Peak Exercise Systolic Blood Pressure Research Articles

Prognostic value of peak exercise systolic blood pressure on long-term survival after myocardial infarction

This study examined the association between peak exercise systolic blood pressure and other exercise test parameters and the long-term (19-year) survival of 625 patients with myocardial infarction who were original participants of the National Exercise and Heart Disease Project, a 3-year (1976 to 1979) multicenter randomized exercise clinical trial. Results show that low peak exercise systolic blood pressure (< or =140 mm Hg) was associated with increased mortality throughout the 19 years of follow-up, and men with this finding obtained no survival benefit from participating in an exercise program.

Gender differences in athlete’s heart: association with 24-h blood pressure.: A study of pairs in sport dancing

Background: Long term athletic training is associated with an increase in left ventricular diastolic cavity dimensions, wall thickness, and mass. These changes are described as the “athlete’s heart”. In comparison to men, athletic training in women athletes is not a stimulus for substantial increase in left ventricular wall thickness. Although many variables are related to these gender differences in cardiac morphology, some factors such as 24-h blood pressure and the level of training have not been studied yet. Therefore pairs in sport dancing, in which the level of training of both partners is the same, were chosen as models in order to evaluate whether 24-h blood pressure contributes to sex-related differences in an athlete’s heart. Methods: Fifteen pairs in the national sport dancing team and 30 control subjects (15 males, 15 females) were studied. In all subjects casual and 24-h ambulatory blood pressures, echocardiography, and maximal stress testing were performed. Results: Female in comparison to male dancers had significantly lower M-mode ( P<0.004) and 2-D left ventricular mass index ( P<0.001), 24-h systolic blood pressure ( P<0.003), day systolic blood pressure ( P<0.002), casual systolic blood pressure ( P<0.025), and achieved significantly lower peak systolic blood pressure at stress testing ( P<0.004). Multiple stepwise regression analysis showed that the best predictors of 2-D left ventricular mass index are maximal work load and peak exercise systolic blood pressure, 24-h systolic blood pressure, day, and casual systolic blood pressure. Conclusions: Lower left ventricular mass index in female dancers can be partly explained by lower systolic blood pressures during 24-h and at exercise.

Relationship between Exercise-induced Blood Pressure Response and Left Ventricular Hypertrophy in Patients with Hypertension

Background：In hypertensive patients who show abnormal blood pressure (BP response during exercise, a more excessive blood pressure response may occur in the daily life and cause end organ damage. However, previous studies concerning exaggerated BP response during exercise have been unable to establish its significance and role in left ventricular hypertrophy. The purpose of this study was to determine the relation between exaggerated BP response during exercise and left ventricular hypertrophy. Methods：A treadmill exercise test and echocardiography were performed in 117 patients with hypertension. Sixty-six patients showed normal BP response, and fifty-one patients showed exaggerated BP response. Exaggerated BP response was defined as an elevation of peak exercise systolic BP over 210 mmHg or >10 mmHg elevation of peak exercise diastolic BP from baseline. The correlation between BP response and left ventricular mass index were evaluated in two groups. Results：The results were as follows：1 The peak systolic and diastolic BP were significantly higher in patients with exaggerated BP response than that in patients with normal BP response (p<0.05. 2 There was a weakly significant relation between peak exercise systolic BP and left ventricular hypertrophy, however diastolic BP showed no significant correlation with left ventricular hypertrophy. 3 The left ventricular mass index was significantly increased in patients with exaggerated BP response (normal BP response：120±25 gm/m 2 , exaggerated BP response：169±46 gm/m 2 , p＝0.04. Conclusion：These results indicate that, as compared with resting BP, exercise BP response seems to be important in the treatment of hypertension and more strict blood pressure control may be needed in hypertensive patients with exaggerated BP response. Further study is needed to understand the significance of exaggerated BP response in hypertension.(Korean Circulation J 2001;31(8 :809-814

Is Rest or Exercise Hypertension a Cause of a False-Positive Exercise Test?

To determine if a history of hypertension or an exaggerated rise in exercise systolic BP is associated with a false-positive exercise ECG. Retrospective analysis of the associations between exercise-induced ST-segment depression and a history of hypertension, exercise systolic BP, and several other clinical and exercise test variables. Among 20,097 patients referred for exercise tomographic thallium imaging in a nuclear cardiology laboratory at a tertiary care center, 1,873 patients met inclusion criteria for this study, which included no history of myocardial infarction or coronary artery revascularization, a normal resting ECG, and normal exercise thallium images. False-positive ST-segment depression occurred in 20% of the population. A history of hypertension was actually associated with a lower likelihood of ST-segment depression (odds ratio, 0.70; 95% confidence interval [CI], 0.55 to 0.89; p = 0. 004). A higher peak exercise systolic BP was associated with a higher likelihood of ST-segment depression (odds ratio, 1.08 for each 10-mm Hg increase in systolic BP; 95% CI, 1.03 to 1.14; p < 0. 001). However, the association between peak exercise systolic BP and ST-segment depression was so weak that this measurement could not be predictive in the individual patient (R(2) = 0.2%). For every 20-mm Hg increase in peak exercise systolic BP, the percentage of patients with ST-segment depression increased by only 3%. In patients with normal resting ECGs, we conclude the following: (1) a history of hypertension is not a cause of a false-positive exercise test, and (2) higher exercise systolic BP is a significant but weak predictor of ST-segment depression.

Losartan improves exercise tolerance in patients with diastolic dysfunction and a hypertensive response to exercise

OBJECTIVESThe aim of the study was to test the hypothesis that angiotensin II (Ang II) blockade would improve exercise tolerance in patients with diastolic dysfunction and a marked increase in systolic blood pressure (SBP) during exercise.BACKGROUNDDiastolic dysfunction may be exacerbated during exercise, especially if there is a marked increase in SBP. Angiotensin II may contribute to the hypertensive response to exercise and impair diastolic performance.METHODSWe performed a randomized, double-blind, placebo-controlled, crossover study of two weeks of losartan (50 mg q.d.) on exercise tolerance and quality of life. The subjects were 20 patients, mean age 64 ± 10 years with normal left ventricular systolic function (EF >50%), no ischemia on stress echocardiogram, mitral flow velocity E/A <1, normal resting SBP (<150 mm Hg), and a hypertensive response to exercise (SBP >200 mm Hg). Exercise echocardiograms (Modified Bruce Protocol) and the Minnesota Living With Heart Failure questionnaire were administered at baseline, and after each two-week treatment period, separated by a two-week washout period.RESULTSResting blood pressure (BP) was unaltered by placebo or losartan. During control, patients were able to exercise for 11.3 ± 2.5 (mean ± SD) min, with a peak exercise SBP of 226 ± 24 mm Hg. After two weeks of losartan, baseline BP was unaltered, but peak SBP during exercise decreased to 193 ± 27 mm Hg (p < 0.05 vs. baseline and placebo), and exercise time increased to 12.3 ± 2.6 min (p < 0.05 vs. baseline and placebo). With placebo, there was no improvement in exercise duration (11.0 ± 2.0 min) or peak exercise SBP (217 ± 26 mm Hg). Quality of life improved with losartan (18 ± 22, p < 0.05) compared to placebo (22 ± 26).CONCLUSIONSIn patients with Doppler evidence of diastolic dysfunction at rest and a hypertensive response to exercise, Ang II receptor blockade blunts the hypertensive response to exercise, increases exercise tolerance and improves quality of life.

Cardiopulmonary exercise testing identifies low risk patients with heart failure and severely impaired exercise capacity considered for heart transplantation.

The 3-year survival rates of 500 patients with congestive heart failure (CHF) referred for heart transplantation were assessed to evaluate the clinical and exercise variables most useful for estimating prognostic risk. Detailed prognostic risk stratification of patients with a peak exercise oxygen consumption (VO2) < or = 14 ml/min per kg to identify lower risk patient subsets has been limited in earlier series by relatively small sample size. Cardiopulmonary exercise testing was performed in 500 patients with CHF referred for heart transplantation; 154 (31%) had a peak exercise VO2 < or = 14 ml/min per kg. Univariate and multivariate analyses were performed to identify the 3-year prognostic risk. The 55% 3-year survival rate of the 77 patients with a peak exercise VO2 < or = 14 ml/min per kg unable to reach a peak exercise systolic blood pressure (SBP) of 120 mm Hg was significantly lower than the 83% survival rate in the 74 patients able to reach this exercise blood pressure (p = 0.004). Multivariate analysis revealed that peak exercise SBP (p = 0.0005) and percent predicted peak VO2 < or = 50% (p = 0.04) were the two most important predictors for the combined end point of death or listing as Status 1. Peak exercise SBP and percent predicted peak exercise VO2 are two inexpensive and easily measured noninvasive variables that can be used to further prognostically risk stratify ambulatory patients with CHF referred for heart transplantation with a peak exercise VO2 < or = 14 ml/min per kg.

Serial exercise testing and prognosis in selected patients considered for cardiac transplantation

Objectives This study sought to examine the predictive value of variables obtained from serial maximal exercise testing, echocardiography, and ejection fraction in patients referred as potential heart transplant candidates. Background Variables such as peak VO 2, left ventricular dimensions, ejection fraction, and hemodynamic measurements are known to predict prognosis in heart failure, but there are few data on the impact of serial measurements of these variables on subsequent mortality. Methods and Results Two hundred sixty-three ambulatory patients with severe heart failure referred as potential candidates for heart transplantation who underwent two exercise tests (mean 7.8 months apart) after optimal medical treatment were identified. At the same two time points, echocardiography was performed in 106 (37%) and ejection fraction was measured in 84 (30%). During a mean follow-up period of 3.9 ± 0.1 years, 70 (25%) died and 45 (19%) underwent heart transplantation. Exercise capacity, peak exercise heart rate, and peak exercise systolic blood pressure achieved were all significantly higher among survivors compared with nonsurvivors. Among the survivors a slight increase in peak VO 2 and ejection fraction were observed, but there were no significant differences in the changes of any of the measured variables between survivors and nonsurvivors. There were no significant differences in survival between patients with increased versus those with decreased peak VO 2, left ventricular dimensions, or ejection fraction. Conclusion Although peak VO 2, left ventricular dimensions, and ejection fraction predict survival, changes in these parameters do not add any prognostic information in patients with severe heart failure who have been stabilized with optimal medical treatment. Routine use of these procedures therefore does not seem to be warranted and should be performed only in the context of a specific clinical situation. Serial measurements of these parameters do not appear to be useful in the risk stratification of patients referred for heart transplantation. (Am Heart J 1998;135:221-9.)

Predictors of 7-year changes in exercise blood pressure: effects of smoking, physical fitness and pulmonary function.

The health status of 1999 apparently healthy men, aged 40-59 years, was ascertained after 16 years. We found that their systolic blood pressure during an ergometer exercise test added prognostic information beyond that from their blood pressure at rest concerning total cardiovascular mortality and mortality from myocardial infarction. To determine predictors of the change in systolic blood pressure at rest during 7 years and of the change in the prognostically important peak exercise systolic blood pressure at 600 kilopondmetres/min during 7 years. Predictors of the changes in blood pressures were investigated in 1393 middle-aged men who had been healthy without drug treatment for chronic disease or hypertension for 7 years. Twelve potential independent predictors were investigated. Previous blood pressures, age and body mass index were independent predictors and could explain 18% of the change in systolic blood pressure at rest over 7 years. For systolic blood pressure at 600 kilopondmetres/min also smoking was associated with a rise whereas a high body mass index, physical fitness and forced expiratory volume in 1 s (all P< 0.001) were associated with lower blood pressure, explaining 19% of the variability. Beyond a relatively strong tracking of blood pressures and the expected effect of age, smoking is associated with a 7-year rise in exercise systolic blood pressure whereas relatively higher body mass, physical fitness and pulmonary function are associated with lower exercise systolic blood pressure after 7 years in middle-aged healthy men.

Exercise echocardiography in postmenopausal hormone users with mild systemic hypertension

Rest and exercise echocardiography (at dynamic and isometric exercise) were performed in 30 postmenopausal women (aged 54 ± 4 years) with borderline to mild hypertension. They were then divided into 2 groups: 17 women who started oral hormone replacement therapy (0.625 mg/day conjugated estrogens or 2 mg/day estradiol) and a control group of 13 nonusers. After 6 to 9 months, a second echocardiography was performed in 26 women (4 withdrew). There were only a few changes in values obtained in the 12 controls at the end of follow-up compared with baseline. Primarily, these changes included a slight decrease in systolic blood pressure at rest and on exercise. Several significant morphologic and hemodynamic alterations appeared in 14 hormone users. Left ventricular cavity dimensions and mass became smaller: mean end-diastolic diameter decreased from 45.9 ± 3 mm at baseline to 44.4 ± 3 mm at study termination (p = 0.007). The corresponding values for end-systolic diameter were 25.8 ± 4 mm and 23.9 ± 4 mm (p = 0.006); for left atrium diameter, it was 34.5 ± 4 mm and 32.5 ± 4 mm (p = 0.001); for left ventricular wall width, it was 19.9 ± 2 mm and 19.3 ± 2 mm (p = 0.02); for left ventricular mass, it was 197 ± 28 g and 179 ± 32 g (p = 0.006). The resting aortic blood flow velocity and acceleration increased: 119 ± 18 cm/s before therapy versus 129 ± 23 cm/s while on hormone substitution (p = 0.04), and 13.6 ± 3 m/s 2 versus 16.5 ± 4 m/s 2 (p = 0.008), respectively. Mean rest to peak exercise systolic blood pressure difference became smaller after hormones: 39 ± 19 mm Hg versus 28 ± 13 mm Hg (p = 0.03) during dynamic exercise, and 43 ± 22 mm Hg versus 25 ± 13 mm Hg (p = 0.004) during isometric exercise. The above data probably indicate that with hormone replacement therapy, there is an improvement in cardiac function both at rest and during exercise.

Lack of independent relationships between left ventricular mass and cardiovascular reactivity to physical and psychological stress in the Coronary Artery Risk Development in Young Adults (CARDIA) study

The objective of this study was to determine whether exaggerated blood pressure (BP) reactivity to stress and psychosocial characteristics are related to left ventricular mass (LVM) in a large cohort of young adults. Analyses were conducted with 3,742 participants of the CARDIA study (945 white men, 1,024 white women, 781 black men, and 922 black women), evaluated in 1990 to 1091 with echocardiographic measurement of LVM. Analyses were stratified by gender and race. The relationships of LVM/height 2.7 and cardiovascular reactivity to physical and psychological stressors (treadmill exercise, cold pressor, video game, and star-tracing tasks), were examined in both univariate and multivariate analyses adjusting for baseline BP, weight, and other relevant biobehavioral variables. The relationships between LVM and several psychosocial characteristics (hostility, anger suppression, anxiety, depressive symptoms, and education) were also assessed. Systolic blood pressure (SBP) reactivity to exercise was significantly related to LVM in black and white men; LVM was 10% greater among white men with exaggerated (upper quintile) peak exercise SBP than among other white men. SBP reactivity to the cold pressor test was related to LVM in all race/gender groups, although the relationship remained significant only among white men and women in the multivariate analysis. Diastolic blood pressure (DBP) reactivity to the video game was related to LVM only among black men in adjusted analyses. After adjusting for resting BP, weight, and other covariates in linear multiple regression models, SBP reactivity to exercise explained only 3% of the variance in LVM among white men. Otherwise, reactivity to other stressors or psychosocial variables accounted for no more than 1% of the variance in LVM. It was concluded that among a cohort of young adults, blood pressure reactivity to physical and mental stressors did not add substantially to the prediction of LVM when resting BP, weight, and other covariates were taken into account.

Why do exercise-induced ventricular arrhythmias increase with age? Role of M-mode echocardiographic aging changes.

Although advancing age is associated with a higher prevalence and complexity of exercise-induced ventricular arrhythmias (EIVA), the role of age-associated cardiac anatomic and functional characteristics in this relationship has not been explored. We performed both M-mode echocardiography and maximal treadmill exercise testing within two consecutive visits in 366 healthy volunteers ages 20 to 90 years from the Baltimore Longitudinal Study of Aging. Simple (i.e., isolated) EIVA were detected in 79 subjects (21%) and complex EIVA (i.e., EIVA comprising > or = 10% of beats in any minute or occurring in runs) in another 17 (5%). Univariate predictors of any EIVA, whether simple or complex, were older age (p < .0001), greater LV mass index (p < .0001), male gender (p < .001), higher peak exercise systolic blood pressure (p = .003), and larger body surface area (p = .005). By multiple logistic regression analysis, only age (p = .0001) independently predicted the occurrence of EIVA. For complex EIVA alone, the strongest univariate predictors were age (p = .004), male gender (p = .008), lower maximal heart rate (p = .01), greater left atrial size (p = .03), and larger LV posterior wall thickness (p = .04); on multiple logistic regression, only older age (p = .03) and larger left atrial size (p = .04) independently predicted the presence of complex EIVA. In healthy volunteers undergoing maximal treadmill exercise, greater LV wall thickness and mass are associated with the development of EIVA but they do not independently predict EIVA once the powerful effect of age is considered. The association between complex EIVA and left atrial dilatation may be mediated by higher LV end diastolic pressure and volume during exercise in subjects with larger left atria.

Angiographic and prognostic implications of an exaggerated exercise systolic blood pressure response and rest systolic blood pressure in adults undergoing evaluation for suspected coronary artery disease

This study was designed to assess the angiographic and prognostic implications of an exaggerated systolic blood pressure response to exercise ("exercise hypertension") in adults undergoing evaluation for suspected coronary artery disease. The clinical implications of exercise hypertension are unclear. Subjects for this prospective cohort study were derived from a consecutive sample of 9,608 adults who were referred for treadmill testing and who augmented their systolic blood pressure by at least 10 mm Hg. There were 594 subjects who underwent coronary angiography within 90 days of treadmill testing. Exercise hypertension was defined as a peak exercise systolic blood pressure > or = 210 mm Hg in men and > or = 190 mm Hg in women. Severe angiographic coronary disease was defined as left main coronary artery disease (> or = 50% diameter stenosis), three-vessel disease (> or = 70% diameter stenosis) or two-vessel disease with > or = 70% diameter stenosis of the proximal left anterior descending coronary artery. All-cause mortality was assessed during a follow-up period of approximately 2 years. Exercise hypertension was present in 196 subjects (33%). Severe coronary disease was less common in subjects with exercise hypertension (14% vs. 25%, odds ratio 0.51, 95% confidence interval [CI] 0.32 to 0.81, p = 0.004). Exercise hypertension remained associated with a lower rate of severe coronary disease even after adjusting for rest hypertension, age, gender, exercise capacity and other possible confounders. During the follow-up period, there were 23 deaths; only 2 occurred in the group with exercise hypertension. After adjusting for severity of coronary disease, exercise hypertension remained associated with a lower mortality rate (adjusted relative risk 0.20, 95% CI 0.05 to 0.84, p = 0.03). In adults evaluated for coronary artery disease, exercise hypertension is associated with a lower likelihood of angiographically severe disease and a lower adjusted mortality rate.

Fuzzy cluster analysis off positive stress tests, a new method of combining exercise test variables to predict extent of coronary artery disease

Fuzzy set theory is useful in the analysis of data having a graded degree of abnormality. Previous studies using sharp cutoff points between normality and abnormality have resulted in general guidelines for the interpretation of positive stress tests, but do not enable the clinician to simultaneously combine several stress test variables, each having a range of abnormality. In this study, positive stress test results from 109 patients were reviewed. An angiogram recorded within 1 month of the stress tests showed that 100 patients had coronary artery disease (CAD) (15 had left main CAD, and 27 had 3-vessel, 30 had 2-vessel, and 28 had 1-vessel disease) and 9 were normal. Six variables were selected for fuzzy cluster analysis: ST-segment change, difference between resting systolic ana peak exercise systolic blood pressure, total treadmill time, peak exercise heart rate as a percentage of 100% predicted maximum for age, time to onset of angina, and duration of repolarization abnormalities. The analysis used a similarity measure to compute how closely each stress test resembled a prototypical mildly, moderately, or severely abnormal stress test. Stress tests classified by this method showed better correlation with the extent of CAD than the degree of ST-segment depression alone. Unlike tests with mild degrees of ST depression (0.5 to 1.5 mm), tests classified as mild by the method virtually excluded high-grade CAD. Tests classified as severe were associated with severe CAD, were better in detecting left main and 3-vessel CAD than tests with ≥3 mm ST depression, and were useful in detecting high-grade CAD in patients with mild degrees of ST depression. Combining stress test variables by fuzzy cluster analysis can be useful in managing patients with positive exercise test results.

Exercise-induced hypertension in the arms due to impaired arterial reactivity after successful coarctation resection

Exercise-induced hypertension of the arms is a wellknown late complication after coarctation repair. Residual narrowing at the anastomosis site as well as abnormalities of the precoarctation arterial system may be the cause of this problem. Blood pressure response to exercise and flow-mediated arterial dilatation of the arms and legs were studied in 29 young adults after successful coarctectomy in childhood and compared with 13 control subjects. Peak exercise systolic blood pressure was significantly higher in patients than in control subjects: 238 versus 199 mm Hg (p = 0.007). Both groups had a positive systolic arm-leg gradient during exercise: 59 versus 37 mm Hg (p = 0.05). Flow-mediated dilatation of the brachial artery was significantly reduced in patients compared with that in control subjects: 4.2% (range 0% to 9.4%) versus 9.4% (range 3.7% to 16%) (p < 0.0001). Flow-mediated dilatation of the femoral artery was similar in both groups. Dilatation of the brachial artery was inversely correlated to peak exercise systolic pressure in the study patients (r = −0.427, p = 0.02). A positive arm-leg exercise gradient partly represents physiologic circulatory adaptation to ergometry and is therefore not appropriate for evaluation of residual narrowing. Exercise-induced hypertension of the arms late after coarctation repair is caused by impaired arterial reactivity, which results from structural or functional abnormality, or both.

Exercise blood pressure predicts cardiovascular mortality in middle-aged men.

The outcome of 1999 apparently healthy men aged 40 to 59 years investigated from 1972 through 1975 was ascertained after 16 years to determine whether systolic blood pressure measured with subjects in the sitting position during a bicycle ergometer exercise test adds prognostic information on cardiovascular mortality beyond that of casual blood pressure measured after 5 minutes of supine rest. During a total follow-up of 31,984 patient years, 278 patients died, 150 from cardiovascular causes. Casual blood pressure and pulse pressure as well as peak exercise systolic blood pressure during 6 minutes on the starting workload of 600 kpm/min (approximately 100 W, 5880 J/min) were all related to cardiovascular mortality. The relative risk (RR) of dying from cardiovascular causes associated with an increment of 48.5 mmHg (= 2 SD) in systolic blood pressure at 600 kilopondmeter (kpm)/min was significant (RR = 1.5, 95% confidence interval [CI] = 1.1-2.3, P = .040) even when adjusting for a large number of variables measured in the present study, including age, exercise capacity, smoking habits, and casual blood pressures. The influence of blood pressure at 600 kpm/min was so strong that the predictive value of resting casual blood pressures became nonsignificant when these were analyzed as continuous variables also including exercise blood pressure as a covariate. However, the maximal systolic blood pressure during the exercise test was unrelated to cardiovascular mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural adaptation of the heart in borderline hypertensives in response to blood pressure lowering with captopril

To determine whether treatment of borderline hypertension reverses the cardiac 'amplifier' effect associated with increased left ventricular mass. Randomized, double-blind, placebo-controlled trial involving treatment for 6 months. Ambulant outpatients in a teaching hospital. Recruited by local doctor referral or worksite screening. Average of two readings of entry blood pressures taken 1 week apart 140-160 mmHg (systolic) or 90-95 mmHg diastolic, or both. Twenty-six previously untreated males, mean +/- SD age 33 +/- 9.2 years with mean +/- SD blood pressure 138 +/- 7.4/90 +/- 7.0 mmHg entered and completed the study. Twelve subjects received captopril, average dose 72 mg/day for 24 weeks, the remainder receiving placebo. Echocardiographic left ventricular dimensions, mass and transmitral Doppler flow, as well as office, ambulatory and exercise blood pressure. In the captopril group blood pressure was reduced significantly. Left ventricular mass decreased significantly from 205 to 195 g at 8 weeks and to 202 g at 24 weeks, returning to 232 g 4 weeks after treatment. Interventricular septum thickness fell significantly at 24 weeks. Doppler parameters did not alter. Baseline 8-h ambulatory blood pressure did not change with treatment. The reduction in peak exercise systolic blood pressure in the captopril group was not different from the change in the placebo group. Blood pressure can be effectively lowered using captopril in young subjects with borderline hypertension. Treatment is well tolerated and leads to regression of left ventricular wall thickness and mass, suggesting that treatment of blood pressure elevations may be advisable at lower levels than currently recommended.

The effect of systemic hypertension on exercise tomographic thallium-201 imaging in the absence of electrocardiographic left ventricular hypertrophy

This study was designed to assess the effect of systemic hypertension on exercise thallium-201 imaging. The study group consisted of 38 patients with systemic hypertension who were compared with 68 normotensive patients. All patients had a low pretest likelihood of coronary artery disease to minimize the influence of selection bias. Patients with electrocardiographic evidence of left ventricular hypertrophy were excluded. Single-photon emission computed tomographic thallium-201 images were obtained immediately after exercise and 4 hours after exercise. Thallium tomographic images were assessed qualitatively by 14 short-axis segments and were grouped into three coronary distributions. Regional and global quantitative analysis was also performed by using a reference study group at low risk for coronary artery disease. The hypertensive group demonstrated higher resting systolic blood pressure (137 ± 26 mm Hg vs 120 ± 14 mm Hg in the normotensive group, p = 0.0002) immediately before exercise. There was no significant difference between hypertensive and normotensive groups in peak exercise systolic blood pressure (181 ± 31 mm Hg vs 172 ± mm Hg, p = NS). The normotensive group achieved a significantly higher peak exercise heart rate (162 ± 18 vs 146 ± 20 beats/min in the hypertensive group, p = 0.0001) and higher estimated oxygen uptake (11.0 ± 3.4 vs 9.1 ± 2.7 metabolic equivalents [METS] in the hypertensive group, p = 0.003). However, rate-pressure products for both groups were nearly identical. Qualitative thallium-201 analysis revealed no significant difference in the total number of abnormal thallium-201 segments (normotensive 9%, hypertensive 6%, p = NS), the number of patients with at least one poststress abnormal segment (34% normotensive, 26% hypertensive, p = NS), or in the presence of an abnormal coronary distribution (18% normotensive, 21% hypertensive, p = NS). Quantitative thallium-201 analysis also showed no significant difference between these groups for the amount of abnormally perfused left ventricle, either overall (median 1 % of the left ventricle in the hypertensive group vs 2% in the normotensive group, p = NS) or within individual coronary territories ( p = NS for any of the three coronary distributions). In the absence of electrocardiographic evidence of left ventricular hypertrophy, systemic hypertension does not cause an increase in false positive exercise thallium-201 tests.

Aortic “recoarctation” at rest versus at exercise in children as evaluated by stress Doppler echocardiography after a “good” operative result

The mechanism for exercise systolic hypertension after a “good” operative repair of coarctation of the aorta remains speculative. Twenty-four children (mean age ± SD 10.3 ± 3.8 years) were studied with continuous-wave Doppler echocardiography while they performed continuous, graded, maximal treadmill exercise. Patients were free of “recoarctation” based on conventional resting echocardiography. Measurements of ascending and descending aortic peak instantaneous systolic velocity were obtained at rest, throughout exercise and during recovery. Results were compared with 24 age- and gender-matched control subjects. Fifteen patients were normotensive (group 1) (peak systolic Mood pressure, 147 ± 21 mm Hg) and 9 developed systolic hypertension during exercise (group 2) (196 ± 32 mm Hg) (p < 0.05) (control subjects, 143 ± 21 mm Hg). Descending aortic peak systolic velocity at rest ranged from 1.50 ± 0.27 m/s in the control group to 2.57 ± 0.57 m/s (group 1) and 2.93 ± 0.43 m/s (group 2) (p < 0.05, group 2 vs control). Differences were amplified at peak exercise with systolic velocity increasing to 4.26 ± 0.61 m/s in group 2 but only to 3.61 ± 0.70 m/s in group 1 and 2.26 ± 0.38 m/s in control subjects (p < 0.05, group 2 vs group 1 and control). Seven patients developed a descending aortic diastolic velocity during exercise. Stepwise linear regression analysis identified 2 variables to be significant determinants of peak exercise systolic blood pressure in the “total” patient group: (1) age at exercise testing, and (2) descending aortic peak systolic velocity at peak exercise (r 2 = 0.88, p < 0.001) (group 2, alone — r 2 = 0.98, p < 0.001). Stress Doppler echocardiography therefore suggests that residual structural/ functional aortic arch defects may be responsible for exercise hypertension in children thought to have a “successful” coarctation repair by conventional resting assessment.

Abnormal postexercise systolic blood pressure response is a good indicator of impaired left ventricular filling during supine cycle ergometer exercise in patients with coronary artery disease.

To determine whether the postexercise systolic blood pressure (SBP) response is a useful marker of left ventricular filling abnormalities, supine leg exercise testing was conducted in 14 control subjects and 70 patients with coronary artery disease (CAD). An abnormal postexercise SBP response (the ratio of SBP after 3 min of recovery to the peak exercise SBP) was defined as 0.85 or more, which represented the cutoff point with the highest sensitivity and specificity for prediction of pulmonary artery wedge pressure (PAWP) of at least 20 mmHg at peak exercise in CAD patients. There was a significant difference between the SBP ratios of the two groups (Control, 0.72 +/- 0.05; CAD, 0.86 +/- 0.13; p < 0.01). There was no significant difference between the PAWP of the two groups at rest, but the PAWP at peak exercise was significantly higher in the CAD group (20.2 +/- 8.9 mmHg) than in the control group (11.5 +/- 4.0 mmHg)(p < 0.01). PAWP at peak exercise was > or = 20 mmHg in 35 (50%) of the 70 CAD subjects. The SBP ratio was significantly correlated with PAWP at peak exercise (r = 0.67, p < 0.01) in the CAD group, but not in the control group. An SBP ratio of > or = 0.85 showed a sensitivity of 80% and a specificity of 80% for predicting a peak exercise PAWP of > or = 20 mmHg in CAD patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Exaggerated pressor response to treadmill exercise in chronic cocaine abusers with left ventricular hypertrophy.

Chronic cocaine abuse has been associated with a high prevalence of left ventricular hypertrophy (LVH) in normotensive individuals at rest. This study was conducted to determine whether chronic cocaine abusers with LVH would manifest an exaggerated pressor response to treadmill exercise. Forty-nine normotensive chronic cocaine abusers underwent Bruce protocol treadmill exercise testing until they attained 85% maximum predicted heart rate. A peak exercise systolic blood pressure greater than or equal to 210 mm Hg was defined as abnormal. In addition, they underwent two-dimensional echocardiography and had left ventricular mass determined by the area-length method. LVH was defined as left ventricular mass greater than or equal to 105 g/m2 and a posterior wall thickness greater than or equal to 1.2 cm. Age- and race-matched control subjects also underwent echocardiography and exercise testing. Group differences in peak exercise blood pressure in cocaine abusers with LVH, cocaine abusers without LVH, and control subjects were assessed by ANOVA: Groups were similar concerning age, race, heart rate, resting blood pressure, body surface area, and exercise duration. LVH was present in 16 of 49 (33%) cocaine abusers and three of 30 (10%) control subjects (p = 0.02). Of the 16 cocaine abusers with LVH, 10 (63%) had peak exercise blood pressures greater than or equal to 210 mm Hg, and three others had exercise blood pressures of 200 mm Hg. Therefore, peak exercise systolic blood pressure was significantly higher in cocaine abusers with LVH than in all other groups (p = 0.0001). Chronic cocaine abusers with LVH manifest an exaggerated pressor response to treadmill exercise. These data suggest that chronic cocaine abuse predisposes a subset of individuals to a heightened pressor response to a given sympathetic stimulus such as exercise and that this may contribute to the pathogenesis of LVH in chronic cocaine abusers.