Jacqueline O'Donnell

Exercise echocardiography: detection of coronary artery disease in patients with normal left ventricular wall motion at rest.

Most studies investigating the ability of exercise two-dimensional echocardiography to identify patients with coronary artery disease have included patients with left ventricular wall motion abnormalities at rest. This has the effect of increasing sensitivity because patients with only abnormalities at rest are detected. To determine the diagnostic utility of exercise echocardiography in patients with normal wall motion at rest, 64 patients were studied with exercise echocardiography in conjunction with routine treadmill exercise testing before coronary cineangiography. All 24 patients who had no angiographic evidence of coronary artery disease had a negative exercise echocardiogram (100% specificity). Nine of 40 patients with coronary artery disease (defined as greater than or equal to 50% narrowing of at least one major vessel) also had a negative exercise echocardiogram (78% sensitivity). Of the nine patients with a false negative exercise echocardiographic study, six had single vessel disease. Among 25 patients with single vessel disease, exercise echocardiography was significantly more sensitive (p = 0.01) than treadmill exercise testing alone (76 versus 36%, respectively). Among 15 patients with multivessel disease, the two tests demonstrated similar sensitivity (80%). In conclusion, exercise echocardiography is highly specific and moderately sensitive for the detection of coronary artery disease in patients with normal wall motion at rest. Although exercise echocardiography is significantly more sensitive than treadmill exercise electrocardiographic testing alone in patients with single vessel disease, the two tests are similar in their ability to detect coronary artery disease in patients with multivessel disease and normal wall motion at rest.

Complementary Value of Two-Dimensional Exercise Echocardiography to Routine Treadmill Exercise Testing

Two-dimensional echocardiograms were done during rest and after exercise in 95 patients who subsequently had coronary arteriography. Prior myocardial infarction was present in 36 patients, 35 of whom had wall motion abnormalities. There was no evidence of prior infarction in 59 patients, 44 of whom had coronary disease. In these 44 patients, the exercise electrocardiogram showed ischemia in 19, was normal in 13, and was nondiagnostic in 12. Exercise echocardiograms were abnormal in 35 of these 44 patients. In 15 patients without coronary disease, the treadmill response was nondiagnostic in 6, ischemic in 1, and normal in 8. Exercise echocardiograms were normal in 13 of these 15 patients. We conclude that exercise echocardiography is a valuable addition to routine treadmill testing. It may be of special value in patients with an abnormal resting electrocardiogram or a nondiagnostic response to treadmill testing or when a false-negative treadmill test is suspected.

Risk stratification after acute myocardial infarction by means of exercise two-dimensional echocardiography

To determine whether exercise two-dimensional echocardiography contributes to the prognostic information provided by exercise testing in patients recovering from acute myocardial infarction, 40 patients were prospectively studied by means of pre- and postexercise echocardiography 10 to 21 days after myocardial infarction. Patients were followed for 6 to 10 months or until one of the following clinical end points occurred: death, recurrent myocardial infarction, unstable angina, or coronary artery bypass grafting. Results of treadmill exercise tests were negative in 13 of 20 patients with good clinical outcome (65% specificity) and positive in 11 of 20 patients with poor clinical outcome (55% sensitivity). The resting echocardiogram was abnormal in 37 of 40 patients. The exercise echocardiogram was negative in 19 of 20 patients with good clinical outcome (95% specificity) and positive in 16 of 20 patients with poor clinical outcome (80% sensitivity). We conclude that exercise echocardiography is more sensitive and specific than treadmill exercise testing for predicting the occurrence of subsequent cardiac events after acute myocardial infarction.

The abnormal exercise electrocardiogram in apparently healthy men: a predictor of angina pectoris as an initial coronary event during long-term follow-up.

A group of 916 apparently healthy men between the ages of 27 and 55 years (mean 37) were followed up with serial medical and exercise test evaluations for a period of 8 to 15 years (mean 12.7) to determine (1) the prevalence and specific types of new coronary events observed in subjects with and without abnormal ST segment responses to exercise and (2) the predictive value of a serial conversion to an abnormal ST segment response to exercise for new coronary events. During the initial evaluation there were 23 subjects (2.5%) with an abnormal ST segment response to exercise. During follow-up there were nine (39%) coronary events in this group: eight cases of angina and one of sudden death. With serial testing, an additional 38 subjects (5.1%) experienced conversion to an abnormal ST segment response to exercise. During follow-up there were 12 (32%) coronary events in this group: 10 cases of angina, one of myocardial infarction, and one other. There were 833 subjects with normal ST segment responses to exercise with all tests. In this group there were 44 (5.3%) coronary events: 25 cases of myocardial infarction, seven of sudden death, and 12 of angina. We conclude that in apparently healthy middle-aged men an abnormal ST segment response to exercise is predictive of angina pectoris but not of myocardial infarction or sudden cardiac death as an initial coronary event.

Detection of Coronary Artery Disease With Upright Bicycle Exercise Echocardiography

This study examined the advantages and limitations of upright bicycle exercise echocardiography in the evaluation of a large series of patients with known or suspected coronary artery disease. The study population consisted of 309 patients (231 men, mean age 57 +/- 11 years) who underwent exercise echocardiography within 8.5 +/- 16.1 days of coronary angiography. All stress electrocardiographic, echocardiographic, and angiographic data were reinterpreted in a blinded manner by the investigators. No patient was excluded because of poor echocardiographic image quality. Wall motion was analyzed at baseline, peak exercise, and immediately after exercise with a 16-segment model, and a regional wall motion score index was calculated at each stage. Abnormalities were ascribed to the distribution of the three coronary arteries and correlated with qualitative angiography. There were 126 patients with wall motion abnormalities at rest and 211 (75%) with coronary artery disease. The stress electrocardiogram (ECG) was negative in 61, positive in 144, and nondiagnostic in 104, yielding a sensitivity of 40% and a specificity of 89%. Echocardiography was normal in 76 of 98 patients without coronary disease (78% specificity) and abnormal in 193 of 211 patients with disease (91% sensitivity). Sensitivity was higher among patients with multivessel disease compared with those with single vessel disease (95% versus 86%, respectively, p = 0.03). Among patients with normal wall motion at rest (n = 183), sensitivity was 83% and specificity was 84%. Of the 104 patients with a nondiagnostic stress ECG, echocardiography correctly identified 95% of those with coronary disease and 75% of those without disease. Among 82 patients with a wall motion abnormality at rest, an additional exercise-induced wall motion abnormality developed in 32 of 46 patients (70%) with multivessel disease and seven of 32 (22%) with single-vessel disease. Overall, echocardiography detected 258 of 392 (66%) individual coronary lesions. Accuracy was higher for lesions in the left anterior descending and right coronary arteries (both 79%) compared with the left circumflex artery (36%, p < 0.001). In conclusion, upright bicycle exercise echocardiography is an accurate technique for the evaluation of patients with known or suspected coronary artery disease and is especially valuable in patients with a nondiagnostic stress ECG. The test provides supplemental information on the extent and location of coronary lesions and is useful in patients with and without prior myocardial infarction.

Exercise-induced left bundle branch block and its relation to coronary artery disease

The records of 2,584 consecutive patients who underwent both treadmill exercise testing and coronary cineangiography were reviewed to determine the relation between exercise-induced, acceleration-dependent left bundle branch block (LBBB) and the presence of coronary artery disease (CAD). Rate-dependent LBBB during exercise was identified in 28 patients (1.1%), who were categorized according to their presenting symptoms: classic angina pectoris, atypical chest pain, symptomatic cardiac arrhythmia and asymptomatic. Asymptomatic patients underwent a screening exercise test. CAD was present in 7 of 10 patients who presented with classic angina pectoris, but 12 of 13 patients presenting with atypical chest pain had normal coronary arteries. All 10 patients in whom LBBB developed at a heart rate of 125 beats/min or higher were free of CAD, whereas 9 of 18 patients in whom LBBB developed at a heart rate of less than 125 beats/min had CAD. Normal coronary arteries were present in 3 patients who presented with angina and in whom both chest pain and LBBB developed during exercise. It is concluded that patients who present with atypical chest pain in whom rate-dependent LBBB develops on the treadmill are significantly less likely to have CAD than patients who present with classic angina; the onset of LBBB at a heart rate of 125 beats/min or higher is highly correlated with the presence of normal coronary arteries, regardless of patient presentation; and patients with angina in whom both chest pain and LBBB develop during exercise may have normal coronary arteries.

Computer quantitation of Q-T and terminal T wave (aT-eT) intervals during exercise: Methodology and results in normal men

Computer-quantitated measurements of the Q-T intervals, the Q-T/Q-Tc ratio (Q-T/corrected Q-T) and the terminal T wave (apex to end of T [aT-eT] interval) were evaluated in resting and exercise electrocardiograms of 130 normal men with a mean age of 40 years. Pseudo-orthogonal, bipolar X, Y and Z axis leads were recorded during treadmill exercise testing, and 25 consecutive QRS-T complexes from standing rest and three exercise stages were computer-averaged. The Q-T intervals, Q-T/Q-Tc ratio and aT-eT interval measurements were then computed in the X and Z axis leads only, because the Y lead proved to be too noisy for accurate interpretation. A correlation coefficient of 0.9830 resulted between measurements made manually from the plotted, composite QRS-T complexes and those made by computer. No significant differences , in the paired sense, were found between any of the measurements. Measurements made on the Z axis lead; however, the differences in the measurements remained constant across all stages of exercise. A Q-T/Q-Tc ratio of greater than 1.08, previously reported to be a reliable indicator of coronary disease, was observed in the majority of our normal subjects during exercise. Although the Q-T interval is substantially influenced by many factors, the aT-eT interval proved not to be age- or heart rate-dependent. It appears that the aT-eT interval can be measured with a high degree of reliability during exercise and it may prove to be a relatively specific indicator of repolarization alterations that occur with myocardial ischemia.

Exercise echocardiography, angiography, and intracoronary ultrasound after cardiac transplantation

Fifty-one consecutive patients underwent exercise echocardiography, angiography, and intracoronary ultrasound (ICUS) 2.5 years (range from 1 to 6) after cardiac transplantation. The average age of the donor was 29 years (range 13 to 50), and the average age of the recipient was 49 +/- 12 years. In total, 78 studies were performed, as 25 patients had >1 annual evaluation and 2 patients had 3 consecutive annual evaluations. Of the 78 angiographic studies, 40 (26 patients) had evidence of coronary artery disease, defined as a focal stenosis (>20%, n=4) or luminal irregularities (n=36). However, by ICUS all 51 patients had intimal thickening at some point, with 34 patients possessing diffuse disease and 17 focal intimal thickening only. Of the 25 serial studies, 12 progressed by at least 1 Stanford class. The sensitivity of angiography for determination of class III to IV intimal thickening was 64% and the specificity was 76%. On exercise echocardiography, 6 examinations revealed resting wall motions abnormalities, whereas 6 had inducible wall motion abnormalities with exercise. The sensitivity of exercise echocardiography to determine class III to IV intimal thickening was 15%, and the specificity was 85%. In conclusion, exercise echocardiography is an insensitive method for predicting transplant-mediated coronary artery disease, whereas luminal irregularities on angiography may predict the presence of Stanford grade III to IV intimal thickening.

Restrictive hemodynamic patterns after cardiac transplantation: Relationship to histologic signs of rejection

Hemodynamic and echocardiographic data from 33 consecutive patients undergoing cardiac transplantation were correlated with endomyocardial biopsy results to determine whether reversible restrictive hemodynamics accompany histologic evidence of transplant rejection. During the study period 251 biopsy specimens were obtained during periods of no histologic evidence of transplant rejection and 52 episodes of mild, 20 episodes of moderate, and one episode of severe rejection. Right atrial mean pressure increased significantly during episodes of moderate transplant rejection (9.9 +/- 6.2 mm Hg, p less than 0.001) compared with pressures obtained during periods when there was no evidence of rejection (4.6 +/- 3.2 mm Hg), mild rejection (5.8 +/- 3.9 mm Hg), or resolving rejection (4.3 +/- 3.4 mm Hg). Y descent was elevated during moderate rejection (9.6 +/- 4.2 mm Hg, p less than 0.001) compared with pressures during episodes of no rejection (5.6 +/- 2.5 mm Hg), mild rejection (6.6 +/- 2.7 mm Hg), and resolving rejection (5.8 +/- 3.1 mm Hg) and showed a wave morphology consistent with a restrictive hemodynamic pattern. Pulmonary capillary wedge pressure was increased during moderate rejection (14.4 +/- 6.4 mm Hg) when compared with pressures obtained during episodes of no rejection (10.2 +/- 5.8 mm Hg) or resolving rejection (10.2 +/- 5.4 mm Hg) (p less than 0.02). Sensitivity for a right atrial mean pressure of 11 mm Hg indicating moderate rejection was 41% with a specificity of 96%. Sensitivity for Y descent (greater than or equal to 10 mm Hg) was 52% and specificity was 94%.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Angioplasty and Stenting in Orthotopic Heart Transplants: A Fruitful Act or a Futile Attempt?

Accelerated allograft coronary artery disease remains the major cause of mortality after the first year of transplantation. Despite the extensive use of stents and angioplasty in coronary artery disease, there is a paucity of data about the efficacy of such interventions in orthotopic heart transplants. The authors herein report the outcome of those patients in their institution who had undergone percutaneous coronary artery angioplasty and stenting at a late stage of their transplantation. Within a 12-year period, 106 adult patients underwent orthotopic heart transplantation at their institution. Eight of these patients with 17 lesions underwent deployment of nine stents and eight angioplasties 8.1 ±3.2 years posttransplantation. There were 15 denovo and two restenotic lesions. The indications for intervention were presence of symptoms in five patients and severity of lesions in three asymptomatic patients detected on their follow-up angiogram. All patients had angiographic worsening of lesions at their follow-up angiogram. The initial procedural success for both stented and angioplastied lesions was 100%. Within a mean angiographic follow-up of 261 days, all balloon angioplastied lesions had developed restenosis, whereas within a mean period of 67 days, 50% of stented lesions had developed restenosis. On the follow-up angiogram, deterioration of the nontreated segments were noted throughout the coronary arterial tree; however, the immediate proximal and distal parts of the target segments demonstrated an exaggerated hyper proliferative response as compared to other sites. The overall median time to the detection of restenosis for both stented and angioplastied lesions was 5.2 months (inner quartile 2.5-6.2 months). The authors conclude that angioplasty and stenting late in the course of transplantation is associated with a significant restenosis rate and in such patients earlier or alternative catheter-based interventions must be considered.