La velocidad de onda de pulso, el QKd y la monitorización ambulatoria de presión arterial como indicadores de riesgo vascular en un grupo de pacientes sometidos a diálisis peritoneal continua ambulatoria / Pulse wave velocity, QKd and ambulatory blood pressure monitoring as vascular risk indicators in a group of patients submitted to continuous ambulatory peritoneal dialysis

Introducción, material y métodos. En un intento de estudiar los factores de riesgo cardiovascular en un grupo de 22 pacientes sometidos a diálisis peritoneal continua ambulatoria (DPCA) se practicó en todos una monitorización ambulatoria de la presión arterial (MAPA) de 24 h, junto con la medición del QKd y velocidad de onda de pulso (VOP). Resultados. Como grupo estos pacientes tienen unas presión arterial (PA) diurna normal: PA sistólica (PAS)/PA diastólica (PAD): 126,8 ñ 17,3/80,2 ñ 10,8 mmHg, pero sin variación en el período nocturno: 120,3 ñ 24,7/76,2 ñ 13,2 mmHg; p : no significativa (NS), presentando un patrón no-dipper, lo cual es un factor de riesgo cardiovascular. La VOP se correlaciona con otros parámetros también propios del riesgo cardiovascular, como son: la edad, r = 0,59, p < 0,006. La PP diurna, r = 0,50, p < 0,003, nocturna y 24 h. Positivamente con la variabilidad de la PAS nocturna, r = 0,60, p < 0,005 y variabilidad de la presión diferencial (PP) nocturna, r = 0,56, p < 0,01 y negativamente con las diferencias día/noche de la PAS, r = -0,55, p < 0,009 y la PAD, r = -0,64, p < 0,003. Por otro lado, el QKd nocturno mantiene una correlación negativa con la VOP, r = -0,64, p < 0,009. La QKd y la variabilidad del PP diurno tienen una correlación positiva, r = 0,52, p < 0,02. Entre QKd de 24 h y la frecuencia cardíaca (FC) 24 h se establece una correlación negativa: r = -0,50, p < 0,02.Conclusiones. Los valores de la VOP son mayores que los valores controles de referencia, no así el QKd, que no varía significativamente de sus controles (100;60). En este estudio la VOP nos da más información que el QKd. Ambos definen una serie de correlaciones inherentes al daño cardiovascular. (AU)

[Study of the clinically useful interval in ambulatory monitoring of blood pressure]. / Estudio del intervalo clínicamente útil para monitorizar la presión arterial ambulatoria.

BACKGROUND: Ambulatory blood pressure monitoring (ABPM) throughout 24 hours has been introduced for clinical practice, improving the diagnosis and treatment of hypertension. However, there is not an agreement concerning how often the blood pressure have to be measured. SUBJECTS AND METHODS: An ABPM was performed in 29 normotensive and hypertensive subjects (16-73 years) throughout 24 hours recording the blood pressure every 15 minutes. The average of systolic and diastolic blood pressure of the diurnal and nocturnal periods of the interval of 15 minutes, were compared with the two intervals of 30 minutes and the four of 60 minutes, according to Bland and Altman method. RESULTS: Between 90% and 100% of the differences of the interval 15 minutes versus 30 minutes, and 15 minutes versus 60 minutes, were within +2 and -2 standard deviation of the mean. However, only between 95% and 100% of the difference of the intervals 15 minutes versus 30 minutes were within the limits of agreement for systolic and diastolic blood pressure in the nocturnal period. CONCLUSIONS: A clinical satisfactory information using ABPM can be obtained monitoring the blood pressure every 15 minutes during the day and 30 minutes at night.

[The evaluation of a noninvasive monitor to record ambulatory arterial pressure: the DIASYS 200 Novacor]. / Validación de un monitor no invasivo de registro de presión arterial ambulatoria: el DIASYS 200 Novacor.

BACKGROUND: The aim of this study was to validate the measurement precision of the portable automatic non invasive monitor of blood pressure-Novacor DIASYS 200. METHODS: A mercury sphygmomanometer was used as the reference measurer. To validate the DIASYS 87 persons (45 males, 42 females--age range 17-76 years) with a systolic blood pressure between 90-225 mmHg and diastolic blood pressure of between 64-149 mmHg were selected. RESULTS: The differences between the two apparatus were: systolic blood pressure 6.1 +/- 12.2 mmHg (r = 0.909); diastolic blood pressure -1.9 +/- 6.8 mmHg (r = 0.929) and cardiac frequency -2.0 +/- 6.3 ppm (r = 0.942). In healthy subjects of under 31 years of age (n = 20) the differences for systolic and diastolic blood pressure and cardiac frequency were 0.2 +/- 8.0 mmHg; -1.3 +/- 5.8 mmHg and -0.1 +/- 8.0 ppm, respectively. For subjects over the age of 59 years (n = 29) the measurements were 9.2 +/- 12.0 mmHg, 2.5 +/- 6.0 mmHg, -1.5 +/- 4.4 ppm, respectively. With the sample subdivided according to blood pressure the differences found in the normotensive subgroup (n = 23) were: -1.7 +/- 7.8 mmHg, -2. +/- 4.9 mmHg, and -2.4 +/- 7.9 ppm, respectively; in the subgroup with slightly high blood pressure (n = 40) 6.4 +/- 14.0 mmHg, -2.8 +/- 6.0 mmHg and -2.3 +/- 5.1 ppm, and in the subgroup with moderate-severe high blood pressure (n = 24) 10.4 +/- 10.9 mmHg, 0.2 +/- 9.1 mmHg and -0.9 +/- 6.5 ppm, respectively. CONCLUSIONS: The DIASYS fulfills the criteria of validation and precision for the measurement of diastolic blood pressure and cardiac frequency in all the cases. However criteria for systolic blood pressure are only fulfilled in normotensive and young subjects (less than 31 years of age).

[A clinical study of the verapamil and captopril combination in hypertensive patients uncontrolled by monotherapy. An evaluation by recording the 24-hour ambulatory blood pressure]. / Estudio clínico de la asociación verapamilo y captopril en pacientes hipertensos no controlados con monoterapia. Valoración mediante el registro de presión arterial ambulatoria durante 24 horas.

BACKGROUND: By measuring ambulatory blood pressure monitoring (ABPM), the pharmacologic association of verapamil plus captopril in essential hypertensive patients not responding to isolated monotherapy of these drugs was studied since a synergism has been described between these two drugs. METHODS: A lineal clinical trial with a previous period of selection (PeSe) in which verapamil and captopril were administered in two consecutive phases was carried out in 57 essential hypertensive patients of 52 +/- 19 years of age with those controlling their blood pressure (BP) being excluded. Following a lavage phase the remaining subjects were included in the experimental period (ExPe) in wash out the association of verapamil 120 mg+captopril 25 mg was administered and if the BP was not controlled this was increased to 240 mg + 50 mg, respectively. ABPM was performed prior to and at the end of the ExPe. RESULTS: Of the 57 patients 21 were excluded in the SePe due to control or adverse effects. Of the 26 individuals who passed into the ExPe 20 presented mild-moderate HTA (M-HTA) and 6 severe HTA (S-HTA). In the M-HTA group, the reduction of BP (in mmHg) was 157 +/- 15/106 +/- 5 to 147 +/- 12/97 +/- 7 (p < 0.05/p < 0.001), five controlled BP, in the remaining subjects the reduction in the following phase was 150 +/- 11/100 +/- 6 at 136 +/- 11/93 +/- 6 (p < 0.01/p < 0.01). In the S-HTA group the BP descended in the ExPe from 184 +/- 15/121 +/- 6 to 167 +/- 24/107 +/- 10 (p < 0.05/p < 0.05). The 24 hour measurement of BP in the ExPe decreased from 140 +/- 13/96 +/- 8 to 124 +/- 10/86 +/- 7 (p < 0.001/p < 0.001). BP descended significantly in all the hours with the exception of the hours 24, 1, 6, 7, and 5. CONCLUSIONS: The association of verapamil-captopril demonstrates efficacy and synergism in hypertensive patients previously uncontrolled by monotherapy of these drugs.

White coat hypertension and related phenomena. A clinical approach.

In this paper, several clinical problems associated with the diagnosis of hypertension are discussed. Blood pressure variability and reactivity are factors underlying the difficulties in the diagnosis of hypertension. These phenomena are interrelated and mixed. White coat hypertension (WCH), referring to the phenomenon of a high diastolic pressure at the doctor's office and a normal diurnal diastolic pressure when it is measured by ambulatory monitoring, is the most important clinical problem of diagnosis. Blood pressure variability is described, since it is essential to understand changes in pressure throughout the day, and its phasic and tonic components. Blood pressure differences between activity and rest, usually seen as daytime/night-time differences, allow for blood pressure control in most patients with moderate hypertension. Prevalence of WCH depends on the cut-off point used by the investigators for normal diurnal blood pressure; thus, between 53% and 12% of patients may have WCH. In our studies, a prevalence of 35% has been found. The alert reaction, labile and borderline hypertension and WCH result from a mix of both variability and reactivity, and patients with these conditions are at a higher cardiovascular risk than normotensive controls. Ambulatory blood pressure monitoring, which enables true hypertensives to be distinguished from false hypertensives, is the most useful technique available to date for the diagnosis of hypertension.

[Day-night differences of arterial pressure in "white coat" arterial hypertension]. / Diferencias día-noche de presión arterial en la hipertensión arterial de "bata blanca".

Prevalence and day-night differences of blood pressure (BP) are studied in "White Coat" Hypertension (AHT). An outpatient register of BP was performed during 24 hours in 95 patients with mild AHT. "White Coat" Hypertension was defined when diastolic BP during the day was below 90 mmHg (WCH group) and with no "White Coat" Hypertension (non-WCH) when it was over said figure. BP values for WCH group (n = 36) in comparison with non-WCH (n = 59) were: Day period 130 +/- 13/85 +/- 4 versus 143 +/- 14/99 +/- 7 mmHg (p < 0.001; p < 0.001). Night period 119 +/- 18/74 +/- 8 versus 127 +/- 15/84 +/- 8 mmHg (p < 0.05/p < 0.001). Day-night differences in BP were lower in WCH in comparison with non-WCH group: 11 +/- 9/11 +/- 8 versus 17 +/- 10/15 +/- 7 mmHg (p < 0.01; p < 0.01). A positive correlation was observed between BP variability in 24 hours and day-night difference in non-WCH group (Systolic BP: r = 0.512, p < 0.001; Diastolic BP: r = 0.676, p < 0.001). This correlation was not found in the WCH group. "White Coat" Hypertension is present in 38% of the subjects with mild AHT and could constitute an independent aspect of the alert reaction.

[Validation of a model of an automatic device for the ambulatory monitoring of blood pressure: the Spacelab 5200]. / Validación de un modelo de aparato automático de registro de la presión arterial ambulatoria: el Spacelabs 5200.

BACKGROUND: The aim of this study was to test two of the same models of portable automatic devices for monitoring blood pressure over 24 hours. These devices were the Spacelabs 5200 (Kontron 1 and Kontron 2). METHODS: A mercury shygmomanometer was used as reference measurer. To validate Kontron 1, 22 persons (10 males and 12 females) of 45 +/- 12 years of age were selected. For Kontron 2, 25 subjects (12 males and 13 females) of 44 +/- 17 years of age were chosen. RESULTS: The results expressed as arithmetic mean and standard deviation were (manual vs Kontron 1); systolic blood pressure (SBP) 139 +/- 19 mmHg vs 135 +/- 16 mmHg, p less than 0.05; diastolic (DBP) 96 +/- 12 mmHg vs 93 +/- 12 mmHg, p less than 0.05, heart rate (HR) 77 +/- 13 ppm vs 76 +/- 14 ppm, NS. The correlation between the two methods was: SBP r = 0.870; DBP r = 0.875 and HR r = 0.949. The results of Kontron 2 were: SBP 137 +/- 17 mmHg vs 130 +/- 15 mmHg, p less than 0.05; DBP 93 +/- 11 mmHg vs 94 +/- 11 mmHg, NS; HR 75 +/- 10 ppm vs 73 +/- 12 ppm, NS. The correlations were: SBPr = 0.820; DBP r = 0.877 and HR r = 0.847. CONCLUSIONS: The Spacelabs 5200 automatic blood pressure monitoring underestimates systolic blood pressure while diastolic blood pressure and heart rate are reliable according to international norms.

[Casual arterial pressure versus ambulatory continuous monitoring of arterial pressure]. / Presión arterial casual frente a registro continuo de presión arterial ambulatoria.

Ambulatory continuous blood pressure monitorization (ACBPM) has shown that casual blood pressure (CBP) obtained at the Doctors' office is accompanied by alarm reaction (AR) which could overestimate the true blood pressure. We placed a ACBPM (24 hours) in 190 subjects (35 normotense and 155 hypertense). In normotense subjects the CBP was 137 +/- 19/84 +/- 9 mmHg and the mean value in those 24 hours was 121 +/- 11/74 +/- 6 mmHg (p less than 0.001) while in hypertense patients it was 159 +/- 22/104 +/- 11 mmHg versus 139 +/- 17/95 +/- 9 mmHg (p less than 0.001). According to the WHO classification the number of normotense and hypertense subjects varies according to wether we recommend CBP or the mean daily ACBPM. Normotense: 37 versus 53, borderline, arterial hypertension: 22 versus 26, mild arterial hypertension: 52 versus 65, moderate arterial hypertension: 54 versus 38, severe arterial hypertension: 25 versus 8 (p less than 0.005). It is therefore observed that ACBPM offers lower blood pressure values that CBP.

[Variability of arterial pressure and of heart rate in essential arterial hypertension]. / Variabilidad de la presión arterial y de la frecuencia cardíaca en la hipertensión arterial esencial.

BACKGROUND: Blood pressure (BP) and heart rate (HR) show multiple oscillations. The aim of the present study was to evaluate their variability by means of a noninvasive device for the continuous recording of ambulatory BP. METHODS: A 24 hour recording was programmed (minimal interval 30 minutes) in 190 individuals: 35 normotensive individuals aged 46 +/- 20 years and 155 patients with essential hypertension aged 49 +/- 12 years. RESULTS: In the whole population a significant positive correlation was found between systolic BP (SBP) and its variability (r = 0.360; p less than 0.001). This correlation was found for both normotensive (r = 0.506; p less than 0.01) and hypertensive (r = 0.384; p less than 0.001) groups. There also was significant positive correlation between HR and its variability in the overall population (r = 0.374; p less than 0.001) and in the normotensive (r = 0.594; p less than 0.001) and hypertensive (r = 0.356; p less than 0.001) groups. There was a significant positive correlation between SBP and age in the whole population (r = 0.269; p less than 0.001) and in the normotensive (r = 0.448; p less than 0.001) and hypertensive (r = 0.193; p less than 0.05) groups. When the individuals were divided in those older than 65 years and those younger than 60 years, with same levels of SBP and DBP, it was found that the variability (given as standard deviation) of both SBP and DBP were higher in the older group (similar SBP: 19 +/- 7/13 +/- 4 mmHg vs 15 +/- 4/11 +/- 3 mmHg, p less than 0.01/p less than 0.01; similar DBP: 19 +/- 7/13 +/- 4 mmHg vs 15 +/- 5/11 +/- 3 mmHg, p less than 0.001/p less than 0.01). Multiple regression analysis showed that the most important determinant of this variability was the baseline SBP value, followed by age. CONCLUSIONS: SBP and HR show a greater variability with higher baseline values. The variability of both SBP and DBP are greater in elderly patients.

[The continuous recording of ambulatory arterial pressure. The value of monitoring 4-hour subperiods]. / Registro continuo de presión arterial ambulatoria. Valor de la monitorización de subperíodos de cuatro horas.

The ambulatory continuous arterial pressure monitoring permits a more exact definition of the degree of arterial hypertension. A ACMPA was performed in 86 subjects, 64 hypertensive and 22 normotensive controls during a daytime period of 16 hour with a noninvasive device. The results were compared to those obtained in the four four-hour subperiods. The correlation of each subperiod with the global studied period was: r = 0.915; subperiod 16-19 hours, r = 0.933; subperiod 20-23 hours, r = 0.924. It was observed that in any four-hour subperiod was quite similar to the mean value of the whole period. We conclude that in those cases in which it is not possible to perform a 24 hour ACMAP or during the whole daytime, a short four-hour monitoring is valid.

Pharmacodynamic effects of a single 10-mg dose of the angiotensin converting enzyme inhibitor ramipril in patients with impaired renal function.

A single oral 10-mg dose of ramipril, a long-acting angiotensin converting enzyme (ACE) inhibitor, was given to 24 hypertensive patients with different degrees of renal function. Creatinine clearance ranged from below 15 ml/min (n = 9) to above 80 ml/min (n = 3). Serial blood samples were taken for the determination of ACE activity, plasma renin activity (PRA), aldosterone (ALDO), angiotensin II (AT II), and serum creatinine (CR). Blood pressure was also monitored before and after medication. After administration of ramipril systolic and diastolic blood pressure (BP) fell; the decreases were unrelated to renal function. Peak BP-lowering effect was seen at 6 h basal, 174 +/- 19.5/102.6 +/- 8.9 to 149.8 +/- 19.7/87.6 +/- 13.3 mm Hg (mean +/- SD; p less than 0.001). ACE inhibition occurred within 2 h, being maximal at 4 h: basal, 82.6 +/- 17.9 to 0.2 +/- 0.6 nmol/ml/min (p less than 0.001). The greater the renal impairment, the longer the ACE inhibition. Angiotensin II was reduced maximally at 10 h after dosing, from 10.4 +/- 5.4 to 6.2 +/- 3.6 pg/ml (p less than 0.01). Aldosterone also fell from 212 +/- 188.4 to 134 +/- 73.3 pg/ml at 6 h (p less than 0.01). Plasma creatinine was unchanged: 401.3 +/- 315.7 to 394.9 +/- 306.1 nmol/L (NS). Ramipril, given as a single oral dose, lowers BP in hypertensives with both normal and impaired renal function, inhibits ACE activity, and causes no change in serum creatinine.

Steady-state kinetics of ramipril in renal failure.

In an open trial, the pharmacokinetics of ramipril and its active metabolite ramiprilat were studied in 23 hypertensive patients with various degrees of renal insufficiency. During a 2-week treatment period, each subject took daily a 5-mg tablet of ramipril. Serum profiles and urinary excretion of the parent compound and ramiprilat, the active metabolite, were then evaluated. Peak concentrations of ramipril were slightly greater in patients with severe renal insufficiency; however, most of the ramipril was metabolized in the liver. The drug concentration-time curve was almost independent of renal function and no accumulation was observed after multiple dosing. In contrast, ramiprilat kinetics were significantly influenced by renal function. Initial apparent half-lives (8-16 h), mean trough concentrations (5-19 ng/ml), and absolute accumulation all increased with worsening renal function, and renal clearance of ramiprilat was significantly correlated with creatinine clearance. The subsequent long terminal phase at low ramiprilat serum concentration represents the slow dissociation of the angiotensin converting enzyme (ACE)-bound drug. This study indicates that in patients with severe renal insufficiency (creatinine clearance below 30 ml/min), smaller doses of ramipril will be required than in patients with normal or borderline normal renal function.

Therapeutic efficacy and tolerance of ramipril in hypertensive patients with renal failure.

In an open trial, the antihypertensive and hormonal effects of ramipril, a new nonsulfhydryl angiotensin converting enzyme (ACE) inhibitor, were studied in 23 hypertensive patients with various degrees of renal failure: group I, creatinine clearance 5-15 ml/min, n = 10; group II, creatinine clearance 15-40 ml/min, n = 7; group III, creatinine clearance 40-80 ml/min, n = 6. In a 2-week placebo run-in period, antihypertensive agents were reduced or discontinued. During the treatment phase, patients received a 5-mg tablet of ramipril once daily for a period of 2 weeks. Concomitant medication remained unchanged. In all groups, ramipril significantly decreased mean arterial blood pressure. Blood pressure response was not different in the three groups, although plasma ramipril levels were higher in patients with severe renal failure. In patients with high plasma renin activity (PRA), reduction of blood pressure was greater than in subjects with low PRA. Plasma ACE activity was suppressed to less than 20% of its initial value in all groups during the whole treatment period, and the suppression was more marked and lasted longer in patients with severe renal failure. A strong correlation between the plasma ramiprilat levels and the inhibition of plasma ACE activity was noted for all groups. Mean serum creatinine did not increase significantly; serum potassium levels rose from 4.5 to 4.9 mmol/L on day 14 (p less than 0.01). In conclusion, in patients with various degrees of renal failure, ramipril represents an effective and well-tolerated antihypertensive agent.(ABSTRACT TRUNCATED AT 250 WORDS)

Small kidney and hypertension: selection of patients for surgery.

We studied 37 patients with various degrees of hypertension and a small unilateral kidney. Renal vein renin studies were shown to be positive on 19 occasions and negative on 18. Of those positive, 10 had severe and 1 moderate hypertension. Surgery cured 63.3%. In 27% blood pressure improved and 1 patient failed to respond. Eight patients had mild hypertension with a positive renal vein renin ratio (RVRR), but on observation their home blood pressures were normal without medication and they were not considered for surgery. Eighteen patients with mild hypertension and negative RVRR were also not operated. We believe that RVRR is important for a surgical decision, but only in severe and moderate hypertensives. In mild hypertension, measurement of blood pressure at home is normal on most occasions. These are hyperreactive patients and should not have surgery, regardless of the results of their RVRRs.