D. Piccolo

White-coat hypertension: a selection bias?

BACKGROUND Results of several studies have shown that subjects with white-coat hypertension (WCH) have more target-organ damage than do normotensive controls with similar ambulatory blood pressures. OBJECTIVE To investigate whether this is due to a selection bias. SETTING Seventeen hypertension clinics in northeast Italy. MAIN OUTCOME MEASURES Echocardiographic data in relation to WCH status. PATIENTS AND METHODS Mild hypertensive subjects from the HARVEST (n = 565) who underwent two ambulatory blood pressure monitorings 3 months apart and M-mode echocardiography, and 95 normotensive control subjects. RESULTS From first ambulatory monitoring, 90 hypertensive subjects were classified as having WCH (mean daytime blood pressure < 130/80 mmHg). Their 24 h blood pressure was similar to that of the normotensive subjects, but their left ventricular mass index was greater. From second ambulatory monitoring, only 38 of the 90 subjects still had WCH, whereas 24 h blood pressure in the other 52 had risen beyond the limit of WCH. Left ventricular mass index (89.2 +/- 2.4 g/m2), wall thickness (18.1 +/- 0.3 mm), and relative wall thickness (0.359 +/- 0.006%) of the 38 subjects with WCH at both recordings were still greater than those of the normotensive subjects (82.4 +/- 1.5 g/m2, P = 0.02; 17.2 +/- 0.2 mm, P = 0.002; and 0.337 +/- 0.004%, P = 0.025) and similar to those of the 52 subjects who no longer had WCH (88.5 +/- 2.0 g/m2, 18.7 +/- 0.2 mm, and 0.375 +/- 0.005%, all NS). CONCLUSIONS Owing to regression toward the mean, over 50% of the subjects with WCH could no longer be classified as such from repeated ambulatory monitoring, indicating that the current diagnosis of WCH is subject to selection bias. Cardiac remodeling was present also in the subjects confirmed to have WCH by repeated blood pressure recording, suggesting that the effect of WCH has an actual impact on target organs.

The Effects of Alcohol Consumption on Ambulatory Blood Pressure and Target Organs in Subjects With Borderline to Mild Hypertension

The objective of this study was to examine the relationship of alcohol consumption to target organ involvement and ambulatory blood pressure (BP) in a population of young borderline to mild hypertensive subjects. Participants were 793 male subjects, aged 18-45 years, from the HARVEST Study. The analysis was performed in three age-matched groups with similar body mass index. Casual and 24-h ambulatory BP monitoring, routine biochemistry, echocardiography, and albumin excretion rate were measured. The men were divided into three groups: 1) nondrinkers, 2) drinkers of < 50 g/day, and 3) drinkers of > or = 50 g/day. Office systolic BP was not significantly different among the three groups, whereas 24-h and daytime BPs increased progressively from the first to the third group (group 1 v 3; P = .01 for 24-h systolic BP and P = .02 for daytime systolic BP). These differences remained significant even after adjusting for smoking. Left ventricular mass index, interventricular septum thickness, and wall thickness increased progressively from group 1 to group 3; this difference also remained significant after adjusting for smoking and 24-h BPs. The albumin excretion rate was much higher in group 3 than in group 1 (P = .003), but when 24-h BP was added to the model the difference was no longer significant. These results indicate that alcohol has a detrimental effect on the heart and the kidney. Alcohols effect on LV wall thickness appears to be direct, whereas its action on albumin excretion rate seems to be mediated mainly by its effect on BP.

Relationship between albumin excretion rate, ambulatory blood pressure and left ventricular hypertrophy in mild hypertension

Objective To study the relationship of urinary albumin excretion to ambulatory blood pressure and other cardiovascular risk factors in borderline to mild hypertension. Patients and methods We studied 779 patients with borderline to mild hypertension (mean±SEM age 33±0.3 years; mean±SEM office blood pressure 146±0.4/94±0.2 mmHg) at 17 hypertension clinics in northeast Italy. Office and 24-h blood pressures were recorded with simultaneous urine collection for albumin measurement. In 510 subjects, left ventricular mass was measured by echocardiography. Results Subjects with overt (>30 mg/24 h) and borderline (16–29 mg/24 h) microalbuminuria had similar 24-h blood pressure levels, higher than those in the subjects without microalbuminuria. In the univariate and multiple regression analyses the albumin excretion rate was closely correlated with 24-h systolic blood pressure and not related to age, body mass index, metabolic parameters, lifestyle factors and degree of left ventricular hypertrophy. Conclusions Borderline values of urinary albumin excretion (16–29 mg/24 h) may be clinically relevant in subjects with borderline to mild hypertension. Renal and cardiac damage do not develop in parallel in the initial phases of hypertension.

Left Ventricular Performance in the Early Stages of Systemic Hypertension

Abstract 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

Ventricular myosin and creatine-kinase isoenzymes in hypertensive rats treated with captopril.

In the myocardium, myosin and creatine kinase isoforms possess different capacities for using O2 and energy-rich phosphates. We studied electrophoretically the distribution of these isoforms in 19 hypertensive rats (two-kidney, one clip model of hypertension) and in age-matched controls. After 6 weeks of hypertension, seven rats were treated with captopril (2 mg/kg daily) for 4 weeks, six were left hypertensive for another 4 weeks, and the remaining rats were killed under ether anesthesia. In the latter, ventricular mass was significantly higher than in controls; V3 isomyosin was 32.3 ±6.8% versus 0%, and both creatine kinase-MB and -BB were increased at the expense of creatine kinase-MM (creatine kinase-MB=29±2.8% vs. 14.7±1.8%, p < 0.001; creatine kinase-BB=3.1±0.6% vs. 1.7±0.8%, p < 0.001). After 10 weeks of hypertension, ventricular mass, V3 isomyosin, and both creatine kinase-MB and -BB isoforms were found to be persistently higher than in controls. At the same time, captopril-treated rats showed reduced but not normalized blood pressure levels, normalized ventricular mass, and prevalence of the V1 isomyosin (56.9±22% vs. 47.9±23.8% in normotensive controls, p < =NS). However, higher levels of creatine kinase-MB and -BB were still found in these rats in comparison with the normotensive controls (creatine kinase-MB=22.4±5.4% vs. 15.8±2.8%, p < 0.025; creatine kinase-BB=2.3±0.1% vs. 1.8±0.3%, p < 0.02). Therefore, despite the normalization in ventricular mass and isomyosin pattern, captopril-treated rats partly maintain the adaptive changes in creatine kinase isoenzymes that lead to a better use of energy-rich phosphates.

The idiopathic dilated cardiomyopathy in man. A biochemical and molecular study on myosin

SummaryWe studied subunit composition and Ca++-activated ATPase activity of myosin isolated from atria and ventricles of hearts explanted from patients suffering from idiopathic dilated cardiomyopathy. At variance with previously published data, we have been unable to detect in the ventricular subendocardial layers a significant amount of myosin atrial-like light chain 1 (ALC1), which has been reported to be related to some hemodynamic features of the hypertrophied and failing heart. Such a subunit was not visible in the septum and in the subepicardial layers either. On the contrary, in both atria a ventricular-like light chain 2 (VLC2) was found. The nature of this additional light chain was confirmed on the basis of two-dimensional electrophoresis and immunoblotting techniques with polyclonal antibodies reacting with VLC2. In these patients we also observed a depressed Ca++-activated ATPase activity, both in atrial and ventricular myosin. The explanation for this finding in ventricles still remains obscure since neither myosin light chains, nor myosin heavy chains showed any difference between patients with dilated cardiomyopathy and controls. On the contrary, in atria we clearly identified changes consistent with the expression of myosin heavy chains of ventricular type and VLC2, which can account for the depressed Ca++-activated ATPase activity.

Response to orthostatic stress predicts office-daytime blood pressure difference, but not nocturnal blood pressure fall in mild essential hypertensives: results of the harvest trial.

1. The aim of the present study was to evaluate whether postural blood pressure (BP) change could predict office‐daytime BP disparity and the nocturnal BP fall in young, mild essential hypertensives. We investigated 411 males aged between 18 and 45 years with never treated borderline to mild hypertension. BP was measured three times after a 5 min rest in the supine position and thereafter three times after 2 min of standing. The mean of six BP measurements obtained during two visits in the lying position was defined as office BP.

Left ventricular hypertrophy in hypertension: Changes in isomyosins and creatine-kinase isoenzymes

In hypertension, the heart of small mammals can express different isoenzymic forms of proteins under the influence of overload and other modulating factors. The increase in ventricular mass is generally paralleled by progressive changes in the isoforms of at least two proteins that are involved in the contraction process, namely, myosin and creatine-kinase. This review summarizes the biochemical and molecular changes occurring during progression and with regression of cardiac hypertrophy in rats, humans, and other animals, and focuses on the role played by antihypertensive drugs in modulation of ventricular isomyosins. The implications of these observations for humans remain to be fully determined.

Results of long-term performance and subsequent laboratory tests of RPCs of the L3 forward-backward muon spectrometer

Abstract The RPC chambers in the L3 forward–backward muon spectrometer have been operational from 1994 to the end of LEP running. After dismantling of the L3 detector some of the RPCs modules have been transported to Napoli where their performance has been re-measured with cosmic rays. Results of long-term performance in the LEP environment and of laboratory tests with cosmic rays will be presented. One of the 20 tested chambers, the one with the worst performances, was opened. The chamber was inspected with microscope and also a chemical analysis of the oil coating was performed. We will report in detail about this analysis.

Performances of the RPC trigger system of the L3 Forward—Backward muon spectrometer

In view of LEP200 physics, the L3 detector has been upgraded installing the Forward—Backward muon spectrometer to increase the angular acceptance in muon detection. We describe the trigger system for this spectrometer which makes use of Resistive Plate Counters (RPC) covering an area of 300 m2. This system is the first large application in high energy physics of this kind of detectors and its operation will constitute an important test for their future use in the LHC experiments. The main features of the RPCs, the trigger architecture and the preliminary results from the 1994 LEP run are given.