Assessment of speech perception and communication skills in adolescents with cochlear implants for pre- and peri-lingual deafness.

OBJECTIVE: This study aimed to assess speech perception and communication skills in adolescents between ages 8 and 18 that received cochlear implants for pre- and peri-lingual deafness. METHODS: We studied 15 adolescents, aged 12 to 23 years, with late cochlear implantation. Speech perception was assessed with the Bishop sentences test and a memory number sequence test at 3-9 years after cochlear implantation. A questionnaire completed retrospectively was used to investigate communication skills pre- and post implantation. RESULTS: Six individuals achieved grammar comprehension scores comparable to children 8-10 years old with normal hearing; only 3 individuals achieved a percentile rank higher than 50% in the memory number sequence test. The self-reported communication skills improved after cochlear implantation in all adolescents. CONCLUSIONS: Speech perception skills of adolescents with late implantation for pre- and peri-lingual deafness are typically inferior to those of children with normal hearing at the age of 10. However, when the evaluation of the cochlear implant outcome was broadened with the use of a questionnaire, many individuals reported that they participated more actively in conversations, spoke more actively to unknown individuals, and were more easily understood by others.

Radiation dose reduction in computer assisted navigation for functional endoscopic sinus surgery--cadaver head experiments and clinical implementation.

OBJECTIVES: Computed tomography based navigation for endoscopic sinus surgery is inflationary used despite of major public concern about iatrogenic radiation induced cancer risk. Studies on dose reduction for CAS-CT are almost nonexistent. We validate the use of radiation dose reduced CAS-CT for clinically applied surface registration. METHODS: Dose reduced CAS-CT of mineral salt fixed, human cadaver heads with 9.6, 6, 4, 2 and 1.1 mGy were compared with the reference dose at 65 mGy CTDI (CT-Dose Index). For each CT dose with different surface resolution, the precision of the soft touch registration was measured with target registration error (TRE). In a practical step, dose reduced protocols were tested for 12 months. RESULTS: Using surface registration at highest and lowest doses, TRE did not differ significantly for registration accuracy. Protocols tested preserved technical registration accuracy and the pragmatics of dose reduction was limited only by different needs for picture quality of the individual surgeon, use for uncomplicated or revision surgery, and reserve for other unexpected factors (movement artifacts). CONCLUSIONS: The accuracy of today's surface registration technology was not the limit for dose reduction. It is the amount of diminished picture quality tolerated by the individual surgeon and the question of how much of the ever refined radiological picture resolution is necessary at all. For the majority of operations, consensus for a significant 6-fold radiation dose reduction from 65 mGy to 9.6 mGy CTDI could be realized illustrating a big potential for similar approaches in other institutions.

Hydrodissection for subperichondrial septoplasty - an experimental anatomical study.

OBJECTIVES: The effect of hydrostatic infiltrations for subperichondrial dissection is controversial. Classical textbooks promote it as the "key step in elevating the flaps" or consider its practicability "a mere fable". Moreover, case reports describe fatal side effects. Up to now, experimental tests are missing. DESIGN: Experimental study. MATERIALS AND METHODS: Three surgeons simulated subperichondrial hydrodissection with 20 mineral salt fixed human cadaver heads. One ml lidocaine 5% with 1:105 adrenaline and India ink was infiltrated. Each septum was examined histologically using serial 3 microm sections in 150 microm intervals. Tissue cleavage containing the ink deposits with minimal distance to the proposed subperichondrial zone, intravasal spread and tissue deposition were analyzed. RESULTS: Every injection produced a physical dissection (n = 20). However, dissected planes were localized mostly in the supra-perichondrial connective tissue (n = 8) or within the perichondrium (n = 4). Only five cases showed the propagated correct dissection in a subperichondrial zone. Three anomalous septa were excluded from quantitative analysis. Infiltrated matter did not only accumulate within the dissection plane but also penetrated the surrounding vessels of the septal intumescentia (n = 8). CONCLUSION: Hydrostatic infiltrations represent an unreliable surgical technique for dissection of an anatomical correct subperichondrial plane but can be useful for anesthesia and hemostasis, however, using high pressure and high volume infiltrations might foster serious side effects.

[Spontaneous dural arterio-venous fistula at the cavernous sinus: detected by decompensation following endoscopic sinus surgery]. / Spontane durale arteriovenöse Fistel am Sinus cavernosus: Demaskierung nach endoskopischer Nasennebenhöhlen-Operation.

Spontaneous dural arterio-venous fistulas can imperceptibly develop over a long time period before they suddenly develop symptoms like bruit, loss of vision, exophthalmos and conjunctival injection. We present the rare case of an occult, para-infectious, dural arterio-venous fistula which became symptomatic after endoscopic sinus surgery. Conjunctival injection and slight exophthalmos developed due to decompensation of venous drainage probably by intraoperative positioning of the patient, positive pressure ventilation and nasal packing.

Does the rest electrocardiogram after myocardial infarction determine the predictive value of exercise-induced ST depression? A 2 year follow-up study in a veteran population.

The failure of exercise-induced ST segment depression to consistently predict prognosis in patients after myocardial infarction could be a result of population differences and the rest electrocardiogram (ECG). These hypotheses were tested by studying 198 veterans who survived a myocardial infarction, underwent a submaximal predischarge treadmill exercise test and were followed up for cardiac events for 2 years. During the 2 years, 29 deaths, 19 reinfarctions and 28 revascularization procedures were documented. The prevalence of death or reinfarction was two times higher in patients who had exercise-induced ST depression than in patients who did not. However, in the 55 patients without Q waves, the risk increased to 11 times for an abnormal ST response. These findings suggest that exercise-induced ST depression only predicts high risk in patients after myocardial infarction whose ECG at rest does not exhibit Q waves and that differences in the prevalence of rest ECG patterns are the most likely explanation for the failure of agreement among prior studies.

Exercise-induced silent ischemia: age, diabetes mellitus, previous myocardial infarction and prognosis.

The purposes of this study were 1) to determine the prognosis of silent ischemia in an unselected group of patients referred for exercise testing, and 2) to assess whether age or the presence of myocardial infarction or diabetes mellitus influences the prevalence of silent myocardial ischemia during exercise testing. The design was retrospective, with a 2 year mean follow-up period. The study group consisted of 1,747 predominantly male in-patients and outpatients referred for exercise testing at a 1,200 bed Veterans Administration hospital. The main result was that the mortality rate was significantly greater (p = 0.02) among patients with abnormal ST segment depression than in patients without ST depression. The presence or absence of angina pectoris during exercise testing was not significantly related to death. The prevalence of silent ischemia was not significantly different among patients categorized according to myocardial infarction or diabetes mellitus status, but was directly related to age. It is concluded that, in patients with an ischemic ST response to exercise testing, the presence or absence of angina pectoris during the test does not alter the risk of death. The prevalence of silent ischemia during exercise testing is not statistically different among patients with recent, past or no myocardial infarction or with insulin-dependent or noninsulin-dependent diabetes mellitus.

Exercise-induced ST segment depression in the diagnosis of multivessel coronary disease: a meta analysis.

To evaluate the variability in the reported accuracy of the exercise electrocardiogram (ECG) for predicting severe coronary disease, meta analysis was applied to 60 consecutively published reports comparing exercise-induced ST depression with coronary angiographic findings. The 60 reports included 62 distinct study groups comprising 12,030 patients who underwent both tests. Both technical and methodologic factors were analyzed. Wide variability in sensitivity and specificity was found (mean sensitivity 81% [range 40% to 100%, SD 12%]; mean specificity 66% [range 17% to 100%, SD 16%]). All three variables found to be significantly and independently related to sensitivity were methodologic (the exclusion of patients with right bundle branch block, the comparison with another exercise test thought to be superior in accuracy and the exclusion of patients taking digitalis). Exclusion of patients with right bundle branch block and comparison with a "better" exercise test were both significantly associated with sensitivity for the prediction of triple vessel or left main coronary artery disease. Adjustment of exercise-induced ECG changes for changes in heart rate was strongly associated with the specificity for critical disease (partial R2 = 0.436, p = 0.0001).

Effect of high intensity exercise training on central hemodynamic responses to exercise in men with reduced left ventricular function.

OBJECTIVES: The aim of this study was to evaluate the effects of high intensity exercise training on left ventricular function and hemodynamic responses to exercise in patients with reduced ventricular function. BACKGROUND: Results of studies on central hemodynamic adaptations to exercise training in patients with chronic heart failure have been contradictory, and some research has suggested that training causes further myocardial damage in these patients after a myocardial infarction. METHODS: Twenty-five men with left ventricular dysfunction after a myocardial infarction or coronary artery bypass graft surgery were randomized to an exercise training group (mean age +/- SD 56 +/- 5 years, mean ejection fraction [EF] 32 +/- 7%, n = 12) or a control group (mean age 55 +/- 7 years, mean EF 33 +/- 6%, n = 13). Patients in the exercise group performed 2 h of walking daily and four weekly sessions of high intensity monitored stationary cycling (40 min at 70% to 80% peak capacity) at a residential rehabilitation center for a period of 2 months. Ventilatory gas exchange and upright hemodynamic measurements (rest and peak exercise cardiac output; pulmonary artery, wedge and mean arterial pressures; and systemic vascular resistance) were performed before and after the study period. RESULTS: Maximal oxygen uptake (VO2max) increased by 23% after 1 month of training, and by an additional 6% after month 2. The increase in VO2max in the trained group paralleled an increase in maximal cardiac output (12.0 +/- 1.8 liters/min before training vs. 13.7 +/- 2.5 liters/min after training, p < 0.05), but maximal cardiac output did not change in the control group. Neither stroke volume nor hemodynamic pressures at rest or during exercise differed within or between groups. Rest left ventricular mass, volumes and EF determined by magnetic resonance imaging were unchanged in both groups. CONCLUSIONS: High intensity exercise training in patients with reduced left ventricular function results in substantial increases in VO2max by way of an increase in maximal cardiac output combined with a widening of maximal arteriovenous oxygen difference, but not changes in contractility. Training did not worsen hemodynamic status or cause further myocardial damage.

Use of the exercise test to predict prognosis after coronary artery bypass grafting.

The objective of this study was to predict the prognosis of patients who become symptomatic after having undergone coronary artery bypass grafting (CABG) using clinical and exercise test responses. A retrospective analysis was performed of all veterans referred for clinical indications to a Veterans Administration Medical Center for a treadmill test after having undergone CABG. Of 2,044 patients who were exercise tested from April 1984 to May 1987, 296 had previously undergone CABG. Clinical data considered included age, sex, medication and symptom status, history of myocardial infarction, type of myocardial infarction and time from CABG. The exercise test responses considered were MET level, maximal heart rate, maximal systolic blood pressure, chest pain pattern and ST-segment response. During a 2-year follow-up after exercise testing, there were 15 deaths, 11 nonfatal myocardial infarctions, 6 repeat CABGs and 3 percutaneous transluminal coronary angioplasties. Although MET level and maximal heart rate were significantly related to prognosis and no patient who exceeded 8 METs died, the predictive power of these exercise test responses was low and ST-segment depression was not predictive at all. The inability of the exercise electrocardiogram to predict cardiac events in patients after CABG requires the use of other methods of testing to identify those who need invasive studies and intervention.

Progressive functional deterioration of bioprostheses assessed by Doppler ultrasonography.

Doppler echocardiography was used to study the function of bioprosthetic heart valves by noninvasive means in 32 patients aged 29 to 72 years at various postoperative intervals. There were 24 Ionescu-Shiley, four Hancock, and four Carpentier-Edwards prostheses, 19 in the aortic and 13 in the mitral position. Initial studies were performed at a mean of 2.3 years after implantation and were repeated one, two, and three years thereafter. Flow velocities in the mitral orifice, left ventricular outflow tract, and ascending aorta, as well as mitral pressure half-time, were measured from pulsed-wave or continuous-wave Doppler recordings. Mitral and aortic valve areas and aortic pressure gradients were calculated. In aortic prostheses the valve area decreased and pressure gradient increased progressively in relation to the time from implantation. The mean value (+/- SD) of the aortic valve area was 67 +/- 17 percent of the manufacturer's nominal value at the first examination and 57 +/- 20 percent one year later, 51 +/- 14 percent two years later, and 46 +/- 11 percent three years later (overall differences, p less than 0.01). In mitral prostheses, reduction of the valve area was not related to the time from implantation. The mean mitral valve area was 45 +/- 12 percent of the nominal value at rest and increased to 68 +/- 18 percent during exercise at a mean of 45 months after implantation. There was no change in these values at the one-year repeat study. It is concluded that in a population with predominantly pericardial bioprostheses, (1) aortic tissue prostheses showed a progressive functional deterioration demonstrable by Doppler echocardiography, most probably due to degenerative changes; and (2) in mitral tissue prostheses, there was no significant reduction of orifice area in relation to time from implantation. Reduction of mitral valve areas may, to some extent, reflect a less than full opening at rest.

Effect of exercise training on postexercise oxygen uptake kinetics in patients with reduced ventricular function.

BACKGROUND: The time required for oxygen uptake (O(2)) to return to baseline level (recovery kinetics) is prolonged in patients with reduced ventricular function, and the degree to which it is prolonged is related to the severity of heart failure, markers of abnormal ventilation, and prognosis. In the present study, we sought to determine the effect of exercise training on O(2) recovery kinetics in patients with reduced ventricular function. METHODS: Twenty-four male patients with reduced ventricular function after a myocardial infarction were randomized to either a 2-month high-intensity residential exercise training program or to a control group. O(2) kinetics in recovery from maximal exercise were calculated before and after the study period and expressed as the slope of a single exponential relation between O(2) and time during the first 3 min of recovery. RESULTS: Peak O(2) increased significantly in the exercise group (19.4 +/- 3.0 mL/kg/min vs 25.1 +/- 4.7 mL/kg/min, p < 0.05), whereas no change was observed in control subjects. The O(2) half-time in recovery was reduced slightly after the study period in both groups (108.7 +/- 33.1 to 102.1 +/- 50.5 s in the exercise group and 122.3 +/- 68.7 to 107.5 +/- 36.0 s in the control group); neither the change within or between groups was significant. The degree to which O(2) was prolonged in recovery was inversely related to measures of exercise capacity (peak O(2), watts achieved, and exercise time; r = - 0.48 to - 0.57; p < 0.01) and directly related to the peak ventilatory equivalents for oxygen (r = 0.59, p < 0.01) and carbon dioxide (r = 0.57, p < 0.01). CONCLUSION: Two months of high-intensity training did not result in a faster recovery of O(2) in patients with reduced ventricular function. This suggests that adaptations to exercise training manifest themselves only during, but not in, recovery from exercise.

Effect of residential cardiac rehabilitation following bypass surgery. Observations in Switzerland.

BACKGROUND: Cardiac rehabilitation in central Europe traditionally involves isolating patients in a residential idyllic setting where exercise is performed frequently but in a relatively unstructured fashion. Few studies have been performed on the effects of these programs among patients who have undergone bypass surgery. Recent data suggest that postbypass patients may enter these programs too soon after surgery or that exercise is not structured enough to distinguish the benefits of rehabilitation from those experienced by a control group. METHODS: Forty-two male patients (mean age, 58 +/- 7 years) were divided into exercise and control groups approximately 1 month after undergoing bypass surgery. Exercise training consisted of 1 h of group walking twice daily, with the intensity stratified into four levels based on initial exercise capacity. Using a crossover design, patients in the exercise group participated in rehabilitation for 1 month, followed by 1 month of usual care, while control patients underwent the opposite sequence. At 1, 2, and 3 months, patients in both groups underwent pulmonary function testing and maximal ramp exercise testing using lactate and gas exchange analysis. RESULTS: A main effect for maximal oxygen uptake was observed; significant improvements within each group occurred across each testing period (range, 5 to 13%; p < 0.05). However, there was no significant interaction between groups. Mean lactate levels throughout exercise were reduced within both groups (p < 0.01). A reduction in oxygen uptake for test 2 at the lactate threshold in the exercise group resulted in differences between groups in lactate, heart rate, and other gas exchange variables at this point. CONCLUSION: Similar changes occur in the functional status of postbypass surgery patients regardless of their participation in the short but concentrated programs common in central Europe. This suggests that a significant spontaneous effect of healing occurs in the recovery phase after surgery. These programs may have greater efficacy if they began later after surgery, lasted longer, or were more structured, and studies are needed to determine their effect on psychosocial factors and return to work.

Cardiac rehabilitation in Switzerland. Efficacy of the residential approach following bypass surgery.

BACKGROUND: The traditional central European approach to cardiac rehabilitation involves sending patients to an idyllic setting, where they reside for a specified period following a cardiac event. Favorable results have been demonstrated using this approach in Germany, but to our knowledge no data have been reported from Switzerland, where these programs tend to be short (4 weeks) and exercise training is concentrated (2 h daily, 6 days per week). METHODS AND RESULTS: Seventeen patients (aged 58 +/- 6 years) who resided in a rehabilitation center for 4 weeks were compared with 11 patients (aged 54 +/- 7 years) given usual community care beginning approximately 6 weeks after coronary artery bypass surgery (CABS). Exercise training consisted of 1 h of group walking twice daily, with the intensity stratified into 4 levels based on clinical status and initial exercise capacity. All patients underwent pulmonary function testing and maximal ramp exercise testing on a cycle ergometer with continuous ventilatory gas exchange and lactate analysis before and after the study period. Patients receiving beta-blockers and those with cardiomyopathy or valvular heart disease were excluded. Medication status was not changed during the study period. Although maximal oxygen uptake increased by approximately 12 percent within both groups, the change was not significant between groups. Analysis of variance demonstrated that mean lactate levels were reduced throughout exercise within both groups (p < 0.001); however, there were no differences between groups. Oxygen uptake at the lactate threshold was not different in either group after the study period. CONCLUSIONS: Similar changes occur in the functional status of post-CABS patients regardless of their participation in the short but concentrated rehabilitation programs common in Switzerland, suggesting that these programs either begin too soon after CABS or are too short to achieve training benefits.

A randomized comparison of exercise training in patients with normal vs reduced ventricular function.

BACKGROUND: Exercise training is recommended after myocardial infarction (MI) or bypass surgery in order to improve exercise tolerance. In some patients, the decrement in exercise capacity secondary to deconditioning and the left ventricular stunning associated with MI or coronary artery bypass graft (CABG) spontaneously improves after the event. However, the impact of the status of the left ventricle on these improvements is unknown. METHODS: Sixty-seven patients 1 month after MI or CABG were randomized to a training (n=34; age, 59+/-7 years) or a control group (n=33; age, 55+/-6 years). Forty-two patients had an ejection fraction >50% (22 in the training group and 20 in the control group), and 25 patients had an ejection fraction <40% (12 in the exercise group and 13 in the control group). After stabilization for approximately 1 month after the event, patients in the exercise group underwent 8 weeks of twice daily exercise at a residential rehabilitation center, while control patients received usual care. Initially and after 8 weeks, patients in both groups underwent maximal exercise testing with gas exchange and lactate analysis. RESULTS: Exercise training increased peak oxygen consumption (VO2) only in the reduced ejection fraction group (19.4+/-3.0 to 23.9+/-4.8 mL/kg/min; p<0.05); the exercise group with normal ventricular function did not change significantly. Changes in VO2 at the lactate threshold paralleled those of peak VO2 for both groups. Conversely, control patients with normal ventricular function increased peak VO2 spontaneously (20.8+/-3.9 to 24.8+/-3.5 mL/kg/min; p<0.01), whereas control patients with reduced ventricular function did not improve peak VO2. CONCLUSION: These data suggest that patients with depressed left ventricular function strongly benefit from rehabilitation, whereas most patients with preserved left ventricular function following MI or CABG tend to improve spontaneously 1 to 3 months after the event.

The Omnicarbon tilting-disc heart valve prosthesis. A clinical and Doppler echocardiographic follow-up.

From 1986 to 1990, 172 patients with a median age of 60.5 years (range 20 to 79 years) received 187 Omnicarbon valves (109 aortic valve replacements, 48 mitral valve replacements, and 15 double valve replacements). Patients were followed-up for a median observation period of 2.5 years (range 4 months to 5.2 years) by clinical and Doppler echocardiographic examination. Follow-up was complete in 98%. Operative mortality (death within 30 days) was 1.7%, and linearized late mortality was 2.6% per patient-year, corresponding to an actuarial survival rate for operative survivors of 89% after 4 years. The overall 4-year postoperative survival was 87% (93% for aortic valve replacement, 77% for mitral valve replacement). Compared with age- and sex-adjusted Swiss death rates, there was an excess mortality of 5% after 4 years. Percentages for freedom from valve-related complications at 4 years are as follows: thromboembolism, 98% (aortic valve replacement, 98%, and mitral valve replacement, 96%); anticoagulant-related hemorrhage, 95%; valve endocarditis, 96%; reoperation, 96%; and permanent valve-related impairment, 99%. The overall 4-year event-free survival was 76% (80% for aortic valve replacement and 69% for mitral valve replacement). New York Heart Association class improved in 88% of the patients by 1 to 3 grades, and only 3% remained in class III after operation. For the most commonly used aortic valve (23 mm), Doppler echocardiography revealed a peak pressure gradient of 29 +/- 10 mm Hg, a fractional shortening/peak pressure gradient ratio of 1.34 +/- 0.61, and a performance index of 0.35 +/- 0.08. In the most commonly used mitral valve (27 mm), the mean pressure gradient was 4.0 +/- 2.1 mm Hg. We conclude that excellent clinical and hemodynamic results can be obtained with the Omnicarbon prosthesis, in both the aortic and mitral positions.

Motor evoked potentials from masseter muscle induced by transcranial magnetic stimulation of the pyramidal tract: the importance of coil orientation.

BACKGROUND: Reliable recording of motor evoked potentials (MEPs) of the masseter muscle by transcranial magnetic stimulation (TMS) has proved more difficult than from facial or intrinsic hand muscles. Up to now it was unclear whether this difficulty was due to methodological and/or anatomical reasons. METHODS: The mechanism of pyramidal cell activation in masseter MEPs was investigated by using magnetic and electric transcranial stimulation. Analysing the effect of magnetic coil positioning and orientation over the scalp, and scrutinizing the masseter recording technique to avoid compound motor action potential (CMAP) contamination from facial muscles, an optimized method of masseter MEPs was developed. RESULTS: In particular, an antero-lateral inducing current orientation in the stimulating coil, approximately paralleling the central sulcus, proved clearly more effective for the masseter muscles than the postero-lateral orientation (P=0.005) found optimal for intrinsic hand muscles. The thus evoked masseter MEPs by transcranial magnetic stimulation (TMS) were found to be identical in shape, amplitude and latency as those evoked by transcranial electric stimulation (TES), evidencing a direct rather than trans-synaptic activation of the pyramidal cells. CONCLUSIONS: We conclude that in TMS evoked MEPs of masseter muscles, the direct stimulation of the pyramidal tract is more easily achieved than the trans-synaptic activation, which is in contrast to the intrinsic hand muscles. We hypothesize that the presynaptic projections to pyramidal cells of the masticatory muscles are less abundant than in hand muscles, and are therefore less accessible to trans-synaptic stimulation.

Influence of high-intensity exercise training on the ventilatory response to exercise in patients with reduced ventricular function.

BACKGROUND: Exercise training increases exercise capacity in patients with reduced ventricular function in part through improved skeletal muscle metabolism, but the effect training might have on abnormal ventilatory and gas exchange responses to exercise has not been clearly defined. METHODS: Twenty-five male patients with reduced ventricular function after a myocardial infarction were randomized to either a 2-month high-intensity residential exercise training program or to a control group. Before and after the study period, upright exercise testing was performed with measurements of ventilatory gas exchange, lactate, arterial blood gases, cardiac output, and pulmonary artery and wedge pressures. RESULTS: In the exercise group, peak VO2 and VO2 at the lactate threshold increased 29 and 39%, respectively, whereas no increases were observed among controls. Maximal cardiac output increased only in the exercise group (1.7 L x min(-1), P < 0.05), and no changes in rest or peak exercise pulmonary pressures were observed in either group. At baseline, modest inverse relationships were observed between pulmonary wedge pressure and peak VO2 both at rest (r = -0.56, P < 0.05) and peak exercise (r = -0.43, P < 0.05). Maximal VE/VCO2 was inversely related to maximal cardiac output (r = -0.72, P < 0.001). Training did not have a significant effect on these relationships. Training lowered VE/VO2, heart rate, and blood lactate levels at matched work rates throughout exercise and tended to lower maximal Vd/Vt. The slope of the relationship between VE and VCO2 was reduced after training in the exercise group (0.33 pre vs 0.27 post, P < 0.01), whereas control patients did not differ. CONCLUSIONS: Exercise training among patients with reduced left ventricular function results in a systematic improvement in the ventilatory response to exercise. Training increased maximal cardiac output, tended to lower Vd/Vt, and markedly improved the efficiency of ventilation. Peak VO2 and ventilatory responses to exercise were only modestly related to pulmonary vascular pressures, and training had no effect on the relationships between exercise capacity, ventilatory responses, and pulmonary pressures.

Exercise training in chronic heart failure: why, when and how.

The management of patients with chronic congestive heart failure has changed considerably during the last decade. Until recently, restriction of physical activity was recommended for patients with chronic heart failure. However, the knowledge that training influences largely the periphery rather than the heart itself has led to a dramatic change in the approach toward training in patients with chronic heart failure. Why to train patients with chronic heart failure: Training increases exercise tolerance by an average of 20% in chronic heart failure regardless of etiology (ischemic or non-ischemic cardiomyopathy) or severity of left ventricular dysfunction. Available data, while limited, demonstrate that increases in exercise capacity are paralleled by an improvement in quality of life. Studies have consistently demonstrated that training has no deleterious effect on central haemodynamics, left ventricular remodeling, systolic or diastolic function, or myocardial metabolism. At present, there are insufficient data to determine the effect of training on prognosis, but trials are currently underway to address this. When to train patients with chronic heart failure: Exercise training should be performed only with the patients that have been in a stable clinical condition for a period of at least 3-4 weeks. Clinical stability is defined as no change in symptoms, weight, drug regimen, or NYHA class over this period. How to train patients with chronic heart failure: Initially, the program should be supervised for a period of 2 to 4 weeks; home-based programs are usually appropriate thereafter. Activities that can be maintained for a lifetime should be encouraged, and the focus should be on aerobic-type activities. The intensity level should be targeted to about 50%-70% of peak VO2 and/or Borg ratings of 12-14 ("walk and talk").