Total Arterial Compliance Index Research Articles

Obesity-Related Hemodynamic Alterations in Patients with Cushing's Disease.

Background: Cushing's disease (CD) is associated with a specific form of metabolic syndrome that includes visceral obesity, which may affect cardiovascular hemodynamics by stimulating hypercortisolism-related metabolic activity. The purpose of this study was to evaluate the relationship between obesity and the hemodynamic profile of patients with CD. Methods: This prospective clinical study involved a hemodynamic status assessment of 54 patients newly diagnosed with CD with no significant comorbidities (mean age of 41 years). The assessments included impedance cardiography (ICG) to assess such parameters as stroke index (SI), cardiac index (CI), velocity index (VI), acceleration index (ACI), Heather index (HI), systemic vascular resistance index (SVRI), and total arterial compliance index (TACI) as well as applanation tonometry to assess such parameters as central pulse pressure (CPP) and augmentation index (AI). These assessments were complemented by echocardiography to assess cardiac structure and function. Results: Compared with CD patients without obesity, individuals with CD and obesity (defined as a body mass index ≥ 30 kg/m2) exhibited significantly lower values of ICG parameters characterizing the pumping function of the heart (VI: 37.0 ± 9.5 vs. 47.2 ± 14.3 × 1*1000-1*s-1, p = 0.006; ACI: 58.7 ± 23.5 vs. 76.0 ± 23.5 × 1/100/s2, p = 0.005; HI: 11.1 ± 3.5 vs. 14.6 ± 5.5 × Ohm/s2, p = 0.01), whereas echocardiography in obese patients showed larger heart chamber sizes and a higher left ventricular mass index. No significant intergroup differences in blood pressure, heart rate, LVEF, GLS, TACI, CPP, or AI were noted. Conclusions: Hemodynamic changes associated with obesity already occur at an early stage of CD and manifest via significantly lower values of the ICG parameters illustrating the heart's function as a pump, despite the normal function of the left ventricle in echocardiography.

The patient's sex determines the hemodynamic profile in patients with Cushing disease.

Cushing disease (CD) may lead to accelerated cardiovascular remodeling and increased mortality. There are suspected differences in the mechanism of cardiovascular dysfunction between males and females with CD. The purpose of this study was to assess the effect of patient sex on the hemodynamic profile assessed via impedance cardiography and echocardiography in patients newly diagnosed with CD. The 54 patients newly diagnosed with CD (mean age 41 years; 77.8% of females) who were included in this prospective clinical study underwent impedance cardiography to assess specific parameters (including systemic vascular resistance index [SVRI], total arterial compliance index [TACI], Heather index [HI], stroke index [SI], cardiac index [CI], velocity index [VI], and acceleration index [ACI]) and transthoracic echocardiography to assess heart chamber diameters and left ventricular systolic and diastolic function. Males with CD exhibited higher afterload, with higher SVRI (3,169.3 ± 731.8 vs. 2,339.3 ± 640.8 dyn*s*cm-5*m² in males and females, respectively; p=0.002), lower TACI (0.80 ± 0.30 vs. 1.09 ± 0.30 mL/mmHg*m2; p=0.008), and lower hemodynamic parameters of left ventricular function, with lower HI (9.46 ± 2.86 vs. 14.1 ± 5.06 Ohm/s2; p=0.0007), lower VI (35.1 ± 11.9 vs. 44.9 ± 13.1 1*1000-1*s-1; p=0.009), lower SI (36.5 ± 11.7 vs. 43.6 ± 9.57 mL/m2; p=0.04), lower CI (2.36 ± 0.46 vs. 3.17 ± 0.76 mL*m-2*min-1; p=0.0009), and lower ACI (50.4 ± 19.8 vs. 73.6 ± 25.0 1/100/s2; p=0.006). There were no significant differences between the sexes in left ventricular systolic or diastolic function assessed by echocardiography. In comparison with females with CD, males with CD have a less favorable hemodynamic profile, with higher afterload and worse left ventricular function. Sex differences in cardiovascular system function should be taken into consideration in designing personalized diagnostic and therapeutic management of patients with CD.

Noninvasive Assessment of Sex Differences in Arterial Load in Healthy Adults

BackgroundWomen have higher risk of heart failure than their male counterparts. Although the mechanical inefficiency of myocardium against an excessive afterload is an important reason of heart failure, little attention has been paid to the sex differences in arterial load and its clinical relevance.ResultsThe effective arterial elastance index (EaI), total arterial compliance index (TACI), and systemic vascular resistance index (SVRI) were determined using transthoracic echocardiography combined with cuff-measured brachial blood pressure in 460 healthy adults (230 men). The sex differences in these arterial load indexes were analyzed. No statistical difference was found in the age, heart rate, and stroke volume index (all P < 0.05). After adjustment for the cuff-measured blood pressure; the estimated marginal means (95% CIs) of the EaI was higher in women than in men [0.972 (0.952–0.991) vs 0.743 (0.724–0.763) mmHg m2/mL, P < 0.001], the TACI was lower in women than in men [0.924 (0.905–0.944) vs 1.055 (1.036–1.075) mL/mm Hg m2, P < 0.001], and no statistical difference was found in the SVRI between sexes (P > 0.05).ConclusionsFor any given cuff-measured blood pressure, greater integrated and pulsatile arterial load are imposed on left ventricle in women than in men, which is a piece of evidence that women have higher risk of heart failure than their counterparts.

Exercise Intolerance in Heart Failure With Preserved Ejection Fraction: Arterial Stiffness and Abnormal Left Ventricular Hemodynamic Responses During Exercise

BackgroundArterial stiffness is thought to contribute to the pathophysiology of heart failure with preserved ejection fraction (HFpEF). We sought to examine arterial stiffness in HFpEF and hypertension and investigate associations of arterial and left ventricular hemodynamic responses to exercise. Methods and ResultsA total of 385 symptomatic individuals with an EF of ≥50% underwent upright cardiopulmonary exercise testing with invasive hemodynamic assessment of arterial stiffness and load (aortic augmentation pressure, augmentation index, systemic vascular resistance index, total arterial compliance index, effective arterial elastance index, and pulse pressure amplification) at rest and during incremental exercise. An abnormal hemodynamic response to exercise was defined as a steep increase in pulmonary capillary wedge pressure relative to cardiac output (∆PCWP/∆CO > 2 mm Hg/L/min). We compared rest and exercise measures between HFpEF and hypertension in multivariable analyses. Among 188 participants with HFpEF (mean age 61 ± 13 years, 56% women), resting arterial stiffness parameters were worse compared with 94 hypertensive participants (mean age 55 ± 15 years, 52% women); these differences were accentuated during exercise in HFpEF (all P ≤ .0001). Among all participants, exercise measures of arterial stiffness correlated with worse ∆PCWP/∆CO. Specifically, a 1 standard deviation higher exercise augmentation pressure was associated with 2.15-fold greater odds of abnormal LV hemodynamic response (95% confidence interval 1.52–3.05; P < .001). Further, exercise measures of systemic vascular resistance index, elastance index, and pulse pressure amplification correlated with a lower peak oxygen consumption. ConclusionsExercise accentuates the increased arterial stiffness found in HFpEF, which in turn correlates with left ventricular hemodynamic responses. Unfavorable ventricular–vascular interactions during exercise in HFpEF may contribute to exertional intolerance and inform future therapeutic interventions.

Pulsatile and resistive systolic loads as determinants of left ventricular remodelling after physical training

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): British Heart Foundation Barts Cardiovascular Biomedical Research Centre onbehalf The Marathon Study Consortium Introduction Cardiovascular function depends on the inter-relation between heart and vasculature. The contribution of aorta and peripheral vessels to the total systolic load of the left ventricle (LV) can be represented respectively by a "pulsatile" and a "resistive" component. We sought to understand their interrelation by exploring how LV remodelling occurred with altered load associated with an external stimulus (training). Methods: 237 untrained healthy male and female subjects volunteering for their first-time marathon were recruited. At baseline and after 6 months of unsupervised training, race completers underwent 1.5T cardiac magnetic resonance, brachial and non-invasive central blood pressure assessment. For analysis, runners were divided into 4 groups according to the variation (positive versus null or negative) in Total Arterial Compliance Index (TACi), representing the pulsatile component of the LV load, and in Systemic Vascular Resistance Index (SVRI), representing the resistive component of the LV load. Results: 138runners (age 21-69 years; F: 51%) completed the race. Data are reported for each variable as Δ mean [95% Confidence Interval]. In the whole cohort, training was associated with a small increase in LV mass index (+3g/m2, [0, 6 g/m2]), indexed LV end-diastolic volume (EDVi) (+3ml/m2, [-2, 5 3ml/m2]), in LV mass/LVEDV ratio (+0.02g/ml, [0.00, 0.04 g/ml]) and in TACi (+0.02ml/m2, [0.02, 0.38 ml/m2]). SVRi mildly fell (-43dyn·s/cm2[-103, 17dyn·s/cm2]). TACi increase was associated with LVEDVi increase and no change in LV mass/EDV (eccentric remodelling). On the other hand, both TACi reduction and SVRi increase were associated with increase in LV mass/EDV and no significant change in LVEDVi (concentric remodelling). A similar increase in LV mass was observed in all groups. See Table. Conclusion: Cardiac remodelling observed after mild, medium term, unsupervised training seems to be related to the modifications of aorta and peripheral vessels. In particular, a reduction in pulsatile load seems associated with eccentric LV remodelling, while an increase in both pulsatile and resistive with concentric LV remodelling. Further research is needed to understand the interaction between TACi and SVRi. Table 1 LV EDVi (ml/m2) LV mass index (g/m2) LV mass/EDV TACi increase (n = 75) +4 [0, 9] +3 [0, 7] 0 [-0.03, 0.03] TACi decrease (n = 62) -1 [-6, 4] +3 [0, 8] 0.04 [0.01, 0.07] SVRi increase (n = 63) 0 [-4,4] +3 [0, 7] +0.03 [0, 0.06] SVRi decrease (n = 73) +3 [-3, 7] +3 [-1, 6] +0.01 [-0.02, 0.04]

Doppler-Derived Arterial Load Indices Better Reflect Left Ventricular Afterload Than Systolic Blood Pressure in Coarctation of Aorta.

Patients with vascular stiffening may display increased arterial afterload that is out of proportion to systolic blood pressure (SBP). Since vascular and endothelial dysfunction develop in patients with coarctation of aorta (COA), we hypothesized that for any SBP, patients with mild COA (COA peak velocity <2 m/s) will have a higher arterial afterload and increased left ventricular mass index (LVMI) compared with controls, and that Doppler-derived arterial load indices would be a better predictor of LVMI compared with SBP alone. We studied 204 COA patients (age 35±12 y) and 204 matched controls. Doppler-derived arterial afterload was assessed using effective arterial elastance index and total arterial compliance index. Despite similar SBP, the mild COA group displayed higher arterial afterload as evidenced by a higher elastance index (3.3±0.9 versus 2.9±0.7 mm Hg/mL·m2; P<0.001) and lower total arterial compliance index (0.8±0.3 versus 1.2±0.5 mL/mm Hg·m2; P<0.001). This was associated with higher LVMI in COA (109±35 versus 93±32, g/m2; P<0.001). Compared with SBP (β=0.24 [95% CI, 0.02-0.45]), elastance index (β=20.2 [95% CI, 15.8-44.1]) and total arterial compliance index (β=-32.5 [95% CI, -43.8 to -123.6]) were better predictors of LVMI. Elastance index (but not SBP) was predictive of longitudinal increases in LVMI (r=0.43, P<0.001). COA patients had higher arterial afterload compared with controls with similar SBP. In comparison to SBP, Doppler-derived arterial load indices correlate more strongly with LV hypertrophy. These data suggest that SBP may underestimate LV afterload in this population. This has important clinical implications since titration of antihypertensive therapy is currently based on SBP.

Mild Coarctation of Aorta is an Independent Risk Factor for Exercise-Induced Hypertension.

Exercise-induced hypertension is a predictor of cardiovascular events in patients with coarctation of aorta (COA). However, it is unclear whether mild COA diagnosis is an independent risk factor of exercise-induced hypertension. We hypothesized that for every unit increase in exercise, patients with COA (without hemodynamically significant coarctation) will have a higher rise in systolic blood pressure (SBP) compared with matched controls. One hundred forty-nine patients with COA (aortic coarctation peak velocity <2 m/s) who underwent exercise testing were matched 1:1 to controls using propensity score method based on age, sex, body mass index, hypertension diagnosis, and SBP at rest. We compared exercise-induced change in SBP between patients with COA and controls and also assessed the correlation between Doppler-derived aortic vascular function indices (effective arterial elastance index and total arterial compliance index) and exercise-induced changes in SBP. Compared with controls, patients with COA had a greater change in SBP per unit metabolic equivalent (β=2.86; 95% CI, 1.96-4.77 versus 1.07, 95% CI, -0.15 to 1.75; P=0.018) and per unit oxygen pulse (β=4.57; 95% CI, 2.97-7.12 versus 1.45, 95% CI, -0.79 to 2.09, P<0.001). There was a correlation between SBPpeak-SBPrest and elastance index (r=0.38, P=0.032) and between SBPpeak-SBPrest and total arterial compliance index (r=-0.51, P=0.001), suggesting an association between vascular dysfunction and exercise-induced BP changes. Patients with COA, without significant obstruction, had higher exercise-induced changes in SBP after adjustment for other risk factors for hypertension. Considering the already known prognostic importance of exercise-induced hypertension, the current study highlights the potential role of exercise testing for risk stratification of patients with mild COA.

Hemodynamic Patterns Identified by Impedance Cardiography Predict Mortality in the General Population: The PREVENCION Study.

BackgroundBlood pressure is determined by the interactions between the heart and arterial properties, and subjects with identical blood pressure may have substantially different hemodynamic determinants. Whether arterial hemodynamic indices quantified by impedance cardiography (ICG), a simple operator‐independent office procedure, independently predict all‐cause mortality in adults from the general population, and specifically among those who do not meet criteria for American College of Cardiology/American Heart Association stage 2 hypertension, is currently unknown.Methods and ResultsWe studied 1639 adults aged 18 to 80 years from the general population. We used ICG to measure hemodynamic parameters and metrics of cardiac function. We assessed the relationship between hemodynamic parameters measured at baseline and all‐cause mortality over a mean follow‐up of 10.9 years. Several ICG parameters predicted death. The strongest predictors were total arterial compliance index (standardized hazard ratio=0.38; 95% confidence interval=0.31–0.46; P<0.0001) and indices of cardiac contractility: velocity index (standardized hazard ratio=0.45; 95% confidence interval=0.37–0.55; P<0.0001) and acceleration index (standardized hazard ratio=0.44; 95% confidence interval=0.35–0.55; P<0.0001). These remained independently predictive of death after adjustment for multiple confounders, as well as systolic and diastolic blood pressure. Among subjects without stage 2 hypertension (n=1563), indices of cardiac contractility were independently predictive of death and identified a subpopulation (25% of non‐stage‐2 hypertensives) that demonstrated a high 10‐year mortality risk, equivalent to that of stage 2 hypertensives.ConclusionsHemodynamic patterns identified by ICG independently predict mortality in the general population. The predictive value of ICG applies even in the absence of American College of Cardiology/American Heart Association stage 2 hypertension and identifies higher‐risk individuals who are in earlier stages of the hypertension continuum.

The effect of lifelong exercise frequency on arterial stiffness.

This study examined the effect of different 'doses' of lifelong (>25years) exercise on arterial stiffening (a hallmark of vascular ageing) in older adults. There are clear dose-dependent effects of lifelong exercise training on human arterial stiffness that vary according to the site and size of the arteries. Similar to what we have observed previously with ventricular stiffening, 4-5daysweek-1 of committed exercise over a lifetime are necessary to preserve 'youthful' vascular compliance, especially of the large central arteries. Casual exercise training of two to three times per week may be sufficient for middle-sized arteries like the carotid to minimize arterial stiffening with ageing. However, there is little effect of exercise training on the small-sized peripheral arteries at any dose. Central arterial stiffness increases with sedentary ageing. While near-daily, vigorous lifelong (>25years) endurance exercise training prevents arterial stiffening with ageing, this rigorous routine of exercise training over a lifetime is impractical for most individuals. The aim was to examine whether a less frequent 'dose' of lifelong exercise training (four to five sessions per week for >30min) that is consistent with current physical activity recommendations elicits similar benefits on central arterial stiffening with ageing. A cross-sectional examination of 102 seniors (>60years old) who had a consistent lifelong exercise history was performed. Subjects were stratified into four groups based on exercise frequency as an index of exercise 'dose': sedentary: fewer than two sessions per week; casual exercisers: two to three sessions per week; committed exercisers: four to five sessions per week; and Masters athletes: six to seven sessions per week plus regular competitions. Detailed measurements of arterial stiffness and left ventricular afterload were collected. Biological aortic age and central pulse wave velocity were younger in committed exercisers and Masters athletes compared to sedentary seniors. Total arterial compliance index (TACi) was lower, while carotid β-stiffness index and effective arterial elastance were higher in sedentary seniors compared to the other groups. There appeared to be a dose-response threshold for carotid β-stiffness index and TACi. Peripheral arterial stiffness was not significantly different among the groups. These data suggest that four to five weekly exercise sessions over a lifetime is associated with reduced central arterial stiffness in the elderly. A less frequent dose of lifelong exercise (two to three sessions per week) is associated with decreased ventricular afterload and peripheral resistance, while peripheral arterial stiffness is unaffected by any dose of exercise.

Cardiac remodeling following reperfused acute myocardial infarction is linked to the concomitant evolution of vascular function as assessed by cardiovascular magnetic resonance

BackgroundLeft ventricular (LV) remodeling following acute myocardial infarction (MI) is difficult to predict at an individual level although a possible interfering role of vascular function has yet to be considered to date. This study aimed to determine the extent to which this LV remodeling is influenced by the concomitant evolution of vascular function and LV loading conditions, as assessed by phase-contrast Cardiovascular Magnetic Resonance (CMR) of the ascending aorta.MethodsCMR was performed in 121 patients, 2–4 days after reperfusion of a first ST-segment elevation myocardial infarction and 6 months thereafter. LV remodeling was: (i) assessed by the 6-month increase in end-diastolic volume (EDV) and/or ejection fraction (EF) and (ii) correlated with the indexed aortic stroke volume (mL.m−2), determined by a CMR phase-contrast sequence, along with derived functional vascular parameters (total peripheral vascular resistance (TPVR), total arterial compliance index, effective arterial elastance).ResultsAt 6 months, most patients were under angiotensin enzyme converting inhibitors (86%) and beta-blockers (84%) and, on average, all functional vascular parameters were improved whereas blood pressure levels were not. An increase in EDV only (EDV+/EF-) was documented in 17% of patients at 6 months, in EF only (EDV-/EF+) in 31%, in both EDV and EF (EDV+/EF+) in 12% and neither EDV nor EF (EDV-/EF-) in 40%. The increase in EF was mainly and independently linked to a concomitant decline in TPVR (6-month change in mmHg.min.m2.L−1, EDV-/EF-: +1 ± 8, EDV+/EF-: +3 ± 9, EDV-/EF+: -7 ± 6, EDV+/EF+: -15 ± 20, p < 0.001) while the absence of any EF improvement was associated with high persisting rates of abnormally high TPVR at 6 months (EDV-/EF-: 31%, EDV+/EF-: 38%, EDV-/EF+: 5%, EDV+/EF+: 13%, p = 0.007). By contrast, the 6–month increase in EDV was mainly dependent on cardiac as opposed to vascular parameters and particularly on the presence of microvascular obstruction at baseline (EDV-/EF-: 37%, EDV+/EF-: 76%, EDV-/EF+: 38%, EDV+/EF+: 73%, p = 0.003).ConclusionLV remodeling following reperfused MI is strongly influenced by the variable decrease in systemic vascular resistance under standard care vasodilating medication. The CMR monitoring of vascular resistance may help to tailor these medications for improving vascular resistance and consequently, LV ejection fraction.Trial registrationNCT01109225 on ClinicalTrials.gov site (April, 2010).

Hemodynamic circulatory patterns in young patients with predominantly diastolic hypertension

To evaluate the spectrum of hemodynamic patterns in patients with isolated diastolic hypertension-predominantly diastolic hypertension, we re-analyzed a previously reported cohort of 189 non-medicated hypertensive individuals that were assessed by impedance cardiography. We selected 46 patients who were less than 50 years old and had pulse pressure less or equal than 45 mm Hg confirmed by ambulatory blood pressure monitoring. The selected cohort had a mean age of 39.7 years and was 47% men. Three distinct groups were identified: a high cardiac index (CI) “hyperdynamic” group, with normal to near normal systemic vascular resistance (SVR); an intermediate CI and SVR group; and a “vasotonic” group, with low CI and high SVR. Heart rate was similar among the three groups. Stroke volume index (SVI) was significantly higher in the hyperdynamic group (61.8, 49.7, and 39.7 mL/m2 in the high, intermediate, and low CI groups, respectively). The hyperdynamic group had greater total arterial compliance index than the vasotonic group (1.3 ± 0.3 vs 0.92 ± 0.2 mL/m2 mm Hg for high vs low CI, respectively; P < .001).In conclusion, isolated diastolic hypertension-predominantly diastolic hypertension patients can have diverse hemodynamic patterns that cannot be predicted based on peripherally measured blood pressure and heart rate alone. This hemodynamic complexity must be taken into account when considering the genetic and pathophysiologic mechanisms of hypertension.

Relationship of Resistant Hypertension and Treatment Outcomes With Total Arterial Compliance in a Predominantly African American Hypertensive Cohort

Resistant hypertension (RH) affects 8% to 30% of hypertensive patients. Blood pressure (BP) reflects the interaction between vascular compliance, resistance to flow, intravascular volume, and cardiac contractility. The relationship of RH with total arterial compliance index (TACI) has not been adequately explored. The RH period prevalence (RH at baseline or follow-up) was determined in a hypertensive cohort (N=156) and compared across quartiles of TACI. Age- and sex-adjusted systolic BP, diastolic BP, and antihypertensive therapeutic intensity score (TIS) were also determined at the time of first BP control. The cohort was 85.3% African American and 67.3% female. Median follow-up was 7 months. The prevalence of RH at baseline was 14.7% while the period prevalence was 43.6%. The period prevalence of RH by ascending quartile for TACI was 66%, 36.8%, 40%, and 30.8% (P=.008). The average BP and antihypertensive TIS at first BP control across TACI quartiles was 122.3/73.4 mm Hg (2.26), 120.7/72.5 mm Hg (1.88), 122.4/75.3 mm Hg (1.71), and 120.0/79.4 mm Hg (1.64) (P=.62, P=.03, P=.13). Low TACI was linked to higher RH prevalence and antihypertensive TIS at first attainment of goal BP according to the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. TACI provides prognostic information that is clinically and perhaps pathophysiologically relevant in RH.

Noninvasive hemodynamic profiles in hypertensive subjects

Hypertension is a disease state characterized by increased blood pressure (BP) associated with hemodynamic abnormalities, including elevated systemic vascular resistance index (SVRI); and altered cardiac index (CI). The objective of this study was to use noninvasive impedance cardiography (ICG) to evaluate hemodynamic characteristics of subjects with and without hypertension. A total of 19 healthy nonhypertensive and 136 hypertensive subjects were retrospectively evaluated. Hemodynamic parameters were measured with ICG and included CI, SVRI, total arterial compliance index (TACI), and thoracic fluid content (TFC); these were compared with subject type, blood pressure value, demographics, and medications. The BP levels of healthy and hypertensive subjects were 117/71 and 154/90 mm Hg, respectively (P < .0001). Subjects with prehypertension had a lower TACI (0.97 v 1.21, P < .05) compared with those with a normal BP, ie, <120/80 mm Hg. Hypertensive subjects had significantly lower SI, CI, TACI, and TFC and significantly higher SVRI. Subjects with stage 2 hypertension had higher SVRI (4149 v 3418 dyne.sec(2).cm(-5).m(2), P < .01) and lower TACI (0.61 v 0.53 mm Hg/mL/m(2), P < .05) than those with stage 1 hypertension. Compared with subjects with controlled hypertension, normal subjects had significantly lower SVRI (1996 v 2746 dyne.sec(2).cm(-5).m(2), P < .0001) and significantly higher CI (3.23 v 2.63 L/min/m(2), P < .001), SI (48.2 v 37.4 mL/m(2), P < .0001), TACI (1.08 v 0.85 mm Hg/mL/m(2), P < .01), and TFC (29.1 v 24.1/kOhm, P < .0001). The parameters of TACI, SVRI, and CI demonstrated modest correlation (-0.75, 0.62, and -0.30), respectively, with SBP. In the 54 subjects with BP <140/90 mm Hg, SVRI values varied significantly, with 32 subjects (39.2%) with SVRI values in the high range (>2483 dyne.sec(2).cm(-5).m(2)). Hemodynamic parameters from ICG displayed significantly different hemodynamic profiles between hypertensive and nonhypertensive subjects. However, significant individual variation of hemodynamic status exists. Hemodynamic measurements with ICG characterize hemodynamic status and may be helpful in diagnostic, prognostic, and therapeutic decision making in hypertensive subjects.