Echocardiography in the evaluation of patients in chest pain units

Using percutaneous angioplasty to induce the ischemic cascade in the cardiac catheterization laboratory, echocardiographic wall motion abnormalities have been documented to precede electrocardiographic abnormalities and angina. Therefore, detection of cardiac wall motion abnormalities is potentially more sensitive than the history, physical examination, and ECG for identification of myocardial ischemia. Echocardiography is highly reliable for assessing cardiac wall motion and, thus, it has been used for diagnosis and risk assessment in patients presenting to the emergency department (ED) with symptoms suggestive of myocardial ischemia. In patients who have acute ST-elevation myocardial infarction (MI), echocardiography is comparable to invasive left ventriculography for detecting wall motion abnormalities. However, the usefulness of echocardiography in the low-risk population that has chest pain of uncertain origin and a nondiagnostic initial presentation is less well established.     

Prognostic value of exercise echocardiography in patients after coronary artery bypass surgery

To assess the prognostic value of exercise echocardiography in patients with prior coronary artery bypass surgery, follow-up was obtained in 718 patients (591 men [82%] and 127 women [18%], aged 67 +/- 9 years) who underwent clinically indicated exercise echocardiography 5.7 +/- 4.7 years after coronary bypass surgery. Resting wall motion abnormalities were present in 479 patients (67%). New or worsening wall motion abnormalities developed with exercise in 366 patients (51%). During a median follow-up of 2.9 years, cardiac events included cardiac death in 36 patients and nonfatal myocardial infarction in 40 patients. The addition of the exercise echocardiographic variables, abnormal left ventricular end-systolic volume response and exercise ejection fraction to the clinical, resting echocardiographic and exercise electrocardiographic model provided incremental information in predicting cardiac events (chi-square 37 to chi-square 42, p = 0.02) and cardiac death (chi-square 38 to chi-square 43, p <0.02). Exercise echocardiography provides prognostic information in patients after coronary artery bypass surgery, incremental to clinical, rest echocardiographic, and exercise electrocardiographic variables.     

Role of transient ischaemia and perioperative myocardial infarction in the genesis of new septal wall motion abnormalities after coronary bypass surgery.

To evaluate the role of ischaemia in the genesis of new septal wall motion abnormalities after coronary artery bypass surgery 45 patients were studied by cross sectional echocardiography before and 8-10 days after operation. Regional left ventricular wall motion was classified as normal, hypokinetic, akinetic, or dyskinetic. Septal wall motion abnormalities were correlated with electrocardiographic Q wave changes and serial serum MB creatine kinase measured before and 4, 7, 21, 48, and 72 hours after operation. Of the 14 patients who developed new septal wall motion abnormalities after operation two developed septal akinesis (both had perioperative infarction) and one new dyskinesis in the previously akinetic septal segment. Of the 11 patients with new septal hypokinesis, eight had normal serial creatine kinase MB values, two had raised values peaking four and seven hours after operation, with a return to normal values at 21 hours indicating transient ischaemia, and one had enzymatic criteria for perioperative infarction. Most new echocardiographic septal wall motion abnormalities after coronary artery bypass grafting are not caused by transient ischaemia, perioperative infarction, or generalised cell necrosis.     

Role of transient ischaemia and perioperative myocardial infarction in the genesis of new septal wall motion abnormalities after coronary bypass surgery

To evaluate the role of ischaemia in the genesis of new septal wall motion abnormalities after coronary artery bypass surgery 45 patients were studied by cross sectional echocardiography before and 8-10 days after operation. Regional left ventricular wall motion was classified as normal, hypokinetic, akinetic, or dyskinetic. Septal wall motion abnormalities were correlated with electrocardiographic Q wave changes and serial serum MB creatine kinase measured before and 4, 7, 21, 48, and 72 hours after operation. Of the 14 patients who developed new septal wall motion abnormalities after operation two developed septal akinesis (both had perioperative infarction) and one new dyskinesis in the previously akinetic septal segment. Of the 11 patients with new septal hypokinesis, eight had normal serial creatine kinase MB values, two had raised values peaking four and seven hours after operation, with a return to normal values at 21 hours indicating transient ischaemia, and one had enzymatic criteria for perioperative infarction. Most new echocardiographic septal wall motion abnormalities after coronary artery bypass grafting are not caused by transient ischaemia, perioperative infarction, or generalised cell necrosis.     

Prominent negative T waves with QT prolongation indicate reperfusion injury and myocardial stunning.

To observe the clinical course after reperfusion and recovery from myocardial stunning of the left ventricular anterior wall, we prospectively reviewed and analyzed cardiac enzymes, ECG changes, echocardiograms, and cineangiograms in 8 patients with the acute ischemic syndrome who fulfilled the following criteria: 1) no history of previous myocardial infarction, 2) repeated and/or prolonged episodes of chest pain, 3) critical stenosis of the left anterior descending artery with wall motion abnormalities, 4) successful emergency percutaneous transluminal coronary angioplasty, and 5) normal wall motion on repeat cineangiography 4 to 8 weeks later. Creatine kinase (CK) and/or its cardiac isoenzyme (CK-MB) were minimally elevated in all cases. Wall motion was normalized with the reduction of end-systolic volume (end-diastolic volume: from 139 +/- 25 to 140 +/- 37 ml, ns, end-systolic volume: from 68 +/- 16 to 39 +/- 13 ml, p < 0.001, ejection fraction: from 51 +/- 6 to 71 +/- 6%, p < 0.001). Serial echocardiograms showed normalization of wall motion within 4 to 28 days. T wave inversion in the left precordial leads developed 30 min to 5 hours after the cessation of chest pain or successful reperfusion, and prominent negative T waves (1.6 +/- 0.6 mV) with QT prolongation (0.56 +/- 0.08 sec) in V3 or V4 reached their peak values within one to 5 days. ECG abnormalities resolved after 21 to 95 days. These ECG findings may indicate reperfusion injury and the presence of myocardial stunning in the anterior wall of the left ventricle.     

Prevalence of structural cardiac abnormalities in patients with myotonic dystrophy type I

Background

Myotonic dystrophy type 1 (DM1) is a neurological disorder with known cardiac involvement, including conduction disturbances, arrhythmias, and ventricular dysfunction. We studied which clinical and electrocardiographic features are associated with structural cardiac abnormalities.

Methods

History, physical examination, electrocardiography, and genetic testing were performed on 382 patients with DM1, and cardiac imaging was performed on 100 of these patients.

Results

Clinical congestive heart failure was found in 7 of the 382 patients (1.8%). Structural cardiac abnormalities determined with cardiac imaging included left ventricular hypertrophy (19.8%), left ventricular dilatation (18.6%), left ventricular systolic dysfunction (14.0%), mitral valve prolapse (13.7%), regional wall motion abnormality (11.2%), and left atrial dilatation (6.3%). Left ventricular systolic dysfunction was associated with increasing age (relative risk [RR], 1.9 per decade; 95% CI, 1.1-3.2; P = .02), cytosine-thymine-guanine (CTG) repeat length (RR, 2.8 per 500 repeats; 95% CI, 1.3-6.3; P = .01), P-R >200 ms (RR, 14.7; 95% CI, 3.0-73.1; P = .001), and QRS >120 ms (RR, 5.7; 95% CI, 1.5-21.8; P = .01). P-R >200 ms was predictive of regional wall motion abnormalities. QRS >120 ms correlated with regional wall motion abnormalities and left atrial dilatation.

Conclusions

Several clinical and electrocardiographic findings in patients with DM1 are significantly associated with structural heart abnormalities. These results suggest an underlying genetic and pathophysiologic correlate that may lead to cardiac disease in these patients.     

Submaximal exercise testing after acute myocardial infarction: myocardial scintigraphic and electrocardiographic observations.

The relation between global and regional left ventricular function and electrocardiographic signs of ischemia at rest and during submaximal supine exercise was studied in 27 patients 2 to 3 weeks after acute myocardial infarction. Dynamic myocardial scintigraphy was performed at rest and during submaximal exercise utilizing an in vivo method of labeling red blood cells with technetium-99m pertechnetate. Gated radionuclide blood pool scintigrams were obtained in a modified left anterior oblique, and in some patients also in the right anterior oblique projection, to measure left ventricular ejection fraction and segmental wall motion. Electrocardiographic monitoring of heart rate and rhythm was provided during the exercise. The submaximal exercise test was terminated when the patient's heart rate reached 125 beats/min or if angina, malignant ventricular ectopy or electrocardiographic evidence of myocardial ischemia developed before this rate was reached. The data demonstrate that patients with a recent anterior myocardial infarct, in contrast to patients with a recent inferior or nontransmural infarct, manifest a significant reduction in left ventricular ejection fraction with submaximal exercise. Of the eight patients with an anterior infarct, seven had segmental wall motion abnormalities at rest. Four of these eight manifested more severe abnormalities with submaximal exercise; three had abnormalities at rest that did not change with exercise. Four of the eight had a positive electrocardiographic response during exercise (two were taking digoxin). Of these four, only two had more marked wall motion abnormalities with effort. Of the 13 patients with an inferior infarct, 11 had apparently normal wall motion in the modified left anterior oblique projection at rest, including 2 who manifested segmental wall motion abnormalities with submaximal exercise; the 2 remaining patients had wall motion abnormalities at rest that, on exercise, became more marked in one and were unchanged in one. Four of the 13 had a positive electrocardiographic response with exercise (one was taking digoxin); only one of these had a detectably more severe wall motion abnormality with exercise. Of the six patients with a nontransmural infarct, four had no identifiable wall motion abnormalities at rest; in one of these, an abnormality developed with exercise. The remaining two patients had wall motion abnormalities at rest; in one, a positive electrocardiographic ischemic response developed with exercise. Patients with an anterior infarct appear to have a different functional ventricular response to submaximal exercise at the time of hospital discharge than patients with an inferior or nontransmural infarct. To identify ischemic responses with submaximal exercise in these patients one should ideally use both electrocardiographic monitoring and dynamic myocardial scintigraphy.     

Exercise-induced cardiac dysfunction in sickle cell anemia. A radionuclide study

Cardiac performance was studied by radionuclide angiography at rest and during exercise in 22 adolescents with sickle cell (SC) anemia and the results were compared with those in 12 control subjects. At rest, cardiac contractility was normal; cardiac output and end-diastolic volume were increased. At maximal exercise, heart rate, cardiac output response, and work capacity were reduced; the reduction was related to the degree of anemia. Left ventricular end-diastolic volume decreased with exercise most markedly in patients with ischemic exercise electrocardiograms. An abnormal ejection fraction response to exercise occurred in 4 patients; electrocardiographic signs of ischemia developed in all 4, and wall motion abnormalities in 2. Those patients who had electrocardiographic signs of ischemia had a significantly lower heart rate, ejection fraction, and cardiac output response to exercise, and a lower hematocrit level than subjects with normal results on exercise electrocardiography. The increase in cardiac output was not sufficient to maintain a normal level of exercise. The decrease in end-diastolic volume suggests that diastolic function was abnormal during exercise. Cardiac dysfunction was manifested by an abnormal ejection fraction response, wall motion abnormalities, and incomplete left ventricular filling during exercise.     

PET abnormalities in patients with nonischemic cardiomyopathy

BACKGROUND: The abnormalities in dilated cardiomyopathy (DCM) are generally considered diffuse and to affect the left ventricle in a global manner. However, regional wall motion abnormalities and metabolic defects may also occur to varying, but unclear degrees. QRS width and metabolic defects on positron emission tomography (PET) correlate with survival. We sought to ascertain the prevalence of regional defects in DCM by multiple imaging modalities and to establish the relationship between QRS width and these defects. METHODS: In consecutive patients with advanced nonischemic DCM, undergoing cardiac transplant evaluation, we reviewed multiple imaging modalities (PET, 2-dimensional echocardiography, and radionuclide ventriculography) to quantify the incidence of regional metabolic and wall motion abnormalities and correlate them with clinical and electrocardiographic parameters. RESULTS: Of 44 patients studied, PET imaging revealed scar in 91% of patients, with a mean of 25 +/- 18% of the left ventricle involved, predominantly in the distribution of the left anterior descending artery. Regional wall motion abnormalities occurred in 51% of patients who underwent echocardiography and 59% of patients who underwent nuclear scintigraphy (with only 70% concordance). QRS duration on the surface electrocardiogram correlated positively with the degree of scarring (r=.52, P=.0007). CONCLUSIONS: The presence of scar (matched perfusion and metabolic defects) on PET scanning in patients with advanced DCM is not always indicative of coronary disease. Thus coronary angiography is usually required to define the etiology of systolic dysfunction. The extent of scar correlates with QRS duration. This may have implications for the application of cardiac resynchronization therapy.     

Unique phenotypes of typical and inverted Takotsubo cardiomyopathy in young females

Takotsubo cardiomyopathy is an acute cardiac syndrome characterized by transient left ventricular regional wall motion abnormalities (with peculiar apical ballooning appearance), chest pain or dyspnea, electrocardiographic changes and minor elevations of cardiac enzyme level in the absence of coronary artery disease. We present 3 cases of a transient cardiomyopathy, noted in young women with associated emotional, physical or pharmacologic triggering events, that are distinct in that they all manifested initially with acute pulmonary edema with systolic akinesis involving different LV segments with rapid recovery. It is a reversible cardiac condition that should be differentiated from ischemic and peripartum cardiomyopathy.     

Photokymography: a noninvasive method of detecting ischemic segmental myocardial wall motion abnormalities.

The photokymograph is a new and simple noninvasive device for assessing epicardial segmental myocardial wall motion utilizing cardiac fluoroscopy and image intensification. The validity of this technique in detecting wall motion changes occurring with ischemia was assessed in seven closed chest dogs undergoing acute balloon occlusion of the left circumflex coronary artery. Acute occlusion resulted in a prompt change in the analog signal of the photokymogram, characterized first by a decreased systolic inward motion and late systolic outward movement that later became akinetic and dyskinetic. Systolic amplitude decreased 18 +/- 7 percent (mean +/- standard error of the mean) within 5 seconds of occlusion and progressed to systolic outward motion (- 106 +/- 24 percent) at 2 minutes. The time course and type of morphologic changes observed after occlusion were similar to those previously described using invasive methods. Furthermore, such changes preceded electrocardiographic S-T segment elevation. These data suggest that photokymography is a sensitive technique for noninvasive detection of acute ischemic segmental wall motion abnormalities and holds promise as a simple method of detecting ischemic heart disease in man.     

Localization of the site of ventricular premature complexes by radionuclide angiographic phase imaging

To investigate whether gated radionuclide angiographic phase imaging is useful for visually displaying the origin of ventricular premature complexes (VPCs), 82 patients were studied by gating only VPCs. The VPC "origin" by the scintigraphic method was defined as the area of earliest phase and was compared with that predicted by 12-lead electrocardiographic criteria in all patients and to invasive electrophysiologic mapping in 10. Separating the right ventricle into 3 and the left ventricle into 4 segments, the phase imaging method and the electrocardiographic criteria agreed as to ventricle of VPC origin in 69 patients (84%) and segment of origin within each ventricle in 46 (56%). When baseline ventricular wall motion was analyzed, the 2 methods agreed to the ventricle of VPC origin in 31 of 33 patients (94%) with normal wall motion, 20 of 23 (87%) with segmental wall motion abnormalities and 19 of 26 (73%) with diffuse wall motion abnormalities. Agreement between the 2 methods as to specific segmental localization of the arrhythmia focus was noted in 21 of 33 patients (64%) with normal wall motion, 11 of 23 (48%) with segmental wall motion abnormalities and 12 of 26 (46%) with diffuse hypocontractility. In the 10 patients with endocardial mapping studies, the phase imaging technique confirmed the segment of VPC origin in all 10; the electrocardiographic method was accurate in 8. Thus, gated radionuclide angiographic phase imaging methods may be of value in noninvasively defining the origin of spontaneous VPCs. The visual format allows ready interpretation of the arrhythmia origin, and there may be an advantage to this approach over electrocardiographic morphometric criteria.     

Pulmonary edema associated with subarachnoid hemorrhage. Evidence for a cardiogenic origin

A 56-year-old woman with no history of cardiac disease developed acute pulmonary edema following a subarachnoid hemorrhage. A constellation of findings, including elevated creatine kinase MB isoenzyme activity in the absence of electrocardiographic or scintigraphic evidence of acute myocardial infarction, elevated pulmonary artery wedge pressure, segmental wall motion abnormalities, and depressed ejection fraction of the left ventricle demonstrated by two-dimensional echocardiography and radionuclear ventriculography, pointed to a direct myocardial injury leading to cardiac failure. The evidence for cardiogenic origin of pulmonary edema provided by this case is in contrast to the belief that "neurogenic" pulmonary edema is of noncardiac origin.     

Are there differences among patients with inferior acute myocardial infarction with ST depression in leads V2 and V3 and positive versus negative T waves in these leads on admission?

We assessed whether there are differences among patients with inferior acute myocardial infarction and ST segment depression in leads V2-V3 between those with positive versus negative T waves on admission. We found no differences in the prevalence of concomitant significant left anterior descending coronary artery stenosis and anterior or posterior wall motion abnormalities on echocardiography between the two groups. Precordial ST segment depression with negative T wave may be the early electrocardiographic pattern of posterior infarction, reflecting ST segment elevation with positive T waves that would have been detected by leads facing the posterior wall.     

Novel stress echocardiographic model incorporating the extent and severity of wall motion abnormality for risk stratification and prognosis

The prognostic value of stress echocardiography to predict future cardiac events using the extent and severity of wall motion abnormalities is not well defined. The objective of this study was to develop and validate a prognostic model for interpretation of stress echocardiographic studies by using the extent and severity of wall motion abnormalities. We evaluated 1,500 patients (59 +/- 13 years old; 51% men) who underwent stress echocardiography (34% on the treadmill exercise and 66% on dobutamine). Left ventricular regional wall motion was assessed by consensus of 2 experienced echocardiographers. Follow-up periods (mean 2.7 +/- 1.0 years) for confirmed myocardial infarction (n = 31) and cardiac death (n = 44) were identified. Multivariate regression analysis identified 2 independent predictors of cardiac events: the number of left ventricular wall segments with new wall motion abnormalities (an index of the extent of ischemia) and the maximal magnitude of new wall motion abnormalities (an index of the severity of ischemia). The ischemic extent (chi-square 48.7, p <0.0001) and maximal severity (chi-square 52.0, p <0.0001) were exponentially correlated with an increase in event rate. On the basis of these data, a prognostic model was defined that uses ischemic extent and maximal severity as stress-dependent orthogonal variables. With this 3-dimensional model, the predicted event rate ranged over sevenfold, from a low of 0.9%/year in patients without any wall motion abnormalities to a high of 6.7%/year in patients with extensive and severe wall motion abnormalities. The extent and severity of wall motion abnormalities by stress echocardiography are independent and cumulative predictors of prognosis in patients who have suspected or known ischemic heart disease.     

Color Doppler assessment of mitral regurgitation induced by supine exercise in patients with coronary artery disease

Development of mitral regurgitation (MR) during acute myocardial ischemia is a well known occurrence. To assess the feasibility and clinical utility of detecting MR during exercise testing, color Doppler examinations were performed in 22 patients with angiographically proved coronary artery disease (CAD) and in 17 normal subjects before, during and after graded supine bicycle exercise. Not only was MR visualized using color Doppler during dynamic testing, but it was also slightly more sensitive (59% vs 54%) and specific (100% vs 88%) than the electrocardiographic response in identifying patients with CAD. When the appearance of MR or diagnostic electrocardiographic changes or both were used to identify patients with CAD, the sensitivity of exercise tolerance testing increased to 82%, although the specificity was 88%. In addition, exercise-induced MR was observed to be as sensitive and specific as exercise-induced wall motion abnormalities. Combining exercise-induced MR with wall motion abnormalities also increased the sensitivity to 82%, with the specificity remaining at 100%. With use of exercise-induced MR, wall motion abnormalities or electrocardiographic changes, the sensitivity and specificity of the exercise test in diagnosing CAD was 91% and 88%, respectively. The degree of MR as estimated by maximal area of regurgitation signals, as well as by its ratio to left atrial area, did not correlate with extent of CAD. However, the presence of exercise-induced MR suggested an increased likelihood of 3-vessel CAD because it was found in 9 of 11 patients with 3-vessel CAD, compared with 2 of 5 patients with 2-vessel and 2 of 6 patients with 1-vessel CAD.(ABSTRACT TRUNCATED AT 250 WORDS)     

Exercise echocardiography for the prognostic stratification of patients with low pretest probability of coronary artery disease.

PURPOSE: The aim of this study was to determine whether exercise echocardiography provides incremental data for risk stratification of patients with a low pretest probability of coronary artery disease. PATIENTS AND METHODS: The study included patients referred for exercise echocardiography whose probability of coronary artery disease was 25% or less. We calculated an exercise wall motion score index (on a 1-5 scale), an indicator of the extent and severity of exercise-induced abnormalities. The primary outcomes of the study were subsequent cardiac events (cardiac death and nonfatal myocardial infarction). RESULTS: We studied 571 men and 1047 women; their mean (+/- SD) age was 55 +/- 13 years. During a median follow-up of 3 years, there were 19 cardiac events (6 cardiac deaths and 13 nonfatal myocardial infarctions); an additional 37 patients underwent coronary revascularization. In a multivariate analysis of clinical, exercise electrocardiographic, and echocardiographic parameters, exercise wall motion score index (hazard ratio [HR] = 2.1 per 0.5 units; 95% confidence interval [CI]: 1.3 to 3.4), and age (HR = 2.0 per decade; 95% CI: 1.2-2.8) were independently associated with the risk of cardiac events. Although exercise echocardiographic variables contributed significantly (P = 0.01) to a model of the risk of adverse events, only 9 (47%) of the 19 patients with cardiac events were identified by an abnormal exercise echocardiogram. CONCLUSION: Among patients with low pretest probability of coronary artery disease by clinical criteria, exercise echocardiography identifies some, but not all, patients at risk of future events. Because of the low event rate, routine application of exercise echocardiography in a patient with a low pretest probability does not appear to be cost-effective and therefore cannot be recommended.     

Prognostic value of exercise echocardiography in 5,798 patients: is there a gender difference?

OBJECTIVES: This study was designed to determine the effect of gender on the prognostic value of exercise echocardiography. BACKGROUND: Limited information exists regarding gender differences in prognostic value of exercise echocardiography. METHODS: We obtained follow-up (3.2 +/- 1.7 years) in 5,798 consecutive patients who underwent exercise echocardiography for evaluation of known or suspected coronary artery disease. RESULTS: There were 3,322 men (mean age 62 +/- 12 years) and 2,476 women (mean age 62 +/- 12 years) (p = 0.7). New or worsening wall motion abnormalities developed with exercise in 35% of men and 25% of women (p = 0.001). Cardiac events, including cardiac death (107 patients) and nonfatal myocardial infarction (148 patients), occurred in 5.3% of men and 3.1% of women (p = 0.001). Addition of the percentage of ischemic segments to the clinical and rest echocardiographic model provided incremental information in predicting cardiac events for both men (chi(2) = 137 to 143, p = 0.014) and women (chi(2) = 72 to 76, p = 0.046). By multivariate analysis, exercise electrocardiographic and exercise echocardiographic predictors of cardiac events in both men and women were workload and exercise wall motion score index. There was no significant interaction effect of rest echocardiography (p = 0.79), exercise electrocardiography (p = 0.38) or exercise echocardiography (p = 0.67) with gender. CONCLUSIONS: Although cardiac events occurred more frequently in men, the incremental value of exercise echocardiography was comparable in both genders. Of all exercise electrocardiographic and exercise echocardiographic variables, workload and exercise wall motion score index had the strongest association with outcome. The results of exercise echocardiography have comparable implications in both men and women.     

Tissue Doppler echocardiography in patients with thalassaemia detects early myocardial dysfunction related to myocardial iron overload.

AIMS: To compare an echocardiographic method for detecting abnormal cardiac function before development of overt cardiomyopathy with a recently validated technique of quantifying myocardial iron load. METHODS AND RESULTS: We examined thalassaemia patients whose myocardial iron load had been evaluated with magnetic resonance imaging (MRI). By tissue Doppler echocardiography, myocardial velocities were sampled continuously from base to apex in the RV and LV free wall, and the septum in 52 patients aged 29.2 (14.2-43.1) years and 52 age-matched controls. Ninety-six percent of patients had normal LV ejection fraction by MRI. Thirty-eight (73%) had abnormal iron loading of the myocardium, and 33 of those had regional wall motion abnormalities detected in the septum (n=29), LV (n=2), RV (n=1), and septum plus LV (n=1). The incidence of wall motion abnormalities was significantly higher (P<0.04) in patients with myocardial iron overload (87%) than in the 14 without (35%). Furthermore, myocardial iron overload was suggested by a low T2(*)(15.1+/-15.8 ms) in patients with wall motion abnormalities vs those with normal wall motion (T2(*): 30+/-19 ms) (P<0.007). CONCLUSIONS: Wall motion abnormalities may represent an early sign of cardiac disease despite preserved global function. The regional abnormalities are related to iron overload and easily detectable with tissue Doppler echocardiography.     

Late outcome of survivors of out-of-hospital cardiac arrest with left ventricular ejection fractions greater than or equal to 50% and without significant coronary arterial narrowing

In a retrospective survey of 1,195 survivors of out-of-hospital ventricular fibrillation, 43 patients were identified in whom left ventricular ejection fraction was greater than or equal to 0.50 and in whom no coronary artery stenosis of greater than or equal to 50% luminal diameter were present. Thirteen (30%) of these patients had hypokinesia on left ventriculography, and 20 patients (47%) had a persistently abnormal electrocardiogram. Seven patients (16%) had recurrent out-of-hospital cardiac arrest during an average follow-up of 86 +/- 54 months. The presence of either wall motion or electrocardiographic abnormalities defined patients with a several-fold higher risk of recurrent cardiac arrest than those without such abnormalities. The risk for recurrent cardiac arrest within 5 years was 30% in those with abnormal electrocardiograms versus 5% in the others (p less than 0.03). Age was an independent predictor of recurrent cardiac arrest in this group (p less than 0.01); surprisingly, recurrent cardiac arrest was occurring more often among younger patients. Although cardiac arrest is unusual in patients without major structural heart disease, its recurrence in such survivors is common. Patients at relatively high risk for recurrent ventricular fibrillation can be identified by their youth and by abnormalities detected on the surface 12-lead electrocardiogram or by contrast left ventriculography.