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A 40-year-old man with a history of prior closed head injury, insulin-dependent diabetes mellitus type 2, and nicotine dependence was evaluated at Saint Marys Hospital, a Mayo Clinic–affiliated hospital in Rochester, MN, after being found unconscious at his home.

To further characterize the effects of heart rate on systolic and diastolic function in patients with idiopathic dilated cardiomyopathy (IDCM), it was hypothesized that the relationship between heart rate and left ventricular systolic and diastolic function would be unaltered by beta-blockade and exercise.Eighteen patients with IDCM were randomized in a double-blind manner to receive either metoprolol or placebo for 3 months. Before and after 3 months of therapy, resting and exercise radionuclide left ventriculograms were obtained for assessment of left ventricular systolic and diastolic function.At rest, metoprolol treatment compared with placebo was associated with decreased heart rate (61 +/- 11 vs 99 +/- 10 beats/min, P.0001) and an increased left ventricular ejection fraction (0.32% +/- 0.10% vs 0.17% +/- 0.08%, P =.01). With exercise, metoprolol compared with placebo caused a decreased heart rate (86 +/- 18 vs 126 +/- 43 beats/min, P =.056), an increase in left ventricular ejection fraction (0.32% +/- 0.14% vs 0.19% +/- 0.07%, P =.052), a longer time to peak filling rate (164 +/- 21 vs 127 +/- 17 ms, P =.005), and a decreased peak filling rate (5.41 +/- 1.71 vs 8.40 +/- 1.85 stroke volumes/s, P =.012). Before beta-blockade, heart rate at rest was negatively correlated to left ventricular ejection fraction and positively correlated to peak filling rate; with exercise, the relationships of heart rate to left ventricular ejection fraction and peak filling rate were similar. After metoprolol treatment, the heart rate continued to have a similar positive correlation with the peak filling rate at rest and with exercise.In patients with IDCM, systolic and diastolic cardiac function, at rest and with exercise, was related to heart rate. After beta-blockade, at rest and with exercise, diastolic function continued to be related to heart rate.

The prognostic value of exercise thallium-201 imaging has been well established in referral patient populations at tertiary care centers, but these results may be influenced by referral bias.This study was performed to evaluate the prognostic value of thallium imaging in a community-based population of 446 residents of Olmsted County, Minn. Eleven variables were prospectively selected and tested for their associations with outcome end points.Four variables (age, history of myocardial infarction, number of abnormal thallium segments on the postexercise images, and increased thallium lung uptake) contained the most independent prognostic information. For the end point overall mortality rate, the multivariate chi-square values were 17.2 (p0.0001) for age and 20.9 (p0.0001) for the number of abnormal thallium segments on the postexercise images. Five-year survival rate for patients older than the median age of 59 years with an abnormal scan was 84% versus 97% for patientsor = 59 years of age with a normal scan.Exercise thallium imaging was useful for prognostic purposes in this relatively low-risk community population, confirming the findings of referral population studies.

This study sought to determine the prevalence of spontaneous reperfusion of an infarct-related artery (IRA) and associated myocardial salvage in the absence of thrombolysis or angioplasty. Twenty-one patients with acute myocardial infarction received only heparin and aspirin. At a median of 18 hours after presentation, 12 patients (57%) had angiographic patency of the IRA. Technetium-99m sestamibi was injected acutely on presentation and again at hospital discharge. Acute and final perfusion defect sizes were measured. Their difference, myocardial salvage, was calculated along with salvage index (myocardial salvage/acute defect). Comparing patients with a patent versus occluded IRA, myocardium at risk was similar (16% +/- 12% vs 12% +/- 9% left ventricle, p = NS); however, myocardial salvage (9% +/- 9% vs -2% +/- 7% left ventricle, p = 0.01), and salvage index (0.62 +/- 0.37 vs 0.19 +/- 0.33, p = 0.01) were greater in patients with spontaneous reperfusion. Resolution of chest pain was greater in patients with a patent IRA (100% vs 55%, p = 0.003). Spontaneous reperfusion of the IRA occurs frequently in patients with acute myocardial infarction and is associated with significant myocardial salvage.

Objectives. This study sought to determine the accuracy of the initial 12-lead electrocardiogram (ECG) in predicting final infarct size after direct coronary angioplasty for myocardial infarction and to examine which physiologic variables known to be determinants of outcome the ST segment changes most closely reflect. Background. Myocardium at risk, collateral flow and time to reperfusion have been shown to be independent physiologic predictors of infarct size in animal and clinical models. However, such measurements may be difficult to perform on a routine basis in patients with myocardial infarction. The standard 12-lead ECG is inexpensive and readily available. Methods. Sixty-seven patients with acute myocardial infarction, ST segment elevation and duration of chest pain

Early tomographic myocardial perfusion imaging with technetium-99m sestamibi was performed during inferior wall acute myocardial infarction to determine the relation between the amount and location of myocardium at risk and the presence or absence or anterior ST depression. The total size of the acute perfusion defect and its lateral and septal borders were measured in 29 consecutive patients who were admitted with > 30 minutes of chest pain and acute inferior ST elevation on their initial electrocardiogram. The 22 patients with anterior ST depression had significantly more left ventricular myocardium at risk than the 19 patients who did not have anterior ST depression (23 +/- 2% of the left ventricle vs 15 +/- 1%, p = 0.008). All 8 patients with > 25% of the left ventricle at risk had anterior ST depression. Patients with anterior ST depression had a significantly greater lateral extent of the acute perfusion defect (49 degrees +/- 8 degrees from the midinferior wall vs 23 degrees +/- 7 degrees, p = 0.002). There was no difference in the septal border of the perfusion defect between patients with and without anterior ST depression (-44 degrees +/- 4 degrees vs -46 degrees +/- 7 degrees, p = NS). No patient had a measurable anterior perfusion defect. Although there is considerable overlap between groups with and without anterior ST depression, anterior ST depression is a simple and readily available indicator of myocardium at risk in inferior wall acute myocardial infarction.

Diastolic filling can be measured by radionuclide ventriculography with use of several techniques including those based on gated and list-mode acquisitions, the first-pass method, and the nuclear probe. Radionuclide ventriculography specifically assesses volumes, rates of volume change, and intervals during ventricular filling. Normal values for diastolic filling measurement vary depending on the individual radionuclide methods used and the age of the patient. Comparative studies of the radionuclide method with contrast angiographic and Doppler echocardiographic techniques for measuring diastole are discussed, and the advantages and disadvantages of the radionuclide techniques are explored. The role of radionuclide assessment of diastolic function in specific clinical examples of hypertrophic cardiomyopathy, hypertension, anthracycline-induced cardiomyopathy, and coronary artery disease is reviewed. Radionuclide ventriculography is an accurate and easily applicable procedure for studying left ventricular volume changes in diastole.

Episodic behavior associated with impairment of consciousness is a protean clinical manifestation that may suggest a wide range of medical or neurologic disorders. We describe a patient whose symptoms of an epigastric "aura" followed by loss of consciousness suggested temporal lobe epilepsy. The episodic behavior was refractory to antiepileptic drug therapy. Prolonged video-electro-encephalographic monitoring confirmed that the clinical events were cardiogenic related to asystole. Antiepileptic drug therapy was discontinued, and a cardiac pacemaker was inserted. The clinical patterns that distinguish syncope from seizures and the importance of prolonged video-electroencephalographic monitoring are discussed.

Prior studies that have demonstrated the prognostic utility of exercise thallium-201 (TI) imaging have been performed in tertiary care centers and potentially may have been influenced by patient-referral bias. To evaluate the prognostic value of TI imaging in a community-based population, 250 residents (age 58 ± 12 yrs, M164, F86) of Olmsted County, MN who underwent exercise TI tomographic imaging were followed for a median duration of 5.3 years. There were 32 initial cardiac events—5 deaths, 15 nonfatal myocardial infarctions (MI), and 12 “late” revascularization procedures performed g 3 mos after the TI study. Five-year event-free survival was 87%. The following table shows the univariate association with time to an event by Cox proportional hazards analysis: Variable X2 p Age 25.0 l 0.001 Gender 3.0 NS Prior MI 22.8 l 0.001 Chest pain class 0.4 NS Exercise duration 8.7 0.003 Magnitude ST depression 0.9 NS Exercise angina score 4.2 0.04 Any TI redistribution 6.8 0.009 #segments with TI redistribution 13.0 l 0.001 #abnormal TI segments post exercise 27.9 l 0.001 Increased lung uptake of TI 0.7 NS By multivariate analysis the only variables independently associated with outcome were age (x2 = 13.3, p = l 0.001) and the # abnormal TI segments post exercise (x2 = 8.0, p = 0.005). Conclusion As demonstrated previously for referral populations from tertiary care centers, exercise TI imaging is also useful for prognostic purposes in a community-based population.

Radionuclide angiography was used to study the effects of supine and upright bicycle exercise and handgrip exercise in 17 (12 well-trained) normal subjects before (control) and immediately after the administration of propranolol (160 mg/day for 4 days). Cardiac hemodynamic values were related to position in that control left ventricular volumes and the cardiac index were greater in the supine position than in the upright at rest but resting left ventricular ejection fraction was similar in both positions. The pressure volume index was greater in the upright position than in the supine. At maximal exercise before treatment, however, similar cardiovascular hemodynamic measurements were recorded in both positions. Propranolol increased left ventricular end-diastolic volume at rest and at maximal exercise. Left ventricular end-systolic volume, however, was substantially greater only in the upright position both at rest and at maximal exercise when compared with control values. Heart rate, systolic arterial pressure, cardiac index, and pressure volume index were decreased at rest and maximal exercise after treatment with propranolol. Ejection fraction was decreased in the upright position after propranolol administration but was unchanged in the supine position. Handgrip exercise primarily increased heart rate and arterial pressure and did not affect cardiac volume, and this response was unaffected by propranolol.

This study examines the recently reported gender differences in cardiac responses to exercise. The study group consisted of 192 men and 67 women with a low probability of coronary artery disease who underwent supine exercise radionuclide angiography.Men had a lower rest ejection fraction than that of women (0.63 versus 0.66, p = 0.02) and greater increases in ejection fraction with exercise (0.08 versus 0.02, p = 0.0001). The slope relating ejection fraction to metabolic equivalents of exercise (METs) was greater (p = 0.004) for men, even after adjustment for differences in rest ejection fraction and end-diastolic volume index. Compared with men, women had a smaller rest end-diastolic volume index (87 versus 97 ml/m2, p = 0.003) and a greater increase in end-diastolic volume index with exercise (6 versus −2 ml/m2, p = 0.002).The slope relating end-diastolic volume to METs was greater for women, even after adjustment for differences in rest end-diastolic volume index and peak work load. There are clear gender differences in the supine exercise response of ejection fraction and end-diastolic volume that are not explained by differences in exercise capacity.

Left ventricular (LV) filling at rest was studied by radionuclide ventriculography using alternate R-wave gating in 42 patients (29 men, 13 women) who had a low likelihood of cardiac disease. LV filling measurements differed little between men and women. Age was correlated positively with atrial filling duration (r = 0.55), atrial filling duration fraction (r = 0.52) and atrial filling fraction (r = 0.56) and negatively with rapid filling fraction (r = -0.58). Age was not correlated with peak filling rate, time to peak filling rate and first-half filling fraction. The heart rate at rest was significantly negatively correlated with rapid (r = -0.62), slow (r = -0.81) and atrial (r = -0.72) filling durations, but not with isovolumic duration. The heart rate at rest was weakly positively correlated with peak filling rate in end-diastolic volume per second (r = 0.36) and negatively correlated with first-half filling fraction (r = -0.35). Systolic pressure at rest influenced atrial filling duration. LV ejection fraction and end-diastolic volume index were not correlated significantly with LV filling in relatively normal subjects.

In 622 patients with known coronary artery anatomy, heart rate (HR).blood pressure (BP) product and left ventricular (LV) ejection fraction (EF) at maximal supine exercise measured by radionuclide ventriculography were used to estimate, by logistic regression analysis, the probabilities of absence of significant coronary artery disease (CAD), presence of significant CAD, presence of multivessel CAD and presence of 3-vessel CAD. Thus, for example, estimated probabilities of each of the aforementioned 4 categories of CAD are 0.39, 0.61, 0.32 and 0.12, respectively, for HR.BP product of 26,000 beats.mm Hg/min and LVEF of 0.6 at maximal exercise and 0.08, 0.92, 0.77 and 0.48, respectively, for HR.BP of 15,000 and LVEF of 0.4. The graphic presentations of these estimated probabilities form useful guidelines for interpreting the results of exercise radionuclide ventriculography. In addition, specific cutoff values at maximal exercise defined 2 groups: (HR.BP product greater than or equal to 21,000 beats.mm Hg/min and LVEF greater than or equal to 0.55) with a high (70%) likelihood of absence of significant CAD or 1-vessel CAD and a low (7%) likelihood of 3-vessel CAD, and (HR.BP product less than 21,000 and LVEF less than 0.55) with a high (72%) likelihood of multivessel CAD and a low (8%) likelihood of absence of CAD.

We studied the reproducibility of four tests of peripheral occlusive arterial disease in 54 subjects, 32 of whom had this disease. We found that the reproducibility of systolic blood pressures obtained at rest from the thighs, calves, and ankles approximated that of arm systolic and diastolic blood pressures, as did the ankle-to-arm systolic blood pressure ratios. The average of the tenth and ninetieth percentile ranges of the resting systolic blood pressure ankle-to-arm rations was ± 0.10. Systolic blood pressures from the fingers were somewhat less reproducible, and those from the toes were even more variable. Systolic blood pressure ankle-to-arm ratios measured after the patient had exercised were less reproducible than resting ratios. The average of the tenth and ninetieth percentile ranges of the 1-, 3-, 5-, and 10-minute ratios after exercise was −0.13 to +0.16. Skin temperatures from the fingers and toes were approximately as reproducible as systolic blood pressures from the arms and legs and as the resting ankle-to-arm blood pressure ratios. Pulse-volume recordings from the thighs, calves, ankles, feet, toes, and fingers were very poorly reproducible. We conclude that information on the reproducibility of these measurements is essential in the evaluation of noninvasive arterial tests that are used to determine the course of peripheral occlusive arterial disease. (J VASC SURG 1985;2:678-83.)

In 84 consecutive patients with resting T-wave inversion, radionuclide angiography revealed significant new wall motion abnormalities in 13 (28 percent) of the 47 patients with persistent T-wave inversion and in 23 (62 percent) of the 37 patients with T-wave pseudonormalization during exercise (p less than 0.01). The response of the ejection fraction to exercise was better in patients with persistent T-wave inversion than in those with pseudonormalization (p less than 0.04). Mechanical evidence of ischemia was seen in 14 (61 percent) of the 23 patients with T-wave pseudonormalization but without ST-segment depression. In patients with resting T-wave inversion, pseudonormalization was slightly more sensitive but less specific than a positive exercise test for predicting significant new wall motion abnormalities or decreases in the ejection fraction with exercise. Although pseudonormalization is not extremely useful alone, the presence or absence of this finding can increase the diagnostic accuracy of exercise electrocardiography in patients with resting T-wave inversion and suspected ischemic heart disease.

The significance of a decline in systolic blood pressure (BP) during supine exercise was examined in 820 patients who underwent both supine exercise gated equilibrium radionuclide ventriculography and coronary angiography. Twenty-seven patients, 3% of the study population, had a decrease in systolic BP at peak exercise of more than 10 mm Hg from the systolic BP at rest. Other indicators of ischemia--angina, ST-segment depression, a decrease in ejection fraction and wall motion abnormality during exercise--were present frequently but not uniformly in these patients. Although most patients had a decline in ejection fraction and a new wall motion abnormality with exercise, 4 patients had an increase in ejection fraction with exercise without any regional wall motion abnormalities. Coronary angiography in the 27 patients with systolic hypotension demonstrated severe coronary artery disease (CAD). Twenty-two patients (81%) had 3-vessel or left main CAD. Twenty of these 22 patients with 3-vessel CAD had at least 2 arteries with 90% or more diameter stenoses. Systolic hypotension during supine exercise radionuclide angiography is infrequent, usually associated with evidence of global and regional left ventricular dysfunction, and a marker of very severe CAD.