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Biomedical subjects

C R Prince

Publications and source records attributed to C R Prince.

18 recordsLinked to original sources
PubMed2001

Subjective quality of life in the evaluation of programs for people with serious and persistent mental illness.

Despite the widespread application of the concept of quality of life in mental health evaluation, it has been observed that subjective quality of life measures do not reliably capture changes expected to result from intervention efforts. Moreover, because the domains selected to assess subjective life quality are typically generated by investigators or health professionals, the validity of subjective quality of life measures has also been questioned. Although it represents a conceptual shift from investigator-generated domains to client-elicited domains, it is suggested that a client-elicited approach to measuring subjective quality of life may provide fruitful avenues for resolving some of the conceptual and practical issues associated with understanding and measuring the impact of community-based programs on clients with serious mental illness. Accordingly, while acknowledging the utility of assessing the objective circumstances of people's lives, this paper suggests that client-elicited subjective quality of life domains have the potential to resolve the failure of existing measures to register meaningful change. Unlike previous general reviews of quality of life that have emphasized measurement issues, the present review considers some of the fundamental barriers to our ability to adequately understand and document the experiences of people adjusting to community living with a psychiatric disability.

Community Mental Health Services↗
PubMed1996

Effects of nifedipine and nitroglycerin on left ventricular systolic dysfunction and impaired diastolic filling after exercise-induced ischemia in humans.

OBJECTIVES: This study sought to determine whether calcium antagonist, compared with nitroglycerin, administration attenuates left ventricular dysfunction after exercise-induced ischemia in humans. BACKGROUND: Exercise-induced ischemia impairs left ventricular systolic function and diastolic filling after exercise. The mechanism of this phenomenon is unknown but may relate to intracellular calcium overload. METHODS: Echocardiography was performed in 131 patients before and 30 min, 2 h and 4 h after exercise stress test. Ischemia was defined as a reversible thallium stress defect. No medication, sublingual nitroglycerin or nifedipine was randomly given to each patient at peak exercise. RESULTS: Isovolumetric relaxation time was significantly prolonged from rest (100 +/- 19 ms [mean +/- SD]) to 30 min (118 +/- 20 ms, p < 0.0005), 2 h (117 +/- 18 ms, p < 0.0005) and 4 h (110 +/- 22 ms, p < 0.05) after exercise in 21 patients with exercise-induced ischemia who received no medication (ischemia-none group). Isovolumetric relaxation time similarly increased after exercise in 23 patients who received nitroglycerin and had exercise-induced ischemia (ischemia-NTG group) but was unchanged in 20 patients with exercise-induced ischemia who received nifedipine (ischemia-nifedipine group). Peak early filling velocity decreased in the ischemia-none and ischemia-NTG groups from rest to 30 min and 2 h after exercise, but peak early filling velocity was unchanged in the ischemia-nifedipine group. Ejection fraction decreased from rest to 30 min after exercise in the ischemia-none group (59 +/- 12% vs. 51 +/- 13%, p < 0.025) and ischemia-NTG group (59 +/- 14% vs. 49 +/- 14%, p < 0.005) but was unchanged in the ischemia-nifedipine group (60 +/- 19% vs. 64 +/- 18%, p = NS). A new regional left ventricular wall motion abnormality occurred more frequently 30 min after exercise in the ischemia-none group (11 [52%] of 21) and ischemia-NTG group (9 [39%] of 23) compared with the ischemia-nifedipine group (2 [10%] of 20, both p < 0.05). No change occurred in left ventricular systolic function and diastolic filling after exercise in the control groups. CONCLUSIONS: Exercise-induced ischemia impairs systolic function and diastolic filling after exercise. Sublingual nifedipine but not nitroglycerin attenuates this process and suggests that altered calcium homeostasis may play a role in left ventricular dysfunction that occurs after exercise-induced ischemia.

Adult↗
PubMed1995

Exercise-induced mitral regurgitation is a predictor of morbid events in subjects with mitral valve prolapse.

OBJECTIVES: This study attempted to determine whether a subset of patients with mitral valve prolapse and no mitral regurgitation at rest will develop mitral regurgitation during exercise and have a higher than anticipated risk of morbid cardiovascular events. BACKGROUND: Mitral regurgitation in patients with mitral valve prolapse identifies a subset of patients at higher risk for morbid events. However, mitral regurgitation in patients with mitral valve prolapse may be intermittent and could go unrecognized. A provocative test to unmask mitral regurgitation in these patients would be useful. METHODS: Ninety-four adult patients with mitral valve prolapse and no mitral regurgitation at rest were studied during supine bicycle ergometry using color flow Doppler echocardiography in the apical four-chamber and long-axis views. Patients were prospectively followed up for morbid events. RESULTS: Thirty (32%) of 94 patients had exercise-induced mitral regurgitation. Prospective follow-up (mean 38 months) showed more morbid events in the group with than without mitral regurgitation and included, respectively, syncope (43% vs. 5%, p < 0.0001), congestive heart failure (17% vs. 0%, p < 0.005) and progressive mitral regurgitation requiring mitral valve replacement surgery (10% vs. 0%, p < 0.05). Cerebral embolic events, endocarditis or sudden death were rare and not different between groups. CONCLUSIONS: In patients with mitral valve prolapse without mitral regurgitation at rest, exercise provokes mitral regurgitation in 32% of patients and predicts a higher risk for morbid events.

Adolescent↗
PubMed1995

Transesophageal echocardiographic guidance of cardioversion in patients with atrial fibrillation.

The role of TEE in the guidance of cardioversion of atrial fibrillation was studied. Thirty-seven (18%) of 206 patients had left atrial thrombus. Cardioversion was attempted in 153 patients receiving no (n = 107) or < 7 days (n = 46) of anticoagulation prophylaxis, in 27 patients after > or = 3 weeks of anticoagulation, and was cancelled in 26 patients, primarily on the basis of TEE findings. Left atrial thrombus was observed in 37 (18%) of 206 patients. No embolic complications occurred over a 4-week follow-up period. In 7 (41%) of 17 patients new left atrial appendage spontaneous echocardiographic contrast developed immediately after electric cardioversion. In this group, significant decreases occurred in the left atrial appendage maximal emptying shear rate (11.1 +/- 11.1 sec-1 vs 5.0 +/- 5.1 sec-1; p < 0.05), maximal filling shear rate (6.7 +/- 5.9 sec-1 vs 3.7 +/- 3.5 sec-1; p < 0.05), and peak emptying velocity (0.38 +/- 0.29 cm/sec vs 0.19 +/- 0.14 cm/sec; p < 0.05). In one patient a left atrial appendage thrombus formed after electric cardioversion. Left atrial thrombus resolved in 1 (5%) of 21 patients and became immobile in 0 (0%) of 16 patients after 3 to 5 weeks of anticoagulation but resolved (n = 9) or became immobile (n = 6) in 15 (71%) of 21 patients after > 5 weeks of anticoagulation. TEE-guided cardioversion was safely done without or with < 7 days of anticoagulation prophylaxis in selected patients, but the potential for left atrial thrombus to form after electric cardioversion makes anticoagulation advisable in all patients. The conventional recommendation of 3 to 4 weeks of anticoagulation prophylaxis before cardioversion is usually inadequate for left atrial thrombus to resolve or to become immobile.

Adult↗
PubMed1995

Coronary flow reserve assessment by dobutamine transesophageal Doppler echocardiography.

OBJECTIVES: This study attempted to determine the sensitivity and specificity of coronary flow reserve derived using transesophageal echocardiography for left anterior descending coronary artery stenosis. BACKGROUND: Transesophageal echocardiography can be used to measure coronary flow velocity and may provide a less invasive means of assessing coronary flow reserve. METHODS: Seventy-eight adult patients were studied by pulsed Doppler transesophageal echocardiography of the proximal left anterior descending coronary artery during a control period and peak (i.e., 40 micrograms/kg body weight per min) dobutamine infusion. Coronary flow reserve index was calculated as the ratio of maximal diastolic coronary velocity at peak dobutamine infusion to the control level and was considered abnormal if < 1.81. Two-dimensional transesophageal left ventricular views were obtained for analysis of wall motion. RESULTS: Coronary angiography showed > or = 70% (group A, n = 18), 0% to < 70% (group B, n = 21) and no (group C, n = 39) left anterior descending coronary artery diameter stenosis. An abnormal coronary flow reserve index did not differ from a new regional wall motion abnormality in sensitivity for left anterior descending coronary stenosis in group A (15 [83%] of 18 vs. 15 [83%] of 18, p = NS) but was significantly more sensitive in group B (12 [57%] of 21 vs. 2 [10%] of 21, p < 0.025). The specificity for no left anterior descending coronary stenosis in group C between a normal coronary flow reserve index and no new regional wall motion abnormality did not differ (87% vs. 97%, p = NS). CONCLUSION: Doppler coronary flow reserve and two-dimensional dobutamine transesophageal echocardiography are equally sensitive for the detection of left anterior descending coronary stenosis > or = 70% and equally specific. However, Doppler coronary flow reserve, compared with two-dimensional dobutamine transesophageal echocardiography, is more sensitive for intermediate left anterior descending coronary stenosis and may play a significant adjunctive role to cardiac catheterization and other noninvasive techniques for assessing coronary artery disease.

Blood Flow Velocity↗
PubMed1995

Left atrial appendage thrombus is not uncommon in patients with acute atrial fibrillation and a recent embolic event: a transesophageal echocardiographic study.

OBJECTIVES: The objective of this study was to determine the frequency of left atrial thrombus in patients with acute atrial fibrillation. BACKGROUND: It is commonly assumed but unproved that left atrial thrombus in patients with atrial fibrillation begins to form after the onset of atrial fibrillation and that it requires > or = 3 days to form. Thus, patients with acute atrial fibrillation (i.e., < 3 days) frequently undergo cardioversion without anticoagulation prophylaxis. METHODS: Three hundred seventeen patients (250 men, 67 women; mean [+/- SD] age 64 +/- 12 years) with acute (n = 143) or chronic (n = 174) atrial fibrillation were studied by two-dimensional transesophageal echocardiography. RESULTS: Left atrial appendage thrombus was present in 20 patients (14%) with acute and 47 patients (27%, p < 0.01) with chronic atrial fibrillation. In patients with a recent embolic event, the frequency of left atrial appendage thrombus did not differ between those with acute (5 [21%] of 24) and those with chronic (12 [23%] of 52, p = NS) atrial fibrillation. Patients with acute versus chronic atrial fibrillation, respectively, did not differ (p = NS) in mean age (64 +/- 13 vs. 65 +/- 11 years), frequency of concentric left ventricular hypertrophy (32% vs. 26%), hypertension (32% vs. 41%), coronary artery disease (35% vs. 39%), congestive heart failure (43% vs. 48%), mitral stenosis (4% vs. 7%) or mitral valve replacement (1.4% vs. 6%). The minimally detectable difference in proportions between patients with acute and chronic atrial fibrillation based on a power of 0.80 and base proportion of 0.20 was 14%. CONCLUSIONS: Left atrial thrombus does occur in patients with acute atrial fibrillation < 3 days in duration. The frequency of left atrial thrombus in patients with recent emboli is comparable between those with acute and chronic atrial fibrillation. These data suggest that patients with acute atrial fibrillation for < 3 days require anticoagulation prophylaxis or evaluation by transesophageal echocardiography before cardioversion and should not be assumed to be free of left atrial thrombus.

Acute Disease↗
PubMed1994

Dobutamine two-dimensional transesophageal echocardiographic stress testing for detection of coronary artery disease.

Atrial pacing and dipyridamole transesophageal echocardiography have been shown to be sensitive and specific tests for the detection of coronary artery disease. However, the sensitivity and specificity of dobutamine transesophageal echocardiography have not been reported. The purpose of this study was to determine the feasibility, sensitivity, and specificity of dobutamine transesophageal echocardiography for the detection of coronary artery disease. Transesophageal echocardiographic assessment of left ventricular function was performed in 81 adult patients aged 62 +/- 12 years during stepwise infusion of dobutamine from 5.0 to 40 micrograms/kg/min. Ischemia was diagnosed by the development of severe hypokinesis, akinesis, or dyskinesis of a previously contractile left ventricular segment. Coronary artery disease was defined by angiography as a reduction in luminal diameter of > or = 70% of an epicardial or > or = 50% of the left main coronary artery. In patients who had undergone coronary artery bypass graft surgery, a stenotic bypass graft was defined as a reduction in luminal diameter of > or = 70%. In patients without previous CABG, significant coronary artery disease was present in 21 patients: 5 with single-vessel disease, 7 double-vessel disease, 8 triple-vessel disease, and 1 left main coronary disease. Dobutamine transesophageal echocardiography had a sensitivity of 90% (19 of 21) and specificity of 94% (49 of 52) for the detection of coronary artery disease. In patients with previous CABG (n = 8), the sensitivity and specificity for the detection of bypass graft stenosis were 100% (4 of 4) and 75% (3 of 4), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Two-dimensional transesophageal echocardiographic determination of mitral valve area in adults with mitral stenosis.

Two-dimensional transthoracic echocardiography has been shown to be a reliable and accurate method of measuring stenotic mitral valve orifice area. Little data exist on the role of two-dimensional transesophageal echocardiography for this purpose. Thus in 45 adult patients with mitral stenosis mitral valve area was determined by direct planimetry with the use of two-dimensional transesophageal and transthoracic echocardiography. Transesophageal was less feasible than transthoracic echocardiography in the 45 patients (69% vs. 89%, p < 0.025). In 14 patients, two-dimensional transesophageal echocardiography was not feasible, primarily because of leaflet dropout. In 30 patients, transesophageal and transthoracic echocardiography were feasible, and measurements of mitral valve area by the two techniques correlated well (r = 0.91, SEE = 0.33 cm2, p < 0.0001). Mean mitral valve orifice area determined by transesophageal echocardiography (1.54 +/- 0.75 cm2; range 0.56 to 3.49 cm2) and by transthoracic echocardiography (1.55 +/- 0.78 cm2; range 0.62 to 3.68 cm2) did not differ (p = NS). The absolute (0.24 +/- 0.22 cm2) and percent (19% +/- 21%) differences between mitral valve area determined by transesophageal versus transthoracic echocardiography were small. These data show that mitral valve area in patients with mitral stenosis can be accurately measured by direct planimetry with two-dimensional transesophageal echocardiography. Technical refinements such as lateral-gain-compensation features may improve the feasibility of two-dimensional transesophageal echocardiography for measurements of mitral stenosis area, and this technique may become an adjunct to transthoracic echocardiography in the assessment of severity of mitral stenosis.

Adult↗
PubMed1994

Angle of incidence does not affect accuracy of mitral stenosis area calculation by pressure half-time: application to Doppler transesophageal echocardiography.

Continuous wave Doppler transesophageal echocardiography (TEE) may allow the estimation of stenotic mitral valve area. Intuitively the posterolateral position of the transducer appears to limit the application of TEE for this purpose because of the excessive angle of incidence to mitral valve inflow. However, algebraic equations can be used to predict that the angle of incidence should not affect mitral valve area derived by using pressure half-time. To test the validity of this prediction and the potential application of Doppler TEE to estimate mitral valve area, 28 patients (21 women, 7 men) with a mean age of 59 +/- 14 years with mitral stenosis were studied by continuous wave transthoracic echocardiography (TTE) and TEE guided color flow Doppler. TTE was performed from the apical four-chamber (TEE-0) and a modified parasternal four-chamber (TTE-MAL) plane as a means of intentionally increasing the angle of incidence. TEE was done by using the horizontal (TEE-HAX) and vertical (TEE-VAX) planes. Mitral valve area was calculated by pressure half-time method. Mean mitral valve area did not differ (p = not significant [NS]) between TTE-0 (1.26 +/- 0.84 cm2), TTE-MAL (1.37 +/- 0.94 cm2), TEE-HAX (1.39 +/- 0.92 cm2), and TEE-VAX (1.35 +/- 0.89 cm2). The estimated mean angle of incidence during TTE-MAL was 45 +/- 12 degrees (range 21 to 68 degrees). Six (21%) of 28 and 9 (32%) of 28 patients had an underestimation of transmitral peak velocities with TEE from the horizontal or vertical planes, respectively. However, excellent correlations were found between mitral valve area derived by using TEE-0 versus TTE-MAL (r = 0.97; SEE = 0.25 cm2; intercept = 0.02 cm2; slope = 1.08; and p = 0.0001), TEE-HAX (r = 0.91; SEE = 0.39 cm2; intercept = 0.14 cm2; slope = 1.00; and p = 0.0001) and TEE-VAX (r = 0.92; SEE = 0.36 cm2; intercept = 0.13 cm2; slope = 0.97; and p = 0.0001). These results are directly applicable to Doppler TEE in the determination of mitral stenosis area by pressure half-time, whereby 21% to 32% of patients using the horizontal or vertical transesophageal planes may have a significant angle of incidence leading to underestimation of transmitral valve velocities. Future studies comparing Doppler TEE with cardiac catheterization are of interest. However, the present study suggests that Doppler TEE will play an important role in the hemodynamic assessment of the severity of mitral valve stenosis.

Aged↗
PubMed1994

Intravascular ultrasound imaging of a patent ductus arteriosus in an adult.

A small patent ductus arteriosus (PDA) is compatible with a normal life span. A non-restrictive PDA may present with signs of heart failure, supraventricular arrhythmia's, bacterial endocarditis or endarteritis later in life. Fewer than 50% of patients, including those with small shunts, are symptomatic by the age of 50. Considering that 40% of patients with PDA's will die before the age of 45 as a result of bacterial endocarditis or heart failure, closure of the PDA is recommended. Exceptions are patients with a nondilated heart, a right-to-left shunt, or age greater than 60 years old. Because of the wider use of echocardiography, especially transesophageal echocardiography, many PDA's are now detected incidentally in patients without symptoms.

Ductus Arteriosus, Patent↗
PubMed1993

Pulsed Doppler transesophageal echocardiographic determination of cardiac output in human beings: comparison with thermodilution technique.

Measurement of cardiac output is a clinically valuable and widely used index of cardiac function. Although transesophageal echocardiography has been used to assess left ventricular function, little data exist on the accuracy of this technique in the measurement of cardiac output. Therefore cardiac output derived by pulsed Doppler transesophageal echocardiography and thermodilution methods were compared in adult patients being mechanically ventilated. The left ventricular outflow tract diameter was determined from a transgastric long-axis view of the left ventricle by using the transverse plane and longitudinal plane of the transesophageal scope. The cross-sectional area of the left ventricular outflow tract was calculated from the diameter assuming a circular shape. Pulsed Doppler recordings were obtained at the left ventricular outflow tract. Doppler time-velocity integrals were measured from the leading edge of the velocity curve. Cardiac output derived by transesophageal echocardiography was calculated as time-velocity integral multiplied by left ventricular outflow tract area and heart rate. Cardiac output derived by transesophageal echocardiography from the transverse plane (n = 26) and longitudinal plane (n = 22) were correlated with simultaneous thermodilution measurements. Thermodilution-derived cardiac output demonstrated excellent correlation with cardiac output measured by using transesophageal echocardiography from the transverse plane (r = 0.97, SEE = 0.84 L/min; p < 0.0001) and longitudinal plane (r = 0.95, SEE = 0.97 L/min; p < 0.0001). Transesophageal echocardiography is a promising technique in the measurement of cardiac output and expands the clinical use of this modality in the assessment of cardiac function.

Adult↗
PubMed1993

Is the left main angulated, stenosed, or "bent" by the guiding catheter?

Exact angiographic and identification of significant stenosis of the left main coronary artery is imperative prior to performing elective percutaneous transluminal coronary angioplasty. A patient is presented with an apparent angiographically significant, but physiologically insignificant, left main stenosis. Both angiographic and physiological methods of detecting "false positive and negative" left main stenoses are discussed.

Aged↗
PubMed1990

Situation specific effects of stressor controllability on plasma corticosterone changes in mice.

The immediate and proactive effects of controllable and uncontrollable stressors on plasma corticosterone were assessed in CD-1 mice. A progressive increase of plasma corticosterone concentrations was associated with graded increases in stressor severity. When a footshock stressor was employed, however, the magnitude of the glucocorticoid response, as well as the decay of plasma corticosterone concentrations, was independent of stressor controllability. This was the case regardless of the number of escapable vs. yoked inescapable shock trials mice received, the spacing of shock trials (i.e., applied within a single session or spaced over days), or the degree to which the escape response had been established. In contrast, in a swim task stressor controllability influenced plasma corticosterone concentrations provided that the escape response required of the animal was a highly prepared one (i.e., swim to an illuminated region). When mice were required to emit a contraprepared response (swim to dark) corticosterone concentrations did not differ between escapable and inescapable swim. It is suggested that glucocorticoid secretion is a fundamental response to stressors, and the differential effects of controllable and uncontrollable stressors will be most apparent when the response required of the animal is a highly prepared one.

Animals↗
PubMed1986

Stressor-provoked response patterns in a swim task: modification by diazepam.

When placed in a water-filled arena in which one area is illuminated mice tend to remain in the illuminated region. Moreover, in a forced-swim task mice initially exhibit vigorous responding followed by a rapid decay of active swimming, and the adoption of a characteristic floating posture. Immediately following exposure to inescapable shock the response invigoration was appreciably enhanced, as was the tendency to remain in the illuminated region of the arena. Administration of low doses of diazepam (0.5 and 1.0 mg/kg) prior to testing effectively eliminated the response invigoration, as well as the response of approaching the illuminated region of the arena. It is proposed that the behavioral variations evident soon after uncontrollable shock are related to a transient increase of anxiety or vigilance. Moreover, it is suggested that several time-dependent behavioral variations associated with inescapable shock may be related to alterations of anxiety.

Animals↗
PubMed1984

Acute and chronic stress effects on performance in a forced-swim task.

The effects of uncontrollable stressors on performance in a subsequent forced-swim paradigm were assessed in mice. Uncontrollable shock initially induced behavioral invigoration; however, within 24 h of stressor application, swimming behavior was depressed relative to nonstressed mice. The controllability of the stressor did not influence the initial invigoration, being present among escapably shocked mice as well as among mice that received (yoked) inescapable shock. In contrast, the depression of responding evident 24 h after stressor application was related to the availability of behavioral coping methods. Finally, following repeated exposure to footshock there was no indication of adaptation to the behavioral changes ordinarily induced by acute shock stress. The data were related to the effects of uncontrollable stressors on escape performance, and with respect to the use of this preparation as an animal model of human depression.

Animals↗