Usefulness of a quantitative analysis of the recovery phase patterns of the ST-segment depression in the diagnosis of coronary artery disease.

PURPOSE: To assess the diagnostic value of the recovery phase patterns of the ST-segment depression in patients referred for chest pain. PATIENTS AND METHODS: Continuous plots of ST-segment depression against heart rate during exercise and recovery were constructed within a population of 160 consecutive symptomatic patients who all had undergone catheterization (80 with > or = 1 stenosis > or = 50%). We used a new quantitative method of measurement allowing all kinds of rate recovery loops (even the so-called "intermediate" loops) to be considered for analysis. The measurements of the heart rate (HR)-adjusted ST-segment depression were performed at 20 and 60 ms from the J point, providing two different values of a quantified recovery loop index (RLI): RLI 20 and RLI 60. RESULTS: Both RLI showed a higher specificity (0.81 +/- 0.04 and 0.74 +/- 0.05, respectively) than did the standard criterion (0.65 +/- 0.10), but the difference was significant regarding RLI 20 only (P = 0.011). As to the sensitivity, no significant differences were found among all of the criteria (0.74 +/- 0.05, 0.80 +/- 0.04, 0.76 +/- 0.05, respectively). The timing of measurements of the RLI within the repolarization phase did not affect their overall accuracy (0.77 +/- 0.03 for both RLI). The values of the receiver-operating characteristic (ROC) curve areas were significantly greater for both RLI (0.83 +/- 0.06 and 0.84 +/- 0.06 respectively) than for the standard criterion (0.75 +/- 0.07; P < 0.02). Finally, both RLI allowed to differentiate accurately the study subjects according to the number of diseased vessels, whereas the standard criterion could only distinguish between CAD patients and subjects with normal angiograms. CONCLUSION: The quantitative analysis of the rate recovery phase patterns appears to be useful for the diagnosis of coronary heart disease and the assessment of its severity in symptomatic patients.

[Reproducibility of the blood pressure variability parameters by plethysmographic method (FINAPRES) in normotensive subject]. / Reproductibilité des paramètres de variabilité tensionnelle obtenus par photopléthysmographie digitale (FINAPRES) chez le sujet normotendu.

AIM OF THE STUDY: to assess the reproducibility of blood pressure and heart rate variability measurements in time and frequency domain, by using a Finapres device in healthy volunteers. METHODS: 16 normotensive subjects aged 22 to 51 years underwent within a 5-day interval two non-invasive blood pressure recordings by a Finapres device over 15 minutes both in supine and standing positions, at the same time of the day. STATISTICAL ANALYSIS: non parametric tests, relative errors, and intraclass correlation coefficient. RESULTS: [table: see text] CONCLUSION: the data provided by the FINAPRES device, especially the baroreflex sensitivity measured in standing position, show a good day to day reproducibility.

[Heart rate and blood pressure variabilities in mild to moderate hypertensive patients with or without left ventricular hypertrophy]. / Variabilité sinusale et variabilité tensionnelle de l'hypertendu léger à modéré avec ou sans hypertrophie ventriculaire gauche.

AIM OF THE STUDY: To compare heart rate (HR) and blood pressure (BP) variability in hypertensives with or without left ventricular hypertrophy (LVH). METHODS: Thirty-three mild to moderate hypertensive patients, mean age 45 +/- 15 years, underwent an echocardiogram, a 24 hr ambulatory BP monitoring (ABPM), a 24 hr ECG monitoring and a continuous BP recording over 15 minutes both in supine and standing positions, by using digital plethysmography (Finapres device). STATISTICAL ANALYSIS: non parametric tests. RESULTS: [table: see text] CONCLUSION: LVH is associated with a reduction in the markers of sympathetic activity and a decreased baroreflex sensitivity.

[Short term blood pressure variability and baroreflex sensitivity in mild and moderate hypertensive patients "dipper and non dipper"]. / Variabilité tensionnelle à court terme et sensibilité du baroréflexe chez l'hypertendu léger à modéré "dipper et non dipper".

AIM OF THE STUDY: To compare heart rate (HR) and blood pressure (BP) variability in hypertensive patients with or without a fall in BP during the night. METHODS: 33 mild to moderato hypertensive patients, mean age 45 +/- 15 years, underwent an echocardiogram, a 24-hr ambultory BP monitoring (ABPM), and a 24-hr ECG monitoring. In addition, a continuous BP recording over 15 minutes was performed between 9 and 11 a.m. both in supine and standing positions, by using digital plethysmography (Finapres device). STATISTICAL ANALYSIS: non parametric tests. RESULTS: [table: see text] CONCLUSION: In non dippers, morning BP and HR low-frequency oscillations are shifted to a lower level, as compared to dippers. This characteristic is associated with a reversed circadian pattern of sympathetic activity.

Drug-induced changes in ambulatory blood pressure and pulse pressure in patients with or without sustained hypertension.

We retrospectively studied 216 mild to moderate hypertensive patients receiving either an angiotensin converting enzyme inhibitor (ACEI) or a calcium antagonist (CA), as a once-a-day monotherapy; their blood pressure had been measured using both a sphygmomanometer and an ambulatory blood pressure recorder. Numerous discrepancies were found between the two methods of blood pressure measurement with respect to systolic blood pressure (SBP) and diastolic blood pressure (DBP), as well as pulse pressure (PP). Clinic blood pressure measurement did not show any significant differences between the effects of ACEI and those of CA, whereas ambulatory blood pressure measurements (ABPM) showed that in patients with normal ambulatory blood pressure (so-called 'white coat' hypertensive patients), ACEI only (but not CA) significantly lowered SBP, DBP and PP. Accordingly, a threshold of efficacy was sought: it appeared to be lower for ACEI than for CA (120/80 vs 140/85 mmHg). Furthermore, for a given degree of DBP lowering, SBP and PP were more lowered by ACEI than by CA, indicating a greater effect of ACEI on arterial compliance. Likewise, for a given level of mean blood pressure, SBP and PP were lower and DBP slightly higher in patients on ACEI than in those on CA. Our data are consistent with some recent papers, emphasizing a heightened activity of the renin-angiotensin system in 'white coat' hypertensive patients.

Comparison of the diagnostic accuracy of different methods of measurement of heart rate-adjusted ST-segment depression during exercise testing for identification of coronary artery disease.

Within a population of 160 consecutive symptomatic patients who all had undergone catheterization (80 with > or = 1 stenosis > or = 50%), we compared the accuracy of different computerized measurements of the exercise-induced changes in ST-segment: (1) the standard criterion (> or = 0.1 mV flat/downsloping ST depression or > or = 0.15 mV upsloping depression, both 60 ms after the J point); (2) heart rate (HR)-adjusted ST-segment depression (ST/HR index measured at 0, 20, 40, 60, and 80 ms from the J point); (3) the HR-adjusted ST integral (ST/HR integral measured from 0 to 40 ms and from 40 to 80 ms after the J point). None of the ST/HR indexes or integrals were found to have a significantly greater sensitivity than the standard criterion. On the contrary, all ST/HR indexes and integrals showed a higher specificity (0.78 to 0.89) than did the standard criterion (0.65); moreover, the earlier the measurement within the repolarization phase, the better the overall accuracy: 0.71 for the standard criterion, 0.83 (p < 0.001), 0.80 (p < 0.01), 0.78 (p < 0.02), 0.78 (p < 0.02), 0.74 (p = NS) for the ST/HR indexes at 0, 20, 40, 60, and 80 ms, respectively; 0.81 (p < 0.001) and 0.78 (p < 0.02) for the ST/HR integrals calculated from 0 to 40 and from 40 to 80 ms, respectively. Consistently, the receiver-operating characteristic curve areas of ST/HR at 0, 20, and 40 ms were greater than those of ST/HR at both 60 and 80 ms. These findings are divergent from some other results given in published reports. We conclude that the accuracy of all exercise criteria is influenced by the population analyzed: our patients were representative of those currently seen by clinicians.

[Regression towards the mean and repeated echocardiographic measurements of the left ventricular mass]. / Régression vers la moyenne et mesures échocardiographiques répétées de la masse ventriculaire gauche.

The selection of a group of patients based on a high value of a clinical or biological parameter leads to the finding of a tendency to a reduction of this value when remeasured, known as "regression towards the mean". The amplitude of this phenomenon is greater when the selected subjects are far from normal values and the intra-individual variability of the parameter under consideration is very high. Measurement of left ventricular mass is very affected by this statistical phenomenon. The authors undertook a prospective study to analyse the components of variability of repeated echocardiographic measurements of left ventricular mass and to quantify the expected effect of regression towards the mean in the follow-up of patients with left ventricular hypertrophy. Twenty-five randomly chosen subjects underwent 2 echocardiographic examinations at 2 week intervals: at each visit, the patient had two recordings and each recording was measured twice by the same "blinded" operator. Variance analysis showed intra-individual variability represented 30% of total variability, comprising only 2% for the measurements and 28% for the recordings and the visits. The importance of regression towards the mean was calculated with respect to the initial value of the left ventricular mass index: for example, when the left ventricular mass index was 150 g/m2, a spontaneous regression of 18 g/m2 can be expected at the next measurement. This phenomenon should be taken into consideration in the interpretation of longitudinal echocardiographic studies.

[Coronary artery disease in hypertensive patients: improvement of the diagnostic value of exercise test by heart rate adjusted ST segment depression]. / Insuffisance coronarienne de l'hypertendu: amélioration de la valeur diagnostique de l'épreuve d'effort par ajustement du sous-décalage de ST à la fréquence cardiaque.

UNLABELLED: Hypertensive patients complaining of chest pain often have a normal coronary angiogram despite a pathological exercise tolerance test. The aim of the present study was to establish whether the prevalence of these "false-positive" tests could be lowered by adjusting ST segment depression for exercise-induced increase in heart rate. METHODS: 60 hypertensive patients, mean age 59 years, with typical or atypical chest pain, underwent both a symptom-limited exercise test and a coronary angiogram within a median period of 1 day. The ST segment depression was measured every 20 ms from the J point. A stepwise discriminant analysis was performed: a canonical variable took into account the Detrano index, the quantified rate-recovery loop index (QRL index) as well as the presence of a LV hypertrophy (Romhilt Estes Score). RESULTS: [table: see text] CONCLUSION: in hypertensive patients with chest pain, the specificity and the positive predictive value of exercise test are significantly improved by adjusting ST segment depression for heart rate both during effort and recovery and by taking into account the score of Romhilt Estes on the baseline ECG recording.

Effect of regression to the mean in serial echocardiographic measurements of left ventricular mass. Quantification and clinical implications.

When a study sample is selected on the basis of an increased value of a given parameter, subsequent serial measurements are likely to show a decrease in this measured parameter, that is, the "regression to the mean." This statistical phenomenon undoubtedly affects the results of echocardiographic follow-up studies. Its magnitude is linked to that of the intraindividual variability of the measurements. Therefore, we undertook a prospective study aimed at assessing the different components of the variability of repeated measurements of left ventricular (LV) mass index. For this purpose, 25 consecutive patients underwent two echocardiograms 2 weeks apart. An analysis of variance for the nested design (random-effect model) was performed: inter- and intraindividual variabilities accounted for 70% and 30% of the total variability, respectively. Moreover, the contribution of the readings to the total variability did not exceed 2%, whereas the contribution of both recordings and time reached 28%. Further calculations allowed the expected magnitude of the regression to the mean to be quantified according to the baseline left ventricular mass index. For instance, when patients are selected on the basis of an increased LV mass index with a mean baseline value of 150 g/m2, a spontaneous decrease of 12% (related solely to the regression to the mean) has to be expected for the following measurement. Accordingly, the results of open uncontrolled echocardiographic follow-up studies should be reevaluated: an adjustment for the potential influence of the regression to the mean has to be done.

[Comparative effects of angiotensin converting enzyme inhibitors and calcium antagonists on pulse pressure and blood pressure variability, based on ambulatory measurements in 236 mild to moderate hypertensive patients]. / Effets comparés des inhibiteurs de l'enzyme de conversion et des inhibiteurs calciques sur la pression pulsée et la variabilité tensionnelle mesurées en ambulatoire chez 236 hypertendus légers à modérés.

OBJECTIVE: this retrospective study was aimed: at comparing the effects of angiotensin converting enzyme inhibitors (ACEI) and those of calcium antagonists (CA) on the pulse pressure of mild to moderate hypertensive patients; at assessing whether these effects were associated with some modifications of blood pressure variability or not. METHODS: the ambulatory blood pressure (ABP) recordings of 236 patients who previously entered clinical trials with a mean run-in placebo period of 2 weeks and a mean active treatment phase of 6 weeks (ACEI, n = 115; CA, n = 121) were reviewed. Baseline ABP has been analysed both as a continuous variable and as a categorical one (high when > 139/87 mmHg, low otherwise). Pulse pressure was calculated by the difference systolic ABP-diastolic ABP, whereas BP variability was estimated by the standard deviation and the variation coefficient of each recording. The results are given as percentage (mean +/- standard deviation). In the patients with high baseline systolic ABP, ACEI and CA did not significantly differ regarding their effects on pulse pressure (-11.1 +/- 17.2 vs -6.3 +/- 14.0, NS). By contrast, in the other patients, pulse pressure was lowered to a significantly greater degree by ACEI than by CA (-5.5 +/- 18.7 vs +1.8 +/- 18.8, p = 0.04). These differences were not related to baseline diastolic ABP. No difference at all was found with regard to BP variability which was altered by none of the drugs. In conclusion, pulse pressure, a reliable indicator of arterial compliance, seemed to be more decreased by ACEI than by CA, the difference being significant only in patients with apparent hypertension.

Comparison of angiotensin-converting enzyme inhibitors and calcium antagonists in the treatment of mild to moderate systemic hypertension, according to baseline ambulatory blood pressure level.

This study was aimed at determining whether baseline ambulatory blood pressure (BP) levels influence the efficacy of angiotensin-converting enzyme inhibitors and calcium antagonists in the same manner. Accordingly, the ambulatory BP recordings of 236 mild to moderate hypertensive patients who had previously entered a clinical trial and had received either a calcium antagonist (n = 121) or an angiotensin-converting enzyme inhibitor (n = 115) were reviewed. The inclusion criterion was a clinic diastolic BP between 95 and 115 mm Hg at the end of the placebo period. Patients were classified according to the difference between their observed and predicted ambulatory BP (the latter assessed by regressing the observed ambulatory BP on the clinic BP). Reduction in ambulatory systolic and diastolic BP seemed to be greater (p less than 0.0001, p = 0.01) in patients receiving an angiotensin-converting enzyme inhibitor than in those who were given a calcium antagonist. However, analysis of variance showed (1) there was a significant interaction (F = 6.37 p = 0.01) between the pharmacologic class and the baseline systolic ambulatory BP; and (2) the difference in diastolic ambulatory BP reduction between both classes was no longer significant when adjusted for baseline diastolic ambulatory BP. In patients with higher than predicted ambulatory BP levels, angiotensin-converting enzyme inhibitors and calcium antagonists had roughly a similar effect (reduction in systolic BP, 9 +/- 8% vs 7 +/- 6%, p = not significant; reduction in diastolic BP, 11 +/- 8% vs 8 +/- 6%, p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

[Contribution of sequential voluntary ambulatory monitoring in the diagnosis of arrhythmia. A multicenter study of 1287 symptomatic patients]. / Apport de l'enregistrement ambulatoire séquentiel volontaire à la détection des arythmies. Etude multicentrique sur 1,287 patients symptomatiques.

Voluntary sequential ambulatory recording is a diagnostic method of recording per-critical electrocardiographs in symptomatic patients with the aid of a portable solid-state technology recorder. In order to assess the value of this technique in the detection of arrhythmias, a multicenter study was performed in 1,287 symptomatic patients suspected of having paroxysmal arrhythmias (palpitations in 86.5% of cases). The quality of the sequential ambulatory recording was judged to be good in 54.9% and mediocre in 40.2% of cases: only 4.9% of recordings were uninterpretable. This technique allowed identification of a cardiac arrhythmia related to symptoms in 42.5% of the 1,091 cases which were analysed; sustained supraventricular tachycardia (11.7%), ventricular extrasystoles (14.9%) and simple sinus tachycardia (9.5%) were the principal abnormalities. The per-critical recording was negative in 57.5% of patients, suggesting a purely functional origin of symptoms in these cases. Atrial fibrillation was more common in hypertensive patients (11.3% vs 5.5% in normotensives, p less than 0.01) as were ventricular extrasystoles (23.1% vs 13% in normotensives, p less than 0.001). Voluntary sequential ambulatory recording seems to be a technique well adapted to the detection of symptomatic arrhythmias and a useful complement to Holter recording.

[Identification of overtreated hypertension with statistical analysis of 100 consecutive ambulatory blood pressure monitoring]. / Identification des hypertendus surtraités par analyse statistique de 100 enregistrements tensionnels ambulatoires consécutifs.

The data obtained from 100 consecutive ambulatory blood pressure (BP) recordings performed in treated hypertensive patients (60 men, 40 women, mean age 52 +/- 14 years) were analysed to make a choice between several possible definitions of overtreatment and to evaluate the prevalence of patients thus defined as overtreated. Recordings were studied over two periods: diurnal from 9 a.m. to 7 p.m. (100 patients, 37 +/- 5 measurements/patient), and nocturnal from 11 p.m. to 7 a.m. (98 patients, 19 +/- 2 measurements/patient). The patients were first classified on the basis of reference ambulatory BP values according to sex and age. Subnormal levels were found in 25 patients for diurnal SBP, 25 for nocturnal SBP, 13 for diurnal DBP and 33 for nocturnal DBP. Several criteria of overtreatment were then tested, based on the percentile method and on the number of subnormal values: the median DBP was below the 30th reference percentile in 16 patients, and the percentage of subnormal DBP values was above 80% in 18 patients. Clinically, there was little to differentiate these patients from the rest of the population treated. The goal of treatment which, in terms of BP values, is to normalize the ambulatory BP was therefore overshot in 1 out of 5 or 6 patients depending on the criteria adopted. The significance and consequences of overtreatment cannot yet be evaluated.

[Improvement of the diagnostic value of exercise test by heart-rate adjusted segment depression. Value of ST 20/HR index]. / Amélioration de la valeur diagnostique de l'épreuve d'effort par le sous-décalage du segment ST rapporté à la fréquence cardiaque. Intérêt de l'index ST 20/FC.

One of the new criteria of positivity of exercise stress testing proposed by Detrano and Kligfield is the ST/HR index, obtained by calculating the ratio of additional ST depression on exercise over the corresponding variation in the heart rate. These authors reported that this ratio improved the diagnostic value of the exercise stress test with respect to the traditional ST segment depression, but that the proportion depended on whether the index was measured 80 or 60 ms after the J point. The object of this study was to assess the diagnostic performance of the ST/HR index measured 0, 20, 40, 60 and 80 ms after the J point by automatic analysis and to compare these five diagnostic indices with the classical ST segment depression (standard criterion) by ROC graphs and the Mac Nemar test. One hundred consecutive patients (73 men and 27 women) all symptomatic, underwent submaximal or symptom-limited exercise stress testing and accepted coronary angiography. The prevalence of greater than or equal to 50% coronary stenosis on at least one main vessel was 48%. None had previous myocardial infarction. The ROC graphs and areas under the curve demonstrated generally the superiority of the ST/HR index over the standard criteria. The optimal diagnostic performance was observed when the index was calculated 20 ms after the J point (ST 20/HR index).(ABSTRACT TRUNCATED AT 250 WORDS)

[Average level and variability of 24 hour blood pressure in the normotensive insulin-dependent diabetic patient]. / Niveau moyen et variabilité de la pression artérielle des 24 heures chez le diabétique insulinodépendant normotendu.

This prospective study was designed: 1. to determine both the mean level and the intrinsic variability of blood pressure (BP) and heart rate (HR) in normotensive patients with insulin-dependent diabetes mellitus (IDDM), by using a nonambulatory recorder; 2. to look for a relationship between these parameters and the indices of diabetic target-organ damage. The patient group consisted of 21 subjects with IDDM (6 females, 15 males), aged 19 to 70 years, who were normotensive according to WHO criteria. The duration of the diabetics ranged from 1.5 to 32 years. A control group of 17 age and sex-matched normal volunteers was also examined. Each subject underwent a 24 h non ambulatory BP recording, a 2-dimensional echocardiography and a pulsed doppler examination; furthermore, an index of autonomic nervous system dysfunction was established, as well as an index of microangiopathy. Twenty-four hour BP and HR mean levels appeared to be slightly higher in IDDM patients than in control group, but the difference was significant for night SBP and 24 h DBP only. No difference was found with regard to BP and HR absolute variabilities; the relative variability of night DBP was slightly lower in IDDM group (p less than 0.05). A loss of nocturnal decline in BP was noted in 2 control subjects and in 9 IDDM patients: 8 out of these IDDM patients had an autonomic dysfunction. An abnormal HR circadian pattern was seen in 1 control and in 2 IDDM subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

[Relaxation and diastolic filling of the left ventricle]. / Relaxation et remplissage diastolique du ventricule gauche.

The cardiac cycle, as revisited by modern authors, consists of 3 fundamental phases: contraction, which includes isovolumic contraction and first part of ejection; relaxation which begins with left ventricular peak pressure, continues with second part of ejection and isovolumic relaxation, and ends together with ventricular rapid filling (i.e. as filling rate has decreased by 50 p. cent); finally compliance or slow filling which lasts until atrial systole. The LV diastolic dysfunction refers to filling abnormalities which are related to either relaxation abnormalities or compliance troubles or both. The mechanisms of these abnormalities are biochemical (deficiency in cyclic AMP resulting in calcium handling dysregulation) and mechanical: right ventricular filling, pericardial restraint, coronary arteries perfusion, myocardial inertial forces, myocardial visco-elastic properties, ventricular wall elasticity (depending itself on its thickness and its collagen content). The methods of analysis of LV filling are: left ventriculography, gamma angiography, digitized M-Mode echography and, mainly, Doppler echocardiography. This technique allows 2 types of mitral flow abnormalities to be distinguished: 1) the abnormal relaxation which combines an increased isovolumic relaxation time, an increased deceleration time and a diminished E/A ratio, but this pattern may be "normalized" by an increase in filling pressure; 2) the restriction to filling which results in an increased E/A ratio, a diminished deceleration time and, sometimes, a diastolic mitral regurgitation. The effects of drugs on LV diastolic function are difficult to assess: a beneficial result may be due either to a direct effect on the myocardium or to an improvement in load conditions, heart rate or contractility.

[Critical analysis of the response to antihypertensive therapy. Report of 102 cases]. / Analyse critique de la réponse aux traitements antihypertenseurs. A propos de 102 cas.

UNLABELLED: One hundred and two patients with mild to moderate hypertension, non responding to a placebo therapy, were given an antihypertensive drug for a mean period of 6 weeks (range: 3-12 weeks). Their blood pressure (BP) was measured before and after active treatment by both a mercury manometer at the clinic and an ambulatory apparatus (Spacelabs 5200 or 90202). The clinic BP figures were poorly correlated with the 24 hour ambulatory BP levels, as well as the magnitude of decrease in clinic BP with the reduction in ambulatory BP. Twenty eight patients who were considered as "clinic responders" had in fact not significantly lowered their ambulatory DBP and, conversely, 16 patients were "clinic non responders" whereas they were "ambulatory responders". The patients were divided into 2 groups, according to White's and Morgan Roth's recommendations: group I (n = 61) with a percentage of pathological DBP readings (greater than 90 mmHg) during daytime as high as 50% or more, and group II (n = 41) with a percentage less than 50%. The correlations between the 2 methods of BP measurement were closer within the group I than within the group II and the rate of discrepancies between the "clinic" and "ambulatory responders" was lower. On the other hand, we identified the group II patients as being often "clinic responders" but rarely "ambulatory responders", whereas the inverse trend was observed in the group I. IN CONCLUSION: even in non placebo responding hypertensive patients the clinic BP measurement might be not sufficient for proper evaluation of an antihypertensive drug.(ABSTRACT TRUNCATED AT 250 WORDS)