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R Zulli

Publications and source records attributed to R Zulli.

25 records · Page 2Linked to original sources
PubMed1993

Effect of antihypertensive treatment on daytime and nighttime power spectral analysis of heart rate.

Power spectral analysis of heart rate may provide useful information about cardiac neural activity. The aim of this study was to evaluate cardiac sympathetic and parasympathetic activity, as assessed by power spectral analysis of heart rate, in hypertensive patients before and after antihypertensive treatment. In 14 hypertensive patients and in 7 normotensive subjects 24 h Holter electrocardiogram monitoring was performed under basal conditions and after 6 months of treatment with nifedipine (n = 7) or enalapril (n = 7). Sequences of 512 RR intervals were taken for the evaluation of power spectral analysis (autoregressive method); absolute and normalized power spectral density of the peak at 0.10 Hz (low frequency peak: LF) and at 0.25 Hz (high frequency peak: HF), as well as their ratio (index of sympatovagal interaction: SVI) were calculated. Under basal conditions SVI was significantly decreased from daytime to nighttime in normotensives, while no change was observed in hypertensive patients. In all hypertensive patients a reduction of SVI during nighttime in respect to basal values was observed after treatment. SVI during nighttime was significantly reduced with both nifedipine and enalapril, while SVI during daytime was slightly increased during nifedipine treatment, and significantly reduced during enalapril treatment. Systolic and diastolic arterial pressure as well as left ventricular mass index were significantly reduced with both treatments. In conclusion, long term treatment with nifedipine or enalapril seems to be able to restore an impaired daytime to nighttime SVI modulation in hypertensive patients, even considering the potential limitations of power spectral analysis of heart rate.

Adult↗
PubMed1992

Relationship between initial cardiovascular structural changes and daytime and nighttime blood pressure monitoring.

It has been shown that in hypertensive patients the degree of target organ damage correlates more closely with average blood pressure as recorded by ambulatory monitoring (ABPM) throughout 24 h than with clinic blood pressure. We examined a group of 91 clinically healthy subjects, 23 normotensives and 68 hypertensives according to clinic blood pressure. Cardiac anatomy was investigated by echocardiography. As an index of arterial structural changes forearm minimal vascular resistance was calculated from mean arterial pressure and maximal postischemic blood flow, as assessed by venous occlusion plethysmography. The results were correlated to clinic blood pressure or ABPM values (measured by noninvasive ABPM ICR 5200, Spacelabs, Bellevue, CA). Left ventricular mass was correlated more closely with the average blood pressure recorded during 24 h, or during daytime or nighttime periods, than with clinic blood pressure. Minimal vascular resistance was also significantly correlated to ABPM values, but the correlation was similar to that observed with clinic blood pressure. Minimal vascular resistance was significantly correlated to blood pressure variability, as evaluated by the standard deviation of the mean. Minimal vascular resistance and left ventricular mass were higher in a subgroup of patients in whom blood pressure was not significantly reduced during the night. The results of this study confirm that elevated average ABPM values are associated to higher left ventricular mass; in addition, they suggest that increased blood pressure variability may be associated with vascular structural changes, as evaluated by minimal vascular resistance. It remains to be clarified whether cardiac hypertrophy and/or vascular structural changes are a cause or consequence of increased blood pressure values and variability.

Adult↗
PubMed1992

Reduction of left ventricular hypertrophy after longterm antihypertensive treatment with doxazosin.

The aim of this study was to evaluate the effect of antihypertensive treatment with doxazosin on left ventricular anatomy and function. Therefore, after 4 weeks of washout with placebo (phase 1), doxazosin (dosage range from 1 to 16 mg, plus hydrochlorothiazide when necessary) was given to 11 essential hypertensive patients (6 M, 5 F, age range 34-63 years) for 8 weeks (phase 2) in order to achieve diastolic blood pressure values less than 90 mmHg; this dosage was then maintained for a further 20 weeks up to the end of the study (phase 3). Blood pressure was significantly reduced (Anova P less than 0.05), while heart rate did not change. A significant reduction of left ventricular mass index (from 128.5 +/- 26 to 114 +/- 23 g/m2, at the end of phase 1 and 3 respectively, P less than .001)) was observed. Before and during treatment left ventricular systolic function, both at rest and during stress (handgrip and cold pressor tests), evaluated by fractional shortening as related to end-systolic stress, in every case within 95% confidence limits, was calculated in normal subjects. Diastolic function, as evaluated by the ratio between peak early and atrial velocities of transmitral flow examined by pulsed doppler was significantly improved. Plasma catecholamine concentrations, plasma renin activity and plasma aldosterone did not change. A significant reduction of plasma cholesterol concentration was observed. These results confirm that doxazosin is a well tolerated and effective antihypertensive drug, with a favourable effect on blood lipids and they indicate that its longterm administration can induce a significant reduction of left ventricular mass.

Adrenergic alpha-Antagonists↗
PubMed1990

[Clinical usefulness of non-invasive automatic monitoring of arterial blood pressure].

Recently, new devices for ambulatory blood pressure monitoring have been developed, which have become widely used as highly reliable diagnostic tools. It is now necessary to establish the rationale for their use, and to fully elucidate the diagnostic, prognostic and therapeutic advantages for their use in hypertensive patients. Average 24-hour blood pressure is more closely correlated with the degree of structural cardiovascular alterations than casual blood pressure measurements. Non-invasive blood pressure monitoring therefore seems to be more useful, from a prognostic point of view, than traditional, sphygmomanometric measurement. There is some evidence that ambulatory blood pressure monitoring is more reliable than casual measurements in assessing the efficacy of antihypertensive therapy. From a diagnostic point of view, the significance of blood pressure values obtained with these devices, and the most appropriate index to evaluate the 24-hour blood pressure load remain to be clarified. It is necessary to identify new normal limits for monitored blood pressure values i.e. to establish the baseline level for the start of treatment. At present, due to the lack of widely accepted upper limits of monitored blood pressure, the therapeutic decision should be based on casual blood pressure values, obtained with traditional mercury sphygmomanometer.

Blood Pressure↗