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Biomedical subjects

M J Roman

Publications and source records attributed to M J Roman.

At least 127 records · Page 7Linked to original sources

Relation of obesity and gender to left ventricular hypertrophy in normotensive and hypertensive adults.

Although it is recognized that both hypertension and obesity are associated with increased left ventricular mass, the relative impacts of obesity, arterial hypertension, and gender on the prevalence of ventricular hypertrophy remain uncertain. Accordingly, echocardiographic left ventricular mass normalized for height to the power of the allometric or growth relation between ventricular mass and height was compared in 164 normotensive subjects (85 men [24 obese] and 79 women [28 obese], aged 45 +/- 12 years) and 475 hypertensive patients (325 men [126 obese] and 150 women [85 obese], aged 54 +/- 10 years) from an adult employed population. Gender-specific upper normal limits were used to identify ventricular hypertrophy. Left ventricular mass/height 2.7 was higher in obese than normal-weight normotensive subjects (P < .004) independently of the level of blood pressure and identified a higher prevalence of hypertrophy (mainly eccentric) in obese than in normal-weight normotensive subjects (14% versus 5%, P < .04), a difference that was not detected by left ventricular mass/body surface area. Left ventricular mass/height identified hypertrophy in 52% of obese and 30% of normal-weight hypertensive patients (P < .0001) because of higher prevalences in obese than normal-weight patients of both eccentric (34% versus 20%) and concentric ventricular hypertrophy (18% versus 10%). The increase in left ventricular mass was independent of blood pressure values in obese normotensive women (but not men), and the prevalence of supranormal left ventricular mass/height 2.7 was even higher in hypertensive obese women (58%) than men (49%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Cardiac and arterial hypertrophy and atherosclerosis in hypertension.

Clinical evaluation of the hypertensive patient has traditionally relied on physician measurement of blood pressure and assessment of target-organ involvement by simple laboratory tests. However, this approach is limited in its ability to identify individual patients at high or low risk of complications. In recent years, noninvasive methods have been developed to identify pathological transformations of the heart and arteries that collectively comprise "preclinical hypertensive disease." Measurements by echocardiogram or other methods of left ventricular mass and relative wall thickness identify a spectrum of cardiac adaptations to hypertension, including concentric and eccentric hypertrophy, the recently described pattern of "concentric left ventricular remodeling" (normal mass but increased relative wall thickness), and normal ventricular geometry. In clinical studies, each anatomic pattern is associated with a distinct profile of resting hemodynamics, ambulatory blood pressure, myocardial contractility, and risk of adverse outcomes. Ultrasonic imaging of the carotid or other arteries makes it possible to detect increased arterial wall thickness and discrete atheromas noninvasively. Carotid wall thickness and lumen diameter parallel similar ventricular dimensions in normotensive and hypertensive humans, indicating the presence of integrated patterns of cardiac and vascular adaptation to hypertension. Furthermore, peripheral atherosclerosis is associated with higher ventricular mass and a more adverse 24-hour blood pressure profile. In summary, noninvasive visualization of the heart and blood vessels reveals a spectrum of patterns of anatomic and functional adaptations that are related to the pathophysiology and prognosis of hypertension.

Arteries↗

Left ventricular hypertrophy and geometric remodeling in hypertension: stimuli, functional consequences and prognostic implications.

OBJECTIVE: To provide a coherent overview of the stimuli to development of abnormal left ventricular geometric patterns, their impact on cardiac function and their relationship to the prognosis of hypertension, studies performed by the authors and other investigators are reviewed. RESULTS: Clinical and experimental studies have shown that an elevated left ventricular mass reflects the additive effects on the heart of higher arterial pressure over time, increased cardiac volume load related to obesity, sodium intake or other stimuli, reduced contractile efficiency of the myocardium and altered arterial hemodynamics related to vascular hypertrophy and atherosclerosis. The heart may adapt to hypertension by developing concentric or eccentric left ventricular hypertrophy, or the newly described pattern of concentric left ventricular remodeling, or by retaining normal left ventricular geometry. Each geometric pattern is associated with a distinct combination of pressure and volume stimuli, contractile efficiency (reduced in those with concentric left ventricular hypertrophy or remodeling) and prognosis (worst with concentric hypertrophy and best with normal left ventricular geometry). An appraisal of left ventricular mechanics by a physiologically appropriate midwall-shortening/end-systolic stress relationship can identify impaired contractility in an appreciable proportion of hypertensive patients. Numerous studies have shown that increased left ventricular mass and abnormal geometry have a strong predictive value for cardiovascular death, myocardial infarction and stroke. CONCLUSIONS: Increasing evidence has demonstrated the central importance of left ventricular mass and geometry in the pathophysiology and prognosis of hypertension. These measures of preclinical disease can aid clinical decision-making by separating patients into those with a high or a relatively low risk, and hence a need for pharmacological treatment or its intensification, as well as providing useful bioassays for a spectrum of clinical and experimental research.

Humans↗

Evaluation of left ventricular hypertrophy by M-mode echocardiography in patients and experimental animals.

In validation studies, M-mode echocardiography has been shown to measure left ventricular (LV) mass with reasonable accuracy (r > or = .90 v necropsy measurements) in species ranging in body size from humans to rats. The sensitivity of antemortem echocardiography for the detection of necropsy LV hypertrophy as a qualitative abnormality has also been high (85% to 100%). Increased LV mass is strongly related to both increased blood pressure and to being overweight or to other causes of increased cardiac volume work. LV mass is also increased in the presence of exaggerated blood pressure responses to everyday activity, high sodium intake and blood viscosity, and genetic factors predisposing to hypertension. Indexation of LV mass by body surface area or height has advantages for the detection of hypertrophy related to hypertension or obesity. Indexation of LV mass for the power of its relation to height (2.7) revealed by analysis of growth (allometric) relations may accomplish both these goals. Recent research indicates that the level of LV mass measured by M-mode echocardiography is a stronger predictor of subsequent morbid events and death than blood pressure or other conventional risk factors except age. Preliminary findings of close relations between LV mass and arterial disease and between the change in LV mass during antihypertensive treatment and subsequent events contribute to explaining the strong predictive value of LV mass.

Adult↗

Prognostic significance of the pattern of aortic root dilation in the Marfan syndrome.

OBJECTIVES: The present study examines the incidence of aortic complications (dissection, marked dilation requiring surgery or progressive moderate to severe aortic regurgitation) and their relation to clinical features and aortic root morphology in patients with the Marfan syndrome. BACKGROUND: Considerable phenotypic variability exists in the Marfan syndrome, and the prospective prediction of the risk for aortic complications in individual patients remains elusive. METHODS: One hundred thirteen patients with the Marfan syndrome underwent anthropometric and echocardiographic evaluation and were followed-up for 49 +/- 24 (mean +/- SD) months. Aortic root dilation was defined as localized when confined to the sinuses of Valsalva (based on two-dimensional echocardiographic confidence limits utilizing age and body size) and generalized if dilation additionally involved the supraaortic ridge and proximal ascending aorta. RESULTS: Aortic root dilation was present in 80% of patients and was localized in 28% and generalized in 51%. Aortic complications occurred during follow-up in none of 23 patients with normal initial aortic size, in 2 (6%) of 32 patients with initially localized dilation and in 19 (33%) of 58 patients with generalized dilation (p < 0.0005). Complications were associated with larger initial aortic size (p < 0.00005), higher systolic blood pressure (p < 0.005), height (p < 0.05), aortic growth rate (p < 0.05) and older age (p < 0.01). The only independent predictor of aortic complications was initial aortic root size (p < 0.005). However, when aortic size, one of the indications for surgical referral, was excluded from analyses, the only independent predictor of aortic complications was generalized aortic dilation (p < 0.005). CONCLUSIONS: The present study indicates that generalized aortic root dilation is a potent marker of an increased risk for subsequent aortic complications in Marfan syndrome.

Adolescent↗

Relation of arterial pressure waveform to left ventricular and carotid anatomy in normotensive subjects.

OBJECTIVES: The purpose of this study was to examine the relation of the central arterial pressure waveform to left ventricular and carotid structure. BACKGROUND: The pressure waveform in the central arteries is affected by reflection of the pressure wave from the periphery. When reflected waves merge with the incident wave during systole, a late systolic peak and increment in systolic blood pressure are observed. The consequent increase in hemodynamic load may stimulate left ventricular and vascular adaptive changes. METHODS: Sixty-seven normotensive adults were studied by noninvasive techniques. Anatomy and function of the left ventricle and carotid artery were investigated by ultrasonography. Pressure waveforms were recorded by an external tonometer applied to the carotid artery, and waveform shape was expressed by the augmentation index, calculated from the difference between the maximal systolic pressure and that at the inflection between early and late systolic pressure peaks divided by the pulse pressure. Subjects were assigned to groups with a dominant early (group 1, augmentation index < or = 0) or dominant late systolic peak (group 2, augmentation index > 0). RESULTS: Left ventricular mass index was significantly higher in group 2 than in group 1, a difference that persisted after controlling for the confounding effects of gender, age and blood pressure. Carotid wall thickness and regional arterial stiffness were significantly increased in group 2, but differences disappeared in the analysis of covariance for age. CONCLUSIONS: Left ventricular and carotid artery structure are related to the shape of the central pressure waveform. Although the increase in left ventricular mass seen in subjects with a dominant late systolic peak pressure appears to be directly related to the shape of the pressure waveform, changes in the structural and physical properties of the carotid artery appear to be more closely related to the aging process.

Aging↗

Left ventricular hypertrophy associated with hypertension and its relevance as a risk factor for complications.

Recent research indicates that the level of left ventricular (LV) mass, commonly measured by echocardiography, reflects the combined effects of a variety of factors involved in the pathophysiology of hypertension, including obesity, blood pressure responses to everyday activity, high sodium intake and blood viscosity, the volume work load of the heart, and genetic factors predisposing to hypertension. Prospective studies indicate that LV mass is a stronger predictor of subsequent morbid events and death than blood pressure or other conventional risk factors except age. Preliminary findings of close relations between LV mass and arterial disease and between the change in LV mass during antihypertensive treatment and subsequent events contribute to explaining the strong predictive value of LV mass. Further research is needed to clarify the biologic basis of these observations and to determine whether stratification of hypertensive patients based on their level of LV mass can improve the treatment of hypertension.

Cardiovascular Diseases↗

Acid phosphatase activity in Coxiella burnetii: a possible virulence factor.

High-speed supernatant fluids derived from sonicated Coxiella burnetii contained considerable acid phosphatase activity when assayed by using 4-methylumbelliferylphosphate; they also contained a factor that blocked superoxide anion production by human neutrophils stimulated with formyl-Met-Leu-Phe. The pH optimum of the enzyme was approximately 5.0. The level of phosphatase activity detected in several isolates of C. burnetii implicated in acute (Nine Mile) and chronic (S Q217, PRS Q177, K Q154) Q fever was 25 to 60 times greater than that reported in other microorganisms, including Leishmania and Legionella spp. The enzyme was found in rickettsiae grown in different hosts (L929 cells and embryonated eggs) and, in the case of L929 cells, for both short periods (less than a month) and the long term (years). Cytochemical techniques coupled with electron microscopy localized the phosphatase activity to the periplasmic gap in the parasite. Ion-exchange chromatography revealed a major species of the enzyme and showed that the enzyme of the parasite was distinct from that of the host cell (L929 fibroblasts); its apparent molecular weight was 74,000. Phosphatase inhibitors (i.e., molybdate heteropolyanions) had differential effects on the phosphatases of the parasite and host cell. C. burnetii supernatant fluid inhibited superoxide anion production by formyl-Met-Leu-Phe-stimulated human neutrophils; molybdate inhibitors reversed the inhibition. Treatment of C. burnetii-infected L929 cells with one of the molybdate compounds (complex B') significantly reduced the level of infection and did not affect the viability or growth of the host cell. These data suggest that the acid phosphatase of the parasite may be a major virulence determinant, allowing the agent to avoid being killed during uptake by phagocytes and subsequently in the phagolysosome.

Acid Phosphatase↗

The effect of nitrous oxide on left ventricular pump performance and contractility in patients with coronary artery disease: effect of preoperative ejection fraction.

To elucidate the effects of nitrous oxide (N2O) on left ventricular (LV) pump performance and contractility, 28 patients undergoing coronary artery bypass graft surgery were studied, of whom 15 had depressed global LV function at preoperative catheterization. Transesophageal echocardiography and simultaneous hemodynamic measurements were used to assess LV preload, afterload, and systolic performance during inhalation of 100% oxygen (O2) and 60% N2O:40% O2. Systolic function indices were expressed as a percent of the predicted value for observed end-systolic stress to provide estimates of LV contractility. In the entire study population, N2O reduced pump performance (cardiac index 2.4 +/- 0.8 to 2.2 +/- 0.6 L.min-1 x m-2; P < 0.02). Heart rate and mean arterial pressure were reduced (67 +/- 13 to 64 +/- 13, P < 0.01, and 87 +/- 9 to 80 +/- 15, P < 0.005) as were left and right ventricular stroke work index. Preload, as measured by end-diastolic stress, was unchanged but afterload, as measured by end-systolic stress, tended to decrease (88 +/- 31 to 78 +/- 28, P = 0.053). In the 13 patients with normal preoperative LV function, mean arterial pressure and LV stroke work index decreased significantly (91 +/- 8 to 84 +/- 14, P < 0.04, and 40 +/- 13 to 34 +/- 10, P < 0.04, respectively) and end-systolic stress tended to decrease (P = 0.054).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Left ventricular hypertrophy and hypertension.

The level of left ventricular (LV) mass as measured by echocardiography or other techniques in hypertensive patients reflects the integrated effects of the level of arterial pressure, the concomitant volume load imposed on the heart, and of alterations in arterial waveform morphology as well as of body size and non-hemodynamic variables. The LV may respond to these stimuli by concentric or eccentric hypertrophy or by the recently-described pattern of concentric remodeling, in which LV mass is normal but relative wall thickness is increased. The are strong parallelisms between increases in cardiac and systemic arterial wall thicknesses, and patients with discrete atheromas detectable by carotid ultrasound have elevated LV masses. Patients with eccentric and concentric LV hypertrophy have two to four-fold increases in the incidence of cardiovascular morbid events compared to hypertensive patients with normal LV geometry, and the change in LV mass during treatment has been associated with the risk of subsequent morbidity in initial studies. In contrast to the strong predictive power of LV geometric assessment, use of indirect measures of target organ status in the WHO system for classification of the severity of hypertension does not improve on the prediction of prognosis that can be obtained by consideration of the level of arterial pressure. Current evidence suggests that evaluation of LV geometry may contribute to improved clinical decision-making in situations where more precise stratification of risk would clarify whether or not to institute treatment, or whether it should be with drugs or non-pharmacologic measures.

Adaptation, Physiological↗

Inter-relationships between hypertension, left ventricular hypertrophy and coronary heart disease.

Increased left ventricular mass predicts myocardial infarction: Recent studies have demonstrated that increased left ventricular mass is a more potent predictor than is elevated blood pressure of myocardial infarction or death due to coronary heart disease in hypertensive patients. Other research has shown that hypertensive patients commonly have episodes of asymptomatic ischemic ST-segment depression. Several different factors appear to account for this close relationship between myocardial muscle mass and the occurrence of ischemia and vascular morbid events. These include an increased resting demand for coronary blood flow (to supply the greater amount of myocardium), atherosclerotic obstruction of large coronary arteries and reduced vasodilatory capacity of the coronary microcirculation due to arteriolar hypertrophy and dysregulation, each of which reduces the capacity of the coronary circulation to increase its blood flow during stress (coronary reserve). Increased risk in population with more severe hypertension: Increased ventricular mass and coronary arteriolar abnormalities appear especially important as mechanisms of myocardial ischemia in populations with more severe hypertension, whereas conventional coronary disease predominates in patients with mild hypertension and multiple standard risk factors. Need for further research to optimize therapy: To develop optimal therapeutic approaches, further research is needed to clarify the basis of the inter-relationships between left ventricular hypertrophy and arterial abnormalities, to determine whether cardiac microvascular abnormalities parallel systemic hemodynamic patterns in hypertension and to ascertain the relative importance of reversing or preventing cardiovascular hypertrophy and myocardial ischemia for improving the prognosis of hypertensive patients.

Animals↗

Left ventricular mass and body size in normotensive children and adults: assessment of allometric relations and impact of overweight.

OBJECTIVES: This study was designed to determine the most appropriate method to normalize left ventricular mass for body size. BACKGROUND: Left ventricular mass has been normalized for body weight, surface area or height in experimental and clinical studies, but it is uncertain which of these approaches is most appropriate. METHODS: Three normotensive population samples--in New York City (127 adults), Naples, Italy (114 adults) and Cincinnati, Ohio (444 infants to young adults)--were studied by echocardiography. Relations of left ventricular mass to body size were similar in all normal weight groups, as assessed by linear and nonlinear regression analysis, and results were pooled (n = 611). RESULTS: Left ventricular mass was related to body weight to the first power (r = 0.88), to body surface area to the 1.5 power (r = 0.88) and to height to the 2.7 power (r = 0.84), consistent with expected allometric (growth) relations between variables with linear (height), second-power (body surface area) and volumetric (left ventricular mass and body weight) dimensions. Strong residual relations of left ventricular mass/body surface area to body surface area (r = 0.54) and of ventricular mass/height to height (r = 0.72) were markedly reduced by normalization of ventricular mass for height2.7 and body surface area1.5. The variability among subjects of ventricular mass was also reduced (p < 0.01 to p < 0.002) by normalization for body weight, body surface area, body surface area1.5 or height2.7 but not for height. In 20% of adults who were overweight, ventricular mass was 14% higher (p < 0.001) than ideal mass predicted from observed height and ideal weight; this increase was identified as 14% by left ventricular mass/height2.7 and 9% by ventricular mass/height, whereas indexation for body surface area, body surface area1.5 and body weight erroneously identified left ventricular mass as reduced in overweight adults. CONCLUSIONS: Normalizations of left ventricular mass for height or body surface area introduce artifactual relations of indexed ventricular mass to body size and errors in estimating the impact of overweight. These problems are avoided and variability among normal subjects is reduced by using left ventricular mass/height2.7. Simple nomograms of the normal relation between height and left ventricular mass allow detection of ventricular hypertrophy in children and adults.

Adult↗

Association of aortic dilation with regurgitant, stenotic and functionally normal bicuspid aortic valves.

To determine whether aortic root dilation associated with a bicuspid aortic valve occurs independently of valvular hemodynamic abnormality, aortic root dimensions were measured by two-dimensional echocardiography in 83 adults with a functionally normal (n = 19), mildly regurgitant (n = 26), severely regurgitant (n = 27) or stenotic (n = 11) bicuspid aortic valve and compared with findings in normal subjects matched for age and gender. Aortic root measurements were made at four levels: anulus, sinuses of Valsalva, supraaortic ridge and proximal ascending aorta. Seventy-one percent of patients with a bicuspid aortic valve were men. When compared with control subjects, all hemodynamic subgroups showed a significantly larger aortic root size at three levels: sinuses of Valsalva, supraaortic ridge and proximal ascending aorta (p less than 0.05 to p less than 0.001). The prevalence of aortic root enlargement among all hemodynamic subgroups ranged from 9% to 59% at the level of the anulus, 36% to 78% at the sinuses, 47% to 79% at the supraaortic ridge and 50% to 64% in the ascending aorta. Thus, there is a high prevalence of aortic root enlargement in patients with a bicuspid aortic valve that occurs irrespective of altered hemodynamics or age. These findings support the hypothesis that bicuspid aortic valve and aortic root dilation may reflect a common developmental defect.

Adult↗

Patterns of left ventricular hypertrophy and geometric remodeling in essential hypertension.

The spectrum of left ventricular geometric adaptation to hypertension was investigated in 165 patients with untreated essential hypertension and 125 age- and gender-matched normal adults studied by two-dimensional and M-mode echocardiography. Among hypertensive patients, left ventricular mass index and relative wall thickness were normal in 52%, whereas 13% had increased relative wall thickness with normal ventricular mass ("concentric remodeling"), 27% had increased mass with normal relative wall thickness (eccentric hypertrophy) and only 8% had "typical" hypertensive concentric hypertrophy (increase in both variables). Systemic hemodynamics paralleled ventricular geometry, with the highest peripheral resistance in the groups with concentric remodeling and hypertrophy, whereas cardiac index was super-normal in those with eccentric hypertrophy and low normal in patients with concentric remodeling. The left ventricular short-axis/long-axis ratio was positively related to stroke volume (r = 0.45, p less than 0.001), with cavity shape most elliptic in patients with concentric remodeling and most spheric in those with eccentric hypertrophy. Normality of left ventricular mass in concentric remodeling appeared to reflect offsetting by volume "underload" of the effects of pressure overload, whereas eccentric hypertrophy was associated with concomitant pressure and volume overload. Thus, arterial hypertension is associated with a spectrum of cardiac geometric adaptation matched to systemic hemodynamics and ventricular load. Concentric left ventricular remodeling and eccentric hypertrophy are more common than the typical pattern of concentric hypertrophy in untreated hypertensive patients.

Adaptation, Physiological↗

Left ventricular mass as a measure of preclinical hypertensive disease.

The ability to identify the hypertensive patient who is destined to suffer a morbid or fatal complication in the long presymptomatic phase of this condition, when its natural history would be most subject to amelioration, is limited by the weak relation between the level of blood pressure and the occurrence of complications. Recent research indicates that the level of left ventricular (LV) mass--most conveniently measured by echocardiography--reflects the combined effects of a variety of factors involved in the pathophysiology of hypertension, including obesity, exaggerated blood pressure responses to everyday activity, high sodium intake and blood viscosity, and genetic factors predisposing to hypertension. Prospective studies indicate that LV mass is a stronger predictor of subsequent morbid events and death than blood pressure or other conventional risk factors except age. Preliminary findings of close relations between LV mass and arterial disease and between the change in LV mass during antihypertensive treatment and subsequent events contribute to explaining the strong predictive value of LV mass. Further research is needed to clarify the biologic basis of these observations and to determine whether stratification of hypertensive patients based on their level of LV mass can improve the treatment of hypertension.

Echocardiography↗

Color flow and conventional echocardiography of the Marfan syndrome.

Imaging and color flow Doppler echocardiography are an integral part of any evaluation of a patient with the Marfan syndrome. The major cardiovascular manifestations of this condition are aortic dilation, which may involve the proximal and distal aorta, aortic regurgitation, aortic dissection, mitral valve prolapse, and mitral regurgitation. Patients who have the Marfan syndrome should have serial echocardiograms to measure aortic root diameter carefully at the sinuses of Valsalva and subsequent levels (sinotubular junction, arch, descending and abdominal aorta). Additionally, color Doppler echocardiography assists in the diagnosis of aortic dissection and facilitates evaluation of the severity of aortic and mitral regurgitation that commonly complicate the Marfan syndrome. The risk of aortic dissection, which is the most serious manifestation of the Marfan syndrome, increases as the aorta enlarges. Therefore, elective composite graft surgery is recommended when the aortic root size reaches 60 mm, regardless of symptom status, or 55 mm in the presence of severe aortic regurgitation. Surgical replacement of the aortic root with a composite graft does not end the disease process. Color flow Doppler is useful in the diagnosis of dehiscence of the conduit sewing ring, coronary artery aneurysm, distal aortic dissections, and prosthetic valve dysfunction.

Aortic Dissection↗

Parallel cardiac and vascular adaptation in hypertension.

BACKGROUND: Although vascular damage in the noncoronary circulation is a major cause of complications in hypertension, relatively little is known of the in vivo geometry and function of the arterial circulation in patients with uncomplicated hypertension or of their relation to left ventricular hypertrophy, a marker of enhanced risk of cardiovascular complications. METHODS AND RESULTS: Wall thickness and internal diameter of the common carotid artery and the presence of atherosclerosis within the extracranial carotid arteries were determined by ultrasound in 43 asymptomatic hypertensive patients and 43 normotensive subjects matched for sex, age, and body size. Vascular stiffness was estimated from simultaneous superimposed carotid pressure waveforms obtained with an external solid-state transducer. Left ventricular size and function were determined echocardiographically. Compared with normal subjects, hypertensive patients had greater left ventricular absolute and relative wall thicknesses, left ventricular mass, and carotid absolute and relative wall thicknesses (p < 0.005). Carotid intimal-medial thickness exceeded the 95th percentile of normal values in 28% of hypertensive patients (p < 0.01). Carotid atherosclerosis was equally prevalent within the two blood pressure groups and was associated with older age, larger left ventricular and carotid wall thicknesses, and carotid diameter. Despite similar carotid pulse pressures, vascular stiffness was significantly increased in the hypertensive patients. Among the population as a whole, significant relations existed between cardiac and vascular wall thicknesses and internal dimensions. In multivariate analyses, these relations were statistically independent of age and blood pressure. CONCLUSIONS: The present study documents the presence of geometric and functional changes within the common carotid artery in uncomplicated hypertension that parallel findings within the left ventricle. The potential contribution of these changes to the cardiovascular complications of hypertension, particularly in the setting of left ventricular hypertrophy, is unknown.

Adaptation, Physiological↗

Non-invasive measurements of arterial compliance in hypertensive compared with normotensive adults.

AIM: To determine differences in arterial compliance attributable to hypertension. METHODS: Since measurements of arterial compliance have tended to vary in the past according to the method used, a new technique comprising carotid ultrasound and simultaneous, calibrated, carotid pressure waveform measurements was tested in 43 hypertensives and 43 control subjects matched for age, gender and body size. RESULTS: There was a significant reduction in compliance among the hypertensive patients, as estimated by the elastic modulus and the ratio of stroke volume to pulse pressure. However, when the non-linearity of the pressure-volume relationship and the impact of distending pressure were taken into account, by the arterial stiffness index and by the increase in arterial wall thickness associated with hypertension by Young's modulus, there were no significant differences in arterial compliance between the two groups.

Adult↗