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Biomedical subjects

M J Roman

Publications and source records attributed to M J Roman.

At least 91 records · Page 5Linked to original sources
PubMed1997

Is the absence of a normal nocturnal fall in blood pressure (nondipping) associated with cardiovascular target organ damage?

OBJECTIVE: To determine whether the failure to decrease blood pressure normally during sleep is associated with more prominent target organ damage. METHODS: Cardiac and vascular structure and function were characterized in 183 asymptomatic, unmedicated hypertensive patients and compared with their ambulatory blood pressures. RESULTS: The 104 patients with a normal (> 10%) nocturnal fall in systolic blood pressure (dippers) were similar to the 79 patients with an abnormal fall (nondippers) in sex, race, body size, smoking history, and average awake ambulatory blood pressure. Nondippers tended to be older (57 versus 54 years, P = 0.06). The supine blood pressure upon completion of the ultrasound studies was higher in the nondippers (156/93 versus 146/89 mmHg, P < 0.005) as was the variability of the awake diastolic blood pressure. There were no differences between dippers and nondippers in left ventricular mass (170 versus 172 g), mass index (90 versus 91 gm/m2), prevalence of abnormal ventricular geometry, common carotid artery diameter (5.74 versus 5.75 mm), and vascular strain. Although nondippers were more likely to have carotid artery plaque (41 versus 27%, P = 0.053) and an increased intimal-medial thickness (0.84 versus 0.79 mm, P < 0.05), adjustment for age rendered the differences insignificant. There were no differences in the relation of awake and sleeping systolic pressures to the left ventricular mass (r = 0.36 and 0.35, respectively, both P < 0.005) or to the carotid wall thickness (r = 0.28 and 0.29, respectively, both P < 0.005). When the 114 men and 69 women were considered separately, similar findings were obtained. When the 109 whites and 56 blacks (African-Americans and Afro-Caribbeans) were considered separately, there were no differences in left ventricular structure in either group, and differences in vascular structure were confined to the white subgroup. CONCLUSION: The lack of a normal nocturnal fall in blood pressure is not associated with an increase in left ventricular mass or in arterial disease independently of age. Age-related changes in carotid artery wall thickness and plaque among nondippers may reflect a contribution of an altered baroreceptor function to the lack of normal nocturnal and supine blood pressure decreases.

Adult↗
PubMed1997

Relation of left ventricular longitudinal and circumferential shortening to ejection fraction in the presence or in the absence of mild hypertension.

OBJECTIVES: To study left ventricular longitudinal shortening in arterial hypertension and the relative contribution of longitudinal and circumferential fiber shortening to ventricular ejection. METHODS: Two-dimensional and M-mode echocardiograms were obtained for 50 normotensive subjects (aged 49 +/- 12 years) and 50 never-treated mild hypertensive patients (aged 49 +/- 11 years), to measure the minor-axis endocardial and midwall shortening, long-axis shortening and ejection fraction. RESULTS: The midwall shortening was lower in hypertensive than it was in normotensive subjects (P < 0.001) and was related inversely to the circumferential wall stress for both groups (P < 0.04 and 0.0001, respectively). The long-axis shortening in hypertensive patients (22.2 +/- 4.2%) and in normotensives (23.6 +/- 5.4%) was not statistically different, and was not related either to the meridional or to the circumferential wall stress. The ejection fraction was also similar for the two groups (68.2 +/- 6.3 versus 68.6 +/- 5.6%). Both for normotensive and for hypertensive subjects, the ejection fraction was influenced mainly by the midwall shortening (61 and 40% of the variance for normal and hypertensive individuals, respectively), with a minor contribution from the long-axis shortening, which was 7% for normotensive subjects and 18% for hypertensive patients, a statistically significant difference (P < 0.001). The combined effect of midwall and longitudinal shortenings on the ejection fraction was regulated by the relative wall thickness, and was maximal for hypertensive patients with an ejection fraction greater than that predicted by the midwall shortening. CONCLUSIONS: Left ventricular ejection is produced principally by circumferential shortening and is related independently to the relative wall thickness. In the presence of arterial hypertension and an altered cardiac load, longitudinal shortening becomes an important mechanism by which to augment ejection, thereby offsetting the reduction in midwall shortening.

Adult↗
PubMed1997

Age-related changes in total arterial capacitance from birth to maturity in a normotensive population.

We evaluated the effect of body growth and aging on the ratio of echocardiographic (Teichholz) stroke volume to pulse pressure (SV/PP ratio) in 373 normal-weight, normotensive children to adolescents (1 day to 17 years old; 166 girls, 87 nonwhite) and 393 normal adults (17 to 85 years old; 164 women, 112 nonwhite). Stroke volume increased with age in children (r = .64, P < .0001) and was stable in adults; pulse pressure decreased slightly with age in children (r = -.10, P = .06) and increased in adults (r = .29, P < .0001). As a consequence, SV/PP ratio increased with age in children (r = .51, P < .0001) and decreased in adults (r = -.18, P = .0004). To control for changes in body size that influence the size of the arterial tree, we used ANCOVA to adjust SV/PP for body size. Body size-adjusted SV/PP ratio was no longer related to age in children, whereas the negative relation with aging in adults remained statistically significant (r = -.19, P < .0002). Heart rate was negatively related to SV/PP ratio in both children and adolescents and adults, but this relation did not influence the relation with age. In multivariate analysis, high SV/PP ratio was predicted by greater height (P < .002) and weight (P < .04) and nonwhite race (P < .001) in children and adolescents and by younger age (P < .0001), greater weight (P < .0001), and low heart rate (P < .001) in adults. Sex did not enter the regression models. Thus, (1) SV/PP ratio is a measure of increasing capacity of the arterial tree during growth, whereas it depends on arterial compliance during adulthood through old age; (2) arterial compliance decreases progressively with aging; (3) the apparent difference between males and females might be due to their different body sizes.

Adolescent↗
PubMed1997

Relation of exercise-induced myocardial ischemia to cardiac and carotid structure.

There is a strong relation of carotid atherosclerosis to coronary artery disease and left ventricular hypertrophy. In addition, abnormalities of carotid structure are strongly associated with abnormal left ventricular geometry and structure. However, little is known regarding the relation of exercise-induced ST depression to carotid atherosclerosis, carotid, or left ventricular structure in the absence of apparent coronary disease. The relationship of exercise ECG myocardial ischemia to the presence of carotid atherosclerosis and to carotid and left ventricular structure was assessed in 204 asymptomatic subjects free of clinical evidence of cardiovascular disease. Myocardial ischemia on the exercise ECG, defined by a chronotropically adjusted ST/HR slope of >3.47 microV/bpm, was associated with a nearly threefold greater likelihood of discrete carotid atherosclerosis (50% [6 of 12] versus 17% [29 of 192], P=.007) and with older age, male sex, higher systolic and diastolic blood pressures, greater left ventricular mass and mass index, and greater common carotid artery intimal-medial thickness and cross-sectional area index. Stepwise logistic regression analyses, including standard risk factors, revealed that only carotid artery cross-sectional area index (P=.0007) and systolic blood pressure (P=.005) independently predicted an abnormal chronotropically adjusted ST/heart rate slope. Moreover, among 132 subjects with > or = 10 microV of ST-segment depression, only left ventricular mass index and carotid artery cross-sectional area index were significant predictors of the chronotropically adjusted ST/heart rate slope response. Subendocardial ischemia on the exercise ECG is strongly associated with the presence of carotid atherosclerosis and is related to systolic blood pressure, carotid artery cross-sectional area index, and left ventricular mass index, independent of age, sex, and other cardiac risk factors. These findings provide additional insights into the relation between coronary and carotid atherosclerosis and suggest that an association among ischemia and left ventricular and carotid structural abnormalities may contribute to the pathogenesis of coronary events.

Arteriosclerosis↗
PubMed1997

An examination of the nature of attentional deficits in patients with Parkinson's disease: evidence from a spatial orienting task.

Endogenous and exogenous shifts of attention were examined in nondemented patients with Parkinson's disease (PD). In the endogenous condition, an arrow was used to cue participants' attention to the possible location of an impending target, whereas in the exogenous condition, a brightened box was used to cue attention. Cues were either valid (i.e., the target appeared in the cued location) or invalid (i.e., the target appeared in a noncued location). The time between cue onset and target onset (stimulus onset asynchrony or SOA) was varied in each condition. The results indicated that PD patients were not differentially impaired in shifting attention at the shorter SOAs relative to normal controls. However, at longer SOAs, the PD patients demonstrated less of an effect from cueing than did the normal control participants. PD patients' differential effect from cueing was evident in both exogenous and endogenous conditions. These results suggest that PD patients may experience a rapid decay of attentional inhibition and do not support the notion that a decrement in processing resources underlies their attentional deficits. Moreover, these findings further support the notion that the basal ganglia may play an important role in attentional functions.

Aged↗
PubMed1996

Estimation of left ventricular chamber and stroke volume by limited M-mode echocardiography and validation by two-dimensional and Doppler echocardiography.

This study has been designed to improve estimation of stroke volume from linear left ventricular (LV) dimensions measured by M-mode echocardiography, in symmetrically contracting ventricles. In experimental studies, the ratio of LV epicardial long/short axes "Z" is about 1.3. We measured systolic and diastolic epicardial long and short axes by 2-dimensional echocardiography in 115 adults with widely varying LV short-axis dimensions (LV end-diastolic dimension = 3.95 to 8.3 cm). In a learning series of 23 normotensive and 27 hypertensive subjects, Z(diastole) was 1.3 +/- 0.1 and Z(systole) = 1.2 +/- 0.1, similar to findings in experimental animals. Regression equations were developed by comparing LV volumes by M-mode and 2-dimensional echocardiography. In a test series (65 subjects), LV volumes were calculated using separate regression equations for end-diastolic volume ([LV end-diastolic dimension] 4.765 - 0.288 x posterior wall thickness]) and for end-systolic volume ([LV end-systolic dimension] [4.136 - 0.288 x posterior wall thickness]). Because the term 0.288 x wall thickness was only about 8% of the first term between brackets, the average wall thickness in the learning series was substituted in the Z-volume formulas applied to the test series: end-diastolic volume = (4.5 x [LV end-diastolic dimensions]2) and end-systolic volume = (3.72 x [LV end-diastolic dimension]2). The mean relative error produced with this simplified method was 0.9%. in diastole and 1.4% in systole. Compared with Teichholz' M-mode volume method, Z-derived end-diastolic volume in the test series was equally well related to 2-dimensional volumes (both r = 0.88), with a better intercept (1.5 vs -23 ml, p <0.001) and a slope closer to the identity line (1.1 vs 1.4). Similar results were found for systolic volumes. In a second test series of 1,721 American Indian participants in the Strong Heart Study without mitral regurgitation or segmental LV wall motion abnormalities, Doppler-derived LV stroke volume (70 +/- 14 ml/beat) was similarly predicted by the Z-derived method (r = 0.65, 70 +/- 11 ml/beat) and Teichholz formulas (r = 0.64, 72 +/- 13 ml/beat), but Z-derived volumes had a regression line significantly closer to the identity line (p <0.005). Thus, LV chamber and stroke volumes can be determined from M-mode LV diameters over a wide range of LV sizes and in epidemiologic as well as clinical populations. The performance of this new method appears better than that obtained using the Teichholz formula, with a formula that is easy to handle and makes calculation of LV volumes by pocket calculator possible, even from limited echocardiographic studies.

Adult↗
PubMed1996

Assessment of left ventricular function by meridional and circumferential end-systolic stress/minor-axis shortening relations in dilated cardiomyopathy.

Echocardiographic meridional wall stress-endocardial shortening relations provide estimates of left ventricular (LV) contractility that do not uniformly detect myocardial dysfunction despite severe symptoms in dilated cardiomyopathy. To improve detection of myocardial dysfunction in patients with congestive heart failure (CHF) due to dilated cardiomyopathy, echocardiographic meridional and circumferential end-systolic stress were related to endocardial and midwall shortening in 42 patients (95% dead within a mean of 22 months) with dilated cardiomyopathy and 140 normal subjects. A method to estimate LV long-axis dimension from M-mode minor-axis epicardial measurements was developed in a separate series of 115 subjects. Endocardial shortening to meridional wall stress relation identified 31 of 42 CHF patients falling below the 95% normal confidence interval of the reference population; use of midwall shortening decreased this number to 26 (p = NS). The use of circumferential wall stress identified 39 of 42 patients with subnormal endocardial LV shortening and 41 of 42 patients with depressed midwall performance (p < 0.01 vs use of meridional stress). The circumferential/meridional wall stress ratio was 2.6 +/- 0.5 in normal subjects and 1.3 +/- 0.2 in CHF patients (p < 0.0001). Thus, use of circumferential end-systolic stress as the measure of afterload improves the detection of myocardial dysfunction by stress/shortening relations in patients with CHF. The ratio between the 2 stresses decreases with more spherical LV shape. Midwall and endocardial shortening measurements are equivalent in the setting of thin LV walls as occurs in dilated cardiomyopathy.

Adult↗
PubMed1996

Association of the auscultatory gap with vascular disease in hypertensive patients.

OBJECTIVE: To assess the relation of the auscultatory gap during blood pressure measurement to cardiovascular structure and function. DESIGN: Cross-sectional study. SETTING: A hypertension center in a university hospital. PATIENTS: 168 persons with hypertension who were otherwise healthy and were not receiving medication. MEASUREMENTS: Wideband external pulse recordings and ultrasonographic examination of the left ventricle and extracranial carotid arteries. Vascular stiffness was evaluated using simultaneous carotid pressure waveforms obtained by applanation tonometry of the contralateral carotid artery. RESULTS: Classic auscultatory gaps were present in 21% of patients and were associated with older age (mean age SD, 64 11 years for patients with gaps and 55 13 years for patients without gaps; P < 0.001), female sex (67% of patients with gaps and 44% of patients without gaps were female; P < 0.05), and increased arterial stiffness (arterial stiffness index, 8.5 4.6 in patients with gaps and 5.8 3.2 in patients without gaps; P < 0.005). The prevalence of atherosclerotic plaques was increased more than twofold among patients with gaps compared with patients without gaps (50% compared with 22%; p < 0.002). Patients with and without auscultatory gaps had similar blood pressures, left ventricular structure and function, serum cholesterol levels, and smoking history. Logistic regression analysis indicated that only female sex (P < 0.02), arterial stiffness (P < 0.002), and atherosclerotic plaque (P < 0.02) were independently associated with the presence of an auscultatory gap. CONCLUSIONS: This study provides strong evidence that auscultatory gaps are related to carotid atherosclerosis and to increased arterial stiffness in hypertensive patients, independent of age. Although these observations need to be confirmed prospectively, they suggest that auscultatory gaps may have prognostic relevance.

Adult↗
PubMed1996

Electrocardiographic identification of left ventricular hypertrophy: test performance in relation to definition of hypertrophy and presence of obesity.

OBJECTIVES: This study sought to assess a test performance of the electrocardiogram (ECG) in relation to 1) varying definitions of left ventricular hypertrophy based on different methods of adjusting left ventricular mass for body size, and 2) the presence or absence of obesity. BACKGROUND: Although left ventricular mass is most commonly indexed for body surface area or height when defining left ventricular hypertrophy, recent work suggests that normalization for height to the power of 2.7 (height2.7) may decrease variability among normal subjects and correctly identify the impact of obesity on hypertrophy. METHODS: The product of Cornell voltage and QRS duration (Cornell product) and Framingham-adjusted Cornell voltage were determined from 12-lead ECGs in 212 patients. Left ventricular hypertrophy was defined on the basis of left ventricular mass indexed to body surface area, height and height2.7. RESULTS: Using partitions with matched specificity of 95%, the sensitivity of ECG criteria varied with the definition of hypertrophy, ranging from 39% to 52% for the Cornell product and from 24% to 33% for adjusted Cornell voltage. When left ventricular mass was indexed to body surface area or to height2.7, the 52% and 39% sensitivities of the Cornell product were significantly greater than the 24% (p < 0.001) and 29% (p < 0.05) sensitivities of adjusted Cornell voltage, with a similar trend when left ventricular mass was indexed to height (43% vs. 33%, p = 0.10). Comparison of receiver operating characteristic curves confirmed the superior overall performance of the Cornell product relative to adjusted Cornell voltage for hypertrophy defined by body surface area and height2.7 and demonstrated greater reproducibility of overall performance, as measured by the coefficient of variability, for the Cornell product (1.7%) than for adjusted Cornell voltage (5.8%). Sensitivity of adjusted Cornell voltage was significantly greater in obese than in nonobese subjects (50% to 59% vs. 18% to 24%, p < 0.01), but the Cornell product had only minimally higher sensitivity in nonobese than in obese subjects (40% to 54% vs. 32% to 44%, p = NS). CONCLUSIONS: The ability of ECG criteria to detect left ventricular hypertrophy differs depending on the method of indexing left ventricular mass for body size and with the presence or absence of obesity. Further, the Cornell product provides the best combination of overall accuracy and low variability of performance between definitions of hypertrophy. These findings have important implications for the clinical and epidemiologic use of 12-lead ECG criteria for the detection of left ventricular hypertrophy.

Adult↗
PubMed1996

Relation of arterial structure and function to left ventricular geometric patterns in hypertensive adults.

OBJECTIVES: The present study sought to determine whether conduit artery structure and function vary according to the pattern of left ventricular adaptation to hypertension. BACKGROUND: Although left ventricular geometric pattern has been shown to predict cardiovascular events in hypertension, the arterial status in patients with the different patterns is unknown. METHODS: We evaluated arterial structure and function by carotid ultrasound and applanation tonometry in 271 unmedicated hypertensive patients classified by echocardiography as having normal ventricular geometry (n = 176), concentric remodeling (n = 54), concentric hypertrophy (n = 16) or eccentric hypertrophy (n = 25). RESULTS: All groups were similar in age, gender distribution and body size. Patients with concentric and eccentric hypertrophy had similar blood pressures (mean 173/100 and 171/99 mm Hg, respectively) and left ventricular mass, but compared with patients with normal left ventricular geometry and concentric remodeling, only those with concentric hypertrophy had increased arterial wall thickness (0.96 +/- 0.20 vs. 0.80 +/- 0.18 mm, p < 0.05), end-diastolic diameter (6.38 +/- 0.97 vs. 5.76 +/- 0.87 mm, p < 0.05), cross-sectional area (22.1 +/- 5.71 vs. 16.6 +/- 5.4 mm(1)2 p < 0.05) and elastic modulus (713 +/- 265 vs. 471 +/- 241 dynes/cm2 x 10(-5), p < 0.05). Patients with concentric remodeling and eccentric hypertrophy had similar values for these measures (0.85 +/- 0.22 and 0.89 +/- 0.21 mm, 5.67 +/- 0.77 and 6.04 +/- 0.44 mm, 17.2 +/- 5.4 and 19.7 +/- 5.9 mm2, 558 +/- 263 and 614 +/- 257 dynes/cm2 x 10(-6), respectively), despite lower systolic blood pressures in the former group (156/94 mm Hg, p < 0.001). The prevalence of plaque was comparable in patients with concentric (56%) and eccentric (42%) hypertrophy and significantly greater than that in patients [corrected] with normal geometry (21%). CONCLUSIONS: Among patients with generally mild, uncomplicated systemic hypertension, arterial structure and function are most abnormal when concentric left ventricular hypertrophy is present and may contribute to the more adverse outcome associated with this geometric pattern.

Adaptation, Physiological↗
PubMed1996

Combined rest and exercise electrocardiographic repolarization findings in relation to structural and functional abnormalities in asymptomatic aortic regurgitation.

The relationship of combined rest and exercise electrocardiographic (ECG) repolarization abnormalities to left ventricular geometry and function was examined in 48 patients with asymptomatic chronic pure aortic regurgitation and no recent use of digitalis. Echocardiographic and radionuclide cineangiographic findings were compared in groups defined by the presence or absence of the "strain" pattern of repolarization abnormality on the resting ECG and also by the presence or absence of standard positive repolarization changes during upright treadmill exercise ( > 0.1 mV additional horizontal or downsloping ST depression). These hierarchic groups demonstrated trends toward progressively abnormal left ventricular dimensions, mass, wall stress, and change in ejection fraction with exercise. Although the presence of the strain pattern on the resting ECG alone was most strongly correlated with underlying functional and geometric abnormalities, an abnormal exercise test response was independently associated with abnormal left ventricular systolic dimension. The large group of patients with no symptoms and normal resting repolarization had only 0% to 4% prevalences of markedly increased systolic dimension (> 55 mm), reduced ejection fraction at rest (< 45%), or reduced ejection fraction during exercise (< 40%), whereas the small group of patients with abnormal resting repolarization and a positive exercise test response had 50% to 83% prevalences of these findings. These data suggest a possible role for rest and exercise ECG in the serial evaluation of patients with aortic regurgitation.

Adult↗
PubMed1996

Lack of association between mitral valve prolapse and history of rheumatic fever.

To determine whether rheumatic fever is associated with mitral valve prolapse (MVP) diagnosed by echocardiography, records from 561 subjects participating in a prospective family study were reviewed. The prevalence of a history of rheumatic fever by modified Jones criteria was determined in 92 probands and 112 affected relatives or spouses with M-mode and two-dimensional echocardiographic findings of MVP, accompanied in most instances by classic auscultatory findings, and in 357 family members without MVP. The prevalence of rheumatic fever was 5.4% in both MVP sub-groups and 2.2% in the family members without MVP (p<0.05 vs the combined MVP group). However, people with a history of rheumatic fever were older than the remaining subjects (48 +/- 17 vs 36 +/- 20 years, p<0.01) as expected because of the decline in rheumatic fever in the twentieth century, and subjects with MVP were older than subjects without MVP (39 +/- 16 vs 34 +/- 22 years, p<0.01). Multiple logistic regression showed that after the independent relation of older age with a positive history of rheumatic fever (p<0.01) was taken into account, there was a trend toward a lower likelihood of previous rheumatic fever associated with MVP (odds ration 0.42, p=0.07). These results do not support either a true association or a causal role of rheumatic fever in the pattern of mitral leaflet motion and auscultatory abnormalities in adults, for which the term MVP is generally used.

Adult↗
PubMed1996

ECG identification of left ventricular hypertrophy. Relationship of test performance to body habitus.

Obesity is associated with the presence of left ventricular hypertrophy (LVH) and, conversely, with decreased sensitivity of the electrocardiogram (ECG) for LVH due to attenuating effects on QRS amplitudes. Although the Framingham-adjusted Cornell voltage, incorporating age, sex, and body mass index (BMI), was developed to correct for the effects of obesity on the accuracy of the ECG, the impact of body habitus on ECG detection of LVH for newer, more accurate ECG criteria based on the time-voltage area under the QRS complex has not been determined. The authors examined the test accuracy of the Sokolow-Lyon voltage, Cornell voltage, Cornell product (product of QRS duration and Cornell voltage), Framingham-adjusted Cornell voltage, and time-voltage area of the horizontal plane vector QRS for the detection of echocardiographic LVH in relation to body habitus in 250 patients. Normal-weight or overweight status was based on sex-specific population-based BMI partitions. Using partitions with a matched specificity of 98% in the overall population without LVH, the sensitivity of standard ECG criteria varied according to body habitus. Sensitivity of the Framingham-adjusted Cornell voltage was less in normal-weight than in overweight patients (49 vs 59%, P = .0004); there were also trends toward lower sensitivity in normal-weight patients for the Cornell voltage (40 vs 65%, P = .10) and the Cornell product (43 vs 65%, P = NS), but sensitivity of the Sokolow-Lyon voltage was lower in obese than in nonobese patients (18 vs 50%, P = .025). In contrast, the horizontal plane vector area had similar sensitivity in obese and normal-weight patients (76 vs 74%, P = NS). Specificity varied with body habitus only for the Framingham-adjusted Cornell voltage: 100% in normal-weight vs 95% in overweight patients (P < .05). Thus, accuracy of the Framingham-adjusted Cornell voltage and Sokolow-Lyon voltage varies significantly with body habitus. In contrast, accuracy of the Cornell voltage and the Cornell product appears less dependent on BMI, and the time-voltage area of the QRS minimizes the effects of obesity on the accuracy of the ECG for LVH.

Body Mass Index↗
PubMed1996

Regression of left ventricular hypertrophy as a surrogate end-point for morbid events in hypertension treatment trials.

OBJECTIVE: To assess whether regression of left ventricular hypertrophy (LVH) can be used as a surrogate end-point for morbid events in hypertension treatment trials. DESIGN AND METHODS: Statistical, epidemiologic and treatment trial literature was reviewed to identify the criteria that should be met by a surrogate end-point and to determine whether these criteria are met by existing data on the regression of LVH. RESULTS: Relevant criteria include: (1) a consistent relationship between LVH and subsequent morbid events; (2) prediction of lower or higher complication rates by LVH regression or progression; (3) evidence that the relationship between LVH regression/progression and morbidity/mortality is consistent in different populations and with different treatments; and (4) demonstration of a quantitative relationship that allows prediction of a change in clinical risk from a measured change in LVH. The results of seven electrocardiographic and 10 echocardiographic studies with a total of about 20000 subjects have shown consistently higher risks of morbid events in subjects with than without LVH (odds ratios 1.4-5.4). The available data (four studies, 1145 subjects) suggest that morbid events will occur in a higher proportion of subjects in whom LVH progresses (13-59%) rather than regresses (7-12%). However, the latter data are derived almost entirely from white subjects, predominantly male, with incomplete knowledge of interim treatment and blood pressure in most instances; no information on the mathematical relationship between change in LVH and subsequent morbidity and mortality is yet available. CONCLUSIONS: A strict definition of the information required to establish a fully adequate surrogate end-point for morbid events in antihypertensive has been partially but not completely satisfied. The consistent relationship between baseline LVH and subsequent morbid events and the initial evidence of a parallelism between LVH change and prognosis need to be supplemented by additional studies that examine the latter relationship in diverse populations under varied treatments, and which examine the quantitative relationship between measured change in LVH and the subsequent rates of morbid events. Additional data will come from ongoing treatment trials (approximately 12 000 subjects) and observational studies (approximately 8000 subjects) with serial assessments of LVH.

Antihypertensive Agents↗
PubMed1996

Time-voltage area of the QRS for the identification of left ventricular hypertrophy.

Standard electrocardiographic criteria have exhibited poor sensitivity for left ventricular hypertrophy at acceptable levels of specificity and perform less well in women than men, even when sex-specific criteria are used. The time-voltage integral of the horizontal plane vector QRS complex can improve identification of hypertrophy in men, but performance of this approach in women and the effect of sex-specific criteria on accuracy have not been examined. To evaluate the accuracy of the time-voltage integral of the QRS complex for the identification of left ventricular hypertrophy in women and to examine the effect of sex-and non-sex-specific criteria on test performance, we obtained standard 12-lead and orthogonal-lead signal-averaged electrocardiograms and echocardiograms in 175 control subjects without hypertrophy (43 women and 132 men) and 75 patients with hypertrophy (26 women and 49 men) defined by echocardiographic criteria (indexed left ventricular mass > 110 g/m2 in women and > 125 g/m2 in men). Voltage of the QRS complex was integrated over the total QRS duration in leads X and Z for calculation of the time-voltage integral of the horizontal plane vector complex. With the use of a partition of 99.2 microV.s with a specificity of 98% in the entire normal group, sensitivity of the horizontal plane vector integral was significantly lower in women than men (31% versus 71%, P < .001). In contrast, use of sex-specific partitions of 75.4 microV.s in women and 99.2 microV.s in men with matched 98% specificity significantly improved sensitivity in women to 81% (P < .001), with no change in sensitivity in men (71%). Comparison of receiver operating characteristic curves with the use of sex-specific criteria demonstrated no significant difference in overall performance of the horizontal plane vector integral between men and women. The 81% and 71% sensitivities of the sex-specific horizontal plane vector integral were significantly greater than the 27% to 58% sensitivities of sex-specific 12-lead electrocardiographic criteria in this population. Thus, sex-specific criteria significantly improve performance of the time-voltage integral of the QRS for the identification of left ventricular hypertrophy in women, with no loss of accuracy in men. Use of the time-voltage integral can improve the accuracy of the electrocardiogram for the identification of left ventricular hypertrophy in both women and men.

Analysis of Variance↗
PubMed1996

Association of carotid atherosclerosis with electrocardiographic myocardial ischemia and left ventricular hypertrophy.

Patients with carotid atherosclerosis have an increased risk of coronary events and an increased prevalence of echocardiographic left ventricular hypertrophy. However, little is known regarding the association between electrocardiographic abnormalities and carotid atherosclerosis. The relationship of electrocardiographic evidence of myocardial ischemia and left ventricular hypertrophy to the presence of carotid atherosclerosis was prospectively studied in 349 asymptomatic subjects who underwent echocardiography and carotid ultrasonography. Myocardial ischemia on the electrocardiogram was defined by the presence of localized T-wave inversions, and electrocardiographic hypertrophy was defined by the product of Cornell voltage and QRS duration. Carotid atherosclerosis was present in 21% (72/ 349) of subjects and was associated with older age, higher systolic and pulse pressures, and greater left ventricular mass. Both ischemia and hypertrophy on the electrocardiogram were strongly associated with carotid plaque. Carotid atherosclerosis was more than three times more prevalent in subjects with electrocardiographic ischemia (69% [11/16] versus 18% [61/333], P < .0001) or electrocardiographic left ventricular hypertrophy (78% [7/9] versus 19% [65/340], P = .0003) than in subjects without these findings. Logistic regression analysis, including standard risk factors, revealed that both ischemia and hypertrophy on the electrocardiogram remained significant independent predictors of the presence of carotid atherosclerosis, along with age and echocardiographic left ventricular mass. These findings suggest that the associations of ischemia and left ventricular hypertrophy with carotid atherosclerosis may contribute to the increased incidence of coronary events in patients with carotid atherosclerosis.

Adult↗
PubMed1996

Effect of hypertension on aortic root size and prevalence of aortic regurgitation.

Although early reports suggested that hypertension predisposed to aortic root enlargement and consequent aortic regurgitation, more recent pathological and M-mode echocardiographic studies have not found an association between hypertension and aortic enlargement when age is considered. These discrepancies may partially reflect methodological shortcomings in the accuracy and reproducibility of aortic and blood pressure measurements. Therefore, we measured two-dimensional echocardiographic diameters of the aortic root at four locations and compared findings with ambulatory and resting blood pressures and measures of body size in 110 normotensive and 110 hypertensive men and women matched for age and sex. Aortic diameters at the anulus (2.41 +/- 0.29 versus 2.34 +/- 0.24 cm, P = .06) and sinuses (3.47 +/- 0.44 versus 3.37 +/- 0.36 cm, P = .08) were marginally higher, whereas diameters at the supra-aortic ridge (2.94 +/- 0-38 versus 2.81 +/- 0.32 cm, P < .01) and ascending aorta (3.26 +/- 0.45 versus 3.11 +/- 0.32 cm, P < .01) were significantly increased in hypertensive subjects. Aortic diameters increased with increasing quartiles of diastolic and systolic pressures, particularly at the supra-aortic ridge and ascending aorta. In multivariate analyses, blood pressure remained an independent determinant of distal aortic diameters after body size and age were considered. Aortic regurgitation was seen in 5 normotensive and 7 hypertensive subjects and did not differ in severity. Thus, hypertension is associated with a slight increase in aortic root size, most notably of the supra-aortic ridge and proximal ascending aorta. Although dilatation at the commissural attachment might be expected to predispose to an increase in aortic regurgitation, we did not detect such a difference in this population of healthy, asymptomatic individuals.

Adult↗
PubMed1996

Influence of obesity on left ventricular midwall mechanics in arterial hypertension.

The evaluation of the effect of obesity on left ventricular systolic performance may differ in relation to the method used to measure left ventricular function and to the type of study population. Whether obesity worsens left ventricular midwall mechanics in arterial hypertension has never been investigated. Accordingly, we assessed echocardiographic left ventricular midwall shortening-circumferential end-systolic stress relations in 156 normotensive and normal-weight (reference) adults, 94 normotensive and overweight (1985 National Institutes of Health partition values) to obese (body mass index > 30 kg/m2) adults, 263 hypertensive and normal-weight adults, and 224 hypertensive and overweight-to-obese adults. There was an inverse relation of midwall shortening to circumferential end-systolic stress in all groups (all P < .005). Left ventricular performance as a ratio of observed to predicted midwall shortening fell below the fifth percentile in 4 of 94 (4%) of overweight-to-obese normotensive individuals. Eighty-eight of 487 hypertensive subjects (18.1%) exhibited depressed midwall shortening as a percentage of the value predicted from wall stress, with no difference between normal-weight (50 of 263 [19%]) and overweight (38 of 224 [17%]) subjects. Sixty-one normotensive and 131 hypertensive subjects were frankly obese. After adjustment for sex and age, midwall shortening, as either absolute values or a percentage of predicted, was not statistically different among obese, overweight, and normal-weight subjects in both normotensive and hypertensive groups. For each quartile of observed-to-predicted midwall shortening ratio, obese subjects had greater left ventricular end-diastolic volume than normal-weight subjects among both normotensive and, more evidently, hypertensive subjects. A predicted midwall shortening was generated from both wall stress and left ventricular volume with the use of multiple regression analysis. High body mass index, mean blood pressure, aging, and male sex independently predicted low afterload and left ventricular volume-independent midwall left ventricular performance (multiple R = .31, P < .0001). Thus, (1) midwall left ventricular systolic performance in asymptomatic overweight or frankly obese individuals is comparable to that in normal-weight individuals in both the presence and absence of arterial hypertension; (2) however, maintenance of normal life ventricular performance in obese individuals is associated with the use of Starling reserve; and (3) this compensatory mechanism is especially evident when arterial hypertension and obesity coexist.

Adult↗