented with different electrocardiography T-wave changes. The first case involved a 64-year-old woman who presented to the emergency department with diffuse splayed T-wave inversions and was found to have an MI in the context of an acute cerebrovascular accident. We contrasted this case with that of a 76-year-old man with hypercholesterolemia who presented with T-wave widening and a prolonged QT interval and was found to have a subarachnoid hemorrhage secondary to a basilar aneurysm and no MI. Several mechanisms have been suggested to explain the cardiac and cerebral injury, including microvascular spasm and increased levels of circulating catecholamines. Accurate interpretation of T-wave changes can assist the clinician toward a timely therapeutic intervention and accurate diagnosis.

QT interval prolongation with global T-wave inversion: a novel ECG finding in acute pulmonary embolism

OBJECTIVE

The purpose of this study was to report a novel electrocardiographic (ECG) phenomenon in acute pulmonary embolism characterized by QT interval prolongation with global T-wave inversion.

METHODS

Among a total of 140 study patients with a confirmed diagnosis of acute pulmonary embolism, patients who fulfilled the inclusion criteria for QT interval prolongation with global T-wave inversion were examined. Each of these patients had undergone a detailed clinical evaluation including testing for myocardial injury and echocardiography.

RESULTS

QT interval prolongation with global T-wave inversion was found in five patients (age 51-68 years) with acute pulmonary embolism. Four were women. Acute pulmonary embolism was diagnosed by ventilation-perfusion scan in three patients and by spiral computed tomography in other two patients. None of the patients had any right or left ventricular regional wall motion abnormalities on echocardiography. All patients had changes characteristic of hemodynamically significant pulmonary embolism, including right ventricular stunning or hypokinesis and dilatation in five patients with paradoxical septal motion in four. Acute coronary syndrome was ruled out in each patient by clinical evaluation, serial ECGs and cardiac markers, and lack of regional wall motion abnormalities on echocardiography. Prolongation of QT intervals (QTc 456-521 ms) with global T-wave inversion was noted on presentation. The ECG changes gradually resolved in 1 week in all patients with appropriate treatment of acute pulmonary embolism. One patient died. None of the patients developed torsade de pointes.

CONCLUSIONS

Acute pulmonary embolism may occasionally result in reversible QT interval prolongation with deep T-wave inversion, and, thus should be considered among the acquired causes of the long QT syndrome.

Negative T waves shortly after ST-elevation acute myocardial infarction are a powerful marker for improved survival rate

BACKGROUND

Recent studies have reported that negative T waves in the setting of acute coronary events are associated with Thrombolysis In Myocardial Infarction flow grade 3 in the infarct-related artery and with improved parameters of ventricular function rather than with ischemia.

METHODS

Patients enrolled in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) angiographic substudy (ie, patients with acute infarction randomly assigned to one of 4 thrombolytic regimens who then underwent coronary angiography) were included in this study if they survived at least 24 hours and had no confounding electrocardiographic factors (n = 1505).

RESULTS

More patients had negative T waves develop (NT group, n = 938 [62%]) than not (PT group, n = 567 [38%]). Peak creatine kinase MB, time to thrombolysis, and randomization to accelerated alteplase were no different between the groups. Thirty days after admission, 12 patients in the NT group had died versus 25 patients in the PT group (1.3% vs. 4.4%; P <.001; odds ratio for negative T waves 0.28; 95% confidence interval 0.14-0.56). The difference persisted when only patients who survived at least 3 days were analyzed. After adjusting for relevant covariates (including presence of new Q waves in the follow-up electrocardiogram), negative T waves were an independent predictor for survival (P =. 007; odds ratio for negative T waves 0.38; 95% confidence interval 0. 18-0.78). Patients in the NT group were 35% more likely to have achieved patency of the infarct-related artery, although this difference was not statistically significant.

CONCLUSIONS

Negative T waves shortly after acute myocardial infarction treated with thrombolysis were markers for improved 30-day survival rate. This finding merits prospective testing.

Resting ECG is modified after oophorectomy and regresses with estrogen replacement therapy in premenopausal women

OBJECTIVE

To assess the effects of bilateral oophorectomy on the resting ECG and whether they regress with estrogen replacement therapy.

STUDY DESIGN

Twenty-six premenopausal and 15 postmenopausal women were enrolled in the present study. All women had undergone hysterectomy and bilateral ovariectomy. All women underwent 12-lead ECG on admission to hospital. A second ECG was recorded 20-25 days after surgery. After this second ECG, premenopausal women were randomly divided into two groups. The women of Group A (n=14) received transdermal ethinyl estradiol (EE). The women of Group B (n=12) did not receive any therapy. A third ECG was performed in both groups 30-35 days after randomization.

RESULTS

Bilateral oophorectomy did not induce any significant modifications in the ECG parameters of the postmenopausal women whereas in the premenopausal women, we observed a significant increment in mean duration of the T wave, a significant decrease in its amplitude and significant reduction in ST depression in V2, V3, V4 and V5. The third ECG showed regression of the ECG modifications in Group A. In the women of Group B, the second and third ECGs were not substantially different, but there were statistically significant differences between the first and third ECGs.

CONCLUSIONS

The results of the present study show that ovariectomy induces significant though not clinically evident modifications in resting ECG. These ECG changes are probably due to the sudden reduction in sex hormone plasma levels after ovariectomy. Administration of estradiol induced regression of the ECG modifications.

Large T wave inversion and QT prolongation associated with pulmonary edema: a report of nine cases

OBJECTIVES

The purpose of this study is to describe a new clinical electrocardiographic phenomenon characterized by diffuse symmetrical T wave inversion and QT prolongation after recovery from an episode of cardiogenic but nonischemic pulmonary edema.

BACKGROUND

A variety of clinical conditions, but not acute pulmonary edema, have been previously associated with giant negative T waves and QT prolongation in the postevent electrocardiogram.

METHODS

In nine patients not suspected of having ischemic heart disease, new large or global T wave inversion with QT prolongation was observed after resolution of acute cardiogenic pulmonary edema. Each patient underwent detailed clinical evaluation including testing for myocardial injury and a coronary ischemic etiology.

RESULTS

There were seven women and two men with ages ranging from 32 to 79 years. The etiology of pulmonary edema was diverse, but acute myocardial infarction and significant coronary artery disease were ruled out in each case. During the index event, most patients had elevated blood pressure, sinus tachycardia, minimal nonspecific ST and T wave changes and normal QT intervals. Large inverted T waves with marked prolongation of the QT intervals evolved within 24 h after clinical stabilization. The electrocardiographic changes gradually resolved in one week. There was no in-hospital mortality.

CONCLUSIONS

Acute cardiogenic but nonischemic pulmonary edema may cause deep T wave inversion and QT prolongation after resolution of the symptoms. The repolarization abnormalities may last for several days. These electrocardiographic changes do not adversely effect short-term prognosis.

Sex hormones prolong the QT interval and downregulate potassium channel expression in the rabbit heart

BACKGROUND

Sex hormones are known to exert direct and indirect effects on cardiovascular function, but their effects on cardiac repolarization have not been elucidated. The repolarization phase of the cardiac action potential or QT interval of the ECG is regulated largely by potassium channels such as the delayed rectifier currents HK2 and IsK.

METHODS AND RESULTS

The effects of ovariectomy (OVX) and estradiol (E2) or dihydrotestosterone (DHT) treatment were evaluated on HK2, HERG, and IsK mRNA levels, QT duration, and quinidine-induced changes in QT interval in isolated rabbit hearts. HK2 and 0.7-kilobase IsK mRNA were downregulated in cardiac ventricular tissue from OVX rabbits treated with either E2 or DHT. The QT interval was prolonged in E2- and DHT-treated animals (OVX + vehicle, 223 +/- 6 ms; OVX + DHT, 236 +/- 10 ms; and OVX + DHT, 245 +/- 6 ms; P < .05).

CONCLUSIONS

The association between hormone-induced changes in baseline QT interval and the mRNA level for these channels suggests that sex hormones may play a critical role in regulating cardiac repolarization. However, the changes in baseline QT and potassium channel mRNA after hormone treatment were not concordant with the changes in QT interval after the infusion of quinidine, after which E2-treated animals responded similarly to controls (18.4 +/- 4.6% and 19.3 +/- 4.6% increase in QT interval, respectively) and DHT-treated animals exhibited less QT prolongation (11.4 +/- 3.8% increase; P < .03).

Global T wave inversion: long-term follow-up

OBJECTIVES

This study evaluated 11-year follow-up data from patients with global T wave inversion.

BACKGROUND

In an 8-year prospective investigation, global T wave inversion was characterized by a long QT interval, unexplained marked female preponderance and, despite dramatic electrocardiographic (ECG) changes, an in-hospital prognosis not statistically different from that of the entire hospital population in which the condition it occurred.

METHODS

To assess long-term prognosis, these and an additional 18 patients (total 118 patients; 92 women and 26 men) with global T wave inversion were followed up prospectively for up to 11 years (mean 33.9 +/- 37.3 months). The additional patients did not significantly affect the in-hospital death rate (7.6%; previously reported death rate 8%) and the total series continued not to differ from the entire in-hospital population in which it occurred (7.02%; p = NS).

RESULTS

Long-term survival was shortened by digoxin, faster heart rates, atrial fibrillation and, especially, a malignant condition. Eighteen (78.3%) of 23 patients with a malignant condition died during the follow-up period (p < or = 0.0005), with a mean survival time of only 12 months. Kaplan-Meier curves also revealed the poor prognosis for those patients taking digoxin; 21 (63.9%) of 36 patients died (p = 0.008). Eleven of the 12 patients with atrial fibrillation were taking digoxin; 58.3% of these died, demonstrating a worse prognosis than that of patients with sinus rhythm, 35% of whom died (p = 0.005).

CONCLUSIONS

Global T wave inversion continues to have an unexplained (78% vs. 22%) female preponderance. Although the long-term prognosis depends on underlying or associated diseases, the striking diffuse ECG changes do not in themselves imply a poor prognosis.

Acute pulmonary embolism as the cause of global T wave inversion and QT prolongation. A case report

A 57-year-old man without prior history of organic heart disease was admitted with a diagnosis of unstable angina because of chest pain and new electrocardiographic (ECG) changes of global T wave inversion and QT interval prolongation. Left and right heart catheterization with coronary angiography, pulmonary angiography, ventilation-perfusion scintigraphy, and echocardiography showed absence of coronary artery disease but unequivocally acute pulmonary embolism. Within days following anticoagulant therapy, the lengthened QT interval became normalized while the global T wave inversion persisted. A follow-up ECG 15 months later revealed complete resolution of the T wave inversion. The possible pathophysiologic mechanism of the ECG changes is discussed.