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At least 127 records · Page 7Linked to original sources

PubMed2000

[Diagnostic value of physical examination and electrocardiogram in the initial evaluation of heart murmurs in children].

OBJECTIVE: To investigate the diagnostic value of the physical examination and electrocardiogram in the evaluation of heart murmur in new patients referred to the pediatric cardiologist. METHOD: From 1 April to 30 September 1998, all consecutive patients referred to the pediatric cardiology clinic for evaluation of heart murmur were included. They were prospectively categorized with no heart disease, possible heart disease or definite heart disease based on history and physical examination. They then underwent electrocardiogram with which the diagnosis was reevaluated by the pediatric cardiologist. Lastly, a doppler-echocardiography was systematically performed. RESULTS: In 120 children aged four days to 14 years (median: ten months), 72 (60%) showed abnormalities on doppler-echocardiography and 48 (40%) no heart disease. After physical examination, 52 patients were categorized with no heart disease: 45 patients had a normal doppler-echocardiography; in three of them, the diagnosis was incorrectly modified to possible heart disease on the basis of the electrocardiogram. In the other seven children, the electrocardiogram was normal and the doppler-echocardiography revealed minor (n = 5) or moderate (n = 2) heart defects. Nineteen patients were suspected of having possible heart disease, no diagnosis was modified after analysis of the electrocardiogram and six had normal doppler-echocardiography; 49 patients were correctly diagnosed as having definite heart disease. The sensibility of the physical examination was 90.3%, the specificity was 93.8%, the positive predictive value 95.6% and the negative predictive value 86.5%. CONCLUSION: The electrocardiogram is of no help in the discrimination between heart disease and no heart disease in children referred to the pediatric cardiologist for a cardiac murmur. The physical examination is able to differentiate children with or without heart disease in most of the cases.

Adolescent↗

PubMed1993

Echocardiographic wall motion abnormalities and the signal averaged electrocardiogram in the acute phase of a first myocardial infarction.

We studied the relationship between wall motion abnormalities determined by echocardiography and the signal-averaged electrocardiogram in 82 consecutive patients during the acute phase of a first myocardial infarction. An abnormal signal-averaged electrocardiogram was defined as the presence of two of the following criteria: a QRS duration > or = 114 ms, a root mean square voltage (RMS) of the last 40 ms < or = 25 microV and an amplitude signal lower than 40 microV lasting > or = 39 ms. The left ventricle was divided into 13 segments and the contraction pattern divided into akinesia alone (including dyskinesia) (group A), hypokinesia alone (group B) and both hypokinesia and akinesia (group C). An abnormal signal-averaged electrocardiogram was found in 14/82 patients (17%) and was correlated with the persistence of occlusion of the infarct-related vessel (32% vs 9%, P < 0.02). In patients with a patent vessel, the incidence of an abnormal signal-averaged electrocardiogram was 14% in group A, 9% in group B and 0% in group C (NS). In patients with an occluded vessel an abnormal signal-averaged electrocardiogram was found in 10% of group A patients, in 36% in group B patients and in 75% of group C patients (P = 0.05). Our study suggests that the presence of hypokinetic areas during the acute phase of a first myocardial infarction and an abnormal signal-averaged electrocardiogram indicate an occluded infarct-related vessel.

Aged↗

PubMed1985

Computer detection of atrioventricular dissociation from surface electrocardiograms during wide QRS complex tachycardias.

Differentiation of wide QRS complex tachycardias on surface electrocardiograms is difficult for physicians and computers due in part to their inability to identify atrial activity, specifically atrioventricular (AV) dissociation. We studied 20 examples of AV associated rhythms and 17 examples of AV dissociated ventricular tachycardia. We applied an algorithm consisting of subtraction of a mean beat from each individual beat in leads II and V1 to generate remainder electrocardiograms. The remainder electrocardiograms were visually inspected for the presence of P wave candidates and then autocorrelated. AV dissociated P wave candidates were evident on visual inspection of remainder electrocardiograms in none of 20 AV associated and 15 of 17 AV dissociated rhythms. Atrial cycle length and the presence of AV dissociation were automatically detected by applying a peak selection algorithm to the autocorrelation function. AV association was detected in all 20 AV associated rhythms and AV dissociation was detected for 11 of 17 AV dissociated rhythms (sensitivity 65%, specificity 100%, positive and negative predictive accuracy 100%, 77%). The correlation coefficient of detected vs true atrial cycle length for the 11 correctly detected AV dissociated rhythms was r = .98. Visual inspection of the remainder electrocardiograms along with the original electrocardiogram may increase the ease with which human readers can identify the presence of AV dissociation and thus diagnose ventricular tachycardia. Computer diagnosis of wide QRS complex tachycardias should be significantly improved by use of this algorithm.

Atrioventricular Node↗

PubMed1999

[Identification of patients at high risk in the initial evaluation of unstable angina. Clinical importance of electrocardiogram, Holter and biochemical markers in myocardial lesions].

Beneath the expression of unstable angina are joined an heterogeneous group of patients with different prognosis. In the initial presentation it is difficult to differentiate from non-Q wave myocardial infarction. The present review attempts to establish the relative importance of the clinical presentation, the electrocardiogram, the Holter monitoring and the biochemical markers of myocardial damage for risk stratification of these patients. The clinical factors related with prognosis are the general risk factors related to the prognosis in other presentations of the ischemic heart disease as the presence of previous myocardial infarction, age, presence of heart failure or left ventricular dysfunction, diabetes and peripheral vascular disease. The electrocardiogram is the most helpful method for risk stratification of unstable angina patients, especially depression. The continuous monitoring of the ST-segment through Holter monitoring constitutes an important investigation area, but presumably it can not be recommended as routine utilisation yet in the managing of this sort of patients. The rising of cardiac troponins T or I constitute other important risk marker. Possibly three different risk groups could be established: a) patients at low risk, those with normal electrocardiogram or only negative T-waves and normal cardiac troponins; b) intermediate risk, those patients with rising of cardiac troponins and normal electrocardiogram or electrocardiogram with ST-segment depression and normal cardiac troponins, and c) high risk, corresponding to the patients with rising of cardiac troponins and electrocardiogram with ST-segment depression.

Angina, Unstable↗

PubMed1979

The electrocardiogram in ambulatory medical practice.

The electrocardiogram is one of medicine's most frequently ordered procedures. A review of the current use of electrocardiograms in ambulatory clinical practice and the possible information that might be supplied by an electrocardiogram was undertaken. The electrocardiogram's advantages and disadvantages when used in evaluating specific cardiac disorders are discussed including the use of the electrocardiogram as a baseline. Both their values and their limitations in diagnosis and management are examined to support the authors' conclusion that electrocardiograms should be used as an adjunct to clinical diagnosis, not as a screening procedure.

Ambulatory Care↗

PubMed1975

The omnicardiogram: new approach to detection of heart disease in patients with a normal resting electrocardiogram.

The omnicardiogram is a new technique in which various leads of the standard electrocardiogram are digitized and subjected to a nonlinear mathematical transformation so as to detect subtle degrees of abnormality not apparent in the original electrocardiogram. Its usefulness in the detection of heart disease was studied in 121 male patients with a normal resting 12 lead electrocardiogram who underwent selective coronary cineangiography for a chest pain syndrome. In normotensive patients with a normal resting electrocardiogram, an abnormal omnicardiogram was recorded in 81 percent of those with three vessel disease, 67 percent of those with two vessel disease and 41 percent of those with one vessel disease. Nineteen percent of patients with normal coronary arteries or nonobstructive coronary artery disease had false positive tracings. The omnicardiogram was abnormal in 81 percent of patients with hypertension whether or not cornary artery disease was present. A double Master exercise test was performed by 109 of the 121 patients. In normotensive patients results of the test were positive in 67 percent of those with three vessel disease, 31 percent of those with two vessel disease and 14 percent of those with one vessel disease. There was a 4 percent rate of false positive tracings. Thus in our study, the omnicardiogram appeared to be superior to the Master test and to provide a useful new approach to detection of coronary artery disease in male patients with a normal resting electrocardiogram.

Coronary Angiography↗

PubMed1989

Surface electrocardiogram in the detection of transmural myocardial ischemia during coronary artery occlusion.

To examine whether coronary occlusion causing transmural ischemia was accurately reflected by ST-segment elevation on routine electrocardiograms, intracoronary and surface electrocardiograms were simultaneously recorded during percutaneous transluminal coronary angioplasty (PTCA). The study group consisted of 54 patients who had intracoronary ST-segment elevation during transient coronary occlusion (left anterior descending [LAD]: 25 patients, left circumflex [LC]: 19 patients, right coronary artery: 12 patients). Elevation of the ST segment on the surface electrocardiogram (greater than or equal to 0.1 mV) was recorded in 84% of patients during LAD dilatation, in 32% of patients during LC dilatation (p less than 0.01 vs LAD and right), and in 92% of patients during right coronary dilatation (not significant vs LAD). The magnitude of intracoronary ST elevation was 1.10 +/- 0.8, 1.68 +/- 1.2 and 0.8 +/- 0.6 mV for the LAD, LC and right occlusions, respectively (not significant). Thus, despite the comparable magnitude of intracoronary ST elevation, LC occlusion resulted in ST-segment elevation on the surface electrocardiogram in significantly fewer patients than did LAD or right occlusion. During LC occlusion, 9 patients had no electrocardiographic changes and 4 had only precordial ST depression. Thus, in patients with transmural ischemia during right or LAD occlusions, concordant ST elevation on the surface electrocardiogram is common. In contrast, ST-segment elevation is an insensitive marker of LC occlusion. In patients with ongoing ischemic symptoms and isolated precordial ST depression or no repolarization abnormalities, LC occlusion should be considered in the differential diagnosis.

Adult↗

PubMed1991

Early prediction of acute myocardial infarction from clinical history, examination and electrocardiogram in the emergency room.

The possibility of early prediction of acute myocardial infarction (AMI) was assessed in 7,157 consecutive patients coming to our emergency room during a 21-month period with chest pain or other symptoms suggestive of AMI. Of these patients 921 developed an AMI during the first 3 days in the hospital. Of the 4,690 patients admitted to hospital, 1,576 (34%) had a normal admission electrocardiogram, and 90 of these (6%) developed AMI. Of 1,964 patients with an abnormal electrocardiogram without signs of acute ischemia (42% of those admitted), 268 (14%) developed AMI, and 563 (51%) of 1,109 patients with acute ischemia on the electrocardiogram (24%) developed AMI. All patients were prospectively classified in the emergency room on the basis of history, clinical examination and electrocardiogram into 1 of 4 categories, according to the initial degree of suspicion of AMI. Of 279 admitted patients judged to have an obvious AMI (6% of the 4,690), 245 (88%) actually developed AMI; of 1,426 with a strong suspicion of AMI (30%), 478 (34%) developed one; of 2,519 with a vague suspicion of AMI (54%), 192 (8%) developed one; and of 466 with no suspicion of AMI (10%), 6 (1%) developed one. Thus, only a low percentage of the patients with a normal initial electrocardiogram or a vague initial suspicion of AMI developed a confirmed AMI.

Electrocardiography↗

PubMed1992

Prognostic value of exercise thallium scintigraphy in patients with good exercise tolerance and a normal or abnormal exercise electrocardiogram and suspected or confirmed coronary artery disease.

Exercise thallium scintigraphy is widely used to assess prognosis in patients with suspected or proven coronary artery disease. The incremental prognostic value of this technique in patients who have good exercise tolerance has not been well studied. Two hundred ninety-nine patients with known or suspected coronary artery disease without prior myocardial infarction or revascularization procedure referred for exercise myocardial perfusion imaging and able to exercise to greater than or equal to stage III of the Bruce protocol were included. After a mean follow-up of 50 +/- 10 months, there were 15 cardiac events (5%). The incidence of cardiac events was 10 versus 3% (p less than 0.001) in patients with an abnormal versus normal thallium-201 scan, and 9 versus 3% (p = 0.03) for an abnormal versus normal exercise electrocardiogram. When the 185 patients with a normal exercise electrocardiogram were examined, the incidence of cardiac events was 3% (5 of 150) in patients with a normal scan versus 0% (0 of 35) in patients with an abnormal scan. In the 114 patients with an abnormal exercise electrocardiogram, an abnormal thallium-201 scan was predictive of cardiac events (18% [8 of 44] versus 3% [2 of 70]; p = 0.006). Stepwise logistic regression analysis selected an abnormal thallium-201 scan and abnormal exercise electrocardiogram, low peak exercise heart rate, and male gender as independent variables associated with a significant increased risk of cardiac events. Thus, in patients with known or suspected coronary artery disease and good exercise tolerance, the addition of thallium-201 imaging in patients with an abnormal exercise electrocardiogram provides useful prognostic information.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

PubMedDate not supplied

"Abnormal" electrocardiograms in patients with cocaine-associated chest pain are due to "normal" variants.

"Abnormal" electrocardiograms are found in 56% to 84% of patients with cocaine-associated chest pain. This study was designed to assess whether these findings can be explained by "normal" variations in young patients' electrocardiograms. This cross-sectional study was conducted in a municipal hospital emergency department and walk-in clinic. History and results of an electrocardiogram for consecutive patients with cocaine-associated chest pain, aged 18 to 35 years, were compared to normal controls matched for age, race, and gender. Electrocardiograms underwent detailed analysis by two physicians blinded to both the study protocol and the hypothesis. Interphysician concordance for electrocardiographic diagnosis was substantial. There were 112 patients enrolled, 56 in each group. There was no significant difference found in the mean frequency of electrocardiographic diagnoses between the cocaine-associated chest pain patients and controls. The early repolarization variant was common. In conclusion, "normal" variations (J point and ST segment elevations) account for many of the "abnormal" electrocardiograms observed in young patients with cocaine-associated chest pain. Further study is needed to define the prevalence of these "normal" variations, and to determine if standard electrocardiographic criteria for thrombolysis apply to young patients.

Adolescent↗

PubMed2004

Value of immediate postoperative electrocardiogram to update risk stratification after major noncardiac surgery.

Current consensus guidelines recommend postoperative electrocardiographic surveillance only in patients at relatively high risk of postoperative major cardiac complications, but the usefulness of electrocardiograms after major noncardiac surgery is unknown. We prospectively studied 3,570 patients who underwent major noncardiac procedures and had electrocardiograms performed in the recovery room. Rates of major cardiac complications (acute myocardial infarction, pulmonary edema, ventricular fibrillation or primary cardiac arrest, and complete heart block) were higher in patients who had new postoperative electrocardiographic abnormalities consistent with ischemia (ST-T elevation or depression or T-wave abnormalities compatible with ischemia) compared with those without ischemia (6.7% vs 1.9%, p <0.001). Multivariate analysis, after adjusting for pre- and intraoperative clinical data, indicated that the presence of ischemia on the immediate postoperative electrocardiogram was an independent predictor of major cardiac complications (odds ratio 2.2, 95% confidence interval 1.2 to 3.9, p <0.01). When patients were stratified by a preoperative Revised Cardiac Risk Index, ischemia on the immediate postoperative electrocardiogram identified patients with a higher risk of major cardiac complications in low- and high-risk subsets (odds ratio 4.9, 95% confidence interval 1.6 to 15 in lower risk patients; odds ratio 2.0, 95% confidence interval 1.0 to 3.7 in higher risk patients). We conclude that the immediate postoperative electrocardiogram is a valuable tool to adjust risk stratification, even in patients who have lower risks when undergoing noncardiac surgery.

Aged↗

PubMed1999

Improved detection of posterior myocardial wall ischemia with the 15-lead electrocardiogram.

BACKGROUND: A routine 12-lead electrocardiogram is commonly obtained to evaluate for possible acute myocardial infarction during the initial screening of patients with chest discomfort. Posterior myocardial infarction is commonly missed because it is not usually visible in the standard leads. In this study, we compared the sensitivity and specificity of posterior chest leads (V(7), V(8), and V(9)) and 12-lead electrocardiography in detecting posterior injury pattern during single-vessel percutaneous transluminal coronary angioplasty. METHODS AND RESULTS: Three posterior chest leads in addition to the routine 12-lead electrocardiogram were monitored simultaneously during single-vessel percutaneous transluminal coronary angioplasty of the right, circumflex, and left anterior descending coronary arteries in a total of 223 patients. Posterior injury patterns (95%) were detected mostly during circumflex coronary occlusion. Posterior leads were able to detect injury pattern in 49% (36 of 74) of patients, whereas the 12-lead electrocardiogram was able to detect only 32% (P <.04). When all 15 leads were used to detect all ST elevations, sensitivity increased to 57%, with a specificity of 98% for the circumflex coronary artery. If maximal ST depressions in leads V(2) to V(3) are considered to be from posterior myocardial injury, then the overall sensitivity is increased to 69%. CONCLUSIONS: Posterior leads significantly increased the detection of posterior injury pattern compared with the standard 12-lead electrocardiogram. Using all 15 leads significantly further improved the detection of circumflex coronary-related injury pattern over the standard 12-lead electrocardiogram.

Angioplasty, Balloon, Coronary↗

PubMed1996

Improved intrapartum surveillance with PR interval analysis of the fetal electrocardiogram: a randomized trial showing a reduction in fetal blood sampling.

OBJECTIVE: Our goal was to test the hypothesis that the addition of fetal electrocardiogram time-interval analysis to conventional electronic fetal monitoring would significantly reduce the number of cases requiring fetal scalp blood sampling without an increase in adverse outcome. STUDY DESIGN: A randomized prospective trial was performed in 214 women with high-risk labor. RESULTS: There was a significant reduction in the number of cases that had fetal blood sampling performed in the fetal electrocardiogram plus electronic fetal monitoring group (risk ratio for electronic fetal monitoring alone 3.53; p < 0.01, 95% confidence interval 1.39 to 8.95). The fetal blood samplings performed in the electronic fetal monitoring alone group were less likely to be abnormal (pH < 7.25, base excess < -8.0) than those performed in the fetal electrocardiogram plus electronic fetal monitoring group (risk ratio for electronic fetal monitoring alone 0.62, p = 0.05, 95% confidence interval 0.35 to 1.10). There was a trend of more infants with an arterial umbilical pH < 7.15 and a base excess less than -8.0 mmol/L at birth being unsuspected and more instrumental deliveries for presumed fetal distress being performed in the electronic fetal monitoring alone than in the fetal electrocardiogram plus electronic fetal monitoring group. CONCLUSION: The addition of fetal electrocardiogram analysis to conventional electronic fetal monitoring during labor can reduce significantly the number of parturients undergoing fetal scalp blood sampling and can simultaneously increase its efficiency without an increase in adverse outcome.

Acidosis↗

PubMed1987

The signal-averaged electrocardiogram as a screening test for inducibility of sustained ventricular tachycardia in high risk patients: a prospective study.

The role of the signal-averaged electrocardiogram in predicting the induction of sustained monomorphic ventricular tachycardia in high risk patients was assessed prospectively in 100 consecutive patients. Presenting diagnoses were syncope (38 patients), nonsustained ventricular tachycardia (24 patients), sustained ventricular tachycardia (25 patients) and sudden cardiac arrest (13 patients). Using programmed ventricular stimulation, 71 patients (group I) did not have and 29 patients (group II) did have inducible sustained monomorphic ventricular tachycardia. Using the signal-averaged electrocardiogram with filtering (6 dB/octave) at high pass corner frequencies of 67 and 100 Hz, the two groups were compared. The signal-averaged electrocardiogram was considered abnormal if all of the following criteria were satisfied: 1) the total filtered QRS complex duration was greater than 120 ms, 2) the duration of the terminal QRS complex of less than or equal to 20 microV was greater than or equal to 30 ms, and 3) at least one deflection (late potential) was present in this region. Differences between groups I and II in these three measures were highly significant (p less than or equal to 0.001). The sensitivity and specificity of signal averaging for predicting the induction of sustained ventricular tachycardia were 93 and 94%, respectively. Stepwise logistic regression analysis identified the signal-averaged electrocardiogram as the best predictor of induction of sustained monomorphic ventricular tachycardia, independent of left ventricular ejection fraction, presence of ventricular aneurysm, myocardial infarction and other clinical variables (chi-square = 93.2, p less than 0.0001). The signal-averaged electrocardiogram is a sensitive and specific test for the induction of sustained monomorphic ventricular tachycardia, having independent predictive value.

Coronary Disease↗

PubMed2000

Specificity of the stress electrocardiogram during adenosine myocardial perfusion imaging in patients taking digoxin.

BACKGROUND: In patients taking digoxin, the exercise electrocardiogram has a lower specificity for detecting coronary artery disease. However, the effect of digoxin on adenosine-induced ST-segment depression is unknown. The purpose of this study was to evaluate the specificity of the electrocardiogram during adenosine myocardial perfusion imaging in patients taking digoxin. METHODS: Between May 1991 and September 1997, patients (n = 99) taking digoxin who underwent adenosine stress imaging with thallium-201 or technetium-99m sestamibi and coronary angiography within 3 months were retrospectively identified. Exclusion criteria included prior myocardial infarction, coronary artery angioplasty or bypass surgery, left bundle branch block, paced ventricular rhythm, or significant valvular disease. Twelve-lead electrocardiograms were visually interpreted at baseline, during adenosine infusion, and during the recovery period. The stress electrocardiogram was considered positive if there was > or =1 mm additional horizontal or downsloping ST-segment depression or elevation 0.08 seconds after the J-point compared with the baseline tracing. RESULTS: ST-segment depression and/or elevation occurred in 24 of 99 patients. There were only 2 false-positive stress electrocardiograms, yielding a specificity of 87% and positive predictive value of 92%. All 8 patients with > or =2 mm ST segment depression had multivessel disease by coronary angiography. CONCLUSIONS: ST-segment depression or elevation during adenosine myocardial perfusion imaging in patients taking digoxin is highly specific for coronary artery disease. Marked (> or =2 mm) ST-segment depression and/or ST-segment elevation is associated with a high likelihood of multivessel disease.

Adenosine↗

PubMed2000

The fetal electrocardiogram: relationship with acidemia at delivery.

OBJECTIVE: This study was undertaken to analyze the relationship between the fetal electrocardiogram and arterial pH and base excess at delivery. STUDY DESIGN: In the labor wards of three teaching hospitals a retrospective observational study was conducted on fetal monitor recordings of 679 women for whom there was an indication for continuous fetal monitoring during labor. These women had been recruited as part of either observational studies or a prospective randomized trial related to the Nottingham fetal electrocardiographic project. Fetal heart and uterine contraction data were obtained with the Nottingham fetal electrocardiographic analyzer. Morphologic and time interval analyses of the fetal electrocardiogram were performed. Evaluation was carried out for the last half hour before delivery. Main outcome measures were umbilical arterial pH and base excess at delivery. RESULTS: The study demonstrated a relationship between time interval analysis of the fetal electrocardiogram and a low umbilical arterial pH and base excess at delivery. Analysis of the morphologic characteristics of the fetal electrocardiogram (ST segment and T-wave height) showed no significant relationship. CONCLUSIONS: Time interval analysis of the fetal electrocardiogram during labor is related to relative acidemia at delivery.

Acidosis↗

PubMed2005

Use of an artificial neural network to localize accessory pathways of Wolff-Parkinson-White syndrome with 12-lead electrocardiogram.

Today, radio-frequency ablation has been shown to be a safe and effective method to treat paroxysmal tachycardia with Wolff-Parkinson-White syndrome. The many criteria reported for localizing the sites of accessory pathways from a 12-lead electrocardiogram have not proven adequate to differentiate the correct sites of accessory pathways for all situations. This study trained an artificial neural network to differentiate the varied features needed to localize 10 sites of accessory pathways. One hundred fifty patients underwent successful catheter ablation, with manifest single and antegradely conducting accessory pathways. Using the two electrocardiogram features of polarity of delta wave and R wave's share of QRS complex, an artificial neural network learned the characteristics of electrocardiogram waves for each site of the 10 accessory pathways through 90 learning cases, and an applicable network model was developed for testing. In 58 of 60 test cases (96.7%), sites of accessory pathways were localized correctly by the network. Based on the method employed in the present study, it thus becomes possible to predict the sites of accessory pathways with Wolff-Parkinson-White syndrome in more detail by using an artificial neural network with a 12-lead electrocardiogram. In the future, when this method is incorporated into a conventional automatic electrocardiogram system which could analyze delta waves and ORS complex, it will become useful to automatically diagnose the locations of the accessory pathways with Wolff-Parkinson-White syndrome in clinical practice.

Adolescent↗

PubMed1981

Significance of minor ST segment and T wave changes in the resting electrocardiogram of asymptomatic subjects.

Sixteen thousand resting electrocardiograms were performed on 14000 United Kingdom professional aircrew and air traffic control officers over a two-year period; 103 asymptomatic men with minor ST segment and T wave changes at rest were assessed by exercise electrocardiography and 19 responded abnormally. Five subjects had proven coronary artery disease, one hypertrophic obstructive cardiomyopathy, and one left ventricular dilatation on echocardiography. Eleven subjects were not investigated, of whom three had strongly positive exercise responses. One subject had a false positive response and assuming a false negative response of less than 2 per cent, then a sensitivity of 80.0 per cent, a specificity of 89.1 per cent, a predictive value for the exercise electrocardiogram of 44.46 per cent and for the resting electrocardiogram of 7.8 per cent is obtained. T wave changes induced by hyperventilation were common (53.4% of all). Ten (18.2%) subjects with hyperventilation-induced T wave changes responded abnormally to exercise, three having angiographically proven coronary artery disease lending little support to the contention that the two entities rarely coexist. In spite of the low return from routine electrocardiograms in a population with a low prevalence of coronary artery disease, three-eighths of those with significant coronary artery disease presented with minor ST segment and T wave changes on their resting electrocardiograms.

Adolescent↗