Diurnal variation of endothelial function and arterial stiffness in hypertension.

The onset of cardiovascular events presents a circadian variation that may be mediated by similar temporal patterns of vascular function. Blood pressure also follows circadian variation. We investigated the possible diurnal variation of endothelial function and arterial stiffness in patients with hypertension. Thirty-five individuals with recently diagnosed hypertension (mean age 48.3 years, range 30-60 years, 14 men) were examined. Flow-mediated vasodilatation (FMD), nitrate-mediated vasodilatation (NMD) and carotid-femoral (cf) pulse wave velocity (PWV) were measured at three different occasions: at 0700 hours immediately after awaking, at 1200 hours and at 2100 hours. FMD was markedly lower in the morning (0700 hours, 2.22+/-1.58%; 1200 hours, 4.37+/-2.25%; 2100 hours, 4.28+/-2.12%; P<0.001), whereas NMD was similar at the same time points. This difference remained significant after adjustment for baseline brachial artery diameter and reactive hyperaemia. PWVcf progressively increased from morning to evening (0700 hours, 9.8+/-1.9 m s(-1); 1200 hours, 10.2+/-2.2 m s(-1); 0900 hours, 10.5+/-1.9 m s(-1); P=0.013 for linear trend). Similar temporal patterns were observed in systolic and diastolic blood pressures peaking in the evening. PWVcf changes lost significance after adjustment for changes in mean blood pressure. Endothelial function is decreased in the early morning in hypertensive patients, whereas arterial stiffness is increased in the evening. Changes in BP-dependent passive artery distension may be involved in this phenomenon.

Impact of cardiac transplantation in 24 hours circadian blood pressure and heart rate profile.

OBJECTIVE: The aim of the present study was to evaluate 24 hours blood pressure (BP) and heart rate changes as well as 24-hour circadian BP rhythm of cardiac transplant recipients. METHODS: Twenty-five transplant recipients and twenty-five healthy volunteers underwent 24-hour ambulatory BP monitoring. Parameters of 24-hour ambulatory BP monitoring (24-h/daytime/nightime systolic, diastolic BP, pulse pressure, and heart rate) were determined in all patients. RESULTS: Clinic systolic/diastolic BP, mean 24-h systolic/diastolic BP, mean daytime systolic/diastolic BP, mean nighttime systolic/diastolic BP, and mean 24-h/daytime/nighttime heart rate were significantly higher in transplant recipients than in control group subjects. Standard deviations of 24-h/daytime/nighttime heart rates were significantly lower in transplant recipients. Dippers were 48% of the control and only 12% of the transplantation group. CONCLUSIONS: Cardiac transplant recipients had increased ambulatory BP. They also had increased 24-h/daytime/nighttime heart rate and decreased heart rate variability. Also, diminished nocturnal decrease of BP was found in transplant recipients.

Systemic sclerosis is not associated with clinical or ambulatory blood pressure.

BACKGROUND: Raynaud's phenomenon is often the first symptom and occurs eventually in more than 95% of patients with systemic sclerosis (SSc). Angiographic studies disclose narrowing and obstruction of the digital arteries, which on autopsy histologic study show prominent subintimal connective tissue proliferation without inflammation, as well as adventitial fibrosis. It is also known that primary cardiac problems include pericarditis, left ventricular or biventricular failure, serious supraventricular or ventricular arrhythmias emerge in patients with SSc. It is not known if these patients present hypertension or hypotension and which parameter of the ambulatory blood pressure may influence such a disease course. METHODS: A total of 85 subjects underwent clinical blood pressure (BP) readings, 24-hour ambulatory BP monitoring, left ventricular assessment by echocardiography and measurement of intima media thickness (IMT) of the right-left internal carotid arteries (RICA and LICA) and right-left common carotid arteries (RCCA and LCCA). The population consisted of 40 subjects with SSc according to the criteria of the American College of Rheumatology (SCL-group) who were not receiving any antihypertensive treatment and 45 healthy volunteers (control group). The two groups did not differ in age. RESULTS: Clinical systolic and diastolic blood pressure, clinical heart rate, mean 24 h systolic blood pressure, SD systolic blood pressure, mean 24 h diastolic blood pressure, SD 24 h diastolic blood pressure, mean 24 h heart rate, SD 24 h heart rate, pulse pressure 24 h, serum glucose, cholesterol, triglycerides, HDL, LDL, creatinine, urea, potassium and natrium did not statistically significant differ between the two groups. Furthermore, the left ventricular mass/BSA and IMT of both carotid arteries did not show a statistically significant difference between the groups. CONCLUSION: Systemic sclerosis is not associated with clinical blood pressure or the parameter of 24 h blood pressure monitoring.

Increased prevalence of Chlamydophila pneumoniae but not Epstein-Barr antibodies in essential hypertensives.

Conflicting data exist regarding the relationship between Chlamydophila pneunoniae (C. pneumoniae) and hypertension. In this study, both C. pneumoniae IgG and IgA titres and Epstein-Barr virus antibody levels were measured in 146 sustained hypertensives defined by 24 h ambulatory blood pressure monitoring (ABPM) and 54 normotensives. C. pneumoniae antibodies were measured by microimmunofluorescence test. IgG > or = 80 and IgA > or = 40 were defined as elevated antibody titres. Epstein-Barr antibodies were measured in order to investigate whether a possible association exists between hypertension and other, similarly widespread in the general population, intracellular microorganisms. All participants underwent casual blood pressure (BP) readings and 24 h ABPM. Subjects having mean 24 h systolic/diastolic ambulatory BP>125/80 mmHg, with or without antihypertensive medication were defined as hypertensives. Controls were free of any history or clinical evidence of hypertension, cardiovascular or pulmonary disease. Of the total participants, 77 hypertensives (52.7%) and 10 normotensives (18.5%) had IgA titres > or = 40 (crosstabs P < 0.000), whereas 76 hypertensives (52.1%) and 15 normotensives (27.8%) had IgG titres > or = 80, (crosstabs P < 0.002). No difference was found in Epstein-Barr antibodies, between hypertensives and normotensives. In conclusion, C. pneumoniae, but not Epstein-Barr, antibody levels were found significantly higher in sustained hypertensives, suggesting high frequency of chronic C. pneumoniae, infections in this specific group of patients.

Pulse pressure in normotensives: a marker of cardiovascular disease.

The purpose of the present study was to evaluate the relation of the systemic arterial pulse pressure and other parameters derived from the 24-h arterial blood pressure (BP) monitoring to the severity of coronary artery disease, carotid lesions, and left ventricular (LV) mass index in patients without arterial hypertension. One hundred ten patients with known coronary artery disease underwent coronary arteriography, 24-h arterial BP monitoring, and ultrasound imaging of the carotid arteries and the myocardium. Measurements of 24-h arterial BP monitoring (systolic, diastolic, and average BP, pulse pressure, abnormal values of systolic and diastolic BP, and heart rate), the severity of coronary heart disease (Gensini score), intima-media thickness (IMT) of the common carotid artery and LV mass index were determined in all patients. By univariate analysis, only 24-h pulse pressure was significantly related to the severity of coronary artery disease (P < .01), carotid IMT(P < .01), and LV mass index (P < .01). In a multivariate analysis, 24-h pulse pressure was also the best predictor of the severity of coronary lesions (P = .009), carotid IMT (P = .003), and LV mass index (P = .009). Gensini score was related (P < .01) to LV mass index and not to carotid IMT. In conclusion, systemic arterial pulse pressure derived from 24-h arterial BP monitoring is related to coronary artery disease, carotid IMT, and LV mass index independently of age or any other derivative of 24-h arterial BP monitoring, indicating that this parameter could be a marker of global cardiovascular risk.

Reproducibility of ambulatory blood pressure measurements in essential hypertension.

BACKGROUND: Data on the reproducibility of serial measurements of ambulatory blood pressure in hypertensive patients are lacking. The purpose of this study was to examine (1) the reproducibility of four consecutive ambulatory blood pressure measurements, and (2) the reproducibility of nocturnal falls in blood pressure in hypertensive patients. METHODS: Twenty patients with mild to moderate essential hypertension underwent four separate ambulatory blood pressure monitorings, on the same day of the week, at 30-day intervals. Antihypertensive therapy was discontinued for 2 weeks before each recording. Comparing the mean values of blood pressure over 24h, as well as diurnal, nocturnal and hourly periods, among the four recordings determined the reproducibility of blood pressure measurements. A day/night difference in mean systolic and in mean diastolic blood pressure defined the nocturnal fall in blood pressure. RESULTS: No significant differences were observed in either hourly, 24-h, diurnal or nocturnal systolic blood pressure, diastolic blood pressure and heart rate, or in the nocturnal fall in systolic and diastolic blood pressure among the four recordings. CONCLUSIONS: Hourly systolic blood pressure, diastolic blood pressure, heart rate, and nocturnal fall in blood pressure were reproducible in four ambulatory blood pressure monitorings recorded over 4 months. These findings suggest that ambulatory blood pressure monitoring is a reliable tool to monitor blood pressure changes.

The Athens stroke registry: results of a five-year hospital-based study.

The advent and wide application of new technology, especially noninvasive techniques, has enabled physicians to more completely investigate and clarify the etiopathogenic mechanisms of stroke. Such data have not been available until recently for Southeastern Europe. In addition, during the last decades, strategies for the modification of risk factors and primary prevention may have changed the prevalence of each subgroup of stroke as well. We investigated 1, 042 consecutive patients who had first strokes, during a period of 5 years (from June 1992 to May 1997) and classified them prospectively based on etiopathogenic mechanisms. Patients with transient ischemic attacks and subarachnoid hemorrhage were excluded. There were 613 male and 429 female patients, with a mean age of 70.2 +/- 11.9 years. Forty-six percent of the patients arrived within 3 h from stroke onset. The probable mechanisms were: large-artery atherosclerosis, 156 (15%); lacunes, 177 (17%); cardioembolic, 335 (32.1%); infarct of unknown cause, 182 (17.5%); miscellaneous causes, 35 (3.3%), and intracerebral hemorrhage (ICH), 157 (15.1%). In the cardioembolic group, nonvalvular atrial fibrillation (NVAF) was the probable cause in 225 patients, especially in patients older than 75 years (65%). The overall hospital mortality was 15.2% (from 0.6% for lacunar stroke to 34% for ICH). In our population, cardioembolism is the most frequent subtype of stroke. NVAF is the most likely source, especially in older patients.

A pressure-time index' for assessing the severity of essential hypertension.

OBJECTIVE: A new derivative of 24 h ambulatory blood pressure monitoring (ABPM) is introduced and its association with left ventricular mass index (LVMI) in essential hypertension is examined. PATIENT: population One hundred and fifty-three previously untreated essential hypertension patients. METHODS: Patients underwent casual blood pressure (BP) readings, 24 h ABPM and left ventricular echocardiographic assessment The following 24 h awake and sleep ABP variables were calculated: mean systolic and diastolic BP, systolic and diastolic BP loads (percentage of systolic readings > 140/120 mmHg (day/ night) and diastolic readings > 90/80 mmHg (day/night)), standard deviation of systolic and diastolic ABP and nocturnal fall of systolic BP, as well as the integrated areas under the ABP curve. The area under the BP curve divided in horizontal slices was accurately modelled by a sigmoid curve. The parameters controlling the shape of the curve and in particular that regarding its 'slope' is hereafter called the 'pressure-time index'. RESULTS: 'Systolic pressure-time index 24 h' (SPTI24) is related to left ventricular mass index (multivariate analysis, P= 0.008). Using either partial correlation coefficients or a multivariate analysis, SPTI24 is related to left ventricular mass index, independently of age, casual blood pressure, mean systolic and diastolic ABP, systolic and diastolic BP loads, BP variability (standard deviation (SD), nocturnal fall of systolic BP) and integrated area under the curve (multivariate analysis, P= 0.004). CONCLUSIONS: In essential hypertension, the SPTI24 is related to LVMI independently of age, casual blood pressure, integrated area under the curve or any other derivative of 24 h ABPM, and might be used to assess the extent of hypertensive load.

Treating severe cardiogenic shock by large counterpulsation volumes.

BACKGROUND: Intraaortic balloon pumping is known to be ineffective in severe cardiogenic shock. The efficacy of balloon volumes larger than those commonly used is examined. METHODS: In 18 dogs with severe experimental cardiogenic shock (systolic aortic pressure < 60 mm Hg, aortic flow < 45 mL.min-1.kg-1) the effect of three intraaortic balloon volumes (15, 30, and 45 mL) and a 60-mL paraaortic pump was examined. RESULTS: The 45-mL balloon covering the full length of the aorta induced the highest (+ 12.4 +/- 2.2 mL.min-1.kg-1; mean +/- standard error of the mean) and the 15-mL balloon the lowest increase in aortic flow (F = 14.6, p < 0.0001). Only the 45-mL balloon increased (p < 0.05) urine output and renal artery flow. The 60-mL paraaortic pump induced the highest (F = 10.72, p < 0.002) increase (+ 36.6 +/- 6.5 mL.min-1.kg-1) in aortic flow compared to the three balloons. An 80- to 100-mL paraaortic pump maintained the life of 3 patients in severe cardiogenic shock for 4 hours, 8 days, and 54 days, whereas a 40-mL conventional balloon was completely ineffective. CONCLUSIONS: Experimental and clinical data indicate that the effectiveness of intraaortic balloon pumping in severe cardiogenic shock may be improved by increasing the volume of the balloon (i.e., until it fully occupies the aorta).

Left intraventricular balloon pump optimization during intractable cardiac arrest.

This work aims to determine optimal balloon shape and volume during left intraventricular balloon pumping (IABP) in the fibrillating dog heart. A balloon volume equal to the left ventricular end-diastolic volume (LVEDV) maintained a higher systolic aortic pressure and flow (106.4 +/- 2.7 mmHg and 84.7 +/- 2.35 ml/kg/min, x +/- SEM, respectively) than a 25% smaller (97.8 +/- 3.3 mmHg, P = 0.002 and 63.7 +/- 4.1 ml/kg/min, P = 0.002, respectively) or a 25% larger balloon (87.4 +/- 2.3 mmHg, P = 0.002 and 70.9 +/- 3.4 ml/kg/min, P = 0.002, respectively). Among 5 different balloon shapes tested, a pear-shaped balloon inflated from the apex to the base of the left ventricle induced the highest (P varying from 0.042 to 0.01, compared to the remaining balloon shapes) systolic aortic pressure and flow (104.6 +/- 4.5 mmHg and 77.9 +/- 1.7 mg/kg/min, respectively). In conclusion, a pear shaped balloon, inflated to a volume equal to the LVEDV, from the apex to the base of the left ventricle, induced an optimal hemodynamic effect during LVBP.

Effect of 24-hour blood pressure and heart rate variations on left ventricular hypertrophy and dilatation in essential hypertension.

This study correlates variables derived from blood pressure (BP) and heart rate (HR) monitoring with the degree of left ventricular structural changes in essential hypertension. Forty patients with mild-to-moderate hypertension according to World Health Organization criteria underwent 24-hour ambulatory monitoring. Echocardiographic (posterior wall and interventricular septum thickness, left ventricular mass) or ECG (SV1 + RV5) indices of hypertrophy were significantly (p less than 0.01) correlated (positive correlations) with derivatives of BP monitoring (mean systolic and diastolic BP values) but not with HR derivatives. Echocardiographic indices of dilatation (left ventricular end-diastolic volume and diameter) were significantly (p less than 0.01 to less than 0.001) correlated (negative correlations) with derivatives of HR monitoring (mean HR values, mainly during the night) but not with BP derivatives. It is concluded that in essential hypertension, left ventricular hypertrophy depends on mean 24-hour systolic and diastolic BP values, whereas left ventricular dilatation appears to be more prominent in patients with bradycardia mainly during the night.