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PubMedDate not supplied

Effects of fosinopril on exercise tolerance, symptoms, and clinical outcomes in patients with decompensated heart failure.

The purpose of this prospective, multicenter, randomized, double blind, placebo controlled study was to determine the clinical effects of fosinopril in patients with decompensated or worsening heart failure (HF). Patients >/=18 years with New York Heart Association (NYHA) functional class II-IV HF who had been hospitalized or seen in the ER or outpatient clinic for treatment of worsening or decompensated HF were eligible. Patients had to be on diuretic therapy and have a left ventricular ejection fraction (LVEF) </=35% and a treadmill exercise tolerance test (ETT) duration of </=8 minutes. Randomized patients began 12 weeks of fosinopril 10 mg (or placebo) qAM and were titrated within 4 weeks to fosinopril 20 mg and then to 40 mg (or placebo) qAM (if seated, systolic blood pressure (SBP) >/=90 mm Hg). ETTs (modified Naughton protocol) were performed at weeks 1, 3, 6, and 12. A total of 206 patients (mean age 62 years) were randomized to fosinopril (n=102) or placebo (n=104). Most patients were NYHA functional class III (58%) or IV (30%) at presentation; 145 patients completed 12 weeks of treatment (fosinopril, n=85; placebo, n=60). After adjustment for baseline imbalances and investigator effects, fosinopril-treated patients had a 513 second mean exercise duration at endpoint vs. a 489 second duration in placebo-treated patients (p=0.353). When the analysis was adjusted for the impact of dropouts on ETT time, fosinopril-treated patients had a greater exercise duration than those treated with placebo (p=0.043). Fewer patients in the fosinopril group were discontinued from study medication (p=0.008) or hospitalized (p=0.005) for worsening HF. At endpoint, more patients improved their NYHA Functional Class and fewer had worsened with fosinopril vs. placebo (p=0.018); fosinopril-treated patients showed improvements in dyspnea (p=0.054), fatigue (p=0.052), edema (p=0.012), and paroxysmal nocturnal dyspnea (p=0.003) vs. the placebo group. Once-daily fosinopril had a favorable effect on dropout-adjusted exercise tolerance, reduced the frequency of discontinuations or hospitalizations for worsening HF, improved HF signs and symptoms, and was safe and well tolerated. (c)1999 by CHF, Inc.

Journal Article↗
PubMed1983

Non-ejection cervical spine fracture due to defensive aerial combat maneuvering in an RF-4C: a case report.

An unusual case report is presented describing an incident in which an RF-4C instructor pilot fractured three cervical vertebrae after impacting the rear canopy top during a negative G defensive maneuver. The pilot subsequently developed an incomplete tetraparesis later in flight and the aircraft had to be recovered by the front seat pilot. No similar cases have ever been reported to the USAF Safety Center or described in the aviation literature.

Accidents, Aviation↗
PubMed2004

The effects of water ingestion on orthostatic hypotension in two groups of chronic autonomic failure: multiple system atrophy and pure autonomic failure.

BACKGROUND: Oral ingestion of water increases seated blood pressure in patients with chronic autonomic failure by mechanisms that remain unclear. As orthostatic hypotension is common in chronic autonomic failure, and is not always adequately controlled by medication, the potential benefits of water ingestion on standing blood pressure were studied in two types of autonomic failure: multiple system atrophy (MSA), in which the lesion is central and pre-ganglionic, and pure autonomic failure (PAF), in which the lesion is post-ganglionic. METHODS: In 14 patients with autonomic failure (seven PAF and seven MSA) standing blood pressure and heart rate were measured before, and 15 and 35 minutes after ingestion of 480 ml distilled water. Patients remained seated for 15 minutes after water ingestion, with beat to beat cardiovascular indices measured with the Portapres II device with subsequent Modelflow analysis. RESULTS: Standing prior to water ingestion caused a significant fall in blood pressure in all patients. After water ingestion there was a rise in seated blood pressure. Seated and standing blood pressure at 15 and 35 minutes after water ingestion was significantly higher than before water, with an improvement in orthostatic symptoms. The time to first significant rise in seated blood pressure occurred at 5 minutes post water ingestion in PAF and at 13 minutes in MSA. These increases were accompanied by increases in total peripheral resistance, reaching significance by 5 minutes in PAF and 13 minutes in MSA. There were no significant changes in cardiac output, stroke volume, or ejection fraction. CONCLUSIONS: Water is thus beneficial in improving standing BP in AF, acting within 15 minutes in both MSA and PAF. The earlier onset of the pressor effect in PAF may reflect the differing lesion site and underlying pathophysiology between these conditions.

Aged↗
PubMed2004

Specific occupant and collision characteristics are associated with motor vehicle collision-related blunt cerebrovascular artery injury.

BACKGROUND: Blunt cerebrovascular artery injury (BCI) remains difficult to diagnose but is recognized with increasing frequency after motor vehicle collisions (MVCs). Failure to detect this injury in a timely fashion can be devastating. Criteria that can be used to heighten the suspicion of this injury have been suggested; however, more encompassing screening has been recommended. To address this need, we sought to describe occupant, vehicle, and collision characteristics among MVC occupants who sustained a BCI. METHODS: All cases of BCI identified in the National Automotive Sampling System Crashworthiness Data System, a national probability sample of passenger vehicles involved in police-reported tow-away MVCs, between 1993 and 2001 were selected. Information on occupant (e.g., demographics, seating position, and restraint use), collision (e.g., collision type and severity), and vehicle characteristics were obtained and summarized using descriptive statistics. RESULTS: Nine-hundred forty individuals with BCI were identified in the Crashworthiness Data System data files. Over half were belted (57.4%) and 82.3% had airbag deployment; 16.2% were partially or completely ejected from the vehicle. Head and thoracic injuries were common (44.4% and 40.8%, respectively); 27.8% sustained a cervical spine fracture and 21.0% sustained a soft-tissue injury to the neck. The mean Injury Severity Score was 33.6. The case fatality rate was 44.5%. The majority of BCI occupants were drivers (76.0%). Among belted occupants, the lap/shoulder was the most commonly attributed as the injury source (61.4%). Among unbelted occupants, frequent injury sources included air bags (15.0%), windshield (13.7%), and other interior objects. With respect to collision characteristics, the average change in velocity (Delta V) was 43.3 km/h. The majority of collisions were frontal (76.2%). CONCLUSION: This study indicates that BCI is both a rare and lethal injury typified by specific occupant and collision characteristics. These characteristics provide insight as to the cause of this injury that may aid in the evaluation and management of the blunt trauma patient at risk for BCI.

Accidents, Traffic↗
PubMed1976

[The mitral prolapse syndrome. Observation of 100 cases (author's transl)].

100 patients with mitral prolapse syndrome (MPS) were studied with electrocardiogram, phonocardiogram, thorax radiography and echocardiogram. In 44 of the patients, the effort test and dynamic electrocardiogram were performed; 25 underwent hemodynamic examination, and 10 underwent selective coronarography. The most frequent symptomatologies were palpitations and vertigo; the most-registered electrocardiographic alterations were ventricular extrasystoles and altered electrical repolarization in the inferior seat. The symptomatic patients with rhythm disturbances showed reduced work capacity (RWC) with aggravation of the effort arrhythmias. The phonocardiogram showed variability of the phonoauscultatory reports, not only from patient to patient, but also in the same patient. The apicocardiogram presented a characteristic systolic re-entry which coincided with the non-ejective click. In all cases, the echocardiogram demonstrated a systolic movement backwards from the mitralic strips with different aspects. The endocavitary pressures in the studied cases were normal or only slightly altered. The left ventriculography frequently demonstrated assynergic areas, and constantly, eversion of the posterior mitralic strips in the left atrium. In most of the cases, the selective coronarography showed the absence of the ventricular atrial tract of the circumflex. The sustained role of the mixomatous degeneration in the pathogenetic mechanism of the MPS must be emphasized. The beta-blockers were the most effective drugs against arrhythmias, which in some cases showed themselves impervious to any medicinal treatment. MPS is considered a very diffuse disease which can run its course without detection or which can be accompanied by serious rhythm disturbances that can threaten the patient's life. The importance of echocardiography in the diagnosis of MPS is emphasized. The SPM patient showed undergo a series of wave tests which reveal malignant potentialities, so that the best therapeutic principles, both for the treatment and prevention of the arrhythmias, can be applied.

Adolescent↗
PubMed1992

Effects of fosinopril on cardiac function in patients with hypertension. Radionuclide assessment of left ventricular systolic and diastolic performance.

Numerous pharmacologic agents are capable of lowering the blood pressure of hypertensive patients; however, each drug has a characteristic side effect profile and effect on cardiac performance. In this study, the hemodynamic effects of the angiotensin converting enzyme inhibitor fosinopril were assessed at rest and at peak upright bicycle exercise by first-pass radionuclide cineangiography in 12 patients with essential hypertension. Fosinopril reduced blood pressure at rest in the seated position from 152/101 to 131/85 mm Hg (P less than .01) and at peak exercise from 206/103 to 184/91 mm Hg (P less than .01). Fosinopril therapy was associated with an increase in stroke volume and cardiac output and a decrease in systemic vascular resistance at rest and during peak exercise. Both peak ejection rate and peak filling rate increased significantly at rest during fosinopril therapy. The unique cardiotropic response to fosinopril may reflect its effects on the myocardial renin-angiotensin system, and suggests that this agent may offer a therapeutic advantage compared with other angiotensin converting enzyme inhibitors.

Adolescent↗
PubMed2001

Neuroendocrine and renal effects of intravascular volume expansion in compensated heart failure.

To examine if the neuroendocrine link between volume sensing and renal function is preserved in compensated chronic heart failure [HF, ejection fraction 0.29 +/- 0.03 (mean +/- SE)] we tested the hypothesis that intravascular and central blood volume expansion by 3 h of water immersion (WI) elicits a natriuresis. In HF, WI suppressed ANG II and aldosterone (Aldo) concentrations, increased the release of atrial natriuretic peptide (ANP), and elicited a natriuresis (P < 0.05 for all) compared with seated control. Compared with control subjects (n = 9), ANG II, Aldo, and ANP concentrations were increased (P < 0.05) in HF, whereas absolute and fractional sodium excretion rates were attenuated [47 +/- 16 vs. 88 +/- 15 micromol/min and 0.42 +/- 0.18 vs. 0.68 +/- 0.12% (mean +/- SE), respectively, both P < 0.05]. When ANG II and Aldo concentrations were further suppressed (P < 0.05) during WI in HF (by sustained angiotensin-converting enzyme inhibitor therapy, n = 9) absolute and fractional sodium excretion increased (P < 0.05) to the level of control subjects (108 +/- 34 micromol/min and 0.70 +/- 0.23%, respectively). Renal free water clearance increased during WI in control subjects but not in HF, albeit plasma vasopressin concentrations were similar in the two groups. In conclusion, the neuroendocrine link between volume sensing and renal sodium excretion is preserved in compensated HF. The natriuresis of WI is, however, modulated by the prevailing ANG II and Aldo concentrations. In contrast, renal free water clearance is attenuated in response to volume expansion in compensated HF despite normalized plasma AVP concentrations.

Aldosterone↗
PubMed1994

Cardiovascular responses to postural changes: differences with age for women and men.

The cardiovascular responses to postural change, and how they are affected by aging, are inadequately described in women. Therefore, the authors examined the influence of age and sex on the responses of blood pressure, cardiac output, heart rate, and other variables to change in posture. Measurements were made after 10 minutes each in the supine, seated, and standing positions in 22 men and 25 women who ranged in age from 21 to 59 years. Several variables differed, both by sex and by age, when subjects were supine. On rising, subjects' diastolic and mean arterial pressures, heart rate, total peripheral resistance (TPR), and thoracic impedance increased; cardiac output, stroke volume, and mean stroke ejection rate decreased; and changes in all variables, except heart rate, were greater from supine to sitting than sitting to standing. The increase in heart rate was greater in the younger subjects, and increases in TPR and thoracic impedance were greater in the older subjects. Stroke volume decreased less, and TPR and thoracic impedance increased more, in the women than in the men. The increase in TPR was particularly pronounced in the older women. These studies show that the cardiovascular responses to standing differ, in some respects, between the sexes and with age. The authors suggest that the sex differences are, in part, related to greater decrease of thoracic blood volume with standing in women than in men, and that the age differences result, in part, from decreased responsiveness of the high-pressure baroreceptor system.

Adult↗
PubMed1987

Cardiac size and motion during water immersion: implications for volume homeostasis.

Prior work has shown that head-out water immersion (WI) produces a prompt central hypervolemia, a natriuresis, and a diuresis. To assess if cardiac chamber enlargement modulates these effects, we measured cardiac size, shape, wall motion, and cardiac displacement via serial underwater two-dimensional echocardiography. Six normal volunteers underwent 2.5 hours of WI to the neck, seated, at 34.5 degrees C. Recovery was 30 minutes. The size of both atria increased significantly but transiently during the study (p less than 0.0001 for left atrium, and p = 0.0020 for right atrium). Both atria returned to baseline size during WI. Moreover, for left atrium there was a small overshoot in recovery. Neither left ventricular nor right ventricular dimensions nor ejection fraction changed significantly. Also, no shape changes were detected, although WI was associated with upward and lateral displacement of the acoustic windows. Correlation coefficients (r) for left atrial, or right atrial size vs urinary excretion of sodium or urine volume size ranged from 0.05 to 0.36. These results, in sum, suggest that strong compensatory mechanisms are counteracting the effect of WI on distended cardiac receptors, and that cardiac receptor activation alone does not constitute the afferent limb of the reflex mediating the renal effects of head-out WI.

Adolescent↗
PubMedDate not supplied

Motorized two-point safety belt effectiveness in preventing fatalities.

The effectiveness of two-point motorized restraint systems in preventing fatalities to outboard front-seat car occupants is estimated using published fatality data for one model car equipped with a motorized two-point-belt system, together with a number of assumptions. Effectiveness estimates are obtained for the motorized belt system as used in the field, which reflects the mix of occupants who do and do not fasten the manual lap belt, and for effectiveness when the lap belt is not used. This latter estimate is, therefore, an estimate of the effectiveness of shoulder belts in preventing fatalities. In the data for the one car model, 18% of the fatally injured occupants were ejected. By assuming that three-point belt systems prevent ejection, these data are used to compute the difference in effectiveness between two-point and three-point systems. The result applies to the two-point belt system used in conjunction with whatever manual belt-use rates occurred in traffic. From published observations of lap-belt-use rates for this same vehicle, the effectiveness of the shoulder belt only is estimated. It is found that effectiveness of the two-point restraint system in conjunction with the lap-belt use that occurred in traffic is (32 +/- 5)%. The effectiveness of the shoulder belt only is estimated as (29 +/- 8)%.

Accidents, Traffic↗
PubMed1995

Field effectiveness of two restraint systems: the 3-point manual belt versus the 2-point motorized-shoulder/manual lap belt.

The research question addressed in this paper is whether or not occupant death, injury, and ejection outcomes differ between vehicles equipped with 3-point manual belts versus 2-point motorized-shoulder/manual-lap (motorized/manual) belt systems. Census crash data sets for the states of Washington and Texas, and the Fatal Accident Reporting System (FARS) were subset to provide data on front-outboard occupants of Ford Escorts involved in crashes in calendar years 1981-1991. Logistic regression analyses showed that occupants of vehicles equipped with the motorized/manual system experienced 11.7% to 26.4% fewer K- or A-level injuries than occupants of vehicles equipped with the 3-point system. Similar analyses of FARS data showed lower ejection rates for occupants of vehicles with the motorized/manual system in both rollover and nonrollover crashes. The installation of the motorized/manual system provided a substantial safety benefit over the manual 3-point system in the time periods examined.

Accidents, Traffic↗
PubMed1990

Restraint effectiveness, occupant ejection from cars, and fatality reductions.

The effectiveness of air cushion restraint systems, or airbags, in preventing fatalities is estimated by assuming that they do not affect ejection probability, and protect only in frontal, or near frontal, crashes with impact-reducing effectiveness equal to that of lap/shoulder belts. In order to compute airbag effectiveness, lap/shoulder belt effectiveness and the fraction of fatalities preventable by eliminating ejection are estimated using Fatal Accident Reporting System (FARS) data. Ejection prevention is found to account for almost half of the effectiveness of lap/shoulder belts (essentially all for lap belts only). Airbag effectiveness is estimated as (18 +/- 4)% in preventing fatalities to drivers and (13 +/- 4)% to right front passengers. Drivers switching from lap/shoulder belt to airbag-only protection increase their fatality risk by 41%.

Accidents, Traffic↗
PubMed2003

Hemodynamics during active and passive recovery from a single bout of supramaximal exercise.

The aim of this work was to study the differences in cardiovascular response during two modes of recovery [active (AR): pedalling at 40 W; and passive (PR): complete rest seated] from a single bout of supramaximal exercise. Eight male amateur soccer players underwent two supramaximal cycle-ergometer tests, each consisting of pedalling against a resistance equivalent to 150% of the maximum workload achieved in a previous incremental test, followed by randomly assigned AR or PR. Cardiodynamic variables were obtained using an impedance cardiograph. Subjects were also connected to a sphygmomanometer, for systolic and diastolic blood pressure, and to a metabolimeter for oxygen uptake (VO(2)) assessments. We measured: heart rate (HR), stroke volume (SV), cardiac output (CO), the inverse of myocardial contractility calculated as pre-ejection period/left ventricular ejection time ratio (PEP/LVET), mean blood pressure (MBP), thoracic electrical impedance ( Z(0)) as an index of central blood volume, and arterio-venous oxygen difference (A-V O(2) Diff.). PR caused a lower CO compared to AR [mean (SE): 7 (0.7) vs. 10.4 (0.6) l.min(-1 )at the 5th min of recovery] due to lower HR [106.2 (3.6) vs. 121.8 (4.5) bpm at the 5th min of recovery], SV [67.1 (5) vs. 86.1 (4.8) ml at the 5th min of recovery], and PEP/VET values [0.44 (0.007) vs. 0.39 (0.015) at the 5th min of recovery]. No differences were found in MBP and Z(0) between PR and AR [95.1 (1.9) vs. 92.3 (2.7) mmHg and 26.2 (1.1) vs. 26.6 (1) Omega respectively at the 5th min of recovery], while A-V O(2) Diff. values were higher during AR than during PR [108.8 (4.3) vs. 75.2 (5.4) ml.l(-1) at the 5th min of recovery]. Thus, although after a single bout of supramaximal exercise SV and CO are lower during PR than during AR, these differences are not due to an impairment of cardiovascular function, but are fully explained by the lesser muscular engagement that leads to a reduction in stimuli deriving from mechanoreceptors and central commands, thus causing a faster return of myocardial contractility and HR to resting values.

Adult↗
PubMed1984

Safety belt use, ejection and entrapment.

One in every five occupants thrown from a car receives fatal injuries. A motorist who uses a safety belt, in all probability, will not be thrown from the car during a crash. The rate of fatal injury for ejected occupants was found to be 40 times the rate for occupants not thrown from their cars, as determined from national accident sampling data. These data refute the popular notion that "being thrown clear" has survival benefit. In addition, there was no evidence that wearing a safety belt increased fatality risk from vehicle fire or submersion.

Accidents, Traffic↗
PubMed1995

Computer simulation of human body dynamics.

Understanding human body dynamics is important in many situations, such as automobile and aircraft crashes, aircraft ejections, falls, and other acceleration environments. The design of automobile interiors, cockpits, and safety equipment requires knowledge of the forces and accelerations encountered during an emergency. Because of the limited information available from actual events and the various constraints in testing, computer simulations are often the only means of obtaining detailed information. The Armstrong Laboratory (AL) developed the Articulated Total Body (ATB) model to predict the human body dynamics in many of these environments. This model is a three-dimensional rigid body dynamics program in which the human body is modeled as a series of segments. Forces on the body segments are calculated based on their interaction with the surroundings including seat and cockpit surfaces. The model also calculates the internal joint resistive and constraint forces. Because of this capability to predict both internal and external forces acting on the body, the ATB model can be used in investigating injuries. It is also a valuable design tool for evaluating safety of proposed systems before prototypes are built or costly tests conducted. When testing is conducted, the model provides data that cannot be measured, such as forces within the body, and supplementing test data with parameter variation simulations. To validate the model, tests such as those conducted on the AL impact sled are simulated. Test films and instrumentation data are compared with simulation graphics and quantitative output to gain confidence in the simulation results.

Acceleration↗
PubMed1993

Automobile driver fatalities in frontal impacts: air bags compared with manual belts.

OBJECTIVES: The effectiveness of air bags was estimated in this study by comparing driver fatalities in frontal crashes with driver fatalities in nonfrontal crashes, for cars with air bags and manual belts and cars with manual belts only. METHODS: Fatal Accident Reporting System data for drivers fatally injured during 1985 to 1991 in 1985 to 1991 model year cars that were equipped with air bags in or before model year 1991 were analyzed. RESULTS: Driver fatalities in frontal crashes in air bag cars were 28% lower than those in comparable cars with manual belts only. This percentage was used for estimating the overall fatality reduction in air bag cars. The reduction was greater in large cars (50%) than in midsize cars (19%) or in small cars (14%). Air bags reduced driver fatalities in frontal crashes involving ejection by about 9%. Fatalities in frontal crashes among drivers who were reportedly using manual belts at the time of the crash were reduced by about 15%. The comparable reduction among drivers who were reportedly not using manual belts was 31%. CONCLUSION: It was estimated that air bags reduced the total number of all driver fatalities by about 19%.

Accidents, Traffic↗
PubMed1995

A study of injury-producing crashes on median divided highways in southwestern Ontario.

The University of Western Ontario Accident Research Team investigates every fatal crash, and approximately one out of every 50 personal-injury crash, within a defined geographic area of three counties. Over a seven-year period, the team investigated 107 collisions (62 fatal and 45 personal injury) that occurred on median-divided highways. These crashes were representative of over 2,300 collisions on the highways involving 81 fatalities and injury to over 3,200 vehicle occupants. Vehicle loss of directional control prior to any impact occurred in 55 of the 62 fatal cases and in 36 of the 45 personal-injury cases. In 36 fatal cases and 17 personal-injury cases loss of control was initiated after a vehicle travelled from the roadway onto the gravel shoulder. Rollover collisions were the most frequent collision type investigated and comprised 25 fatal and 25 personal-injury cases. Unrestrained occupants made up 24 of the 29 rollover fatalities with 96% of these unrestrained occupants being ejected from the vehicle. Collision with an oncoming vehicle after median-crossover occurred in 26 fatal cases. These crashes were usually frontal or side impacts characterized by extensive vehicle damage and massive intrusion into the occupant compartment. Severe head injury (AIS 5 or greater) predominated as the cause of death in all collision types.

Accidents, Traffic↗
PubMed1995

Risk factors and mechanisms of occurrence in motor vehicle-related spinal cord injuries: Utah.

The purpose of this paper is to describe the incidence, risk factors, and crash factors of motor-vehicle-related spinal cord injuries in Utah. The Utah Department of Health established a statewide registry of spinal cord injuries (SCIs) occurring in 1989-1991, analyzing data from hospital medical records and police reports. Forty-nine percent of all SCIs involved motor vehicles, including injuries arising from motor vehicle collisions with bicyclists and pedestrians. Adolescent and young adult males were at highest risk of injury. Among occupants of automobiles and trucks with SCI, 70% were involved in a vehicle rollover, while 39% were ejected from the vehicle. Only 25% reported using seatbelts. SCIs were much more likely to be associated with rollover compared with other types of motor vehicle-occupant injuries. These findings suggest areas in which SCI prevention programs and research should be focused.

Accidents, Traffic↗