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Biomedical subjects

E G Giardina

Publications and source records attributed to E G Giardina.

At least 19 recordsLinked to original sources

Effect of age on the exercise response in normal postmenopausal women during estrogen replacement therapy.

Postmenopausal estrogen replacement therapy (ERT) has been associated with a reduced risk of coronary artery disease (CAD). Whether this apparent cardioprotective effect is mediated by a cardiovascular benefit during exercise, however, has not been clearly defined. To evaluate rest and exercise variables with and without ERT, a randomized crossover trial was conducted in 23 postmenopausal women, ranging in age from 44 to 75 years, mean age 57+/-8 years. The rest and exercise variables were compared on ERT and during a drug-free period. The baseline measure was compared to the effects after 4 weeks of ERT and after 4 drug-free weeks. Echocardiographic treadmill exercise variables of heart rate (HR), blood pressure, rate-pressure product (RPP), and cardiac dimensions were determined at baseline and at the end of each treatment period. In response to ERT, there was a decrease in low-density lipoprotein (LDL) cholesterol (drug-free: 142+/-40 mg/dl, ERT: 124+/-34 mg/dl) and an increase in high-density lipoprotein (HDL) cholesterol (drug-free: 52+/-14 mg/dl, ERT: 62+/-15 mg/dl, both p<0.01). At rest, the study population had no overall significant change in HR, blood pressure, RPP, or left ventricular end-systolic and end-diastolic diameters when ERT was compared to the drug-free period. However, subjects with the fastest baseline resting HR had the greatest decrease in HR with ERT relative to the drug-free period (p<0.05). During exercise, ERT effected no change in peak HR, blood pressure, or RPP, although end-systolic diameter decreased slightly (p<0.05). With ERT, subject age correlated negatively with systolic blood pressure (p<0.05) and RPP (p<0.01); both blood pressure and RPP decreased in older subjects. In conclusion, ERT has differential effects dependent on baseline HR and age.

Adult↗

Cardiovascular effects of desipramine in children and adults during exercise testing.

OBJECTIVE: In light of recent reports of sudden death in children being treated with desipramine (DMI), 3 of which were associated with physical exercise, the authors examined the effects of DMI on exercise in children and adults before and during DMI treatment. METHOD: Before treatment, 22 subjects (9 children, 13 adults) participated in a graded treadmill exercise test. Outcome measures included exercise tolerance, cardiovascular, and electrocardiographic parameters at progressive intensity levels and serum norepinephrine (NE) levels before and after exercise testing. Subjects were then treated with DMI, titrated to an average DMI dosage of 3 mg/kg, and underwent repeated exercise testing. RESULTS: DMI treatment was associated with a significant elevation of circulating NE levels in the pre-exercise assessment. Exercise tolerance was not affected by DMI, and blood pressure and heart rate effects were modest. The cardiovascular impact of DMI treatment was similar in children and adults. One 31-year-old subject exhibited a brief episode of ventricular tachycardia associated with exercise during DMI treatment. CONCLUSIONS: DMI has only minor effects on the cardiovascular response to exercise, and these effects do not appear age-related. However, DMI may increase the risk of exercise-associated arrhythmias in rare individuals.

Adolescent↗

Effects of desipramine on autonomic input to the heart.

OBJECTIVE: To examine the impact of age on the effects of desipramine (DMI) on autonomic input to the heart. METHOD: Twenty-four-hour electrocardiograms were obtained from 42 subjects, aged 7 to 66 years, while off and on DMI. To obtain measures of autonomic input to the heart, heart rate variability was assessed via spectral analysis of RR interval variability. RESULTS: DMI treatment was associated with a significant increase in 24-hour mean heart rate and significant decreases in RR interval variability in all spectral bands, including in the high-frequency band, which provides a measure of parasympathetic input to the heart. RR interval variability was greater in younger individuals both off and on DMI. CONCLUSIONS: DMI treatment was associated with a marked decline in RR interval variability, indicating that DMI affects autonomic input to the heart. Specifically, DMI reduced parasympathetic input, which, in theory, may increase vulnerability to arrhythmias. However, the magnitude of DMI's impact on RR interval variability did not vary with age.

Adolescent↗

Call to action: cardiovascular disease in women.

One third of women between the ages of 50 and 75 have cardiovascular disease, which accounts for more than 50% of all deaths among women annually. Cardiovascular disease not only is the leading cause of death among women; it is more lethal and less aggressively treated in women than in men. Twice as many women--505,440--die from heart disease as from all forms of cancer combined. Despite the compelling statistics, only 8% of women consider cardiovascular disease a personal health threat. The scenario is troubling because women appear to understand so little or to deny their cardiac risks and so not recognize their ability to control them. Clearly, there is an urgent and compelling need for physicians to take an active role in identifying health behaviors that may affect the risk of cardiovascular disease in their female patients. Dialogue between the physician and patient should begin early to foster preventive steps, and the communication and education must continue throughout the patient's life span. Cardiovascular risk factors, including cigarette smoking, physical inactivity, hypertension, elevated cholesterol, overweight, diabetes, and menopause, should be identified and addressed for all women.

Age Distribution↗

Development of a prototype for a Center for Women's Health at an academic medical center.

The development of a centralized program in women's health is a challenge in a decentralized academic medical center and in the environment of healthcare transformation. The Center for Women's Health at the Columbia-Presbyterian Medical Center has allowed the clinical and educational abilities of an academic faculty interested in gender-specific health to operate in the delivery of coordinated care. Within the structure of an academic environment come advantages and unique opportunities for solving deficiencies in healthcare but also the need to overcome obstacles inherent in a large system. Flexibility and creative problem solving are key to meeting the challenges of the changing environment of healthcare. Here we describe ventures to develop a model program of clinical care and education in the gender science of women's health.

Academic Medical Centers↗

Estrogen replacement, vascular distensibility, and blood pressures in postmenopausal women.

The pathogenesis of blood pressure (BP) rise in aging women remains unexplained, and one of the many incriminating factors may include abnormalities in arteriolar resistance vessels. The aim of this study was to determine the effects of unopposed estrogen on arteriolar distensibility, baroreceptor sensitivity (BRS), BP changes, and rate-pressure product (RPP). We tested the hypotheses that estrogen replacement therapy (ERT) enhances arteriolar distensibility and ameliorates BRS, which leads to decreases in BP and RPP. Postmenopausal women participated in a single-blind crossover study; the participants of this study, after baseline measurements, were randomly assigned to receive estrogen (ERT) or a drug-free treatment with a 6-wk washout period between treatments. The single-blind design was instituted because subjects become unblinded due to physiological changes (i.e., fluid shifts, weight gain, and secretory changes) associated with estrogen intake. However, investigators and technicians involved in data collection and analyses remained blind. After each treatment, subjects performed identical autonomic tests, during which electrocardiograms, beat-by-beat BPs, and respiration were recorded. The area under the dicrotic notch of the BP wave was used as an index of arteriolar distensibility. The magnitude of the reflex bradycardia after a precipitous rise in BP was used to determine BRS. Power spectral analysis of heart rate variability was used to assess autonomic activity. BPs were recorded from resistance vessels in the finger using a beat-by-beat photoplethysmographic device. RPP, a noninvasive marker of myocardial oxygen consumption, was calculated. Repeated-measures analyses of variance revealed a significantly enhanced arteriolar distensibility and BRS after ERT (P < 0.05). A trend of a lower sympathovagal balance at rest was observed after ERT, however, this trend did not reach statistical significance (P = 0.061) compared with the other treatments. The above autonomic changes produced significantly lower systolic and diastolic BP changes and RPPs (P < 0.05) at rest and during isometric exercise. We conclude that short-term unopposed ERT favorably enhances arteriolar distensibility, BRS, and hemodynamic parameters in postmenopausal women. These findings have clinical implications in the goals for treating cardiovascular risk factors in aging women.

Arterioles↗

Cardiovascular effects of fluoxetine in depressed patients with heart disease.

OBJECTIVE: The purpose of this study was to determine the cardiovascular effects of fluoxetine in depressed patients with cardiac disease. METHOD: Twenty-seven depressed patients (26% of whom were female and whose average age was 73 years) who had congestive heart failure, conduction disease, and/or ventricular arrhythmia were studied in an open medication trial of fluoxetine, up to 60 mg/day, for 7 weeks. The main outcome measures were heart rate and rhythm measured by 24-hour ECG recordings, ejection fraction determined by radionuclide angiography, cardiac conduction intervals, and blood pressure. Baseline values were compared with those at weeks 2 and 7 of fluoxetine treatment. In 60 comparable patients, values of these same cardiovascular measures at baseline and after 3 weeks of treatment with a tricyclic antidepressant, nortriptyline, were also examined. RESULTS: Fluoxetine induced a statistically significant 6% decrease in heart rate, a 2% increase in supine systolic pressure, and a 7% increase in ejection fraction. There was no effect on cardiac conduction, ventricular arrhythmia, or orthostatic blood pressure. Overall, 4% of the fluoxetine patients had an adverse cardiovascular effect. In contrast, nortriptyline treatment caused a significant increase in heart rate and orthostatic hypotension, and 20% of the nortriptyline-treated patients had an adverse cardiovascular effect. CONCLUSIONS: In depressed patients with heart disease, fluoxetine treatment was not associated with the cardiovascular effects documented for the tricyclic antidepressants or with significant adverse cardiac events. However, limited conclusions about fluoxetine's cardiovascular effects and safety can be drawn from this study of only 27 patients monitored for 7 weeks.

Adult↗

Lack of effect of estrogen on rest and treadmill exercise in postmenopausal women without known cardiac disease.

To assess the peripheral vascular effects of estrogen in women without coronary disease, normal postmenopausal women (mean age 56 +/- 8 years) participated in a randomized, crossover trial using treadmill exercise echocardiography, and received oral conjugated estrogen, 0.625 mg/day or underwent a drug-free period. There was no significant effect on heart rate, blood pressure, double product, left ventricular end-systolic and end-diastolic diameters, or electrocardiographic measures after estrogen. In contrast to the profound effects reported in patients with cardiac disease, oral estrogen in normal women does not bestow significant benefit on treadmill exercise echocardiographic variables at rest or during modest levels of exercise.

Adult↗

Atrial fibrillation and stroke: elucidating a newly discovered risk factor.

Atrial fibrillation is the most common sustained arrhythmia reported in the United States; an estimated 1-2 million Americans have chronic nonvalvular atrial fibrillation. This disorder is associated with a substantial risk of stroke. Several recent studies provide evidence that anticoagulation therapy is indicated for stroke prevention in patients with nonvalvular atrial fibrillation after recovery from a minor stroke. Clinical and echocardiographic criteria help to identify those patients who are at especially high risk for thromboembolic stroke and are candidates for carefully controlled anticoagulation. In an effort to reduce the possibility of thromboembolic events following either chemical or electrical cardioversion, the American College of Chest Physicians has recently prepared guidelines for the use of anticoagulation in the conversion of atrial fibrillation. The efficacy of antiarrhythmic drug therapy for cardioversion is often difficult to assess. Furthermore, it is associated with major risks, including heart failure and exacerbation of arrhythmia, and minor risks, including systemic intolerance. A new National Institutes of Health trial, Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM), will clarify the true risks and benefits of antiarrhythmic therapy for conversion of atrial fibrillation to sinus rhythm. Patients who cannot tolerate drug therapy may benefit from interruption of conduction in the bundle of His, followed by implantation of a permanent pacemaker, the use of radiofrequency energy ablation, or the implantation of an atrial defibrillator. Some patients may benefit from surgical procedures, such as left atrial isolation, the corridor operation, and the maze operation.

Anti-Arrhythmia Agents↗

Increased early mortality in women undergoing cardiac transplantation.

BACKGROUND: To evaluate factors that explain sex differences affecting mortality after cardiac transplantation, a retrospective analysis of adult patients undergoing orthotopic cardiac transplantation was undertaken at the Columbia-Presbyterian Medical Center. METHODS AND RESULTS: The study population consisted of 379 patients (75 women, 304 men) > or = 18 years of age who survived for > or = 48 hours after undergoing orthotopic cardiac transplantation between March 1985 and March 1992. The following were analyzed: incidence of death and treated rejection episodes, donor and recipient cytomegalovirus (CMV) matches, use of OKT3 induction therapy, and donor and recipient HLA mismatches. Women 49 +/- 12 years old and men 47 +/- 12 years old were characterized by differences in race and diagnosis. Women were more likely to be nonwhite (P < .01) and have idiopathic cardiomyopathy than were men (P < .01). A trend toward an increase in first-year rejection frequency was seen in women compared with men (P = .08). Overall actuarial survival was significantly reduced in women after transplantation (P < .05). At 36 months, female actuarial survival was 64 +/- 7% versus 76 +/- 3% for men (P < .05). The majority of patients in this study did not receive CMV prophylaxis. Univariate analysis revealed that only CMV(+) donor status and the use of OKT3 induction therapy affected survival in women. Multivariate analysis revealed a marked reduction in survival in female recipients of CMV(+) donors given OKT3 induction therapy. At 36 months, only 25% of women were still alive compared with 86% of women with neither risk factor (P < .001). Even without OKT3 induction there was markedly reduced survival in women with mismatched CMV status, ie, CMV(-) recipients of CMV(+) donors; 17% survival after 36 months versus 86% in women who were CMV(+) recipients (P < .05). Although at this institution during the study time period, CMV prophylaxis was not routinely employed and OKT3 induction was selectively used in higher-risk patients, conclusions regarding differences in outcome that are sex dependent are valid. CONCLUSIONS: (1) Women are at risk for reduced actuarial survival up to 3 years after cardiac transplantation. (2) Univariate analysis shows that women are selectively at risk for death when receiving hearts from CMV(+) donors and after receiving OKT3 induction therapy. (3) Multivariate analysis reveals that women are at even greater risk for death when receiving hearts from CMV(+) donors in conjunction with OKT3 induction therapy. (4) In the absence of OKT3 use, the greatest risk of death occurs in CMV(-) women transplanted with CMV(+) donor hearts. (5) When female to male survival curves are compared, factors that influenced survival in women did not appear to be problematic in men.

Actuarial Analysis↗

Moricizine concentration to guide arrhythmia treatment: with attention to elderly patients.

To test the relationship between plasma moricizine concentration and the electrocardiogram (ECG) and arrhythmia suppression, 17 symptomatic cardiac patients with 30 or more ventricular premature complexes per hour were studied. Seven patients were mature adults, less than 60 years of age; and ten were elderly adults, more than 60 years of age. During steady-state moricizine therapy, patients had plasma moricizine concentration determined over a dosing interval, and had standard 12-lead ECG and a 24-hour ambulatory ECG recorded. The mean moricizine dose was 215 +/- 29 mg every 8 hours; mean maximal moricizine concentration was 1.4 +/- 0.84 micrograms/ml; and mean t1/2 beta was 1.5 +/- 0.7 hours. Baseline age-related differences were found, including prolonged electrocardiographic intervals (PR and QRS) (P < .05), increased ventricular arrhythmias (P < .05), and reduction in creatinine clearance (P < .05) in the elderly. Compared with pretreatment values, PR (P < .05) and QRS (P < .05) prolongation was observed, and was more marked in elderly patients. Over a dosing interval, there were dynamic changes on the ECG that paralleled plasma moricizine concentration; that is, peak and nadir intact moricizine concentration occurred simultaneously with ECG changes: QRS and JTc prolonged (P < .05), and PR prolongation approached significance (P = 0.09). Suppression of ventricular premature complexes of 80% or more occurred in 15 patients, and ventricular tachycardia was abolished in 10 of 12 patients. Probit analysis revealed that the therapeutic antiarrhythmic concentration ranged from 0.20 to 3.6 micrograms/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Effects of desipramine on autonomic control of the heart.

OBJECTIVE: To assess the effects of desipramine (DMI) on autonomic control of the heart. METHODS: Blood pressure, RR interval (the time between successive heart beats), and RR interval variability, a noninvasive measure of autonomic control of the heart, were assessed in 13 subjects younger than 30 years old. RESULTS: DMI treatment was associated with an increase in blood pressure, a decrease in RR interval, and a decline in low and high frequency RR interval variability. CONCLUSIONS: These preliminary data suggest that, in young people, DMI treatment produces a substantial decrease in parasympathetic input to the heart and an increase in the ratio of sympathetic to parasympathetic input, changes that in certain circumstances have been associated with an increased risk of arrhythmia. In exploring the cardiac effects of the tricyclic antidepressants (TCAs) in young people, the impact of TCAs on autonomic input to the heart should be examined.

Adolescent↗

Time course of moricizine's effect on signal-averaged and 12 lead electrocardiograms: insights into mechanism of action.

The mechanism of action of moricizine, a new antiarrhythmic agent used in the Cardiac Arrhythmia Suppression Trial, is incompletely characterized. In addition, because moricizine is extensively metabolized, plasma moricizine concentration has an unknown relation to myocardial drug effect. Signal-averaged and standard electrocardiograms (ECGs) were used to monitor moricizine's myocardial effects in 16 patients with frequent ventricular premature complexes taking 600 to 900 mg daily. Three signal-averaged ECG variables were measured: total filtered QRS duration (fQRS), root-mean-square voltage in the terminal 40 ms of the QRS complex (V40) and the terminal low amplitude duration less than 40 microV (LAS). At steady state, plasma samples were collected and serial recordings of signal-averaged and standard ECGs were taken at 0, 1, 2, 4, 6 and 8 h after moricizine administration. A 24 h ambulatory ECG was recorded throughout the test period. Moricizine prolonged the fQRS (p less than 0.05) and decreased the V40 (p less than 0.05) of the signal-averaged ECG and prolonged the QRS (p less than 0.05) and corrected JT (JTc) intervals (p less than 0.05) of the standard ECG. The time course of the signal-averaged and standard ECG variables paralleled plasma moricizine concentration; that is, the maximal changes occurred at 1 to 2 h and declined to time 0 values at 8 h. The maximal changes were: fQRS (+8%), V40 (-33%), QRS (+8%) and JTc (+4%). Thus, dynamic changes were observed for intraventricular conduction (fQRS, QRS) and ventricular repolarization (JTc) over the dosing interval.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Complexes, Premature↗

Cardiovascular effects of bupropion in depressed patients with heart disease.

OBJECTIVE: The cardiovascular effects of therapeutic plasma levels of tricyclic antidepressants in depressed patients with and without preexisting cardiac disease have been well characterized and include orthostatic hypotension and conduction delay. Bupropion, structurally unrelated to tricyclic antidepressants, is relatively free of cardiac side effects in depressed patients without cardiac disease. However, it is unknown whether bupropion is safe for depressed patients with preexisting heart disease, so the authors studied the cardiovascular effects of bupropion in such patients. METHOD: The subjects were 36 inpatients with DSM-III major depression and preexisting left ventricular impairment (N = 15), ventricular arrhythmias (N = 15), and/or conduction disease (N = 21). The patients continued their cardiac drug regimens and received bupropion for 3 weeks (mean +/- SD dose = 442 +/- 47 mg/day). Cardiovascular functioning was measured by pulse, blood pressure, high-speed ECG, 24-hour portable ECG, and radionuclide angiography. RESULTS: Although bupropion caused a rise in supine blood pressure, it did not cause significant conduction complications, did not exacerbate ventricular arrhythmias, had a low rate of orthostatic hypotension, and had no effect on pulse rate. However, bupropion treatment was discontinued for 14% of the patients because of adverse effects, including exacerbation of baseline hypertension in two patients. CONCLUSIONS: The cardiovascular profile of bupropion may make this drug a useful agent in the treatment of the depressed patient with preexisting cardiovascular disease. Further studies, with longer durations of bupropion treatment and more subjects, are needed to confirm these findings.

Aged↗

Is doxepin a safer tricyclic for the heart?

BACKGROUND: Many clinicians believe that doxepin is the safest tricyclic with respect to cardiovascular effects. This belief has persisted for two decades despite the absence of rigorous prospective evaluation. METHOD: To address this issue, the authors studied the cardiovascular effects of doxepin in 32 depressed patients with preexisting left ventricular impairment, ventricular arrhythmias, and/or conduction disease. RESULTS: Doxepin (1) did not have a robust effect on heart rate, (2) did not adversely affect left ventricular function, (3) did have a significant antiarrhythmic effect, (4) slowed cardiac conduction, and (5) caused a significant increase in orthostatic hypotension. Five (16%) of the 32 patients dropped out due to cardiovascular side effects. The overall dropout rate was 41%. CONCLUSIONS: The cardiovascular effects of doxepin in depressed patients with heart disease are comparable to those documented for imipramine and nortriptyline. Doxepin afforded no greater margin of cardiovascular safety; in fact, the drug was poorly tolerated by this patient population.

Aged↗

Low dose quinidine-mexiletine combination therapy versus quinidine monotherapy for treatment of ventricular arrhythmias.

Low dose quinidine-mexiletine combination therapy was compared with quinidine monotherapy in 15 patients with frequent ventricular premature complexes and nonsustained ventricular tachycardia in a dose escalation cross-over study. Oral combination therapy was initiated with quinidine gluconate (165 mg) plus mexiletine (150 mg) every 8 h. If ventricular premature complexes were not suppressed greater than or equal to 80% and nonsustained ventricular tachycardia greater than or equal to 90%, the dose was increased to a maximum of 330 mg of quinidine plus 200 mg of mexiletine. Quinidine monotherapy was initiated with 330 mg and escalated to a maximum of 660 mg every 8 h if criteria for effectiveness were not met. Combination quinidine-mexiletine therapy suppressed 80% of ventricular premature complexes in 13 of 14 patients and suppressed 100% of episodes of ventricular tachycardia in 6 of 8 patients (mean quinidine dose 200 +/- 70 mg; mean mexiletine dose 146 +/- 24 mg every 8 h). The mean effective trough quinidine and mexiletine concentration was 1.0 +/- 0.7 and 0.9 +/- 0.4 microgram/ml, respectively. Monotherapy was less effective; that is, greater than or equal to 80% suppression of ventricular premature complexes was observed in 5 of 15 patients and 100% suppression of ventricular tachycardia in 2 of 9 patients. The mean quinidine monotherapy dose was 462 +/- 155 mg every 8 h; the mean quinidine concentration was 1.8 +/- 0.8 microgram/ml. Adverse systemic effects occurred in 3 patients on quinidine-mexiletine therapy and in 11 on quinidine monotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗

Myocardial amiodarone and desethylamiodarone concentrations in patients undergoing cardiac transplantation.

Myocardial amiodarone and desethylamiodarone concentrations were measured at multiple sites in the explanted heart in four patients who underwent cardiac transplantation. Patients were taking amiodarone, 200 to 400 mg/day (mean 300 +/- 115), for 88 to 428 days (mean 229 +/- 148). The mean cumulative dose was 58 +/- 21.3 g. Plasma amiodarone concentration in three subjects was 204, 312 and 419 ng/ml and desethylamiodarone concentration was 268, 513 and 880 ng/ml, respectively. Significant interindividual variability in myocardial concentrations of amiodarone and desethylamiodarone was observed (p less than 0.05). Mean myocardial amiodarone concentration ranged from 4 +/- 1.0 to 29 +/- 17.2 micrograms/g (p less than 0.05); mean desethylamiodarone concentration ranged from 22 +/- 8.8 to 141 +/- 102.5 micrograms/g (p less than 0.05). At each site, save for fat, myocardial desethylamiodarone concentration was higher than amiodarone concentration. Greater intraindividual variability was observed in myocardial desethylamiodarone compared with amiodarone concentration particularly in septal and scar tissue (p = NS). No significant relation was found between myocardial concentration and duration of treatment. In patients with significant ventricular disease, usefulness of plasma amiodarone and desethylamiodarone concentration to estimate myocardial concentration is limited by intra- and interindividual variability.

Amiodarone↗