Increased cardiac performance in mild essential hypertension. Left ventricular mechanics

A meta-analysis of the haemodynamics of primary hypertension in children and adults

We performed a systematic review and meta-analysis to determine the relative contributions of elevated cardiac output and systemic vascular resistance to hypertension in children and adults. This included 27 studies on 11 765 hypertensive and normotensive children and adults in whom cardiac output was measured. Cardiac output but not systemic vascular resistance was elevated in hypertensive compared to normotensive children and young adults (difference in means 1.15 [0.78-1.52] l/min, P < 0.001). In older hypertensive adults, both were elevated compared to normotensive individuals (0.40 [0.26-0.55] l/min, P < 0.001 and 3.21 [1.91-4.51] mmHg min/l, P < 0.001 for cardiac output and systemic vascular resistance, respectively). The main haemodynamic alteration in primary hypertension (including obesity-hypertension) in both children and young to middle-aged adults is an elevation of cardiac output. With longer duration and greater severity of hypertension there may be progression from a 'cardiac' to a 'vascular' phenotype with increased systemic vascular resistance.

Basal Septal Hypertrophy as the Early Imaging Biomarker for Adaptive Phase of Remodeling Prior to Heart Failure

Hypertension plays a dominant role in the development of left ventricular (LV) remodeling and heart failure, in addition to being the main risk factor for coronary artery disease. In this review, we focus on the focal geometric and functional tissue aspects of the LV septal base, since basal septal hypertrophy (BSH), as the early imaging biomarker of LV remodeling due to hypertensive heart disease, is detected in cross-sectional clinic studies. In addition, the validation of BSH by animal studies using third generation microimaging and relevant clinical observations are also discussed in the report. Finally, an evaluation of both human and animal quantitative imaging studies and the importance of combined cardiac imaging methods and stress-induction in the separation of adaptive and maladaptive phases of the LV remodeling are pointed out. As a result, BSH, as the early imaging biomarker and quantitative follow-up of functional analysis in hypertension, could possibly contribute to early treatment in a timely fashion in the prevention of hypertensive disease progression to heart failure. A variety of stress stimuli in etiopathogenesis and the difficulty of diagnosing pure hemodynamic overload mediated BSH lead to an absence of the certain prevalence of this particular finding in the population.

Hemodynamic stress and microscopic remodeling

BACKGROUD

Heart responds to physiologic and pathologic conditions and sympathetic drive plays an important role. It has been documented that LV base is more dominantly affected by sympathetic drive compared to the other regions. LV base is more dominantly exposed to wall stress in the initial period of remodeling due to pressure-overload, since LV cavity is the largest at base. Basal septal hypertrophy (BSH) in cross-sectional data is associated with the early phase of hypertensive heart disease. BSH was confirmed by 3rd generation microscopic ultrasound in small animals. BSH as the closest location to increased afterload could be detected in variety of stress stimuli and result in a huge septal hypertrophy in advance cases possibly related to earlier exposure of hemodynamic stress to septal wall.

CONCLUSION

Effective geometric and functional evaluation of initial remodeling due to hemodynamic stress is important according to both human and animal data. These findings possibly contribute to early recognition of adaptive phase of hypertensive remodeling and more effective management in a timely fashion.

Blood Pressure and Left Ventricular Geometric Changes: A Directionality Analysis

[Figure: see text].

Proportionality at birth and left ventricular hypertrophy in healthy adolescents

BACKGROUND

Perinatal growth has important implications for cardiac development. Low birth weight is associated with cardiovascular (CV) events and mortality, and animal studies have shown that fetal growth restriction is associated with cardiac remodeling in the perinatal period leading to a permanent loss of cardiomyocyte endowment and compensatory hypertrophy.

AIMS

To determine associations of birthweight (BW) and multiple proportionality indexes (body mass index (BMI); weight/length² and Ponderal index (PI); weight/length³) at birth on one hand, with left ventricular (LV) structure and function during adolescence.

SUBJECTS

379 healthy adolescents aged 14-18 years in Augusta, Georgia.

OUTCOME MEASURES

LV structure and function parameters, including intraventricular septal thickness in diastole (IVSd), LV internal dimension in diastole (LVIDd), LV internal diameter in systole (LVIDs), LV posterior wall thickness in diastole (LVPWd), relative wall thickness (RWT), midwall fractional shortening (MFS), and ejection fraction, were assessed by echocardiography.

RESULTS

When associations of birthweight, birth BMI, and birth PI with LV structure and function parameters were separately evaluated with linear regression adjusting for age, sex, race, Tanner stage, socioeconomic status, and physical activity, significant positive associations of BW with LVIDd (P = 0.004), birth BMI with LV mass index (P = 0.01), and birth PI with IVSd (P = 0.02), LVPWd (P = 0.03), and LV mass index (P = 0.002) were identified. When LV structure and function parameters were compared across PI tertiles, a significant U-shaped trend for LV mass index (P_quadratic = 0.04) was identified.

CONCLUSIONS

Our adolescent data suggest that proportionality at birth may identify associations between perinatal growth and cardiac remodeling independent of birthweight alone.

Survival after Aortic Valve Replacement for Aortic Regurgitation: Prediction from Preoperative Contractility Measurement

BACKGROUND

Noninvasive measurement of myocardial contractility (end-systolic wall stress-adjusted change in left ventricular ejection fraction from rest to exercise [ΔLVEF - ΔESS]) predicts heart failure, subnormal LVEFrest, and sudden death in asymptomatic patients with chronic severe aortic regurgitation (AR). Here we assess the relation of preoperative ΔLVEF - ΔESS to survival after aortic valve replacement (AVR).

METHODS

Patients who underwent AVR for chronic, isolated, pure severe AR (n = 66) were followed for 13.0 ± 6.4 event-free years. Preoperative ΔLVEF - ΔESS (from combined echocardiographic and radionuclide cineangiographic data) enabled cohort stratification into 3 terciles (-1 to -11% [normal or mild] contractility deficit, -12 to -16% [moderate], and ≤-17% [severe], identical with segregation in our earlier study) to relate preoperative contractility to postoperative survival and to age- and gender-matched US census data.

RESULTS

Since AVR, 22 patients died (average annual risk [AAR] for all-cause mortality for the entire co hort = 3.15%). Preoperative ΔLVEF - ΔESS predicted postoperative survival (p = 0.009, log rank test). By contractility terciles, all-cause AARs were 1.44, 2.58, and 6.40%. Survival was lower than among US census comparators (p < 0.02), but the "mild" tercile was indistinguishable from census data (p = ns). By multivariable Cox regression, survival prediction by pre-AVR ΔLVEF - ΔESS was independent of, and superior to, prediction by age at surgery, gender, preoperative functional class, LVEFrest, LVEFexercise, change in LVEFrest to exercise, and LV diastolic or systolic dimensions (p ≤ 0.01, pre-AVR ΔLVEF - ΔESS vs. other covariates).

CONCLUSION

In severe AR, preoperative contractility predicts post-AVR survival and may be prognostically superior to clinical, geometric and performance descriptors, potentially impacting on patient selection for surgery.

Phylloquinone Intake Is Associated with Cardiac Structure and Function in Adolescents

BACKGROUND

Associations between childhood vitamin K consumption and cardiac structure and function have not been investigated.

OBJECTIVE

We determined associations between phylloquinone (vitamin K-1) intake and left ventricular (LV) structure and function in adolescents.

METHODS

We assessed diet with three to seven 24-h recalls and physical activity (PA) by accelerometry in 766 adolescents (aged 14-18 y, 50% female, 49% black). Fat-free soft tissue (FFST) mass and fat mass were measured by dual-energy X-ray absorptiometry. LV structure [LV mass (g)/height (m)2.7 (LV mass index) and relative wall thickness] and function [midwall fractional shortening (MFS) and ejection fraction] were assessed by echocardiography. Associations were evaluated by comparing the LV structure and function variables across tertiles of phylloquinone intake. Prevalence and OR of LV hypertrophy (LV mass index >95th percentile for age and sex) were also assessed by phylloquinone tertiles.

RESULTS

The prevalence of LV hypertrophy progressively decreased across tertiles of phylloquinone intake (P-trend < 0.01). Multinomial logistic regression-adjusting for age, sex, race, Tanner stage, systolic blood pressure, FFST mass, fat mass, socioeconomic status, PA, and intakes of energy, fiber, calcium, vitamin C, vitamin D, and sodium-revealed that compared with the highest phylloquinone intake tertile (reference group), the adjusted OR for LV hypertrophy was 3.3 (95% CI: 1.2, 7.4) for those in the lowest phylloquinone intake tertile. When LV structure variables were compared across phylloquinone intake tertiles adjusting for the same covariates, there were significant linear downward trends for LV mass index (6.5% difference, tertile 1 compared with tertile 3) and relative wall thickness (9.2% difference, tertile 1 compared with tertile 3; both P-trend ≤ 0.02). Conversely, significant linear upward trends across phylloquinone intake tertiles were observed for MFS (3.4% difference, tertile 1 compared with tertile 3) and ejection fraction (2.6% difference, tertile 1 compared with tertile 3; both P-trend < 0.04).

CONCLUSION

Our adolescent data suggest that subclinical cardiac structure and function variables are most favorable at higher phylloquinone intakes.

[The use of echocardiography left ventricular filling pressures in hypertensive patients with heart failure and preserved systolic function in a North Africa unit day]

OBJECTIVE

To assess the left ventricular (LV) filling pressures by Doppler Tissulaire Imaging (DTI) in the management of hypertensive patients with heart failure and preserved systolic function (HF-PEF) in our outpatient clinic. To involve the patient on the basis of their clinical, biological and echocardiography data, in identifying the risk factors that need change.

PATIENTS AND METHODS

From 2004 to 2014, heart failure with preserved systolic function (HF-PEF) has been diagnosed in 200 consecutive hypertensive patients (pts) at our Algerian outpatient unit. Data were collected on blood pressure at the time of the examination, body mass index (BMI), waist, comorbid conditions including dyslipidemia, diabetes and atrial fibrillation (AF). LV ejection fraction>50 % is taken as the including criteria with acquisition as described in the Chamber Quantification update. Left ventricular global systolic function by biplane disk summation Simpson method and diastolic function is assessed by the mitral inflow measurements regarding recommendations for the evaluation of left ventricular diastolic function by echocardiography from the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE).

RESULTS

Mean age was 65±11 yrs; 66 % were female; waist circumference in men>102cm and in women>88cm was found in 82 % of the pts and 50 % were diabetics. Body weight (BMI)>30kg/m(2) is depicted in 88 (44 %). Dyslipidemia is depicted in 78 pts (39 %). Ischemic heart disease was diagnosed in 64 pts (32 %); history of thromboembolic event in 78 pts (39 %); valvular disease in 40 pts (20 %). ECG showed AF in 60 pts (30 %), complete left bundle branch block (LBBB) in 20 pts (10 %). The echographic findings were as follow: left ventricular hypertrophy (LVH) in 126 pts (63 %) and left atrial (LA) enlargement in 111 pts (55 %). Mean left ventricular ejection fraction (LVEF) is about 55±10 %. Delayed relaxation (Em/Am<1) and deceleration time>150ms (DT) in 80 pts (40 %), of them, 56 had increased filling pressures (Em/Ea>8 and Ap>Am); pseudo-normal patterns (1<Em/Am<2 and DT<150ms) in 80 pts (40 %); restrictive filling pattern (Em/Am≥2) and short DT<100ms in 40 pts (20 %).

CONCLUSIONS

The hypertensive pts referred for an echo examination are often diabetics and frequently demonstrate preserved left ventricular function with increased filling pressures. This is useful for managing their treatments in the context of a cardiac rehabilitation programme.

Recommendations on the Use of Echocardiography in Adult Hypertension: A Report from the European Association of Cardiovascular Imaging (EACVI) and the American Society of Echocardiography (ASE)

Hypertension remains a major contributor to the global burden of disease. The measurement of blood pressure continues to have pitfalls related to both physiological aspects and acute variation. As the left ventricle (LV) remains one of the main target organs of hypertension, and echocardiographic measures of structure and function carry prognostic information in this setting, the development of a consensus position on the use of echocardiography in this setting is important. Recent developments in the assessment of LV hypertrophy and LV systolic and diastolic function have prompted the preparation of this document. The focus of this work is on the cardiovascular responses to hypertension rather than the diagnosis of secondary hypertension. Sections address the pathophysiology of the cardiac and vascular responses to hypertension, measurement of LV mass, geometry, and function, as well as effects of treatment.

Trpm4 gene invalidation leads to cardiac hypertrophy and electrophysiological alterations

RATIONALE

TRPM4 is a non-selective Ca2+-activated cation channel expressed in the heart, particularly in the atria or conduction tissue. Mutations in the Trpm4 gene were recently associated with several human conduction disorders such as Brugada syndrome. TRPM4 channel has also been implicated at the ventricular level, in inotropism or in arrhythmia genesis due to stresses such as ß-adrenergic stimulation, ischemia-reperfusion, and hypoxia re-oxygenation. However, the physiological role of the TRPM4 channel in the healthy heart remains unclear.

OBJECTIVES

We aimed to investigate the role of the TRPM4 channel on whole cardiac function with a Trpm4 gene knock-out mouse (Trpm4-/-) model.

METHODS AND RESULTS

Morpho-functional analysis revealed left ventricular (LV) eccentric hypertrophy in Trpm4-/- mice, with an increase in both wall thickness and chamber size in the adult mouse (aged 32 weeks) when compared to Trpm4+/+ littermate controls. Immunofluorescence on frozen heart cryosections and qPCR analysis showed no fibrosis or cellular hypertrophy. Instead, cardiomyocytes in Trpm4-/- mice were smaller than Trpm4+/+with a higher density. Immunofluorescent labeling for phospho-histone H3, a mitosis marker, showed that the number of mitotic myocytes was increased 3-fold in the Trpm4-/-neonatal stage, suggesting hyperplasia. Adult Trpm4-/- mice presented multilevel conduction blocks, as attested by PR and QRS lengthening in surface ECGs and confirmed by intracardiac exploration. Trpm4-/-mice also exhibited Luciani-Wenckebach atrioventricular blocks, which were reduced following atropine infusion, suggesting paroxysmal parasympathetic overdrive. In addition, Trpm4-/- mice exhibited shorter action potentials in atrial cells. This shortening was unrelated to modifications of the voltage-gated Ca2+ or K+ currents involved in the repolarizing phase.

CONCLUSIONS

TRPM4 has pleiotropic roles in the heart, including the regulation of conduction and cellular electrical activity which impact heart development.

Association of left ventricular hypertrophy with incident hypertension: the multi-ethnic study of atherosclerosis

Increased left ventricular (LV) mass and changes in LV geometry may precede hypertension onset. The authors examined the associations of LV mass and geometry, assessed by cardiac magnetic resonance imaging, with hypertension incidence in 2,567 normotensive participants enrolled in 2000-2002 in the Multi-Ethnic Study of Atherosclerosis, an ethnically diverse, population-based, US study. Over a median follow-up of 4.8 years, 745 (29%) participants developed hypertension. In a fully adjusted model including baseline blood pressure, the relative risks of incident hypertension from the lowest to highest LV mass quartile were 1.00 (referent), 1.13 (95% confidence interval (CI): 0.89, 1.43), 1.28 (95% CI: 1.00, 1.63), and 1.78 (95% CI: 1.38, 2.30) (P < 0.001 for linear trend). Higher levels of LV concentric geometry, defined by higher LV mass to end-diastolic volume quartiles, were associated with higher risk of incident hypertension in a fully adjusted model (P = 0.044 for linear trend). In a final model containing both quartiles of LV mass and LV mass/volume along with all covariates including baseline blood pressure, higher LV mass quartiles were associated with incident hypertension (P < 0.001 for linear trend), whereas higher LV mass/volume quartiles were not (P = 0.643 for linear trend). In this multiethnic cohort, alterations in LV mass preceded hypertension onset among normotensive individuals.

Relationship between left ventricular hypertrophy, hypertensive retinopathy, microalbuminuria and echocardiographic modalities in newly diagnosed hypertensive patients

Longitudinal myocardial function (LMF) may be impaired while systolic function is still normal. We investigated relationship between LMF and hypertensive organ damage in newly diagnosed stage I hypertensive patients. A total of 57 patient with never treated stage I hypertension and 48 matched healthy control subject were enrolled in the study. Conventional 2-D, Doppler and tissue wave Doppler imaging (TDI) echocardiography were used. LMF was evaluated by the septal and lateral strain (S) and strain rate (SR) measurements. Hypertensive complications were evaluated by the urine microalbumin levels and retinal examination. A multivariate regression analysis was perfomed to assess the relation between the variables. Ejection fraction, mid-wall fractional shortenning, systolic movement rates (TDs) in TDI were similar both in hypertensive and control groups. In patients with left ventricular hypertrophy, septal TDs (7.29 +/- 1.28 vs. 8.06 +/- 1.19 cm, P = 0.03), lateral TDs (8.46 +/- 1.83 vs. 9.87 +/- 2.42 cm, P = 0.01) and lateral S (-13.02 +/- 7.83 vs. -18.86 +/- 8.60%, P = 0.01) values were significantly lower. Septal S (-13.67 +/- 3.52 vs. -19.09 +/- 5.96%, P < 0.01) and SR (-0.83 +/- 0.29 vs. -1.22 +/- 0.28 1/S, P < 0.01) were significantly decreased in hypertensive patients with microalbuminuria. Septal S value was also significantly decreased in patients with retinopathy (-14.76 +/- 5.55 vs. -20.20 +/- 5.44%, P = 0.01). Multivariate analysis showed that only septal and lateral S values were independent factors for the retinopathy and left ventricular hypertrophy, respectively. In hypertensive patients, LMF established by the measurement of S and SR, might be impaired and also related with end organ damage while global circumferential function is preserved.

Alterations of mitochondrial enzymes contribute to cardiac hypertrophy before hypertension development in spontaneously hypertensive rats

Mitochondrial dysfunction is recently thought to be tightly associated with the development of cardiac hypertrophy as well as hypertension. However, the detailed molecular events in mitochondria at early stages of hypertrophic pathogenesis are still unclear. Applying two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) combined with MALDI-TOF/TOF tandem mass spectrometry, here we identified the changed mitochondrial proteins of left ventricular mitochondria in prehypertensive/hypertensive stages of cardiac hypertrophy through comparing spontaneously hypertensive rats (SHR) and the age-matched normotensive Wistar Kyoto (WKY) rats. The results revealed that in the hypertrophic left ventricle of SHR as early as 4 weeks old with normal blood pressure, 33 mitochondrial protein spots presented significant alterations, with 17 down-regulated and 16 up-regulated. Such alterations were much greater than those in 20-week-old SHR with elevated blood pressure. Of the total alterations, the expression of two mitochondrial enzymes, trifunctional enzyme alpha subunit (Hadha) and NADH dehydrogenase 1 alpha subcomplex 10 (Ndufa10), were found to have special expression modification patterns in SHR strain. These data would provide new clues to investigate the potential contribution of mitochondrial dysfunction to the development of cardiac hypertrophy.

Cilnidipine Improves Left-Ventricular Midwall Function Independently of Blood Pressure Changes in Chinese Patients With Hypertension

Despite normal indices of left-ventricular (LV) chamber function, patients with hypertension are thought to have depressed LV midwall systolic shortening. This study was designed to investigate effects of short-term therapy with cilnidipine on LV midwall fractional shortening (mFS) in Chinese patients with hypertension. Thirty-seven patients with mild to moderate essential hypertension underwent a 2 week placebo run-in period, then received 5-10 mg/day of cilnidipine orally for 8 weeks. At the end of the placebo period and treatment, patients were examined by echocardiogram, measuring and calculating LV ejection fraction (EF), LV endocardial fraction shortening (eFS), and LV mFS. Compared with the normotensive group, the hypertensive group had a significantly higher eFS (P < 0.05) and EF (P < 0.01), both at the end of the placebo period and at 8 weeks; mFS of patients with hypertension was lower at the end of the placebo period (P < 0.05), but at the end of 8 weeks mFS was not different than that of the control group (P = 0.963). After cilnidipine treatment, EF and eFS did not change (P > 0.05); however, absolute mFS and corrected mFS were increased significantly (P < 0.01). Moreover, changes of mFS showed no correlation with changes of blood pressure (P > 0.05). Midwall fractional shortening is more reliable and sensitive than conventional systolic function measures in assessment of systolic function; cilnidipine can improve left-ventricular systolic function (mFS) independently of blood pressure changes in Chinese patients who have hypertension.

Reduced left ventricular functional reserve in hypertensive patients with preserved function at rest

In many hypertensive patients, left ventricular pump function is normal at rest but abnormal during exercise. Myocardial dysfunction or altered left ventricular loading may be responsible for this finding. To verify the hypothesis of impaired myocardial functional reserve in the hypertensive heart, we assessed the response of stress-adjusted midwall shortening to graded, low-dose dobutamine infusion in hypertensive subjects with normal midwall shortening at rest. Sixty-five subjects (45 never treated hypertensive subjects and 20 normotensive volunteers comparable for age) received dobutamine at 1, 2, 3, 4, and 5 microg x kg(-1) x min(-1) for 5-minute steps; within this range of infusion rates, heart rate and systemic blood pressure were stable. Two-dimensional, M-mode, and Doppler echocardiography were performed at baseline and at the end of each step. In normotensive controls, midwall shortening increased from baseline during 2 microg x kg(-1) x min(-1) dobutamine by an average of 16+/-4.5% (P<0.01); a value of 2 standard deviations below this mean response was taken as the lower limit of normal. In the hypertensive subjects, 24 had a normal midwall shortening response to dobutamine at this dose (group I) and 21 had a subnormal response (group II). Whereas blood pressure and left ventricular mass were similar in group II and group I, the former had greater relative wall thickness (P<0.01) than the latter. beta-adrenergic stimulation by very-low-dose dobutamine unmasks subtle impairment of myocardial functional reserve in hypertensive subjects with normal myocardial performance at rest. This alteration seems to be related mainly to increase in left ventricular relative wall thickness.

Does impaired left ventricular relaxation affect P wave dispersion in patients with hypertension?

OBJECTIVE

P wave dispersion (PD) is considered to reflect the heterogeneous conduction in atria. We investigated whether there was a correlation between the left ventricular (LV) relaxation and PD.

METHOD AND RESULTS

Fifty-three hypertensive patients < or =60 years old were divided into two groups: Group A, 27 patients, aged 54+/-5 years with the impaired LV relaxation and Group B, 26 patients, aged 51+/-8 years with normal LV relaxation. The P wave durations were measured in all 12 leads of ECG and PD was defined as the difference between maximum and minimum P wave duration (Pmax-Pmin). Mitral inflow velocities (E and A), E deceleration time (DT), isovolumic relaxation time (IVRT), left atrial and ventricular diameters, and wall thickness of LV were obtained by echocardiography. Clinical characteristics of both groups were comparable. The wall thickness of LV, Pmax, and left atrial dimension were not different in both groups. A velocity was higher (P<0.001), but E velocity (P=0.03) and E/A ratio (P<0.001) were lower in group A than in group B. IVRT and DT were also significantly longer in group A. PD was significantly higher in group A compared to group B (51+/-9 vs 41+/-11 ms, P=0.01). This difference resulted from the Pmin (61+/-10 vs 67+/-9 ms, P=0.03, respectively). Multivariate analysis revealed a significant correlation between PD and A velocity (r=0.46, P=0.01), E/A ratio (r=-0.53, P=0.001), DT (r=0.65, P<0.001), and IVRT (r=0.73, P<0.001).

CONCLUSION

This study suggests that impaired LV relaxation contributes to the heterogeneous atrial conduction in hypertensive patients.

Blood pressure and left ventricular geometric pattern determine diastolic function in hypertensive myocardial hypertrophy

Abnormal left ventricular (LV) diastolic relaxation is an early sign of hypertensive heart disease. Whether LV diastolic dysfunction is caused directly by raised blood pressure, or by structural changes related to LV hypertrophy remains controversial. We examined 115 hypertensive patients with LV hypertrophy, and two age- and gender-matched groups (38 hypertensive patients without LV hypertrophy and 38 normotensive subjects) by echocardiography to assess determinants of LV diastolic function, and the relation between diastolic function and LV geometric pattern. Diastolic function was evaluated by the E/A-ratio, E wave deceleration time (E-dec), isovolumic relaxation time (IVRT), and the atrioventricular plane displacement method (AV-LA/AV-mean). A multivariate analysis (including gender, age and body mass index) shows diastolic function to be inversely related to blood pressure, LV wall thickness and LV mass, but not to LV end diastolic diameter. The E/A-ratio generally showed the strongest relations. Only the E/A-ratio and AV-LA/AV-mean were related to heart rate. By stepwise regression analysis, age was the strongest determinant for the E/A-ratio, E-dec and AV-LA/AV-mean, followed by systolic blood pressure, heart rate and LV wall thickness. For IVRT, however, LV wall thickness appeared strongest, followed by systolic blood pressure and age. In conclusion, blood pressure and LV wall thickness both have independent influence on LV diastolic function. Age and blood pressure are the most important factors to determine the E/A-ratio and E-dec, whereas LV geometry and blood pressure are most important when IVRT is used. AV-LA/AV-mean may not be useful in hypertensive LV hypertrophy.

Atrial fibrillation: hypertension as a causative agent, risk factor for complications, and potential therapeutic target

Atrial fibrillation and hypertension are 2 prevalent, and often coexistent, conditions in the North American population. Their incidence increases with advancing age, and they are responsible for considerable morbidity and mortality. Although the relation between the 2 conditions has long been known, the treatment of hypertension is not currently a focus in the clinical management of atrial fibrillation. Hypertension is associated with left ventricular hypertrophy, impaired ventricular filling, left atrial enlargement, and slowing of atrial conduction velocity. These changes in cardiac structure and physiology favor the development of atrial fibrillation, and they increase the risk of thromboembolic complications. Conventional therapy of atrial fibrillation has focused on interventions to control heart rate and rhythm and the prevention of stroke through the use of anticoagulant medications. In patients with atrial fibrillation, aggressive treatment of hypertension may reverse the structural changes in the heart, reduce thromboembolic complications, and retard or prevent the occurrence of atrial fibrillation. Specific pharmacotherapy could potentially play a major role in the primary and secondary prevention of atrial fibrillation and its complications.

Total peripheral vascular resistance in pediatric renal transplant patients

BACKGROUND

Abnormal cardiovascular reactivity at rest and during physical exercise may be a risk factor for left ventricular hypertrophy (LVH) in pediatric renal transplanted (Tx) patients. Data on total peripheral vascular resistance (TPR) are not available.

METHODS

Eleven renal Tx patients treated with cyclosporine (7 females and 4 males; mean age 14.6 +/- 3.3 years; mean time since transplantation 43 +/- 35 months) were evaluated for 24-hour blood pressure (BP), TPR and echocardiographic left ventricular mass (LVM). TPR values of patients were compared with data of a group of 11 healthy controls matched for sex and age.

RESULTS

Twenty-four-hour ambulatory blood pressure monitoring showed that all but one patient had normal daytime BP values and six patients showed a reduced or inverse nocturnal dip. LVH was found in 72% of the patients. In comparison with healthy controls, patients showed significantly elevated TPR at rest and during exercise suggesting an increased vascular tone. The degree of LVH in these patients is severe and appears disproportionate to the BP values.

CONCLUSION

The high incidence of LVH can reflect an augmented cardiovascular reactivity associated with a disturbed circadian pattern. The increase in TPR and the reduction of the nocturnal fall of BP also might contribute to the development of LVH in young renal Tx patients.

Change in systolic left ventricular performance after 3 years of antihypertensive treatment: the Losartan Intervention for Endpoint (LIFE) Study

BACKGROUND

We have shown that hypertensive patients with left ventricular (LV) hypertrophy have decreased LV midwall mechanics, but the effect of antihypertensive therapy remains unclear.

METHODS AND RESULTS

Echocardiograms were recorded at baseline in 679 hypertensive patients and ECG LV hypertrophy and repeated yearly during 3 years of blinded treatment to achieve target blood pressures (BPs) of 140/90 mm Hg. On average, BP was reduced from 174+/-21 to 147+/-19 over 95+/-11 to 82+/-10 mm Hg and LV mass from 234+/-56 to 194+/-50 g. Endocardial fractional shortening (FS) decreased slightly, whereas midwall FS increased from 15.4+/-2.0% to 16.8+/-2.1% and stress-corrected midwall FS increased from 97+/-13 to 105+/-12% (all P<0.001). Change in midwall FS was related inversely to change in LV mass (LVM), relative wall thickness (RWT), and diastolic BP and directly to change in Doppler stroke volume (SV, all P<0.001). Multivariate analysis showed that change in MWS was independently inversely related to changes in LVM (beta=-0.211), RWT (beta=-0.334, all P<0.001), and diastolic BP (beta=-0.088, P<0.05) and directly related to SV (beta=0.192, P<0.001) with control for blinded therapy. Change in stress-corrected midwall shortening was inversely independently associated with changes in LVM (beta=-0.153) and RWT (beta=-0.562) and directly with changes in SV (beta=0.145) and systolic BP (beta=0.s221, all P<0.001) with control for blinded therapy.

CONCLUSIONS

Antihypertensive therapy reduced LVM and increased LV midwall shortening and contractility with a small decrease in LV chamber function and significant increase in SV. Change in systolic LV performance was independently associated inversely with change in LVM, RWT, and BP and directly with change in SV.

The relation between left ventricular geometric patterns and left ventricular midwall mechanics in hypertensive patients

To evaluate the alteration of myocardial contractility in hypertensive patients with different left ventricular geometric patterns by the end-systolic stress-midwall fractional shortening relation. Echocardiography was applied to study the left ventricular geometry and cardiac function among 117 cases of essential hypertension, with 45 normal cases as control(s). Left ventricular mass index (LVMI) and relative wall thickness (RWT) were calculated using echocardiographic data. All patients were divided into four kinds of left ventricular geometry pattern based on LVMI and RWT. Patients of the eccentric hypertrophy group suffered the most serious damage of left ventricular systolic function. Myocardial contractility shown by end-systolic stress-midwall fractional shortening relation was significantly decreased in the concentric remodeling group, eccentric hypertrophy group and concentric hypertrophy group, and those with concentric hypertrophy showed the worst contractility. The degree of myocardial contractility damage was different in patients with different left ventricular geometric patterns. Geometric changes may have compensated for the reduction of myocardial contractility in some phases in order to maintain the normal pump function.

Myocardial function and geometry in hypertensive subjects with low levels of afterload

BACKGROUND

It has been hypothesized that the level of end-systolic wall stress (sigma(m)) is a feedback signal that regulates the level of hypertrophy. Thus, low levels of sigma(m) may signify inappropriate hypertrophy.

METHODS

To characterize left ventricular (LV) structure and systolic function in hypertensive subjects with low levels of sigma(m), we studied 763 patients. LV function was studied by midwall stress-shortening analysis. Partition values for sigma(m) were derived from a separate group of normal subjects, and the study population was divided into low stress (group I, n = 136), high stress (group III, n = 157), and intermediate stress group II (n = 470). LV chamber and myocardial function were characterized by relating shortening at the endocardium and at the midwall, respectively, to stress.

RESULTS

As expected, group III patients had the highest values for systolic blood pressure and LV cavity size but the lowest values for wall thickness and relative wall thickness. Surprisingly, however, there were no significant differences among stress groups with regard to age or body mass index. Contrary to the hypothesis that low levels of stress are indicative of excessive hypertrophy, there were no significant differences among the 3 groups with regard to LV mass or any form of LV mass index. Furthermore, despite lower mean values for afterload, group I patients had significantly lower values for midwall shortening, and this finding was indicative of reduced myocardial function; stress-shortening plots demonstrated that 28% of group I patients fell below 95% CI compared with 10% of group II and only 5% of group III patients.

CONCLUSIONS

Hypertensive subjects with low values for sigma(m) have more concentric LV geometry (higher relative wall thickness) and, on average, reduced myocardial function.

Effect of regression of left ventricular hypertrophy from systemic hypertension on systolic function assessed by midwall shortening (HOT echocardiographic study)

Depressed midwall shortening has been shown to be an independent predictor of cardiovascular morbid events in hypertensive patients with left ventricular (LV) hypertrophy despite normal endocardial fractional shortening. The effects of LV mass changes in hypertensive patients on midwall shortening are unclear. To determine the impact of LV hypertrophy regression on LV systolic function assessed at the endocardium and the midwall level, 508 patients (58% men, 57% Caucasians, mean age 60 +/- 7 years) participating in the Hypertension Optimal Treatment study were prospectively studied by serial echocardiography at baseline, year 1, year 2, and at the end of the study. The Hypertension Optimal Treatment study was designed to challenge the existence of the J-curve phenomenon in hypertension. This study enrolled men and women between 50 and 80 years of age with mild to moderate hypertension. Patients were treated with a regimen based on felodipine with the addition of other antihypertensive drug classes as needed to reduce the diastolic blood pressure to a predefined target of < or =80, < or =85, or < or =90 mm Hg. From baseline to year 1, year 2, and end of the study, body mass index was unchanged (30.4, 30.1, 30.2, and 30.5 kg/m(2)); however, diastolic blood pressure was significantly reduced (99, 83, 80, and 80 mm Hg, p <0.0001), as was systolic blood pressure (161, 139, 137, and 134 mm Hg, p <0.0001) and LV mass index (117, 119, 107, and 106 g/m(2), p <0.0001). Over the same period of observation the endocardial fractional shortening did not change significantly (40%, 42%, 43%, and 44%); however, shortening at the midwall level showed improvement (20%, 21%, 22%, and 30%, p <0.001). In conclusion, midwall shortening is a more sensitive index of systolic function in subjects with pressure-overload hypertrophy, and it identifies high-risk patients who may benefit from a more aggressive antihypertensive program. The disparity between midwall and endocardial shortening suggests reduced myofibril function in patients with hypertension-induced hypertrophy.

Relative wall thickness is an independent predictor of left ventricular systolic and diastolic dysfunctions in essential hypertension

The objective of this study was to elucidate the relationship between left ventricular geometry and left ventricular (LV) function in patients with untreated essential hypertension. We evaluated LV systolic and diastolic functions by M-mode echocardiography in 24 normotensive control subjects (NC) and 129 patients with essential hypertension. Patients were divided into four groups according to the relative wall thickness and LV mass index: a normal left ventricle (n=57), a concentric remodeling (n=7), a concentric hypertrophy (n=31), and an eccentric hypertrophy (n=34) group. LV systolic function as measured by midwall fractional shortening (FS) was significantly decreased in both the concentric remodeling and concentric hypertrophy groups; no differences were observed for endocardial FS. LV diastolic function as measured by isovolumic relaxation time (IRT) was also decreased in both the concentric remodeling and concentric hypertrophy groups. In multivariate analysis, relative wall thickness (p<0.0001), end-systolic wall stress (p<0.0001), and systolic blood pressure (p=0.002) were independently associated (r2=0.72) with midwall FS in a model including age, LV mass index, body mass index, diastolic blood pressure and IRT. In addition, relative wall thickness (p=0.0008) and age (p<0.0001) were independently associated (r2=0.31) with IRT in a model including LV mass index, end-systolic wall stress, body mass index, systolic and diastolic blood pressures and midwall FS. We conclude that LV geometry as evaluated by relative wall thickness may provide a further independent stratification of LV systolic and diastolic functions in essential hypertension.

Changes in midwall systolic performance and cardiac hypertrophy reduction in hypertensive patients

OBJECTIVE

To investigate changes in left ventricular (LV) performance, as evaluated by measurement of midwall LV fractional shortening (FS), after reduction of cardiac hypertrophy.

DESIGN AND METHODS

Echocardiographic evaluation of LV anatomy and function was performed by M-mode echocardiography at baseline, after long-term antihypertensive therapy, and after treatment withdrawal in 68 asymptomatic hypertensive patients (50 males, 18 females, age range 22-62 years). Patients were divided according to the presence of LV hypertrophy (LVH) at baseline (LV mass index, LVMI, > or = 51 g/m(2.7)).

RESULTS

At baseline patients with concentric (relative wall thickness > 0.44) LV hypertrophy (n = 38) or remodelling (n = 7) had reduced midwall shortening with respect to patients with normal LV geometry (n = 4) or eccentric LVH (n = 19); no differences were observed for endocardial FS. After long-term treatment (average 15 months), in 11 patients LV mass remained within normal limits, in 45 patients LVH reduction was obtained, while in 12 patients LV mass remained persistently elevated. Midwall FS was significantly increased in patients with reduction of LVH both during treatment and after withdrawal of treatment, while it remained significantly lower in patients with persistently elevated LV mass. Changes in midwall fractional shortening were independently associated with modifications in relative wall thickness (P < 0.00001), with changes in end-diastolic dimensions (P < 0.0001) and those of LVMI (P< 0.02) as shown by multivariate analysis.

CONCLUSION

LV midwall systolic performance significantly improved after reduction of LVH, even in the presence of high blood pressure values. Modifications in relative wall thickness are more independently associated with changes, in LV diastolic dimensions and mass, to midwall improvement

Subclinical left ventricular dysfunction in systemic hypertension and the role of 24-hour blood pressure

The relation between blood pressure (BP) and left ventricular (LV) systolic function in systemic hypertension is controversial. We assessed the relation of LV midwall fractional shortening (FS) to 24-hour BP in 1,702 never-treated hypertensive subjects (age 48 +/- 12 years), who underwent 24-hour BP monitoring and echocardiography. Stress-corrected endocardial and midwall FS (the latter calculated taking into account the epicardial migration of midwall during systole) were predicted in hypertensives on the basis of the values observed in 130 healthy normotensives (age 43 +/- 13 years, office BP 126/78 mm Hg). Subjects below the fifth percentile of observed-to-predicted FS had depressed LV function. The use of midwall FS resulted in an increase from 3.5% to 17.5% in the proportion of patients with depressed chamber function. Compared with the group with normal function, subjects with low midwall LV function had similar office systolic BP (155 +/- 21 vs 154 +/- 17 mm Hg), but increased 24-hour systolic BP (140 +/- 17 vs 133 +/- 12 mm Hg, p <0.001). Midwall FS had a closer negative relation to 24-hour systolic BP than to office systolic BP (r = -0.27 vs -0.08, p <0.001), whereas this difference was not apparent for diastolic BP (r = -0.23 vs -0.20). Compared with endocardial FS, midwall FS had a stronger inverse association to LV mass (r = -0.45 vs -0.16, p <0.001). Thus, an increased 24-hour BP load may chronically lead to depressed myocardial function in systemic hypertension in the absence of clinically overt heart disease.

Morphologic left ventricular patterns and prevalence of high-grade ventricular arrhythmias in the normotensive and hypertensive elderly

In the elderly, systemic hypertension is the main risk factor for cardiovascular diseases. Left ventricular hypertrophy, the most common adaptation to chronic pressure overload, has been recognized as an independent risk factor for an increased incidence of sudden death and arrhythmic disturbances. This study compared the prevalence of serious ventricular arrhythmias in elderly individuals with uncomplicated hypertension and in normotensive age-matched controls, using left ventricular mass index (LVMI) to differentiate patterns of anatomic adaptation to systolic, diastolic, or systolic-diastolic hypertension. The study enrolled 378 consecutive untreated elderly subjects (> or = 65 years of age), without clinical evidence of heart failure; 203 were hypertensive and 175 were normotensive. Each participant underwent standard 12-lead electrocardiography, M-mode and B-mode echocardiography, and 24-hour ambulatory electrocardiographic monitoring. Serious, statistically significant arrhythmias (Lown classes > or = 3) were present in 6.8% of normal subjects versus 17.1% of individuals with systolic, 31.5% of those with diastolic, and 20.4% of participants with systolic-diastolic hypertension. Arrhythmias did not differ in terms of left ventricular morphologic patterns or LVMI or between subgroups of hypertensive patients. Our data support the hypothesis that the pathogenesis of arrhythmias is related not to the electrophysiologic derangement of hypertrophied muscle but, rather, to the effects of hypertension on the cardiac structure. Cardiac fibrosis, one of the deleterious events accompanying hypertension, may be the main substrate for ventricular arrhythmias.

Clinical study to investigate the predictive parameters for the onset of atrial fibrillation in patients with essential hypertension

BACKGROUND

The risk factors involved in the onset of atrial fibrillation (AF) are well known, but the predictive clinical and paraclinical parameters for the onset of AF in hypertensive patients have not been investigated specifically.

METHODS AND RESULTS

We retrospectively analyzed 97 consecutive patients with hypertension and no known history of AF or cardiovascular events who attended the cardiology outpatient clinic. The analysis was based on clinical data, the noninvasive ambulatory 24-hour measurement of blood pressure (AMBP), a standard 12-lead electrocardiogram, and a Doppler echocardiogram. After a mean follow-up of 25 +/- 3 months, 19 (19. 5%) patients had AF, 3 (15.8%) of whom had a cerebrovascular accident. The patients with AF were older than the others and their AMBP showed higher mean systolic diurnal and nocturnal blood pressures, though no differences in the clinical blood pressure readings were present. On the electrocardiogram, the maximum duration of the P wave and its dispersion were more prolonged in the patients with AF. On the Doppler echocardiogram, left ventricular mass and left atrial dimension were higher in the patients with AF, and the A-wave velocity of diastolic mitral flow was reduced in these patients. In the multivariate analysis, age (odds ratio 3.28, P <.001), diurnal systolic blood pressure (odds ratio 1.35, P <.01) and nocturnal systolic blood pressure (odds ratio 1.16, P <.01), maximum duration of the P wave (odds ratio 2.09, P <.01), dispersion of the P wave (odds ratio 2.52, P <.001), echocardiographic left ventricular mass (odds ratio 1.43, P <.01), left atrial dimension (odds ratio 2.81, P <.001), and velocity of the A wave (odds ratio 2. 24, P <.01) were independent predictors for the onset of AF. After correction for age, maximum duration of the P wave (odds ratio 1.34, P <.01), dispersion of the P wave (odds ratio 1.63, P <.001), and the velocity of the A wave (odds ratio 1.42, P <.01) remained independent predictors for the onset of AF.

CONCLUSIONS

In patients with hypertension, age and the level of diurnal and nocturnal systolic blood pressures measured by 24-hour AMBP are important independent predictors for the onset of AF. Independent of age, increases in left atrial dimension and left ventricular mass, prolongation of the maximum duration and dispersion of the P wave and reduced A-wave velocity are also predictors for the onset of AF.

Noninvasive assessment of left ventricular systolic function by stress-shortening relation, rate of change of power, preload-adjusted maximal power, and ejection force in idiopathic dilated cardiomyopathy: prognostic implications

Indexes of left ventricular systolic function that are considered relatively load-insensitive were assessed to determine their relation to the severity of heart failure symptoms and their ability to predict the outcome of idiopathic dilated cardiomyopathy. Stress, flow, power, and ejection force were calculated throughout ejection by echocardiography at rest in 35 patients with idiopathic dilated cardiomyopathy and in 20 control subjects. Patients were evaluated prospectively every 6 months for 2 years. Asymptomatic patients were separated most clearly from New York Heart Association (NYHA) class II by end-systolic stress; NYHA class II patients were separated from NYHA class III and the latter from NYHA class IV by peak rate of change of flow. Ten patients showed improvement in symptoms as well as in systolic indexes; none of them died during the follow-up. Improvement was unpredictable with the evaluated variables. One- and 2-year cardiovascular mortality rates were 17% and 26%, respectively. Patients whose condition did not improve after the first year had a 17% second-year mortality rate. Peak rate of change of power predicted death with 100% sensitivity, 56% specificity, and 64% positive predictive value in NYHA III and IV patients.

Midwall fractional shortening is an independent predictor of left ventricular diastolic dysfunction in asymptomatic patients with systemic hypertension

Conventional measures of left ventricular (LV) systolic performance suggest that diastolic dysfunction precedes the development of systolic dysfunction in hypertension. Midwall fractional shortening is a new measure of systolic function that identifies hypertensive patients who have evidence of target-organ damage, impaired contractile reserve, and increased mortality. We therefore sought to determine whether depressed midwall fiber shortening is associated with abnormal diastolic function. Echocardiograms were obtained in 102 otherwise healthy hypertensive patients without treatment with normal conventional measures of systolic function. Of these, 15 had depressed midwall shortening based on previously described normative relations. Patients with depressed midwall shortening had slightly higher blood pressure. Abnormal diastolic function, defined as late (A) LV inflow velocity greater than early (E) velocity, was observed in 33% of those with normal midwall shortening but in 60% of those with depressed shortening (p <0.05). Patients with A/E >1 had lower absolute midwall fiber shortening (15 +/- 3% vs 18 +/- 3%, p <0.0001) but similar endocardial shortening. Patients with abnormal midwall shortening had higher A/E and longer isovolumic relaxation times (both p <0.05). In multivariate analysis, midwall fractional shortening, age, and heart rate were independent predictors (p <0.01) of A/E in a model including blood pressure, LV mass, and endocardial shortening. We conclude that subnormal midwall shortening predicts LV diastolic abnormalities in this population of hypertensive patients with otherwise normal measures of LV systolic function. Contrary to our previous understanding, depressed LV systolic performance, when identified with this newer method, occurs coincidentally with impaired diastolic function.

Early impairment of coronary flow reserve in young men with borderline hypertension

OBJECTIVES

The purpose of this study was to investigate whether functional abnormalities in coronary vasomotion are present in young healthy asymptomatic men fulfilling the World Health Organization (WHO) criteria for borderline hypertension.

BACKGROUND

Previous studies have reported reduced coronary flow reserve in middle-aged subjects with sustained hypertension and hypertension-induced microvascular heart disease or left ventricular hypertrophy.

METHODS

Myocardial blood flow was measured at baseline and during dipyridamole-induced hyperemia by means of positron emission tomography and oxygen-15-labeled water in asymptomatic young men with borderline hypertension (group 1: n = 16, mean +/- SD age 37 +/- 4 years, 24-h ambulatory blood pressure 135 +/- 10/81 +/- 9 mm Hg) and matched healthy control subjects (group 2: n = 19, age 35 +/- 3 years, 24-h ambulatory blood pressure 119 +/- 8/69 +/- 8 mm Hg, p < 0.001). Left ventricular (LV) mass, dimensions and function were measured by echocardiography.

RESULTS

LV mass, dimensions and diastolic function were similar in the study groups. Baseline myocardial blood flow was similar (0.83 +/- 0.21 vs. 0.80 +/- 0.22 ml/g per min, group 1 vs. group 2, respectively, p = NS), and a significant increase in flow was detected after dipyridamole infusion (0.56 mg/kg body weight in 4 min intravenously) in both groups. However, the flow response to dipyridamole was significantly lower in group 1, leading to lower hyperemic flow in group 1 than in group 2 (2.85 +/- 1.20 vs. 3.80 +/- 1.44 ml/g per min, respectively). Consequently, the coronary flow response was lower in hypertensive than in normotensive men (3.46 +/- 1.23 vs. 4.99 +/- 2.5 ml/g per min, group 1 vs. group 2, respectively, p < 0.05).

CONCLUSIONS

These results demonstrate reduced coronary reactivity present in young asymptomatic men with borderline hypertension and no signs of hypertension-induced angina or left ventricular hypertrophy. Because baseline basal myocardial blood flow was unchanged, the reduction in coronary flow reserve depends on an impaired maximal vasodilator capacity.

Relation of left ventricular midwall function to cardiovascular risk factors and arterial structure and function

Left ventricular (LV) midwall shortening (MWS) is subnormal in relation to LV circumferential end-systolic stress (ESS) (ESS-corrected MWS) in many hypertensive patients with normal LV chamber function and predicts subsequent morbidity and mortality. However, little is known of the relations of LV midwall function to demographic and metabolic variables or to arterial geometry. Asymptomatic, unmedicated normotensive (n=366) or hypertensive (n=282) adults were assessed with echocardiography and carotid ultrasound. In normal adults, lower LV MWS and ESS-corrected MWS, an index of LV contractility, were related independently to high total peripheral resistance, high heart rate, and male gender (all P<.00001), lower serum HDL cholesterol (P=.001) and diastolic pressure (P=.003), and for ESS-corrected MWS only, arterial relative wall thickness (RWT, P=.03). Among hypertensive patients, lower values for both midwall function indices were associated independently with higher peripheral resistance (P<.00001), heart rate (P<.00005), body mass index (P<.01), and arterial RWT (P=.04), as well as male gender (P<.0002). In the entire population, lower LV MWS was independently related to higher peripheral resistance, heart rate (both P<.00001), body mass index (P=.0006) and arterial RWT (P=.009); male gender (P<.00001); and lower age (P=.004), diastolic pressure (P=.042), and systolic carotid artery expansion (P=.032). Lower ESS-corrected MWS in the entire population was independently associated with higher peripheral resistance and heart rate (both P<.00001), body mass index (P=.0006), arterial RWT (P=.004); male gender; and lower diastolic pressure (both P<.00001), age (P<.00005), arterial expansion in systole (P=.006), and serum HDL cholesterol levels (P=.04). Among a subset (n=60), ESS-corrected MWS was positively related to apolipoprotein A1 (P=.004) and negatively to hemoglobin A1c (P<.01). Thus, higher LV midwall function is associated with female gender and more favorable profiles of hemodynamics, metabolic pattern, and arterial structure and function.

Prediction of indications for valve replacement among asymptomatic or minimally symptomatic patients with chronic aortic regurgitation and normal left ventricular performance

BACKGROUND

Optimal criteria for valve replacement are unclear in asymptomatic/minimally symptomatic patients with aortic regurgitation (AR) and normal left ventricular (LV) performance at rest. Moreover, previous studies have not assessed the prognostic capacity of load-adjusted LV performance ("contractility") variables, which may be fundamentally related to clinical state. Therefore, 18 years ago, we set out to test prospectively the hypothesis that objective noninvasive measures of LV size and performance and, specifically, of load-adjusted variables, assessed at rest and during exercise (ex), could predict the development of currently accepted indications for operation for AR.

METHODS AND RESULTS

Clinical variables and measures of LV size, performance, and end-systolic wall stress (ESS) were assessed annually in 104 patients by radionuclide cineangiography at rest and maximal ex and by echocardiography at rest; ESS was derived during ex. During an average 7.3-year follow-up among patients who had not been operated on, 39 of 104 patients either died suddenly (n = 4) or developed operable symptoms only (n = 22) or subnormal LV performance with or without symptoms (n = 13) (progression rate=6.2%/y). By multivariate Cox model analysis, change (delta) in LV ejection fraction (EF) from rest to ex, normalized for deltaESS from rest to ex (deltaLVEF-deltaESS index), was the strongest predictor of progression to any end point or to sudden cardiac death alone. Unadjusted deltaLVEF was almost as efficient. Symptom status modified prediction on the basis of the deltaLVEF-deltaESS index. The population tercile at highest risk by deltaLVEF-deltaESS progressed to end points at a rate of 13.3%/y, and the lowest-risk tercile progressed at 1.8%/y.

CONCLUSIONS

Currently accepted symptom and LV performance indications for valve replacement, as well as sudden cardiac death, can be predicted in asymptomatic/minimally symptomatic patients with AR by load-adjusted deltaLVEF-deltaESS index, which includes data obtained during exercise.

Left ventricular performance in the early stages of systemic hypertension. HARVEST Study Group. Hypertension and Ambulatory Recording Venetia Study

To investigate whether and how frequently left ventricular (LV) systolic performance assessed with endocardial and midwall measurement is depressed in young subjects with mild systemic hypertension, we studied 722 borderline to mild hypertensive patients (mean age +/- SEM 33 +/- 0.3 years, mean office blood pressure (BP) 146 +/- 0.4/94 +/- 0.2 mm Hg) enrolled in the Hypertension and Ambulatory Recording Venetia Study and 50 normotensive controls with similar age and sex distribution. BP was measured with 24-hour ambulatory monitoring. LV dimensional and functional indexes were assessed by M-mode echocardiography and sympathetic activity from 24-hour urinary catecholamines. In 64 hypertensive subjects (8.9%) the LV midwall shortening-stress relation was < 95% of the confidence interval in 50 normotensive controls. Subjects with depressed LV myocardial function had age, duration of hypertension, and LV mass similar to those of hypertensives with normal performance, and greater relative wall thickness (0.42 vs 0.37, p < 0.001). Stroke volume and cardiac output were lower (p < 0.001) in the former group. Among these 64 subjects, endocardial performance was depressed in 35 (group 1) and normal in 29 (group 2). Group 2 subjects had greater posterior wall (10.0 vs 9.5 mm, p = 0.03), ventricular septum (10.6 vs 10.1 mm, p = 0.05), and relative wall (0.44 vs 0.40, p < 0.001) thicknesses than group 1 subjects. Urinary norepinephrine was 50% higher in group 2 subjects (106 vs 70 g/24 hours, p = 0.03). Stroke volume and cardiac output were similar in both groups. In conclusion, these results show that LV contractility may be depressed in young subjects with borderline to mild hypertension.

Systolic function in hypertensive men with concentric remodeling

Hypertensive patients with concentric remodeling (relative wall thickness > or = 0.45 and normal left ventricular [LV] mass index) may have poor outcomes. It is unclear whether systolic function abnormalities, shown to be present in some patients with concentric LV hypertrophy (increased LV mass index and relative wall thickness > or = 0.45), are also present in patients with concentric remodeling. To assess LV pump, chamber, and myocardial function in hypertensive men with concentric remodeling, clinical and echocardiographic data of 118 hypertensive men with concentric remodeling were compared with data from 104 hypertensive men with normal relative wall thickness and normal LV mass index. Chamber function was assessed by relating endocardial fractional shortening to end-systolic circumferential stress, myocardial function was assessed by relating midwall fractional shortening to circumferential stress, and pump performance was assessed by stroke volume (Teichholz method). Compared with hypertensive men with normal relative wall thickness, concentric-remodeling patients had lower stroke volume (84 +/- 20 versus 111 +/- 20 mL, P < .001). Endocardial shortening was no different between the two groups (38 +/- 7% versus 40 +/- 7%, P=NS), but midwall shortening was lower in patients with concentric remodeling (20 +/- 3% versus 22 +/- 3%, P < .001), despite lower end-systolic stress (81 +/- 25 versus 117 +/- 37 g/cm2, P < .001). Endocardial and midwall stress-shortening regression plots classified 28% and 42%, respectively, of the concentric remodeling patients below the fifth percentile of hypertensive patients with normal geometry. These data indicate that indexes of chamber and myocardial function are lower than those observed in hypertensive patients with normal geometry. Thus, indices of chamber, myocardial, and pump performance indicate potential abnormalities in systolic function in men with concentric remodeling.

Usefulness of subnormal midwall fractional shortening in predicting left ventricular exercise dysfunction in asymptomatic patients with systemic hypertension

We have recently shown that a subgroup of asymptomatic hypertensive patients exhibit subnormal left ventricular (LV) midwall fiber shortening at rest and that this finding predicts morbidity and mortality independently of age, blood pressure (BP), or the presence of LV hypertrophy. However, it is unknown whether abnormal midwall fractional shortening predicts either subnormal LV functional reserve or extracardiac damage in asymptomatic hypertensive patients. Accordingly, we compared radionuclide cineangiographic LV ejection fraction at rest and maximum exercise as well as clinical findings between 89 patients with normal and 16 patients with subnormal midwall fractional shortening by echocardiogram. Patients with low midwall fractional shortening were similar in gender, age, and systolic BP to those with normal shortening but had higher mean diastolic BP and body mass indexes (both p < 0.05). The 2 groups also had similar resting ejection fraction (56 +/- 9% vs 55 +/- 15%, with normal or subnormal shortening, respectively, p = NS). Patients with subnormal midwall fractional shortening had higher LV mass and tended to have higher urinary protein excretion and serum creatinine levels. Subnormal LV ejection fraction with exercise (< 54%) was observed in 13 of 89 patients (15%) with normal midwall fractional shortening but in 7 of 16 patients (44%) with subnormal shortening (p < 0.05). Multiple linear regression analysis revealed that midwall fractional shortening independently predicted exercise performance (p < 0.001). Thus, subnormal midwall fractional shortening predicts depressed LV fractional reserve in asymptomatic hypertensive patients and may contribute to identification of patients with extracardiac target-organ damage.

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.

Prognostic value of left ventricular mass and geometry in systemic hypertension with left ventricular hypertrophy

To determine the independent prognostic significance of left ventricular (LV) mass and geometry (concentric vs eccentric pattern) in hypertensive subjects with LV hypertrophy at echocardiography, 274 subjects were followed for up to 8.7 years (mean 3.2). All patients had systemic hypertension and LV mass > or = 125 g/body surface area (BSA) and underwent ambulatory blood pressure (BP) monitoring and echocardiography before treatment. Eccentric and concentric hypertrophy were defined by the ratio between LV posterior wall thickness and LV radius at telediastole <0.45 and > or = 0.45, respectively. Age, sex ratio, body mass index, office BP and serum glucose, cholesterol, and triglycerides did not differ between the groups with eccentric (n=145) and concentric (n=129) hypertrophy. Average 24-hour daytime, and nighttime systolic ambulatory BPs were higher in concentric than in eccentric hypertrophy (all p <0.01). LV mass was slightly greater in concentric than in eccentric hypertrophy (157 vs 149 g/BSA, p <0.05). Endocardial and midwall shortening fraction were lower in concentric than in eccentric hypertrophy (96.5% vs 106.0% of predicted and 71.4% vs 89.7% of predicted, respectively; both p <0.01). The rate of major cardiovascular morbid events was 2.20 and 3.34 per 100 patient-years in eccentric and concentric hypertrophy, respectively (log rank test, p=NS). Age >60 and LV mass above median (145 g/BSA) were significant adverse prognostic predictors, while LV geometry (eccentric vs concentric hypertrophy) and ambulatory BP were not. The event rates per 100 patient-years were 1.38 and 3.98, respectively, in the patients with LV mass below and above median (age-adjusted relative risk 2.70; 95% confidence interval [CI] 1.03 to 6.63; p=0.015). In hypertensive subjects with established LV hypertrophy, LV mass, but not its geometric pattern, provides important prognostic information independent of conventional risk markers including office and ambulatory BP.

Left ventricular systolic and diastolic function assessed with two-dimensional and doppler echocardiography in "white coat" hypertension

OBJECTIVES

The aim of this study was to investigate left ventricular function in subjects with "white coat" hypertension, defined as office arterial diastolic pressure > or = 90 and ambulatory daytime pressures < 140/90 mm Hg.

BACKGROUND

The white coat arterial pressure response may, by influencing left ventricular function, have a confounding effect in studies of heart disease.

METHODS

Two-dimensional and Doppler echocardiography combined with the calibrated subclavian arterial pulse tracing, were used to assess variables of left ventricular function in 26 subjects with white coat hypertension (office arterial diastolic pressure > or = 90 and < 115 mm Hg and ambulatory daytime diastolic pressure > or = 90 mm Hg) and 32 normotensive subjects.

RESULTS

In subjects with white coat hypertension, systolic arterial pressure during the echocardiographic examination was significantly higher than ambulatory daytime systolic pressure. This pressure response was positively related to the ratio of the systolic to diastolic pulmonary venous flow peak velocities and to the peak velocity of flow reversion during atrial systole; it was inversely related to the ratio of early to late mitral flow peak velocities. Left ventricular stroke volume, ejection fraction and velocity of circumferential fiber shortening did not differ in the study groups, but left ventricular external work and end-systolic wall stress were increased in the white coat group.

CONCLUSIONS

The arterial pressure response in subjects with white coat hypertension is associated with increased left ventricular external work, increased end-systolic wall stress and alterations of left ventricular filling but normal ejection fraction and velocity of circumferential fiber shortening.

Correlates of the hemodynamic determinants of blood pressure

The purpose of this study was to investigate the association of sex, race, lean body mass, and fat mass with the hemodynamic determinants of blood pressure, including stroke volume, heart rate, and total peripheral vascular resistance. The study included 201 subjects aged 6 to 17 years, 105 of whom were male and 98 of whom were black. Lean body mass and fat mass were both significant (P < .05) independent determinants of stroke volume, cardiac output, and total peripheral vascular resistance. However, the direction of the effect of lean body mass was opposite for stroke volume and cardiac output compared with that of total peripheral vascular resistance. The direct relationship of lean body mass with systolic blood pressure (SBP) and diastolic blood pressure (DBP) (regression coefficients, 0.55 +/- 0.05 for SBP and 0.47 +/- 0.05 for DBP) indicates that the effect of lean body mass on cardiac output may predominate. Lean body mass explained substantially more of the variance of the hemodynamic variables than did fat mass. After control for the effects of body size, male subjects had higher heart rate and cardiac output, and female subjects had higher vascular resistance. White subjects had higher stroke volume and cardiac output, and black subjects had higher peripheral vascular resistance. This study demonstrates that lean body mass is a more important correlate of the hemodynamic determinants of blood pressure than is fat mass and that sex and race have significant independent relationships with the hemodynamic determinants of blood pressure in children and adolescents.

Is blood pressure the major determinant of left ventricular mass in subjects over 50 years of age?

The weak relation of systolic blood pressure to left ventricular (LV) mass in hypertension has frequently been regarded as evidence of non-hemodynamic stimuli to muscle growth. Anyway, left ventricular hypertrophy (LVH) is associated with a significantly increased risk for cardiovascular events. Data were obtained from M-mode echocardiograms in 10 normotensives and 58 hypertensives over 50 years (range 50-85 years); 18 hypertensives; were without (LVH -) and 40 were with LVH (LVH +) - when LV mass, normalized for body surface area, was calculated according to the Penn's Convention. Cardiac output was derived by Teicholz formula for LV volumes. End-systolic stress/end-systolic dimension ratio (ESS/ ESD r), an index of myocardial contractility, was calculated as previously validated in the literature. We found that, in subjects ranging from 50 to 85 years of age, the presence of LV hypertrophy is not necessarily associated with raised blood pressure levels. Systolic function was substantially preserved among the study groups, irrespective of their age, hypertensive condition and/or presence of LVH. The increased wall thickness in subjects with LVH was associated with a significant reduction in wall stress (thus suggesting an adequateness of the compensatory role of LVH - at least at the observed stage of the hypertrophy process) and with a significant decrease of the contractile performance. On the multivariate analysis, the observed relation of LV mass to blood pressure and myocardial contractility (r = 0.621, P < 0.001) may explain some apparently conflicting findings, such as the lack of LV hypertrophy in a number of hypertensive patients.

Midwall left ventricular mechanics. An independent predictor of cardiovascular risk in arterial hypertension

BACKGROUND

An appreciable proportion of asymptomatic hypertensive patients have depressed left ventricular (LV) performance that is identified by midwall shortening/endsystolic stress relations but not by indexes that use endocardial shortening. It has not been established, however, whether depressed midwall ventricular performance has prognostic implications.

METHODS AND RESULTS

Echocardiographic endocardial and midwall LV fractional shortening/circumferential end-systolic stress relations in 294 hypertensive patients were analyzed as predictors of the occurrence of cardiovascular morbid events that occurred in 50 patients (including 14 deaths) during a 10-year mean follow-up. Patients with initially lower midwall but not endocardial shortening, either in absolute terms or as a percentage of predicted from observed end-systolic stress, were more likely to suffer morbid events than those with initially normal values (P < .004). Cardiovascular events occurred in 29 of 100 patients (29%) and death in 10 of 100 patients (10%) among those who were in both the two highest quartiles of LV mass index and the two lowest quartiles of midwall shortening, as opposed to 21 of 194 (11%) and 4 of 194 (2.1%) of the remaining patients (odds ratio, 3.4; 95% CI, 1.8 to 6.3; P < .0001; and odds ratio, 5.3; 95% CI, 1.6 to 17.3; P < .006, respectively). In logistic analysis, increasing age, high LV mass, high systolic blood pressure, and low values for an interaction term between LV mass index and midwall shortening independently predicted cardiovascular events (.04 < P < .001); increasing age, low midwall LV shortening as a percentage of predicted, and high value of the interaction term predicted the occurrence of cardiac death (.004 < P < .0002). Survival analysis controlling for age confirmed that low midwall shortening independently predicted cardiac morbidity or death, especially in the subgroup of patients with LV hypertrophy.

CONCLUSIONS

Depressed midwall shortening is a predictor of adverse outcome in arterial hypertension; the combination of higher LV mass and lower midwall shortening identifies individuals at markedly increased risk.