The spread of methicillin-resistant Staphylococcus aureus in a rural community: will it become a common microorganism colonizing among the general population?

Myocardial perfusion imaging with 99mTc-MIBI was studied in 80 patients with coronary artery disease (CAD), 29 cases of normal controls and 37 cases of noncoronary heart diseases. The perfusion imaging was analysed both by qualitative and quantitative methods. The results revealed that the diagnostic sensitivity, specificity and accuracy for CAD were 91.5%, 83.8%, and 88.5% respectively by qualitativ method, and were 88.1%, 94.6% and 90.6% respectively by quantitative method. The diagnostic sensitivity of electrocardiogram (ECG) was 69.5%. Fourteen cases with the narrowing of coronary artery > 50% shown by coronary angiography also had abnormal myocardial perfusion imaging. It suggests that analysis of perfusion imaging by quantitative method in detecting CAD is superior than qualitative method and ECG.     

The importance of adequate exercise in the detection of coronary heart disease by radionuclide ventriculography

Rest and exercise radionuclide ventriculograms were obtained on 77 symptomatic patients without prior documented coronary artery disease (CAD). Coronary artery disease was present by angiograms in 48. Radionuclide ventriculography (RNV) was abnormal in 41 patients (overall sensitivity 85%). In 29 patients with normal coronary arteries, RNV was normal in 24 (specificity 83%). To determine if the exercise level affects sensitivity, the studies were graded for adequacy of exercise. It was considered adequate if patients developed (a) chest pain, or (b) ST segment depression of at least 1 mm, or (c) if they achieved a pressure rate produce greater than 250. Among the 48 patients with coronary artery disease, 35 achieved adequate exercise. Thirty-three had an abnormal RNV (sensitivity 94%). In 13 patients who failed to achieve adequate exercise, RNV was abnormal in eight (sensitivity of only 62%). Some patients with coronary artery disease may have a normal ventricular response at inadequate levels of stress.     

Exercise tolerance in asymptomatic elderly men with fluoroscopically detected coronary artery calcification

STUDY OBJECTIVE: The value of detecting coronary artery calcification (CAC), by cardiac imaging, for the diagnosis of coronary artery disease (CAD) in asymptomatic middle-aged men has been demonstrated. However, the incidence of CAC increases with age. The functional significance of CAC remains unknown in asymptomatic elderly men. The purpose of this study is to explore whether CAC in asymptomatic aging men signifies the presence of cardiovascular dysfunction during exercise. DESIGN: This study was designed to address whether elderly asymptomatic men, selected because they have CAC, have reduced exercise tolerance due to functionally significant CAD. Participants and setting: Thirty-eight asymptomatic male volunteers (ages 50 to 75 years, mean [+/-SD] 64+/-7 years) with a normal resting ECG and at least one coronary risk factor, in a population study. Nineteen subjects had CAC detected by digital subtraction fluoroscopy in at least two major coronary arteries, and 19 subjects had no identifiable CAC. METHODS AND RESULTS: Each subject underwent a symptom-limited incremental exercise test with 12-lead ECG monitoring and respiratory gas analysis. Four indexes of exercise oxygen transport were evaluated: peak oxygen uptake (VO2), lactic acidosis threshold, peak VO2/heart rate ratio, and VO2 relative to a work rate increase. Eleven of 38 subjects (28%) were found to have reduced oxygen transport, which was defined as an abnormal reduction in more than two of the above four indexes of oxygen transport. Five of the 11 subjects with reduced oxygen transport had CAC, and 6 subjects did not (not significant). Only one subject with CAC had exercise ST depression. CONCLUSION: Significant CAC in asymptomatic men over age 50 does not signify exercise limitation due to CAD.     

Global alteration in perfusion response to increasing oxygen consumption in patients with single-vessel coronary artery disease

BACKGROUND: Recent evidence suggests that, in coronary artery disease (CAD), myocardial blood flow (MBF) regulation is abnormal in regions supplied by apparently normal coronary arteries. However, the relation between this alteration and MBF response to increasing metabolic demand has not been fully elucidated. METHODS AND RESULTS: MBF was assessed at baseline, during atrial pacing tachycardia, and after dipyridamole (0.56 mg/kg IV over 4 minutes) in 9 normal subjects and in 24 patients with ischemia on effort, no myocardial infarction, and isolated left anterior descending (n = 19) or left circumflex (n = 5) coronary artery stenosis (> or = 50% diameter narrowing). Perfusion of both poststenotic (S) and normally supplied (N) areas was measured off therapy by positron emission tomography and [13N]ammonia. Normal subjects and CAD patients showed similar rate-pressure products at baseline, during pacing, and after dipyridamole. In CAD patients, MBF was lower in S than in N territories at rest (0.68 +/- 0.14 versus 0.74 +/- 0.18 mL.min-1.g-1, respectively, P < .05), during pacing (0.92 +/- 0.29 versus 1.16 +/- 0.40 mL.min-1.g-1, respectively, P < .01), and after dipyridamole (1.18 +/- 0.34 versus 1.77 +/- 0.71 mL.min-1.g-1, respectively, P < .01). However, normal subjects showed significantly higher values of MBF both at rest (0.92 +/- 0.13 mL.min-1.g-1, P < .05 versus both S and N areas), during pacing tachycardia (1.95 +/- 0.64 mL.min-1.g-1, P < .01 versus both S and N areas), and after dipyridamole (3.59 +/- 0.71 mL.min-1.g-1, P < .01 versus both S and N areas). The percent change in flow was strictly correlated with the corresponding change in rate-pressure product in normal subjects (r = .85, P < .01) but not in either S (r = .04, P = NS) or N regions (r = .08, P = NS) of CAD patients. CONCLUSIONS: Besides epicardial stenosis, further factors may affect flow response to increasing metabolic demand and coronary reserve in patients with CAD.     

Decreased baroreflex sensitivity in patients with stable coronary artery disease is correlated with the severity of coronary narrowing

Although studies have shown that arterial baroreflex sensitivity (BRS) is decreased in patients with acute myocardial infarction, BRS changes in patients with stable coronary artery disease (CAD) have not been studied extensively. We assessed BRS by the phenylephrine method in 55 normotensive and nondiabetic patients with chronic effort angina, old myocardial infarction, or both. The control group consisted of 24 age-matched patients without coronary lesions. To identify factors that determine BRS in stable CAD, we performed multivariate analysis using age, sex, left ventricular ejection fraction, pulmonary artery wedge pressure, resting systolic blood pressure, resting heart rate, the number of stenotic coronary arteries, history of myocardial infarction, and the presence or absence of angina pectoris as variables. BRS was significantly lower in patients with CAD than in control subjects (5.9 +/- 2.9 vs 6.9 +/- 2.4 ms/mm Hg, p < 0.05). In patients with CAD, BRS was inversely correlated with age, the resting heart rate, and the number of stenotic coronary vessels (p < 0.001, p < 0.005, and p < 0.005, respectively), but was independent of other clinical parameters, including the history of myocardial infarction. In control subjects, BRS was significantly correlated only with age. These results indicate that BRS is decreased in patients with stable CAD, and this decrease is correlated with the extent and severity of coronary narrowing.     

Effects of clonidine in a primed rat model of acute hepatic porphyria

The hypothesis that local release of prostanoids may contribute to the pharmacologic effect of nitroglycerin (NTG) has long been debated. Results of prostanoid blockade by indomethacin on NTG-induced effects, to date, have been inconclusive. To quantitate the effects of intravenous indomethacin on NTG-induced myocardial blood flow by using positron-emission tomography, we conducted a prospective, controlled, parallel-design study comparing patients with coronary artery disease with healthy volunteers. Eight subjects, four Canadian Class II-III coronary artery disease (CAD) with luminal narrowing of > 80% in a minimum of two vessels, and four healthy volunteers were evaluated. Baseline global myocardial blood flow was equivalent between the groups. NTG produced a 49.3 +/- 4.7% increase in myocardial blood flow in healthy volunteers (p = 0.006) and an -0.5 +/- 19.8% decrease in the group with CAD (p = 0.62 between groups). After indomethacin, both groups had a 24% decline in myocardial blood flow (CAD, p = 0.25; healthy, p = 0.03). One patient with CAD had acute ischemia after indomethacin. The study demonstrated that short-term intravenous indomethacin decreases NTG-induced myocardial blood flow to the same degree in both subjects with CAD and healthy individuals. Impairment of myocardial blood flow from this pharmacologic combination may be most important in patients with severe fixed lesions.     

Postexercise decrease in arterial blood pressure, total peripheral resistance and in circulatory responses to brief hyperoxia in subjects with mild essential hypertension

The objective of our study was: (1) to compare the influence of moderate exercise on circulatory after-response in mildly hypertensive (n = 8) and normotensive male subjects (n = 9); (2) to examine the circulatory response to 3-min hyperoxic inactivation of arterial chemoreceptors at rest and during postexercise period in both groups. Hypertensive men (HTS) with a systolic blood pressure (SBP) 148 +/- 5 mm Hg, diastolic blood pressure (DBP) 92.4 +/- 4 mm Hg; and normotensive men (NTS), with a SBP 126 +/- 3 mm Hg, DBP 75.6 +/- 1.3 mm Hg, were submitted to 20-min of moderate exercise on a cycloergometer (up to the level of 55% of each subject's resting heart rate reserve). Finger arterial BP was recorded continuously with Finapres, impedance reography was used for recording stroke volume, cardiac output and arm blood flow. In HTS a significant decrease in SBP by 14.5 +/- 3.4 mm Hg, DBP by 8.9 +/- 1.9 mm Hg, total peripheral resistance (TPR) by 0.45 +/- 0.05 TPR u. (33.7 +/- 2.7%), and in arm vascular resistance (AVR) by 11.0 +/- 2.7 PRU u. (35.6 +/- 7%), was observed over a 60-min postexercise period. NTS exhibited insignificant changes in SBP, DBP, AVR except a significant decrease in TPR limited only to 20-min postexercise period. Hyperoxia decreased SBP, DBP and TPR in HTS. This effect was significantly attenuated during the postexercise period. Long-lasting antihypertensive effect of a single dynamic exercise in HTS suggests that moderate exercise may be applied as an effective physiological procedure to reduce elevated arterial BP in mild hypertension. We suggest also that the attenuation of the sympathoexcitatory arterial chemoreceptor reflex may contribute to a postexercise decrease in arterial BP and in TPR in mildly hypertensive subjects.     

Heart rate variability in multiple sclerosis during a stable phase

BACKGROUND: Patients with ambulatory electrocardiographic (AECG) ST-segment depression and critical coronary narrowing are known to be at increased risk for adverse outcome, but little is known about patients with AECG ST-segment depression without critical coronary narrowing. HYPOTHESIS: The objectives of this study were to characterize the coronary angiographic pathology in patients with AECG ST-segment depression but without critical (< 50% diameter stenosis) coronary narrowing and to compare demographic and clinical findings in these patients with those enrolled in the Asymptomatic Cardiac Ischemia Pilot Study with AECG ST-segment depression and critical (> or = 50% diameter stenosis) coronary narrowing. METHODS: Coronary angiograms from patients with AECG ST-segment depression were reviewed in a central laboratory and quantitative measurement of percent stenosis was performed. Clinical and angiographic comparisons were made between patients with and without critical coronary narrowing. RESULTS: Patients without critical coronary narrowing (n = 64) were younger (p = 0.02), less likely to be male (p < 0.001) or to have risk factors for coronary atherosclerosis or a history of myocardial infarction (p < 0.001), and had fewer ischemic episodes per 24 h on the screening AECG (p = 0.02) than patients with critical coronary narrowing (n = 441). Of patients without critical narrowing, one half had angiographic evidence for coronary artery disease (> or = 20% stenosis) and 60% had an ejection fraction > 70%. CONCLUSIONS: Patients with AECG ST-segment depression without critical coronary narrowing are heterogeneous, with half having measurable coronary artery disease. Demographically and clinically, they appear to be different than patients with AECG ST-segment depression with critical coronary narrowing.     

Postexercise systolic blood pressure response: clinical application to the assessment of ischemic heart disease

Stress test parameters indicating the presence and extent of coronary artery disease have traditionally included such variables as exercise duration, and the blood pressure and ST-segment responses to exercise. The three-minute systolic blood pressure ratio, another important indicator of significant coronary artery disease, is a useful and readily obtainable measure that can be applied in all patients who are undergoing stress testing for the evaluation of known or suspected ischemic heart disease. The ratio is calculated by dividing the systolic blood pressure three minutes into the recovery phase of a treadmill exercise test by the systolic blood pressure at peak exercise. A three-minute systolic blood pressure ratio greater than 0.90 is considered abnormal and has a diagnostic accuracy of approximately 75 percent for the detection of coronary artery disease (i.e., an accuracy comparable to that of ST-segment depression). Higher values for the ratio are associated with more extensive coronary artery disease, as well as an adverse prognosis after myocardial infarction. Thus, the three-minute systolic blood pressure ratio provides information that is complementary to the traditional exercise test parameters for identifying high-risk ischemic heart disease.     

Effect of cigarette smoke on CYP1A1, CYP1A2 and CYP2B1/2 of nasal mucosae in F344 rats

BACKGROUND: Dobutamine stress echocardiography (DSE) is sensitive and specific in detecting myocardial ischemia of male patients. However, there have been few reports about the use of DSE for the detection of coronary artery disease (CAD) in women. METHODS: DSE was evaluated in 51 consecutive women who underwent concomitant quantitative coronary angiography. Forty-four of the 51 patients received stress thallium-201 single-photon emission computed tomography (SPECT), and 30 of the 51 patients had interpretable results (exercise level > or = 85% of age-predicted maximal heart rate) of treadmill exercise. Twenty-nine patients had angiographically documented CAD defined as > or = 50% diameter stenosis. RESULTS: The overall sensitivity of DSE and stress 201Tl SPECT in detecting CAD was 93% and 79% (p = nonsignificant), and the specificity was 82% and 75% (p = nonsignificant), respectively. A combination of both tests increased the sensitivity (96%) at the expense of some decrease in specificity (60%). The agreement of DSE and 201Tl SPECT was 68% (30 of 44; kappa statistic = 0.35; p < 0.0001). The overall sensitivity, specificity, and accuracy in detecting CAD by treadmill exercise test and DSE were 71% vs 93% (p = nonsignificant), 44% vs 82% (p = 0.036), and 57% vs 88% (p = 0.003). In patients with abnormal results of treadmill exercise testing, the false-positive rate in detecting CAD was 2 (18%) of 11 in patients with abnormal results of DSE and 7 (88%) of 8 in those with normal results of DSE (p = 0.005). In patients with normal results of treadmill exercise testing, the false-negative rate in detecting CAD was 4 (100%) of 4 in patients with abnormal results of DSE and 0 (0%) of 7 in those with normal results of DSE (p = 0.003). CONCLUSION: The diagnostic accuracy of DSE was similar to that of stress 201Tl SPECT in women. DSE was able to stratify female patients with either abnormal or normal results of treadmill exercise testing and to avoid unnecessary cardiac catheterization.     

G1 accumulation caused by iron deprivation with deferoxamine does not accompany change of pRB status in ML-1 cells

In hypertension, several factors disturb coronary circulation and the metabolic reserve of the heart. This study was undertaken to test whether in hypertensive patients global and regional left ventricular (LV) function is related during exercise to the presence of significant coronary stenosis and whether lowering of coronary perfusion pressure through rapid normalization of the diastolic pressure may modify the dynamics of the left ventricle. Thirty-five patients with mild to moderate hypertension undergoing coronary angiography for the evaluation of chest pain were included in the study; upright bicycle exercise echocardiography tests were performed without therapy and 1 day later 1 h after sublingual administration of nifedipine. LV ejection fraction and regional wall motion scores were evaluated and compared at baseline, peak exercise, immediate postexercise, and recovery phases in each test through digital on-line storing of echocardiographic images. Twenty-one patients had normal coronary arteries (group 1) and 14 significant coronary stenoses (group 2); age, gender, heart rate, blood pressure, left ventricular diameter and mass index, and ejection fraction were similar in the two groups. At peak exercise LV ejection fraction slightly increased in group 1, whereas it slightly decreased in group 2 (both during the test without therapy and after nifedipine administration). All patients in group 1 had normal left ventricular wall motion during exercise; 13 of 14 patients in group 2 had LV wall motion abnormalities at peak exercise. Nifedipine did not produce any effect on LV regional wall motion in group 1, but it induced significant changes in LV regional wall motion in seven patients in group 2. Changes in LV wall motion between the two test groups were related to the number of the stenotic coronary vessels: the normal exercise test before and after therapy and the two normalized tests after nifedipine administration were in fact observed in patients with one-vessel disease, whereas worsening or changes in the site of ischemia were observed only in patients with multivessel disease. Regional and global left ventricular dynamics during exercise is mainly dependent on the existence of significant coronary artery disease. Rapid decrease of blood pressure does not alter the regional dynamics of the left ventricle during exercise in patients without coronary artery disease, but it may induce normalization, worsening, or changes in the site of wall motion abnormalities in hypertensives with significant coronary stenoses.     

The use of a new wire in a 6-year-old coronary artery occlusion: the Jagwire recanalization guidewire

Selective, coronary arteriographic, catheter-based, intravascular ultrasound images were obtained to determine the presence and extent of angiographically undetected or underestimated left main (LM) coronary arterial narrowing in patients receiving coronary interventional therapy. Coronary arteriograms were determined to be either normal or abnormal by visual inspection. Abnormal arteriograms were digitized and quantitated using a semiautomated edge-detection algorithm. Thirty-eight patients receiving percutaneous treatment of stenoses in the left coronary artery system were studied. Optimal LM coronary angiograms were obtained in 2 views, and intravascular ultrasound images were obtained after the coronary interventional procedure. Intravascular ultrasound detected plaque in 24 of 27 angiographically normal LM arteries (89%), whereas narrowing was observed in 11 of 11 angiographically abnormal LM arteries (100%). Eight of 38 patients (21%) had > 40% area stenosis by intravascular ultrasound. In patients with angiographic disease, there was no correlation between quantitative angiographic and ultrasound percent area stenosis (r = 0.12; p = 0.72; SEE 19%). The median plaque area was not different between angiographically normal (0.05 cm2; 0.03, 0.08 [25th, 75th percentile]) and abnormal (0.06 cm2; 0.03, 0.1) patients. The median percent area stenosis in arteriographically normal subjects (26%; 14, 32%) was less than that in abnormal ones (37%; 20, 46%) (p = 0.03). Unrecognized LM disease is widespread and often underestimated in patients with normal LM angiograms undergoing interventional procedures. Plaque area is similar for angiographically normal and insignificantly abnormal vessels. This study suggests that intravascular ultrasound overcomes the limitations of silhouette imaging and can be a clinically useful, adjunctive method to evaluate LM coronary artery disease.     

Normalization of abnormal coronary vasomotion by calcium antagonists in patients with hypertension

BACKGROUND: Endothelial dysfunction with a loss of endothelium-dependent vasodilation has been reported in patients with arterial hypertension. The purpose of the present study was to evaluate coronary vasomotor response to dynamic exercise in patients with coronary artery disease with and without arterial hypertension and to determine the effect of calcium antagonists on coronary vasomotion. METHODS AND RESULTS: Cross-sectional areas of a normal and a stenotic coronary vessel segment were examined in 79 patients with coronary artery disease at rest and during supine bicycle exercise (Ex). Change in luminal area after acute administration of a calcium antagonist (diltiazem or nicardipine), during exercise, and after sublingual nitroglycerin (percent change compared with rest = 100%) was assessed by biplane quantitative coronary arteriography. Patients were divided into two groups: Group 1 (control) consisted of 48 patients without (normotensive subjects, n = 30; hypertensive subjects, n = 18) and group 2 of 31 patients with (normotensive subjects, n = 15; hypertensive subjects, n = 16) pretreatment with a calcium antagonist immediately before exercise. The groups did not differ with regard to clinical characteristics or hemodynamic data measured during exercise. Mean aortic pressure at rest, however, was significantly increased in hypertensive patients compared with normotensive subjects in group 1 (103 mm Hg versus 92 mm Hg, P < .01) and group 2 (110 mm Hg versus 98 mm Hg, P < .025). In group 1, exercise-induced vasomotor response was significantly different between normotensive and hypertensive patients in normal (+20% versus +1%, P < .003) and stenotic vessels (-5% versus -20%, P < .025). However, in group 2 there was coronary vasodilation in normotensive and hypertensive patients for both normal (delta Ex +23% versus +21%, P = NS) and stenotic vessel segments (+24% versus +26%, P = NS). CONCLUSIONS: Abnormal coronary vasomotion during exercise can be observed in hypertensive patients with reduced vasodilator response in normal arteries and enhanced vasoconstrictor response in stenotic arteries. Calcium antagonists prevent the abnormal response of normal and stenotic coronary arteries to exercise in hypertensive patients and thus may compensate for endothelial dysfunction with reduced vasodilator response to exercise.     

Value of QT dispersion in the interpretation of exercise stress test in women

BACKGROUND: Exercise testing in women is associated with a high incidence of false-positive ECG changes and should be combined with an imaging study. The QT dispersion (QTD), recorded as the difference between maximum and minimum QT intervals on a 12-lead ECG, is sensitive to myocardial ischemia and may improve the accuracy of exercise testing in women. METHODS AND RESULTS: Exercise ECGs were analyzed in 64 women who had undergone exercise ECG and coronary angiography for clinical indications: 20 patients with normal exercise stress test and nonsignificant (< or = 50% diameter narrowing of a major epicardial coronary artery) coronary artery disease (CAD) on angiography (true-negative; TN group), 20 patients with positive exercise stress tests (> or = 1 mm ST-segment depression or reversible perfusion defects) and significant CAD (true-positive; TP group), and 24 patients with positive exercise stress tests but no significant CAD (false-positive; FP group). The exercise QTD was 45+/-15 ms in TN, 80+/-23 ms in TP (P<.0001 versus TP), and 41+/-14 ms in FP (P=NS versus TN and <.0001 versus TP) groups. A stress QTD of > 60 ms had a sensitivity of 70% and specificity of 95% for the diagnosis of significant CAD compared with 55% (P<.05) and 63% (P<.01), respectively, for > or = 1 mm ST-segment depression during stress. When QTD of > 60 ms was added to ST-segment depression as a condition for positive test, the specificity increased to 100%. CONCLUSIONS: Exercise QTD is an easily measurable ECG variable that significantly increases the accuracy of exercise testing in women.     

Enhanced detection of proximal right coronary artery stenosis with the additional analysis of right ventricular thallium-201 uptake in stress scintigrams

The value of right ventricular thallium-201 analysis in detecting proximal right coronary artery stenosis in exercise myocardial scintigraphy was analyzed in 52 patients, 27 with and 25 without proximal right coronary artery stenosis. For the detection of proximal right coronary artery stenosis, the sensitivity and specificity of thallium scintigraphic analysis were 59 and 88% for a right ventricular abnormality, 67 and 68% for a left ventricular inferior wall abnormality, and 93 and 56% for an abnormality of either. When both right and left ventricular thallium images were abnormal, all 9 patients had proximal right coronary artery stenoses, and when both were normal, 26 of 28 patients had a normal proximal right coronary artery. The sensitivity and specificity of blood pool scintigraphic variables during exercise (right ventricular ejection fraction and left ventricular inferior wall motion) were not significantly different for detection of proximal right coronary artery stenosis. Thus, the additional analysis of the right ventricle on thallium-201 stress scintigrams can improve the detection of proximal right coronary artery stenosis. When both right ventricular and left ventricular thallium scintigrams are abnormal (or normal), the ability to predict the presence (or absence) of proximal right coronary artery stenosis is very high.     

The molecular genetics of pancreatic cancer

Exaggerated blood pressure (BP) response to exercise in normotensive subjects is considered as a predictor of future hypertension. The aim of the study was to find out whether elevated BP response to exercise is associated with any other haemodynamic, metabolic or hormonal abnormalities. Abnormal BP response to exercise, i.e. systolic BP (SBP) > 200 mmHg at 150 W or lower workload, was found in 37 out of 180 normotensive, male students, aged 20-24 years. Fifteen students with elevated exercise BP (group E) volunteered for further examinations. Their resting and ambulatory BP showed high normal values. Eight of them had a family history of hypertension. Four subjects met the criteria of cardiac hypertrophy. Significant correlations were found between exercise SBP and left ventricular mass index, average 24 h and daytime SBP recordings. In comparison with normal subjects of the same age (group N, n = 13), those from group E did not differ in body mass index, plasma lipid profile, fasting glucose, insulin and catecholamine (CA) concentrations, but had increased erythrocyte sodium content, slightly elevated plasma renin activity and cortisol level. During exercise, E subjects showed greater cardiac output (CO) increases with normal heart rate, total peripheral resistance (TPR) and plasma CA. There were no significant differences between groups in haemodynamic and plasma CA responses to posture change from supine to standing. Glucose ingestion (75 g) caused smaller increases in CO and smaller decreases in TPR in E than in N subjects without differences in BP, blood glucose plasma insulin and CA. It is concluded that young normotensive men with exaggerated BP response to exercise show some other characteristics that may be considered as markers of predisposition to hypertension or factors promoting the development of hypertension.     

Value of the electrocardiogram in diagnosing the number of severely narrowed coronary arteries in rest angina pectoris

The aim of this study was to assess the value of the electrocardiogram recorded during chest pain for identifying high-risk patients with 3-vessel or left main stem coronary artery disease (CAD). Therefore, the number of leads with abnormal ST segments, the amount of ST-segment deviation, and specific combinations of leads with abnormal ST segments were correlated with the number of coronary arteries with proximal narrowing of > 70%. Electrocardiograms recorded during chest pain were compared with one from a symptom-free episode. In this retrospective analysis, 113 consecutive patients were included. One-vessel CAD was present in 47 patients, 2-vessel CAD in 22, 3-vessel CAD in 24 and left main CAD in 20. Stratification was performed according to the presence of an old myocardial infarction. The number of leads with ST-segment deviations, and the amount of ST-segment deviation in the electrocardiogram obtained during chest pain at rest showed a positive correlation with the number of diseased coronary arteries. These findings were more marked when the absolute shifts from baseline were considered, because ST-segment abnormalities could be present also in the electrocardiogram obtained during the symptom-free episode. Left main and 3-vessel CAD showed a frequent combination of leads with abnormal ST segments: ST-segment depression in leads I, II and V4-V6, and ST-segment elevation in lead aVR. The negative predictive and positive accuracy of this pattern were 78 and 62%, respectively. When the total amount of ST-segment changes was > 12 mm, the positive predictive accuracy for 3-vessel or left main stem CAD increased to 86%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prior revascularization increases the effectiveness of enhanced external counterpulsation

BACKGROUND AND HYPOTHESIS: Enhanced external counterpulsation (EECP) is an effective noninvasive treatment for chronic angina. However, its usefulness has been felt to be limited in patients with angiographically demonstrated triple-vessel coronary artery disease (CAD), in accord with the hypothesis that a patent vessel is necessary for transmission of the EECP-augmented coronary artery pressure and volume to the distal coronary vasculature. METHODS: The effect of revascularization [coronary artery bypass grafting (CABG)] prior to EECP was examined in 60 patients with CAD and chronic angina (35 without and 25 with prior CABG). Patients were grouped by the extent of CAD (single-, double-, triple-vessel disease in the unrevascularized group) and by the extent of residual disease (number of stenotic native vessels unbypassed or supplied by a stenotic graft in the CABG group). Significant CAD or graft stenoses were defined as stenoses demonstrating > or = 70% luminal diameter narrowing. Benefit was assessed by improvement in post-EECP treatment over pretreatment radionuclide stress testing. RESULTS: Radionuclide stress testing demonstrated a comparable favorable response (80 vs. 71%; p = NS) in patients with prior CABG versus unrevascularized patients. Enhanced external counterpulsation was highly and comparably effective in patients with unrevascularized native single- and double-vessel CAD and in patients with CABG with residual single- and double-vessel CAD (88 vs. 80%; p = NS). Most notably, CABG significantly increased the beneficial response to EECP in those patients with triple-vessel CAD and stenotic grafts compared with unrevascularized patients with triple-vessel CAD (80 vs. 22%; p < 0.05 by chi-square test). CONCLUSION: The results suggest a new role for EECP as an effective treatment for post CABG ischemia, despite extensive CAD and even in the presence of stenotic grafts.     

Prevalence of episodes of ST-segment depression among mild-to-moderate hypertensive patients in northern Italy: the Cardioscreening Study

OBJECTIVES: To assess the prevalence of episodes of ST-segment depression in a population of consecutive patients with mild-to-moderate essential hypertension who are free of clinical signs of coronary artery disease. METHODS: The study involved 28 Italian centers that enrolled 414 hypertensive patients (aged 50-70 years; diastolic blood pressure > or = 95-115 mmHg or systolic blood pressure > or = 150-220 mmHg, or both, 10 days after withdrawal of medications). Silent myocardial ischemia was assessed by means of exercise stress testing and 48 h Holter monitoring. An ischemic episode was defined as a horizontal or downward sloping ST-segment depression > or = 100 microV, occurring 80 ms after the J point, and lasting for at least 1 min. RESULTS: Of the 414 patients enrolled, 411 completed the exercise stress test. During the test significant ST-segment depression occurred for 25 patients (6.1%) and all episodes but one were asymptomatic and not associated with arrhythmias. Of the 396 patients for whom we analyzed a 48 h Holter recording, 43 (10.9%) had at least one episode of ST-segment depression and seven of these had also had one during the exercise stress test The median number of episodes per patient was five (range 1-19), median duration was 9 min (range 1-20 min), and the mean amplitude of the ST-segment depression was 190 +/- 180 microV. None of these episodes was associated with symptoms and all of them occurred under resting condition. Patients with (n = 61) and without (n = 335) ST-segment depression during Holter monitoring or exercise stress testing had similar ages (59 +/- 6 versus 58 +/- 6 years) and did not differ for tobacco smoking, plasma lipid levels, blood pressure values and prevalence of echocardiographic left ventricular hypertrophy (57% of patients had left ventricular mass indexes > or = 134 g/m2 for men and > or = 110 g/m2 for women in both groups). Women had a higher prevalence of ST-segment depression than did men during Holter monitoring [32 of 183 (17.5%) versus 11 of 213 (5.2%)], whereas the prevalences of ischemia during the exercise stress test were similar. Female sex was the only significant factor associated with the occurrence of silent myocardial ischemia [odds ratio 2.56 (95% confidence interval 1.40-4.71)]. CONCLUSIONS: Our results show that 15% of patients with mild-to-moderate hypertension, who are free of clinical signs of coronary artery disease, experience episodes of ST-segment depression during Holter monitoring or exercise stress testing. Most of these episodes are asymptomatic and are not associated with the severity of hypertension, the presence of left ventricular hypertrophy, and other risk factors for coronary artery disease. Episodes of ST-segment depression are more common for women than they are for men, particularly during Holter monitoring. The early detection of silent myocardial ischemia by Holter monitoring or by the exercise stress test might be useful for the identification of hypertensive patients who should be investigated further and administered a more specific treatment.     

Role of the central endogenous opiate system in patients with syndrome X

BACKGROUND: To evaluate the role of the endogenous opioid system (EOS) in abnormal pain perception in patients with syndrome X, we used a neuroendocrine approach, evaluating plasmatic luteinizing hormone (LH) changes after naloxone, a competitive antagonist of opioid receptors able to unblock tonic EOS inhibition on gonadotropin release. Thus LH response to naloxone test indicates the central EOS activity on hypothalamic luteinizing hormone-releasing hormone (LH-RH) inhibitory opioid receptors. METHODS: Ten patients with syndrome X, 10 age-matched male patients with coronary artery disease (CAD), and 10 normal subjects were analyzed. Naloxone tests were performed between 8 and 9 am. Basal beta-endorphin and LH levels were determined on 4 blood samples at 20-minute intervals; after naloxone (0.1 mg/kg intravenously in 4 minutes), LH was measured on 8 samples at 15-minute intervals. In all patients the test was also performed after LH-RH administration. Anginal pain on exercise testing was subjectively scored on a 1 to 10 analogic scale and wall motion abnormalities were quantified by a wall motion score index. RESULTS: Significant differences were found in LH release after naloxone (CAD 260.3 +/- 42.6 vs syndrome X 151.6 +/- 48.5 mIU/mL, P <.05), angina score (CAD 5.5 +/- 1.3 vs syndrome X 7.2 +/- 1.7, P <.05), and wall motion abnormalities (CAD 3.6 +/- 1. 2 vs syndrome X 2.8 +/- 1.9, P <.05). CONCLUSIONS: The reduced LH release after naloxone in syndrome X, with a normal LH-RH response, suggests a lower central EOS activity, which may be related to the higher anginal pain perception.