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J T Bigger

Publications and source records attributed to J T Bigger.

At least 37 records · Page 2Linked to original sources
PubMed1998

Epicardial cardioverter-defibrillators do not cause postoperative arrhythmias. The CABG Patch Trial Investigators. Coronary Artery Bypass Graft.

The CABG Patch Trial is a controlled, multicenter clinical trial that randomized high-risk patients undergoing coronary artery bypass grafting (CABG) to prophylactic implantation of an epicardial implantable cardioverter-defibrillator (ICD) or to no additional treatment, permitting a controlled evaluation of the effect of epicardial ICDs on the incidence of postoperative arrhythmias. We found no significant difference in the development of postoperative arrhythmias between patients who received epicardial ICDs and the control group treated with CABG alone.

Aged↗
PubMed1998

Baroreflex sensitivity and heart-rate variability in prediction of total cardiac mortality after myocardial infarction. ATRAMI (Autonomic Tone and Reflexes After Myocardial Infarction) Investigators.

BACKGROUND: Experimental evidence suggests that autonomic markers such as heart-rate variability and baroreflex sensitivity (BRS) may contribute to postinfarction risk stratification. There are clinical data to support this concept for heart-rate variability. The main objective of the ATRAMI study was to provide prospective data on the additional and independent prognostic value for cardiac mortality of heart-rate variability and BRS in patients after myocardial infarction in whom left-ventricular ejection fraction (LVEF) and ventricular arrhythmias were known. METHODS: This multicentre international prospective study enrolled 1284 patients with a recent (<28 days) myocardial infarction. 24 h Holter recording was done to quantify heart-rate variability (measured as standard deviation of normal to normal RR intervals [SDNN]) and ventricular arrhythmias. BRS was calculated from measurement of the rate-pressure response to intravenous phenylephrine. FINDINGS: During 21 (SD 8) months of follow-up, the primary endpoint, cardiac mortality, included 44 cardiac deaths and five non-fatal cardiac arrests. Low values of either heart-rate variability (SDNN <70 ms) or BRS (<3.0 ms per mm Hg) carried a significant multivariate risk of cardiac mortality (3.2 [95% CI 1.42-7.36] and 2.8 [1.24-6.16], respectively). The association of low SDNN and BRS further increased risk; the 2-year mortality was 17% when both were below the cut-offs and 2% (p<0.0001) when both were well preserved (SDNN >105 ms, BRS >6.1 ms per mm Hg). The association of low SDNN or BRS with LVEF below 35% carried a relative risk of 6.7 (3.1-14.6) or 8.7 (4.3-17.6), respectively, compared with patients with LVEF above 35% and less compromised SDNN (> or = 70 ms) and BRS (> or = 3 ms per mm Hg). INTERPRETATION: ATRAMI provides clinical evidence that after myocardial infarction the analysis of vagal reflexes has significant prognostic value independently of LVEF and of ventricular arrhythmias and that it significantly adds to the prognostic value of heart-rate variability.

Aged↗
PubMed1998

Comparison of paroxetine and nortriptyline in depressed patients with ischemic heart disease.

CONTEXT: Depression and ischemic heart disease often are comorbid conditions and, in patients who have had a myocardial infarction, the presence of depression is associated with increased mortality. Patients with heart disease need a safe and effective treatment for depression. OBJECTIVE: To compare the efficacy, cardiovascular effects, and safety of a specific serotonin reuptake inhibitor, paroxetine, with a tricyclic antidepressant, nortriptyline hydrochloride, in depressed patients with ischemic heart disease. DESIGN: Two-week placebo lead-in followed by a double-blind randomized 6-week medication trial. SETTING: Research clinics in 4 university centers. PATIENTS: Eighty-one outpatients meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for major depressive disorder and with documented ischemic heart disease. INTERVENTIONS: Treatment with either paroxetine, 20 to 30 mg/d, or nortriptyline targeted to a therapeutic plasma level, 190 to 570 nmol/L (50-150 ng/mL), for 6 weeks. MAIN OUTCOME MEASURES: For effectiveness of treatment, a decline in the score of the Hamilton Rating Scale for Depression by 50% and final score of 8 or less; for cardiovascular safety, heart rate and rhythm, supine and standing systolic and diastolic blood pressures, electrocardiogram conduction intervals, indexes of heart rate variability, and rate of adverse events. RESULTS: By intent-to-treat analysis, 25 (61%) of 41 patients improved during treatment with paroxetine and 22 (55%) of 40 improved with nortriptyline. Neither drug significantly affected blood pressure or conduction intervals. Paroxetine had no sustained effects on heart rate or rhythm or indexes of heart rate variability, whereas patients treated with nortriptyline had a sustained 11% increase in heart rate from a mean of 75 to 83 beats per minute (P<.001) and a reduction in heart rate variability, as measured by the SD of all normal R-R intervals over a 24-hour period, from 112 to 96 (P<.01). Adverse cardiac events occurred in 1 (2%) of 41 patients treated with paroxetine and 7 (18%) of 40 patients treated with nortriptyline (P<.03). CONCLUSIONS: Paroxetine and nortriptyline are effective treatments for depressed patients with ischemic heart disease. Nortriptyline treatment was associated with a significantly higher rate of serious adverse cardiac events compared with paroxetine.

Adrenergic Uptake Inhibitors↗
PubMed1998

Changes in sample size and length of follow-up to maintain power in the coronary artery bypass graft (CABG) patch trial.

The CABG Patch Trial is testing the hypothesis that prophylactic use of implantable cardiac defibrillators (ICDs) will improve survival in high-risk coronary heart disease patients undergoing CABG surgery. The original design called for 800 patients to be randomized to ICD prophylaxis or to no therapy and followed for 2 to 6.5 years (average, 40 months) to a common termination date. Since the ICD pulse generators used in this trial lasted about 42 months, the original design required ICD replacement in many patients. At its first two meetings in 1993, the Data and Safety Monitoring Board (DSMB) formalized a plan to adjust sample size in October 1994 if the control group mortality rate was lower than expected. In June 1994, an unanticipated and unique event--a subpoena from the Office of the Inspector General (OIG)--made it impossible to replace about half of the ICD generators and threatened to shorten follow-up substantially. If follow-up had been stopped on the date originally planned, but without replacing ICDs, the average follow-up would have fallen from 40 months to about 33 months. Also, in October 1994, the control group mortality rate was found to be somewhat lower than expected. Together, the abbreviated follow-up and lower control group mortality threatened to reduce power substantially. The DSMB reviewed several options for restoring power. Because mortality rates in the first month after CABG surgery were about seven times as high as thereafter and because ICD therapy did not reduce surgical mortality (death during the first 30 days), extending the follow-up benefits power more than does increasing the sample size. However, the limit on extending follow-up was 42 months (the expected battery life of the ICD). Data from the ICD-treated group was not reviewed or considered in making the decision. After reviewing many options for restoring power, the DSMB recommended that the sample size be increased from 800 to 900 patients and that almost all patients be followed for 42 months. This recommendation extended follow-up for 2 years beyond the original termination date planned for the trial and dictated that patients close out after 42 months rather than on a common termination date.

Cause of Death↗
PubMed1998

R-R variability detects increases in vagal modulation with phenylephrine infusion.

High-frequency power, measured from power spectral analysis of R-R variability, reflects vagal modulation of the sinus node. Unexpectedly, a recent study reported a decrease in high-frequency power during the infusion of phenylephrine despite a prolongation of R-R intervals, indicating an increase in vagal activity. To better define the limitations of high-frequency power to quantify vagal modulation, we measured high-frequency power during the infusion of phenylephrine (0.4, 0.8, and 1.2 micrograms.kg-1.min-1) into 10 normal subjects. We found increasing doses of phenylephrine produced progressive increases in systolic blood pressure from 118 +/- 4 to 129 +/- 5 mmHg (P < 0.005), R-R intervals from 881 +/- 44 to 1,274 +/- 69 ms (P < 0.0001), and the logarithm of high-frequency power from 5.83 +/- 0.22 to 7.73 +/- 0.24 ln(ms2) (P < 0.0001). The conclusion was high-frequency power increases with increasing doses of phenylephrine. These data strongly support the ability of high-frequency power to detect an increase in vagal modulation during baroreceptor activation from an increase in systolic blood pressure with the infusion of phenylephrine.

Adult↗
PubMed1998

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↗
PubMed1997

Prophylactic use of implanted cardiac defibrillators in patients at high risk for ventricular arrhythmias after coronary-artery bypass graft surgery. Coronary Artery Bypass Graft (CABG) Patch Trial Investigators.

BACKGROUND: Patients with coronary heart disease, left ventricular dysfunction, and abnormalities on signal-averaged electrocardiograms have an increased risk sudden death. We evaluated the effect on survival of the prophylactic implantation of cardioverter-defibrillators in such patients at the time of coronary-artery bypass surgery. METHODS: Over the course of five years, 37 clinical centers screened all patients who were scheduled for elective coronary bypass surgery. Patients were eligible for the trial if they were less than 80 years old, had a left ventricular ejection fraction of less than 0.36, and had abnormalities on signal-averaged electrocardiograms. We identified 1422 eligible patients, enrolled 1055, and randomly assigned 900 to therapy with an implantable cardioverter-defibrillator (446 patients) or to the control group (454 patients). The primary end point of the study was overall mortality, and the two groups were compared in an intention-to-treat analysis. RESULTS: The base-line characteristics of the two groups were similar. During an average follow-up of 32+/-16 months, there were 101 deaths in the defibrillator group (71 from cardiac causes) and 95 in the control group (72 from cardiac causes). The hazard ratio for death from any cause was 1.07 (95 percent confidence interval, 0.81 to 1.42; P=0.64). There was no statistically significant interaction between defibrillator therapy and any of 10 preselected base-line covariates. CONCLUSIONS: We found no evidence of improved survival among patients with coronary heart disease, a depressed left ventricular ejection fraction, and an abnormal signal-averaged electrocardiogram in whom a defibrillator was implanted prophylactically at the time of elective coronary bypass surgery.

Aged↗
PubMed1997

Long-term carvedilol therapy increases parasympathetic nervous system activity in chronic congestive heart failure.

To determine the effect of beta blockade on parasympathetic nervous system activity, we assessed RR variability during 24-hour Holter monitoring in 10 patients with congestive heart failure before and after 3 to 4 months of treatment with the beta blocker carvedilol. High-frequency power increased from 26 to 64 ms2, root-mean-square of successive differences in RR interval increased from 14.3 to 23.7 ms2, and percentage of absolute differences >50 ms between successive normal RR intervals increased from 0.8% to 4.7%, all p <0.01, indicating a substantial increase in parasympathetic modulation of RR intervals.

Adrenergic beta-Antagonists↗
PubMed1997

Passive head-up tilt and actively standing up produce similar overall changes in autonomic balance.

The primary objective of this study was to compare, in normal subjects, the average change in autonomic balance during a 5-minute period by using two methods of changing posture: actively standing up and passive head-up tilt. We hypothesized that the average effect of these two methods of changing posture on autonomic balance would not significantly differ. After collecting supine baseline measurements, subjects were first tilted head up to 60 degrees for 15 minutes, then returned to the supine position for 5 minutes, before they stood up for 5 minutes. Comparing the average (over a 5-minute period) autonomic response to head-up tilt with that of standing, there were no significant differences in the decrease in average R-R intervals (-18% vs -18%, p = not significant), the drop in high-frequency power (-73% vs -69%, p = not significant), or the increase in the low-frequency/high-frequency ratio (+252% vs +298%, p = not significant). The changes in autonomic balance that occur during the first 5 minutes of passive 60-degree head-up tilt are nearly identical to the change in autonomic balance that occurs during the first 5 minutes of quiet standing.

Autonomic Nervous System↗
PubMed1997

Baseline characteristics of patients in the coronary artery bypass graft (CABG) Patch Trial.

BACKGROUND: Patients with left ventricular dysfunction who undergo coronary artery bypass graft (CABG) surgery frequently have late sudden cardiac death. The CABG Patch Trial is a prospective, randomized, multicenter clinical trial that randomized patients at high risk at the completion of CABG surgery to implantation of an epicardial implantable cardioverter defibrillator (ICD) or to no antiarrhythmic treatment. The trial was designed to determine whether prophylactic implantation of an ICD at the time of CABG surgery would result in a lower total mortality in long-term follow-up. METHODS: Patients undergoing CABG surgery were eligible for the trial if they were younger than 80 years, had a left ventricular ejection fraction less than 0.36, and had an abnormal signal averaged electrocardiogram. Patients with a history of sustained ventricular tachycardia or ventricular fibrillation were excluded from the trial. All patients were scheduled to undergo follow-up at 3-month intervals until 42 months after surgery. RESULTS: Randomization of patients in the trial ended in February 1996. During the recruitment period 71,855 patients were screened, 1,422 were eligible, 1,055 were enrolled (signed consent forms), and 900 patients (76% of eligible patients) were randomized. The mean age of the 446 patients in the ICD group was 64 years versus 63 years for the 454 patients in the control group. A total of 87% of the participants in the ICD group were men versus 82% in the control group (p = NS). Most of the patients had a history of hypertension (55%), smoking (78%), and hypercholesterolemia (54%). Half of the patients had clinical heart failure, and the mean ejection fraction for both patient groups was 0.27 +/- 0.06. No difference was seen in the history of myocardial infarction (83%), congestive heart failure (50%), or atrial (11%) or ventricular (17%) arrhythmias between the two groups. Major clinical characteristics (age, sex, number of previous infarctions, incidence of heart failure, and mean left ventricular ejection fraction) were almost identical to those found in another ICD primary prevention trial, the Multicenter Automatic Defibrillator Implantation Trial (MADIT). CONCLUSIONS: A high risk sample of patients was enrolled in The CABG Patch Trial, as shown by examination of their baseline characteristics.

Adult↗
PubMed1997

Physical fitness as a determinant of vagal modulation.

The association between increasing age and decreasing vagal modulation is well known. However, the importance of fitness as a determinant of the decline in vagal modulation with age is not established. To test the hypothesis that decreasing vagal modulation is largely a function of declining fitness rather than increasing age, we studied a sample of healthy volunteers with a wide range of fitness levels, but a narrow age range. We assessed fitness by measuring the maximal oxygen uptake (VO2max) achieved during incremental bicycle exercise. Vagal modulation was assessed by calculating high frequency power (0.15-0.40 Hz) of the RR variability power spectrum from 24-h ECG recordings. We studied 37 healthy volunteers who were 22-44 yr old. In our sample, VO2max ranged from 25 to 70 mL.min-1.kg-1 (mean of 45 +/- 13). Age was not significantly related to high frequency power, but VO2max was highly correlated with high frequency power (r = 0.74, P = 0.0001), indicating that physical fitness is strongly associated with vagal modulation. Thus, the decline in vagal modulation often attributed to increasing age may, instead, be the result of a decline in fitness.

Adult↗
PubMed1997

Heart rate variability: origins, methods, and interpretive caveats.

Components of heart rate variability have attracted considerable attention in psychology and medicine and have become important dependent measures in psychophysiology and behavioral medicine. Quantification and interpretation of heart rate variability, however, remain complex issues and are fraught with pitfalls. The present report (a) examines the physiological origins and mechanisms of heart rate variability, (b) considers quantitative approaches to measurement, and (c) highlights important caveats in the interpretation of heart rate variability. Summary guidelines for research in this area are outlined, and suggestions and prospects for future developments are considered.

Animals↗
PubMed1996

Surgical aspects of a randomized trial of defibrillator implantation during coronary artery bypass surgery. The CABG Patch Trial.

BACKGROUND: Whether prophylactic insertion of an implantable cardioverter defibrillator (ICD) improves the survival of high-risk patients undergoing coronary artery bypass graft surgery (CABG) is being assessed in the CABG Patch Trial. This report describes the surgical aspects of the study. METHODS AND RESULTS: As of February 28, 1995, 847 patients (1.6% of 54102 screened) were enrolled and eligible for randomization to CABG or CABG plus ICD. Intraoperatively, 56 were eliminated by postenrollment exclusions, 67 were judged too unstable for randomization, and 724 were randomized (80% of the goal of 900). The average preoperative ejection fraction was 0.27 +/- 0.06 (n = 724); left ventricular (LV) end-diastolic pressure averaged 22 +/- 12 mm Hg (n = 548) Cardiopulmonary bypass (CPB) time averaged 108 minutes in control subjects, 126 minutes in the ICD group. After CPB, mechanical support was employed in 23% of patients and inotropic support in 73%; shock occurred in 8% and deep sternal wound infection in 1.3%. The surgical mortality was 6%; median length of stay was 8 days. Compared with randomized patients, patients whom surgeons judged too unstable to randomize were distinguished by statistically significant increases in mechanical support after CPB (51% versus 23%, P < .05) and postoperative shock (19% versus 8%, P < .05). Also, surgical mortality was greater (9% versus 6%) but was not statistically significant. CONCLUSIONS: The initial phases of the CABG Patch Trial have been conducted with acceptable surgical mortality, morbidity, and length of stay. Surgical exclusion of some patients from randomization has been corroborated by data indicating hemodynamic instability. This trial will provide information about the risks and outcome of CABG surgery in patients with impaired LV function.

Aged↗
PubMed1996

Power law behavior of RR-interval variability in healthy middle-aged persons, patients with recent acute myocardial infarction, and patients with heart transplants.

BACKGROUND: The purposes of the present study were (1) to establish normal values for the regression of log(power) on log(frequency) for, RR-interval fluctuations in healthy middle-aged persons, (2) to determine the effects of myocardial infarction on the regression of log(power) on log(frequency), (3) to determine the effect of cardiac denervation on the regression of log(power) on log(frequency), and (4) to assess the ability of power law regression parameters to predict death after myocardial infarction. METHODS AND RESULTS: We studied three groups: (1) 715 patients with recent myocardial infarction; (2) 274 healthy persons age and sex matched to the infarct sample; and (3) 19 patients with heart transplants. Twenty-four-hour RR-interval power spectra were computed using fast Fourier transforms and log(power) was regressed on log(frequency) between 10(-4) and 10(-2) Hz. There was a power law relation between log(power) and log(frequency). That is, the function described a descending straight line that had a slope of approximately -1 in healthy subjects. For the myocardial infarction group, the regression line for log(power) on log(frequency) was shifted downward and had a steeper negative slope (-1.15). The transplant (denervated) group showed a larger downward shift in the regression line and a much steeper negative slope (-2.08). The correlation between traditional power spectral bands and slope was weak, and that with log(power) at 10(-4) Hz was only moderate. Slope and log(power) at 10(-4) Hz were used to predict mortality and were compared with the predictive value of traditional power spectral bands. Slope and log(power) at 10(-4) Hz were excellent predictors of all-cause mortality or arrhythmic death. To optimize the prediction of death, we calculated a log(power) intercept that was uncorrelated with the slope of the power law regression line. We found that the combination of slope and zero-correlation log(power) was an outstanding predictor, with a relative risk of > 10, and was better than any combination of the traditional power spectral bands. The combination of slope and log(power) at 10(-4) Hz also was an excellent predictor of death after myocardial infarction. CONCLUSIONS: Myocardial infarction or denervation of the heart causes a steeper slope and decreased height of the power law regression relation between log(power) and log(frequency) of RR-interval fluctuations. Individually and, especially, combined, the power law regression parameters are excellent predictors of death of any cause or arrhythmic death and predict these outcomes better than the traditional power spectral bands.

Adult↗
PubMed1996

Patency of infarct-related artery. Effect of restoration of anterograde flow on vagal reflexes. ATRAMI (Automatic Tone and Reflexes After Myocardial Infarction) Investigators.

BACKGROUND: In post-myocardial infarction (MI) patients, the restoration of anterograde flow in the infarct-related artery (IRA) significantly improves survival. Limitation of infarct size and increased electrical stability of the myocardium are likely operating mechanisms for this beneficial effect. We tested the hypothesis that patency of the IRA may enhance vagal reflexes, a factor known to affect electrical stability of the infarcted myocardium. METHODS AND RESULTS: Analysis of angiographic data was performed in 359 of 1284 post-MI patients enrolled in a multicenter prospective study within 8 weeks after the index MI. All the patients underwent baroreflex sensitivity (BRS) assessment by the phenylephrine method. The BRS of the entire population averaged 8.2+/-5.5 ms/mm Hg and was significantly related to age but not to ejection fraction (EF). One-, two-, and three-vessel disease was present in 138, 96, and 99 patients, respectively, while no coronary stenosis was observed in 26. IRA patency was documented in 234 patients (65%), while in the remaining 125 (35%), the artery remained occluded. Patients with occluded IRAs had more extensive coronary disease (2 to 3 vessels, 71% versus 46%, P<.01) and more depressed left ventricular (LV) function (LVEF, 48+/-13% versus 53+/-12%, P<.001). Patency of the IRA was associated with higher BRS values (BRS, 8.9+/-5.8 versus 7.1+/-4.7 ms/mm Hg, P<.005) and with a lower incidence (9% versus 18% P<.02) of markedly depressed BRS (<3 ms/mm Hg), a condition suggested by preliminary studies to be associated with an increased risk of post-MI mortality. The association between IRA patency and BRS was more evident in anterior than in inferior MI. Multivariate regression analysis showed that age of the patient and patency of the IRA were the major independent determinants of BRS, while LVEF was weakly related to BRS and only when analyzed as a categorized variable. CONCLUSIONS: The presence of an open IRA is associated with higher baroreflex sensitivity, and this effect is largely independent of limitation of infarct size by IRA patency. These data offer new insights into the mechanisms by which coronary artery patency may affect cardiac electrical stability and survival.

Adult↗
PubMed1996

Clinical trial enrollers vs. nonenrollers: the Cardiac Arrhythmia Suppression Trial (CAST) Recruitment and Enrollment Assessment in Clinical Trials (REACT) project.

The Recruitment and Enrollment Assessment in Clinical Trials (REACT) was a National Heart, Lung, and Blood Institute (NHLBI)-sponsored substudy to the Cardiac Arrhythmia Suppression Trial (CAST). Two-hundred-sixty (260) patients who enrolled in CAST and 140 partially or fully eligible patients who did not enroll were compared across several parameters, including demographic variables, disease severity, psychosocial functioning, health beliefs, recruitment experience, and understanding of informed consent procedures used in CAST. Significant predictors of enrollment included several demographic variables (e.g., being male, not having medical insurance), episodes of ventricular tachycardia, and health beliefs (e.g., extra beats are harmful, a higher degree of general health concern). Enrollment was higher for those who read and understood the informed consent and those who were initially recruited after hospital discharge, particularly nondepressed patients. In the multivariate model, the key variables that emerged were the patient's reading of the informed consent form and the patient's lack of medical insurance. These results suggest that (1) the clinical trial staff's interaction with the patient and the time when recruitment is initiated contribute significantly to the decision to enroll; and (2) it may be a greater challenge to motivate patients to enroll in future clinical trials if health care reform improves access to medical insurance coverage. Some of the significant variables are modifiable, suggesting interventions that may increase enrollment rates in future trials.

Aged↗
PubMed1996

Heart rate reactivity and heart period variability throughout the first year after heart transplantation.

Heart rate reactivity to mental stress is substantially blunted early after heart transplantation, suggesting that the loss of neural modulation limits the cardiovascular response to mental stress. We tested whether reactivity to mental stress recovers during the first year after heart transplantation. Hemodynamic and respiratory responses to mental arithmetic challenge were studied in 20 heart transplant recipients 3, 6, and 12 months after surgery. A normal comparison group was studied at equivalent intervals. Heart rate reactivity to mental arithmetic was significantly reduced in the cardiac transplant group compared to the normal subjects. This effect persisted up to 1 year after transplantation. Heart period variability in the heart transplant recipients was minimal in all three test sessions. The findings suggest that no functional reinnervation or other compensatory adaptation occurs up to 1 year after heart transplantation.

Female↗