Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Systole”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 667 records · Page 37Linked to original sources
PubMed1989

Compilation of regression equations employing the RR interval for the correction of systolic time interval measurements for heart rate in sheep.

The aim of this study was to determine the validity of regression equations relating RR interval and heart rate to systolic time intervals in sheep. Regression equations were compiled employing the RR interval to correct systolic time intervals for heart rate in six Merino ewes. A range of heart rates was obtained by means of pharmacological intervention as well as electrical pacing. Heart rate did not affect the pre-ejection period, isovolumetric contraction time, the pre-ejection period to left ventricular ejection time ratio, the ratio QS2/QT, electrical delay (Q1), or the PR interval. Heart rate did, however, affect the duration of electromechanical systole (QS2), left ventricular ejection time and mechanical systole (S1S2). The study showed that it was preferable to correct the systolic time intervals using the RR interval rather than the heart rate. Bazett's equation to correct electrical systole (QT) for heart rate in humans was also validated in sheep.

Animals↗
PubMed1993

Aortic distensibility and left ventricular structure and function in isolated systolic hypertension.

Aortic mechanical properties were assessed in a group of elderly subjects with untreated isolated systolic hypertension using two-dimensional echocardiography. Echocardiographic (two-dimensional and Doppler) assessment of left ventricular structure and function was also made. Ten subjects (mean age 71.7 +/- 1.9 years, 20% male, mean clinic blood pressure 163.6/79.2 +/- 1.2/2.0 mmHg) were compared with 16 normotensive subjects of similar age (69.4 +/- 1.6 years, 38% male, mean clinic blood pressure 129.8/78.2 +/- 3.2/2.9 mmHg). Aortic distensibility at the level of the transverse aortic arch was significantly reduced among subjects with isolated systolic hypertension. The thickness of the interventricular septum was approximately 20% greater in the hypertensive subjects (P < 0.01) and the average wall thickness to radius ratio was increased by 30%. Patterns of transmitral diastolic flow were also different in subjects with isolated systolic hypertension. Deceleration time was significantly greater (P < 0.01) and the ratio of early to late transmitral diastolic peak flow velocities was significantly less in the hypertensive (P < 0.05) than in the normotensive group. Left ventricular systolic function was well preserved. These findings are consistent with the suggestion that isolated systolic hypertension represents a state of increased aortic stiffness which may contribute to the development of left ventricular hypertrophy. Whether this increase in aortic stiffness is the cause or effect of the elevated systolic blood pressure remains unresolved.

Aged↗
PubMed1995

Plasma atrial natriuretic peptide is related to systolic but not diastolic myocardial function. Determination by echocardiography 24 h after myocardial infarction.

The relationship between plasma ANP and systolic and diastolic left ventricular myocardial function, as determined by echocardiography, was investigated. Thirty-one patients were examined 24 h after onset of acute myocardial infarction. The systolic parameters measured were: wall motion index (WMI), ejection fraction, systolic volume index and diastolic volume index. Diastolic function was evaluated by mitral flow analysis and isovolumic relaxation time. The following parameters were measured in the mitral flow: peak velocity of early flow, peak velocity of atrial flow, the earlylatrial ratio, deceleration rate of the early flow and atrial filling fraction. A blood sample was drawn from each patient for ANP analysis at the same time as the echocardiographic examination. A correlation between plasma-ANP and systolic function was found (ejection fraction: r = -0.60, P < 0.001; systolic volume index: r = 0.68, P < 0.001; diastolic volume index: r = 0.47, P < 0.01; WMI: r = -0.42, P < 0.05) whereas no correlation was found between any of the diastolic parameters and plasma ANP (P > 0.10 for all the variables). We conclude that there is a significant correlation between plasma ANP and systolic function, as evaluated by echocardiography 24 h after AMI, whereas there was no corresponding relationship between plasma ANP and diastolic function.

Adult↗
PubMed1984

Isolated systolic hypertension and its relationship to the risk of myocardial infarction, cerebrovascular disease and death in a middle-aged population.

The prevalence of hypertension in general and of those complications associated with isolated systolic hypertension (at least 165 mmHg systolic and less than 95 mmHg diastolic pressure) were assessed in a random sample of 3888 men and 4336 women aged 30-59 years at the beginning of the study. The prevalence of isolated systolic hypertension was about 5% both in men and women aged 30 to 49 years; in those aged 50 to 59 years the prevalence was 7% in men and 13% in women. Systolic hypertension was associated with an increased risk of acute myocardial infarction (AMI), cerebrovascular stroke and death both in men and women in the seven-year follow-up period. The relative risk of AMI in men and women with isolated systolic hypertension was 1.65 (P less than 0.05) and 0.87, respectively, and the relative risk of stroke 0.57 and 1.29, respectively. Isolated systolic hypertension is not uncommon in the middle-aged population and its impact on cardiovascular complications seems to be significant not only on the elderly but also in the middle-aged.

Adult↗
PubMed1983

Systolic pressure amplification in pedal arteries in children.

Sphygmomanometric indirect blood pressure readings on the arm were compared to direct blood pressure readings from the radial and pedal arteries in pediatric patients. The direct systolic pressure in the pedal arteries was significantly (p less than 0.001) greater (25.1 +/- 12.3 mm Hg) than the indirect arm systolic pressure. The direct systolic pressure from the radial artery was identical to the indirect systolic arm pressure. Although there were no statistical differences between direct and indirect diastolic pressures, correlations for diastolic pressures were relatively poor. These data indicate that (1) there is a significant and unpredictable amplification of systolic pressure in the pedal arteries which may result in erroneous diagnosis of hypertension or jeopardize early detection of circulatory shock, (2) indirect blood pressure measurement with the recommended cuff width (125% of arm diameter or 40% of arm circumference) accurately reflects direct systolic pressure in the radial artery, and (3) indirect blood pressure measurement gives a relatively poor prediction of direct diastolic pressures.

Adolescent↗
PubMed1991

Systolic and diastolic time intervals in the critically ill patient.

OBJECTIVE: The waveform of the first derivative of thoracic electrical bioimpedance was used to calculate systolic time intervals of the cardiac cycle, preejection period/left ventricular ejection time ratio, and diastolic time intervals, isovolumic relaxation period/filling time ratio. DESIGN: Prospective clinical study. Waveforms were examined from 913 normal and abnormal tracings from a thoracic electrical bioimpedance monitor. This monitor was coupled to a two-channel strip-chart recorder that identified preejection period/LV ejection time and isovolumic relaxation period/filling time in 86% of the tracings. SETTING: Two university-affiliated hospitals and one community hospital. PATIENTS: We assessed 100 subjects (ranging in age from 17 to 93 yrs) under various conditions. MEASUREMENTS AND MAIN RESULTS: Data from 15 normal subjects were used as a reference series to define normative values. Preejection period/left ventricular ejection time ratio was 0.35 +/- 0.1 (SD) and was consistent with data from systolic time intervals derived from simultaneous study of the ECG recording, carotid artery tracing, and phonocardiography. The diastolic time ratio (isovolumic relaxation period/filling time) was 0.4 +/- 0.2, in agreement with normal values derived by echocardiography and angiography. In a subgroup of 17 critically ill patients, a correlative study of simultaneously measured thoracic electrical bioimpedance, nuclear stethoscope, and radionuclide ventriculography was conducted. Systolic functions were compared by the ejection fraction derived by preejection period/left ventricular ejection time ratio displayed on the thoracic electrical bioimpedance monitor and by the radionuclide technique, and were found to be 57 +/- 13.8% and 58 +/- 8.6%, respectively (r2 = .49; y = 4.06x + 0.94; p less than .02; n = 17). Increased diastolic time ratios with normal or near-normal systolic time intervals were documented in nine (53%) of 17 critically ill patients with low systolic index. CONCLUSION: Both systolic and diastolic time intervals can be investigated noninvasively at the bedside by the thoracic electrical bioimpedance technique to provide a better understanding of left heart function.

Adolescent↗
PubMed1996

Arterial alterations in hypertension with a disproportionate increase in systolic over diastolic blood pressure.

BACKGROUND: Although systolic and diastolic blood pressure and cardiovascular risk are directly related in epidemiologic studies, the results of large therapeutic trials in mild to moderate hypertension have indicated that the prevention of cerebrovascular accidents was much more effective than that of coronary ischemic accidents. Actually, a significant decrease in coronary events was observed only in aged populations in which systolic (and not diastolic) blood pressure was chosen as criterion of entry. Whether the choice of the mechanical factor (systolic or diastolic blood pressure or both) used to define hypertension might have created a bias in the studied populations remains an important question. FINDINGS: Above 50 years of age, most hypertensive populations are characterized by a disproportionate increase in systolic over diastolic blood pressure, so that the pulsatile component of blood pressure is strikingly augmented. This pattern is commonly observed in old people with essential hypertension, in hypertensive subjects with advanced renal failure undergoing hemodialysis and in atherosclerotic subjects with hypertension, particularly those with atherosclerosis of the lower limbs and cerebral vessels. In all these populations, the disturbed pulse pressure is associated with significant alterations in large conduit arteries involving hypertrophy of central and peripheral large vessels and increased values of operational stiffness and altered wave reflections which return during the systolic (and not the diastolic) component of the aortic blood pressure curve. Sodium sensitivity is commonly observed in these patients, so that low doses of diuretics correct the increased pulse pressure, particularly in those with normal or low plasma renin activity. CONCLUSIONS: Although strong interactions may be observed between the pulsatile component of blood pressure and the arterial changes in hypertension, much more research is required before a clear-cut cause-effect relationship can be established between these two variables. With the exception of diuretic therapy in the elderly, there are at present no treatments that can selectively reduce pulse pressure or reverse the arterial changes or both in patients with essential hypertension and a disproportionate increase in systolic blood pressure.

Arteries↗
PubMed2000

Sympathetic and reflex alterations in systo-diastolic and systolic hypertension of the elderly.

BACKGROUND: Previous studies have shown that young and middle-aged essential hypertensives are characterized by a sympathetic activation coupled with an impaired baroreflex-heart rate control. The present study aimed to determine whether these neuroadrenergic and reflex alterations also characterize systo-diastolic and systolic hypertension of the elderly. SUBJECTS AND METHODS: In 20 untreated elderly essential hypertensive subjects [10 with a systo-diastolic and 10 with an isolated systolic hypertension, aged 67.2 +/- 1.5 years and 66.9 +/- 1.7 years (mean +/- SEM)], we measured beat-to-beat arterial blood pressure (finger photoplethysmographic device), heart rate (electrocardiogram) and efferent postganglionic muscle sympathetic nerve activity (microneurography) at rest and during baroreceptor stimulation and deactivation induced by stepwise intravenous infusions of phenylephrine and nitroprusside, respectively. Data were compared with those obtained in 11 age-matched normotensive control subjects. RESULTS: Compared to the elderly normotensive group, muscle sympathetic nerve activity was increased to a similar degree in the group of systo-diastolic and systolic hypertension (50.8 +/- 4.2 versus 75.2 +/- 5.2 and 70.4 +/- 5.1 bursts per 100 heart beats, respectively, P< 0.01 for both). In the control group, the stepwise increase in arterial pressure induced by phenylephrine caused progressive bradycardia and sympathoinhibition, while the stepwise decrease in arterial pressure had opposite effects. While baroreceptor-heart rate control was markedly impaired (average reduction 41.6%), in both systo-diastolic and systolic hypertensive patients, baroreceptor modulation of sympathetic nerve traffic was similar to that seen in normotensive individuals. CONCLUSIONS: These data demonstrate that sympathetic activation is not only a feature of young and middle-aged, but also of elderly hypertensives, regardless of whether both systolic and diastolic or only systolic blood pressure is increased. They also show that hypertension of the elderly is not accompanied by an impaired baroreceptor modulation of sympathetic nerve traffic.

Adult↗
PubMed2003

Systolic blood pressure variability as a risk factor for stroke and cardiovascular mortality in the elderly hypertensive population.

OBJECTIVE: To investigate whether baseline systolic blood pressure variability was a risk factor for stroke, cardiovascular mortality or cardiac events during the Syst-Eur trial. DESIGN: The Syst-Eur study was a randomized, double-blind, placebo-controlled trial, powered to detect differences in stroke rate between participants on active antihypertensive treatment and placebo. Systolic blood pressure variability measurements were made on 744 participants at the start of the trial. Systolic blood pressure variability was calculated over three time frames: 24 h, daytime and night-time. The placebo and active treatment subgroups were analysed separately using an intention-to-treat principle, adjusting for confounding factors using a multiple Cox regression model. PARTICIPANTS: An elderly hypertensive European population. MAIN OUTCOME MEASURES: Stroke, cardiac events (fatal and non-fatal heart failure, fatal and non-fatal myocardial infarction and sudden death) and cardiovascular mortality (death attributed to stroke, heart failure, myocardial infarction, sudden death, pulmonary embolus, peripheral vascular disease and aortic dissection). RESULTS: The risk of stroke increased by 80% (95% confidence interval: 17-176%) for every 5 mmHg increase in night-time systolic blood pressure variability in the placebo group. Risk of cardiovascular mortality and cardiac events was not significantly altered. Daytime variability readings did not predict outcome. Antihypertensive treatment did not affect systolic blood pressure variability over the median 4.4-year follow-up. CONCLUSION: In the placebo group, but not the active treatment group, increased night-time systolic blood pressure variability on admission to the Syst-Eur trial was an independent risk factor for stroke during the trial.

Aged↗
PubMed2004

Effects of immediate versus delayed antihypertensive therapy on outcome in the Systolic Hypertension in Europe Trial.

BACKGROUND: To assess the impact of immediate versus delayed antihypertensive treatment on the outcome of older patients with isolated systolic hypertension, we extended the double-blind placebo-controlled Systolic Hypertension in Europe (Syst-Eur) trial by an open-label follow-up study lasting 4 years. METHODS: The Syst-Eur trial included 4695 randomized patients with minimum age of 60 years and an untreated blood pressure of 160-219 mmHg systolic and below 95 mmHg diastolic. The double-blind trial ended after a median follow-up of 2.0 years (range 1-97 months). Of 4409 patients still alive, 3517 received open-label treatment consisting of nitrendipine (10-40 mg daily) with the possible addition of enalapril (5-20 mg daily), hydrochlorothiazide (12.5-25 mg daily), or both add-on drugs. Non-participants (n = 892) were also followed up. RESULTS: Median follow-up increased to 6.1 years. Systolic pressure decreased to below 150 mmHg (target level) in 2628 participants (75.0%). During the 4-year open-label follow-up, stroke and cardiovascular complications occurred at similar frequencies in patients formerly randomized to placebo and those continuing active treatment. These rates were similar to those previously observed in the active-treatment group during the double-blind trial. Considering the total follow-up of 4695 randomized patients, immediate compared with delayed antihypertensive treatment reduced the occurrence of stroke and cardiovascular complications by 28% (P = 0.01) and 15% (P = 0.03), respectively, with a similar tendency for total mortality (13%, P = 0.09). In 492 diabetic patients, the corresponding estimates of long-term benefit (P < 0.02) were 60, 51 and 38%, respectively. CONCLUSIONS: Antihypertensive treatment can achieve blood pressure control in most older patients with isolated systolic hypertension. Immediate compared with delayed treatment prevented 17 strokes or 25 major cardiovascular events per 1000 patients followed up for 6 years. These findings underscore the necessity of early treatment of isolated systolic hypertension.

Aged↗
PubMed1995

The correlation of cavernous systolic occlusion pressure with peak velocity flow using color duplex Doppler ultrasound.

This prospective study involved 27 patients who underwent dynamic infusion cavernosometry/cavernosography and color duplex Doppler ultrasound. Phase III dynamic infusion cavernosometry/cavernosography determination of cavernous artery systolic occlusion pressure and color duplex Doppler measurements of peak velocity flow were performed. Four subpopulations were defined: 1) normal cavernous artery systolic occlusion pressure and peak velocity flow, 2) abnormal systolic occlusion pressure and normal peak velocity flow, 3) normal systolic occlusion pressure and abnormal peak velocity flow, and 4) abnormal systolic occlusion pressure and peak velocity flow. Peak velocity flow significantly correlated with cavernous artery systolic occlusion pressure and, using a normal value of greater than 25 cm. per second, resulted in a sensitivity and specificity of 95%. The positive predictive value of an abnormal peak velocity flow was calculated to be 95%. We conclude that peak velocity flow is an effective, reliable and noninvasive means of evaluating corporeal arterial function in an office setting.

Adult↗
PubMed2005

Plasma homocysteine levels and the left ventricular systolic function in coronary artery disease patients.

BACKGROUND: Numerous studies have shown a relationship between hyperhomocysteinemia, atherothrombosis and cardiovascular mortality. However, an association between hyperhomocysteinemia and the extent of coronary artery disease (CAD) remains controversial whereas its relationship with left ventricular systolic function has not been established. METHODS: One hundred and fifty-seven patients with angiographically defined CAD were included. The relationships between hyperhomocysteinemia, severity of CAD and left ventricular systolic function were studied. Left ventricular systolic function was determined primarily by ventriculography. The severity of CAD was determined through coronary angiography using the Gensini score and the number of vessels with > or = 50% stenosis. RESULTS: The mean fasting plasma homocysteine level was 13.4 mumol/l+/-0.5 SE. Elevated levels of homocysteine correlated significantly with increased severity of CAD both by the Gensini scores (r-value = 0.344, P < 0.0005) and the total number of diseased vessels (r-value = 0.387, P < 0.0005). The patients with hyperhomocysteinemia were found to have significantly reduced left ventricular ejection fraction (r-value = -0.382, P < 0.0005). A multivariate regression analysis revealed homocysteine level to be an independent predictor of left ventricular systolic function. In addition, adjusted analysis revealed hyperhomocysteinemia to be associated with global left ventricular dysfunction. CONCLUSION: In patients with CAD, homocysteine levels correlate independently with left ventricular systolic function. The mechanism of this association between homocysteine and left ventricular systolic function is unknown but may be due to a direct effect of homocysteine on myocardial function separate from its effects on coronary atherosclerosis.

Aged↗
PubMed2004

Prognostic value of echocardiographic indicators of left ventricular systolic function in asymptomatic dialysis patients.

Patients with end-stage renal disease (ESRD) are at high risk for heart failure, but the prevalence and the prognostic value of asymptomatic systolic dysfunction in these patients are unknown. In this prospective cohort study, the authors have therefore assessed by echocardiography the prevalence and the prognostic value of systolic function as estimated by ejection fraction (EF), fractional shortening at endocardial level (endoFS), and at midwall (mwFS), in a cohort of 254 asymptomatic dialysis patients. Systolic dysfunction had a prevalence rate of 26% by endoFS and of 48% by mwFS. During the follow-up period, 125 patients had one or more fatal and nonfatal CV events. On multivariate COX regression analysis, the three LV systolic function indicators were independently associated with incident fatal and nonfatal CV events, and there were no differences in the predictive power of these indicators (P > 0.30). The prediction power of LV function indicators was largely independent of traditional and novel risk factors in ESRD such as C-reactive protein and asymmetric dimethyl arginine (ADMA). ADMA was significantly related with LV function indicators as well as with mortality and incident CV events, but these links were much reduced (P = NS) in models including LV function indicators. Of note, the risk of CV events was minimal in patients with normal LV mass and function, intermediate in patients with either LVH or systolic dysfunction, and maximal in patients displaying both alterations. The study of myocardial contractility by echocardiography provides prognostic information independently of LV mass and other risk factors in ESRD. Risk stratification by simple systolic function parameters may prove useful in secondary prevention strategies in these patients.

Aged↗
PubMed2005

Birth characteristics and risk of high systolic blood pressure in early adulthood: socioeconomic factors and familial effects.

BACKGROUND: Although an inverse association between size at birth and blood pressure has been found in several studies, few studies have adjusted for the influence of socioeconomic and familial effects. METHODS: We investigated whether the association between birth weight and systolic blood pressure in young men is confounded by socioeconomic factors in adolescence or familial factors (ie, common genes and shared environment). Our population-based cohort study comprised 330,768 Swedish men born between 1973 and 1981, and conscripted for military service between 1991 and 2000. The analyses of family effects were restricted to 89,856 siblings from the initial cohort. A high systolic blood pressure at conscription was defined as a systolic blood pressure >/=140 mm Hg. Birth weight for gestational age <-2 standard deviation scores was considered "light for gestational age." RESULTS: Compared with men who had normal birth weight for gestational age, men who had been born light for gestational age were at increased risk of high systolic blood pressure (odds ratio = 1.14; 95% confidence interval = 1.07-1.22), even after adjustment for important confounders such as socioeconomic status. The increase in risk of high systolic blood pressure related to 1 standard deviation score decrease in birth weight for gestational age was similar within families (1.08; 1.04-1.12) and between families (1.05; 1.03-1.08). CONCLUSIONS: This study suggests that low birth weight for gestational age slightly increases the risk of high systolic blood pressure, and that the association appears not to be confounded by socioeconomic or familial effects.

Adult↗
PubMedDate not supplied

Effect of the diastolic and systolic duration on valve cavitation in a pediatric pulsatile ventricular assist device.

Minimization of cavitation is of high importance in the design of pulsatile ventricular assist devices because cavitation can cause blood and valve surface damage. Cavitation is associated with valve closure and has been previously correlated to high dP/dt, high valve closing velocity, and decreased pump filling. In this study, the effects of diastolic and systolic duration on the inlet and outlet valve cavitation were investigated. A low volume (280 ml) mock circulatory loop filled with room-temperature saline was used. A high-fidelity hydrophone was mounted into the inlet valve connector approximately 0.5 cm upstream from the inlet valve to quantify inlet valve cavitation. The inlet valve connector and hydrophone were placed symmetrically on the outlet side when measuring outlet valve cavitation. The RMS intensity of a 6-millisecond window pressure trace, bandpass filtered from 50 to 500 kHz, was used to quantify cavitation intensity. Approximately 80 beats were recorded at every test condition. High-speed video and an accelerometer were used to determine the position of the valves during closure. The cavitation intensity of the inlet valve was minimal when the onset of systole occurred at the moment when the pump just completed filling (RMS was approximately zero). The cavitation intensity increased when the onset of systole occurred before the pump was completely filled (valve partially opened), reaching a plateau of approximately 16 mm Hg when the valve was fully open. The cavitation intensity increased again when diastolic duration exceeded pump filling time by more than 30 milliseconds. The outlet valve cavitation intensity was very low (<4 mm Hg) regardless of the systolic duration, which can be attributed to the position of the hydrophone being on the opposite side of cavitation events. Although very small, the outlet cavitation intensities with respect to systolic duration show a trend similar to the inlet valve cavitation with respect to diastolic duration. Both inlet and outlet valve cavitation increased with increased peak regurgitant flow. An understanding of the relationship of the inlet and outlet valve cavitation to the diastolic and systolic duration can be used to determine the optimal operating conditions of the pulsatile pediatric pump.

Blood Pressure↗
PubMed2000

The effect of acidosis on systolic Ca2+ and sarcoplasmic reticulum calcium content in isolated rat ventricular myocytes.

We have investigated the mechanisms responsible for the changes of systolic Ca2+ that occur in voltage-clamped rat ventricular myocytes during acidosis produced by application of the weak acid butyrate (30 mM). Intracellular pH regulation was inhibited with dimethylamiloride (bicarbonate-free solution). The application of butyrate produced an intracellular acidification of 0.33 pH units. This was accompanied by a decrease in systolic Ca2+ to about 50% of control. However, within 2 min, systolic Ca2+ returned to control levels. The decrease in systolic Ca2+ was accompanied by a decrease in the Na+-Ca2+ exchange current observed on repolarisation so that the calculated Ca2+ efflux on Na+-Ca2+ exchange was less than the entry on the L-type Ca2+ current. The magnitude of the Na+-Ca2+ exchange current recovered along with systolic Ca2+ until it equalled the Ca2+ entry on the L-type Ca2+ current. From the measurement of Ca2+ fluxes, it was calculated that, during acidosis, the cell gains 121.6+/-16.2 micromol l(-1) of Ca2+. This is equal to the measured increase of sarcoplasmic reticulum (SR) calcium content obtained by applying caffeine (20 mM) and integrating the resulting Na+-Ca2+ exchange current. We conclude that the recovery of the amplitude of the systolic Ca2+ transient is due to decreased SR calcium release, resulting in reduced Ca2+ efflux from the cell leading to increased SR calcium content.

Acidosis↗
PubMedDate not supplied

Physician practice patterns in the treatment of isolated systolic hypertension in a primary care setting.

The authors evaluated the treatment of isolated systolic hypertension based on medical record review of charts between 1998 and 1999 in a multispecialty physician practice group. Two age-stratified random samples of ambulatory medical records were examined (393 patients aged > or =65 years and 251 patients aged 50-64 years). The samples corresponded to the practices of 35 primary care physicians who were surveyed about their hypertension care. Isolated systolic hypertension was defined as systolic blood pressure > or =140 mm Hg and diastolic blood pressure <90 mm Hg. Results showed that isolated systolic hypertension represented 76% and 45% of uncontrolled blood pressure in the older and middle-aged samples, respectively. Isolated systolic hypertension was often undiagnosed and untreated. Physicians reported treatment thresholds and goals that were significantly less aggressive for their patients > or =65 years of age. Physician awareness and treatment of isolated systolic hypertension have not yet caught up with consensus guidelines, and older patients may be affected most by this gap.

Aged↗
PubMedDate not supplied

Factors influencing the systolic blood pressure response to drug therapy.

In the early stage of hypertension, diastolic blood pressure has greater prognostic importance, but in the elderly, systolic blood pressure is the most important marker of cardiovascular complications. Therefore, the need for more strict control of this component of blood pressure must be reconsidered. The benefit obtained in different studies in the elderly suggests that the treatment of isolated systolic hypertension is associated with a reduction in overall cardiovascular mortality of 22%, in coronary heart disease mortality of 26%, and in stroke mortality of 33%. However, a higher percentage of patients (73%) attain the diastolic goal of <90 mm Hg, while only 34% have systolic pressure reduced to <140 mm Hg. In a review of randomized trials comparing at least four different antihypertensive drugs, significant differences in systolic blood pressure reduction have not been demonstrated, except in black populations, in whom calcium channel blockers and diuretics seem to be more effective. In patients with isolated systolic hypertension, data are inconclusive, but calcium channel blockers and diuretics appear to lower blood pressure to a greater degree than do other antihypertensive drugs. Two main predictors of difficulty in controlling systolic blood pressure are the baseline blood pressure and the presence of diabetes. Other predictors are the duration of arterial hypertension, older age, the presence of target organ damage and associated clinical conditions (myocardial infarction, stroke, chronic renal failure), and an elevated serum uric acid level. It appears that the profile of patients with a poorer therapeutic response includes a greater severity of hypertension and/or the presence of cardiovascular disease.

Antihypertensive Agents↗