Wolfgang Schulte

Sodium intake modulates left ventricular hypertrophy in essential hypertension.

In order to assess the impact of dietary sodium intake on the degree of left ventricular hypertrophy, we determined posterior wall thickness, relative wall thickness and left ventricular mass by two-dimensionally guided M-mode echocardiography, and related these parameters to sodium excretion over 24 h. There was no restriction on sodium intake. The first cohort comprised 43 subjects (residents of New Orleans) with mild to moderate essential hypertension who had not been treated for at least 4 weeks; in this cohort sodium excretion correlated with posterior wall thickness (r = 0.64, P < 0.001), relative wall thickness (r = 0.67, P < 0.001) and left ventricular mass (r = 0.37, P < 0.02). A stepwise multiple regression analysis confirmed that sodium excretion was a determinant of posterior wall thickness (P < 0.02) and relative wall thickness (P < 0.05) independently of age, arterial pressure and body weight. The second cohort comprised 60 white male patients (residents of Bonn) with mild essential hypertension who had never been treated in the past; in this cohort sodium excretion correlated with diastolic diameter (r = 0.36, P < 0.001) and with left ventricular mass (r = 0.35, P < 0.001). Sodium excretion and systolic pressure emerged as independent variables (P < 0.02) for left ventricular mass as evaluated by multiple regression analysis. These results identify dietary sodium intake as an independent powerful determinant of left ventricular hypertrophy in two disparate patient cohorts. Thus, for a similar haemodynamic load, sodium intake might accelerate, and conversely salt restriction mitigate, cardiac structural adaptation in patients with essential hypertension.

Zur reaktion der fingerpulsamplitude auf belärmung

Summary1.Forty-three (30 male and 13 female) subjects were exposed to traffic noise of ca. 72 dB. Their reactions concerning blood pressure, pulse pressure, finger pulse amplitude and radialis pulse amplitude, heart rate, breathing rate, and integrated EMG were analyzed.2.Each of the circulatory parameters exhibited significant reactions in either direction in more than 40% of the subjects. The vasoconstrictive reaction in finger pulse amplitude was most outstanding. Moreover, pulse pressure, radialis pulse amplitude and, heart rate also tended to decrease whereas diastolic blood pressure tended to increase. Breathing rate and EMG remained mainly unchanged.3.Owing to the different direction of reactions the mean values of a sample can yield possibly misleading information. Furthermore, it is suggested that the reaction of finger pulse amplitude should be related to the standard deviation of the prestimulus resting period instead of to the mean value of this period.4.Male subjects react with a stronger decrease of heart rate than female subjects. Male subjects with higher diastolic casual blood pressure and heart rate values exhibit stronger decreases in finger pulse amplitude and heart rate. Older male subjects tend to react with an increase of heart rate.5.Within the male subjects, the reaction of finger pulse amplitude correlated positively with the reactions of pulse pressure and heart rate, but not with the reaction of radialis pulse amplitude. The attempt to distinguish between vasoactive and pressure-dependent components in finger pulse amplitude means of radialis pulse amplitude failed, which is probably a consequence of artifacts in radialis pulse amplitude.6.These results confirm the hypotheses that compensatory mechanisms influence the reactions caused by noise. There is no essential increase in blood pressure, sympathetic and parasympathetic activity being simultaneously increased.Zusammenfassung1.Dreiundvierzig Versuchspersonen (30 Männer und 13 Frauen) wurden mit Verkehrslärm von ca. 72 dB (A) belastet. Ihre Reaktionen in Blutdruck, Blutdruck-, Fingerpuls- und Radialispulsamplitude, Herzfrequenz, Atemfrequenz and Myointegral wurden untersucht.2.Jeder Kreislaufparameter zeigte in über 40% der Versuchspersonen signifikante Reaktionen in unterschiedlicher Richtung. Am deutlichsten war dabei ein Trend der Fingerpulsamplitude zur Verengung erkennbar. Blut druck- und Radialispulsamplitude sowie Herzfrequenz neigten ebenfalls zum Abfall, der diastolische Blutdruck zum Anstieg. Demgegenüber blieben Atemfrequenz und Myointegral weitgehend unverändert.3.Die unterschiedliche Richtung der Reaktionen läßt Mittelwertbildungen im Kollektiv als potentiell irreführend erscheinen. Weiterhin wird vorgeschlagen, die Fingerpulsreaktion auf die Standardabweichung der Vorruhe statt auf den Mittelwert der Vorruhe zu beziehen.4.Männer reagieren mit stärkeren Herzfrequenzabfällen als Frauen. Innerhalb der Männer zeigten Fingerpulsamplitude und Herzfrequenz bei erhöhten diastolischen Gelegenheitsblutdruckwerten und -herzfrequenzen stär kere Abnahmen. Ältere Männer reagieren eher mit Herzfrequenzanstiegen.5.Innerhalb der Männer korrelierte die Fingerpulsamplitude positiv mit der Reaktion von Blutdruckamplitude und Herzfrequenz, nicht aber mit der der Radialispulsamplitude. Der Versuch, mit Hilfe der Radialispulsamplitude vasoaktive und druckpassive Anteile der Fingerpulsamplitude zu trennen, zeigte keine befriedigenden Ergebnisse. Ursache ist vermutlich eine starke Artefaktanfälligkeit der Radial ispulsamplitude.6.Die dargestellten Ergebnisse stützen die Hypothese, daß Gegenregulationen die Reaktionen auf Dauerlärm beeinflussen. Bei gleichzeitiger sympathischer und parasympathischer Erregung kommt es zu keiner nennenswerten Blutdruckerhöhung.1. Forty-three (30 male and 13 female) subjects were exposed to traffic noise of ca. 72dB. Their reactions concerning blood pressure, pulse pressure, finger pulse amplitude and radialis pulse amplitude, heart rate, breathing rate, and integrated EMG were analyzed. 2. Each of the circulatory parameters exhibited significant reactions in either direction in more than 40% of the subjects. The vasoconstrictive reaction in finger pulse amplitude was most outstanding. Moreover, pulse pressure, radioalis pulse amplitude and, heart rate also tended to decrease whereas diastolic blood pressure tended to increase. Breathing rate and EMG remained mainly unchanged. 3. Owing to the different direction of reactions the mean values of a sample can yield possible misleading information. Furthermore, it is suggested that the reaction of finger pulse amplitude should be related to the standard deviation of the prestimulus resting period instead of to the mean value of this period. 4. Male subjects react with a stronger decrease of heart rate than female subjects. Male subjects with higher diastolic casual blood pressure and heart rate values exhibit stronger decreases in finger pulse amplitude and heart rate. Older male subjects tend to react with an increase of heart rate. 5. Within the male subjects, the reaction of finger pulse amplitude correlated positively with the reactions of pulse pressure and heart rate, but not with the reaction of radialis pulse amplitude. The attempt to distinguish between vasoactive and pressure-dependent components in finger pulse amplitude means of radialis pulse amplitude failed, which is probably a consequence of artifacts in radialis pulse amplitude.

Efficacy of four antihypertensive drugs (clonidine, enalapril, nitrendipine, oxprenolol) on stress blood pressure

The impact of 4 antihypertensive drug regimens on blood pressure (BP) during everyday life stress and on BP during experimental stress in the laboratory was examined in an open clinical study. Sixty middle-aged men with mild-to-moderate essential hypertension never previously treated were treated either with low-dose clonidine (n = 10), oxprenolol (n = 20), nitrendipine (n = 20) or enalapril (n = 10). Before therapy, all 4 groups did not differ in age, weight, degree of obesity, BP at work site and casual BP measured in the outpatient clinic. After 6 months of effective therapy (casual BP within the normotensive range), casual diastolic BP was identical among the 4 groups, whereas systolic BP was lower in patients treated with clonidine or oxprenolol than in those who received enalapril. A disparate pattern of antihypertensive efficacy among the 4 groups emerged when stress BP was compared, with average ambulatory BP higher in patients receiving clonidine or enalapril than in those who had oxprenolol or nitrendipine. During ambulatory BP monitoring, patients treated with oxprenolol had the lowest level at each level of physical activity and self-reported emotional arousal. During bicycle exercise, patients receiving clonidine had the highest increase in systolic BP and those administered oxprenolol the lowest, whereas the BP response during mental stress was similar among all 4 therapeutic groups. The analysis of the hemodynamic response pattern during mental stress unmasked further disparities. Oxprenolol provoked an abnormal hemodynamic response during mental stress tests (increase in total peripheral resistance), whereas nitrendipine and enalapril preserved the physiological hemodynamic profile (decrease of total peripheral resistance).(ABSTRACT TRUNCATED AT 250 WORDS)

Traffic noise and hypertension: An epidemiological study on the role of subjective reactions

SummaryTraffic noise is discussed as a possible risk factor for hypertension. However, no data are available concerning the moderating effect of the subjective reactions and the noise attitudes. In the present epidemiological study the relationship between these subjective factors and blood pressure was investigated separately for the inhabitants of two residential areas. One area had high traffic volumes, resulting in a high sound level (Leq > 73 db (A), noisy area); the other was socially comparable but with an essentially low sound level (Leq < 51 db (A), control area). The relationship between the subjective reactions and blood pressure was checked by analyzing the incidence of treatment for hypertension (n =919) and by analyzing the change of casual blood pressure after living 2.25 years in the respective residential area in a subgroup of those who had been normotensive (n = 36).The results obtained by either of these approaches indicate that the subjective factors do not modify the risk of hypertension in noisy areas, whereas they seem to be relevant for medium size stimuli. It is concluded that one can physiologically cope with low stimuli, but this is impossible for extreme stimuli. The results suggest also that the subjective reaction to extreme stimuli is strongly biased by attitudes which cannot be related to blood pressure. The family history of hypertension was found to be independent of the subjective reactions to noise.

Renal hemodynamics and cardiovascular reactivity in the prehypertensive stage.

To examine whether sympathetic nervous activation has an impact on renal circulation in subjects at risk for high blood pressure, we assessed renal hemodynamics and cardiovascular response to mental stress in 40 healthy young white males, 12 normotensive subjects without and 14 with familial hypertension, and 14 with borderline hypertension. The response of systolic and diastolic blood pressure to mental stress was assessed while each patient performed a mental arithmetic task; this was taken as the parameter for the activation of the sympathetic nervous system. Renal plasma flow was measured by para-aminohippuric acid clearance under steady-state conditions. In parallel, glomerular filtration rate as a parameter for functional impairment of the kidneys was determined by creatinine clearance, and filtration fraction was also calculated. Patients with borderline hypertension were characterized by a reduced renal blood flow and increased filtration fraction in comparison with both normotensive groups. The increase in systolic blood pressure during mental stress was more pronounced in borderline hypertensives. We observed no significant difference in renal hemodynamics and cardiovascular response to mental stress between normotensives with and without a family history of hypertension. In the total population, cardiovascular response to mental stress was correlated with renal hemodynamics: The greater the increase in systolic blood pressure during mental stress, the lower was the renal plasma flow and the greater the filtration fraction. Thus, renal plasma flow was found to be already reduced and filtration fraction increased before sustained hypertension developed. Because this pattern in renal hemodynamics was related to cardiovascular response to mental stress, our data suggest that sympathetic activation already appeared to affect renal hemodynamics at the onset of essential hypertension.

Efficacy of Long-Term Antihypertensive Therapy with Enalapril

We examined whether long-term antihypertensive monotherapy with enalapril decreased clinical casual blood pressure (BP) as well as BP at work and during stress, and whether this angiotensin-converting enzyme (ACE) inhibitor had an adverse effect on the physiologic hemodynamic pattern during experimental mental stress. Seventeen male patients with hitherto untreated mild-to-moderate essential hypertension (mean age: 47 +/- 8 years) had 24-hour BP monitored noninvasively with the Physioport system before and during treatment with enalapril (5-10 mg/day) for 6 months. They also had a mental stress test, physical exercise test, and the cold pressor test before and after therapy. After the diagnostic observation period, average clinical casual BP was 150 +/- 12/102 +/- 7 mg Hg. Average BP at work, stress BP during all types of stimulation in the laboratory, and clinical casual BP significantly decreased during monotherapy with enalapril. Neither the circadian rhythm nor the hemodynamic pattern during mental stress was significantly altered by enalapril. BP increases during emotional stress were not significantly attenuated by the ACE inhibitor. These results demonstrated that enalapril effectively lowers BP without altering the physiologic hemodynamic pattern during emotional stress.